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Volume 53 (2004): Issue 1-6 (December 2004)

Journal Details
Format
Journal
eISSN
2509-8934
First Published
22 Feb 2016
Publication timeframe
1 time per year
Languages
English

Search

Volume 53 (2004): Issue 1-6 (December 2004)

Journal Details
Format
Journal
eISSN
2509-8934
First Published
22 Feb 2016
Publication timeframe
1 time per year
Languages
English

Search

50 Articles
Open Access

Population Genetics of Heterosis: Effects of Hardy-Weinberg Disequilibrium

Published Online: 27 Oct 2017
Page range: 1 - 6

Abstract

Summary

The mechanistic explanation of heterosis has been traditionally based on quantitative differences of gene effects. However, for outcrossing populations, heterosis is also a property of populations. In this paper, the effects of the deviation of a population from Hardy-Weinberg equilibrium (HWE) on the magnitude of heterosis have been examined numerically. The mating of two populations in HWE may generate directions and magnitudes of heterosis different from the mating of two populations in Hardy-Weinberg disequilibrium (HWD). Such differences of heterosis between these two types of population mating may be due to the release of vigor restored in the parental populations during the process of HWD. Results from this study can provide guidance on the selection of parental populations for the effective exploitation of heterosis and the prediction of genetic structure and organization for hybrid zones in nature.

Keywords

  • Hardy-Weinberg disequilibrium
  • heterosis
  • hybrid population
  • outcrossing population
  • population genetics
Open Access

Studies on the Pollination Characteristics and Pollination Level of Chinese fir Seed Orchard

Published Online: 27 Oct 2017
Page range: 7 - 11

Abstract

Abstract

Data from three seed orchards (Chongyang, Zhangle and Laoshan) and Lintian forest were used to study pollination characteristics, pollination level, pollen and ovule production in Chinese fir. The results show that male and female cones have their own distribution patterns within crowns. Male cones are located in the middle to top and female cones the middle to bottom part of the crown. Because of lower density of trees in seed orchard than that in a stand, female cones are distributed over the entire crown in seed orchard trees. Chinese fir male and female cones appear to be very well adapted for wind as the pollination mechanism. There is no difference in the number of pollen grains produced by one pollen sac among trees in the same clone, but there are differences between clones. There are differences between both clones and years in female cone number, male cone number and their ratio. The pollen accumulation rate during pollination should be 3 to 5 pollen grains/mm2 to ensure fertilization. The Chinese fir seed orchards in this study produced too much pollen and could be improved by stimulation of more female flowers in order to produce more seeds.

Keywords

  • Cunninghamia lanceolata (Lamb.) Hook
  • Chinese fir
  • seed orchard
  • clones
  • pollen
  • ovules
Open Access

Variation and Population Structure at Enzyme Gene Loci in Araucaria angustifolia (Bert.) O. Ktze

Published Online: 27 Oct 2017
Page range: 12 - 19

Abstract

Abstract

We describe alloenzyme variation in A. angustifolia populations of three separate geographical areas in southern Brazil. The genetic structure of populations was examined in seedtrees, embryos and effective pollen. Seven out of 24 enzyme loci were polymorphic. The average number of alleles per locus (24 loci) was 1.54, with 2.44 alleles per polymorphic locus. Mean expected and observed heterozygosities at the polymorphic loci were He = 0.128 and Ho = 0.132 for seed-trees, and He = 0.142 and Ho = 0.161 for embryos. All measures of genetic variability were highest in the most northern populations. Differences among localities explained 84.14% and 92.06% of the total genetic diversity in embryos and seed trees, respectively. Sex ratio was 1:1 in almost all populations. Female and male gene pools differed in allele frequencies, most significantly at loci 6- Pgdh-B and Skdh-B. This explains the excess of heterozygotes detected among embryos. No inbreeding or excess of heterozygotes was detected among adult seed trees. Genetic variation in A. angustifolia revealed a latitudinal gradient.

Keywords

  • Paraná pine
  • alloenzymes
  • genetic variation
  • differentiation of populations
  • paleohistory
Open Access

Progeny Testing Preceded by Phenotypic Pre-selection – Timing Considerations

Published Online: 27 Oct 2017
Page range: 20 - 26

Abstract

Abstract

Progeny-testing is a common element in tree breeding. It takes long time until trees reach the sexual maturity. That time could be used for field testing followed by progeny-test of the selected phenotypes (two-stage strategy), or the time until mating could be reduced by forcing early flowering (singlestage strategy). Benefit of phenotypic pre-selection followed by progeny testing in long-term breeding was assessed as a function of the age at the pre-selection by the aid of a deterministic tree breeding simulator. As a criterion of goodness of a breeding program, annual progress in group merit (GM/Y-refers to the rate of change in the average of genetic gain and gene diversity) at a total budget constraint was used. For simplicity, a long-term program with balanced selection was studied. Scenarios with different genetic parameters, cost and time components were evaluated and optimised for resource allocation. At the optimum age of mating for progeny test, two-stage Phenotype/ Progeny strategy generated higher GM/Y than singlestage Progeny strategy at the age of mating for progeny test equal to three years, except for a typical scenario with weak JM correlation, low heritability and long rotation time. High heritability, short rotation and strong J-M genetic correlation favoured phenotypic pre-selection. Optimum age for phenotypic pre-selection varied from 6 to 17 years and the percentage of GM/Y lost in comparison to the maximum due to delay of mating for the progeny test until age 15 and 25 years ranged from 0 to 14% and from 1 to 29%, respectively. In the case of low heritability, long rotation, low J-M correlation, high cost for cycling and low budget, early mating age would bring little benefit if compared to mating at the optimum age. We suggest that, in long-term breeding based on progeny testing, investment in phenotypic pre-selection is more beneficial than investment to achieve early flowering to initiate the progeny test early.

Keywords

  • annual gain
  • juvenile-mature correlation
  • gene diversity
  • group merit
  • optimisation
  • two-stage selection
  • stage-wise selection
  • flowering induction
Open Access

Retrospective Evaluation of Parental Selection in Nursery Tests of Juglans regia L. Using a Mixed Model Analysis

Published Online: 27 Oct 2017
Page range: 26 - 33

Abstract

Summary

Results of early testing in Juglans regia performed over the period 1993-2002 are presented. A total of 37 progenies were evaluated for establishment, growth traits, and phenology at ages one and two during two or more sowing years in the nursery. Independent culling selection was applied on parental trees to the family-mean values using specific truncation points for establishment, diameter and total height. In addition, parental selection was performed on unbiased predictions (BLUPs) of parental breeding values using a multivariate mixed model analysis in order to account for the unbalanced nature of the entire data set. Genetic parameters (heritabilities, correlations) of juvenile traits were also estimated. Except for second year growth traits, the genetic control of most characters was quite high, with heritability estimates ranging from 0.51 (establishment) to 0.93 (flushing date). Growth performance and establishment did not bear a common genetic control according to non-significant genetic correlations, but a higher growth was typical of early flushing families. Changes in parental ranking for growth after comparison of familymean and BLUP-based estimates of parental performance were considerable. This observation, together with the larger proportion of culled progenies in the former method (about 70%), suggests a sizeable loss of genetic gain by using unadjusted parental means. It is concluded that current evaluation and selection schemes using family-mean values should be reconsidered by i) relaxing truncation points for selection on establishment and growth traits and ii) re-evaluating progeny test data using a mixed model framework to unveil valuable material otherwise neglected due to unaccounted environmental influence on family performance.

Keywords

  • Juglans regia
  • early selection
  • genetic parameters
  • BLUP
  • mixed model
Open Access

Genetic Variation in Growth and Blister-Rust Resistance in a Pinus strobus x P. wallichiana Hybrid Population

Published Online: 27 Oct 2017
Page range: 33 - 41

Abstract

Summary

This experiment consists in a controlled crossing according to a factorial design performed between 7 female trees of P. strobus and 4 male trees of P. wallichiana to combine the rapid growth of former species with high resistance to Cronartium ribicola of the latter one. The hybrid families were artificially inoculated at age 2, and field planted at age 6. Blister rust resistance (BRR), tree survival (TS), total height growth, (H) annual height growth (h), diameter (D), basal area (BA), stem volume (V), stems straightness (SS) and branch thickness (BT) were the traits measured at age 17. Statistical analysis produced the results presented below. Significant (p<0.05) and highly significant (p<0.01; p<0.001) differences were found among hybrid families. Differences among female effects were highly significant (p<0.001) for all tested traits including BRR, suggesting that nuclear additive genes controlled these traits. Significant differences were found among male parents for H but no significant differences for BRR; therefore, all four male parents transmitted a similar level of resistance. The ratio σ2GCA2SCA variance accounted for 8.1 for BRR, 8.5 for H, 3.5 for V, 9.3 for SS and 1.9 for BT. Similarly, the ratios of σ2GCA-F2GCA-M variance due to female parents were 70.5 for BRR, 23.6 for H, 1.0 for V, 0.4 for SS and 1.0 for BT, were found. Narrow-sense heritabilities, at individual level, were low to moderately high, ranging between 0.085 for BT and 0.421 for BRR. By comparison with the mean of P. strobus parent species, the BRR heterosis was highly positive, but negative for all growth traits. If the hybrids will be used in operational planting programs, a significant genetic gain for BRR and growth traits could be achieved.

Keywords

  • Pinus strobus
  • P. wallichiana
  • Cronartium ribicola
  • hybrid
  • heterosis
  • additive variance
  • heritability
  • genetic correlation
  • genetic gain
Open Access

Stability of Outcrossing Rates in Eucalyptus globulus Seedlots

Published Online: 27 Oct 2017
Page range: 42 - 44b

Abstract

Summary

Eucalyptus globulus has a mixed mating system and selfing leads to severe inbreeding depression. Thus, outcrossing rate is an important measure of seed quality in this species. Outcrossing rates were estimated on the frequency of a rare recessive chlorophyll deficient mutant in open pollinated seed. Variation of outcrossing rates across different flowering seasons, seed sizes and storage times was assessed in E. globulus seedlots. Although there was a significant difference between the trees studied, outcrossing rates within a tree were found to be stable across four flowering seasons and three seed sizes. Storage either on the tree or in the laboratory did not alter the outcrossing rate in a consistent manner. The stability of outcrossing rates with season of pollination, age and size of seed is noteworthy as these factors may vary widely in multi-tree seedlots used for plantation establishment.

Keywords

  • Selfing
  • seed size
  • seed age
Open Access

Identification of Molecular Markers for Selected Wood Properties of Norway Spruce Picea abies L. (Karst.) I. Wood Density

Published Online: 27 Oct 2017
Page range: 45 - 50

Abstract

Abstract

The identification of AFLP markers and their subsequent conversion to SCAR-markers linked to wood density of Norway Spruce (Picea abies L [Karst.]) is described for the first time. In AFLP-analyses, 102 different primer enzyme combinations were screened in a bulked segregant approach comparing individuals with high and low wood density. A total of 107 polymorphic AFLP fragments were obtained between the DNA-pools. Twenty-three markers were selected for further analyses to verify their linkage to wood density based on individuals used for pool constitution and additional unrelated clonal material. For 15 markers, a significant linkage to wood density was confirmed by a two-sided Fisher’s-exact test. Four markers were converted into SCAR markers and validated for plant material assayed for wood density by X-ray microdensitometry. For each marker a monomorphic band was obtained using sets of nested primers or restriction site-specific primers (RSS), which include the AFLP-restriction recognition sites. For two markers that are linked to high wood density, a separation from unlinked size homologous marker-alleles was realized by a PCR-restriction approach. Validation of these markers in different full-sib families confirmed their usability to separate the classes for low and high wood density of Picea abies.

Keywords

  • AFLP
  • Bulked segregant analysis
  • Marker assisted selection (MAS)
  • Molecular markers
  • Wood properties
Open Access

Clonal Propagation of Dalbergia sissoo Roxb. by Softwood Nodal Cuttings: Effects of Genotypes, Application of IBA and Position of Cuttings on Shoots

Published Online: 27 Oct 2017
Page range: 50 - 55

Abstract

Summary

Softwood nodal shoot cuttings were collected from the hedge garden at New Forest campus of Forest Research Institute, Dehra Dun. The cuttings were rooted in mist chamber to investigate the effect of IBA application and position of cuttings on shoots on rooting ability in different clones of Dalbergia sissoo Roxb. As compared to the 0% (control) and 0.1%; 0.2% IBA showed maximum adventitious root formation. Overall percent rooting, percent sprouting, mean number of shoots and their length, mean number of roots and their length increased with increasing concentration of IBA. Among different positions of cuttings within the shoots, the best rooting response was recorded in the middle part followed lower and upper part. The findings exhibited significant interclonal variation regarding adventitious rooting and maximum response was observed in C42 (Gonda, Uttar Pradesh) clone. Interactive effect of clone C42 and middle position significantly increased percent sprouting while; interactive effects of middle position and 0.2% IBA treatment significantly increased percent rooting. It is concluded that the selection of genotypes with good rooting ability with respect to shoot position in hedged plants and concentration of IBA can be made to produce high quality planting stock material to start clonal forestry programme of D. sissoo.

Keywords

  • Dalbergia sissoo
  • IBA
  • position on shoots
  • clone
  • nodal cuttings
  • rooting
Open Access

Sexual Asymmetry based on Flowering Assessment in a Clonal Seed Orchard of Pinus densiflora

Published Online: 27 Oct 2017
Page range: 55 - 59

Abstract

Abstract

Two equations were formulated in order to estimate the degree of sexual asymmetry for monoecious species. The concepts of the equations were formulated on the basis of the effective population numbers of female and male parents [i.e, As(v)], and the differences of relative frequency between genders [i.e., As(x)]. These equations were applied to estimate the degree of sexual asymmetry based on the empirical data of flowering assessment in a clonal seed orchard of Pinus densiflora. The yearly variation in the production of female and male strobili was found. The effective population numbers at gamete levels (vf and vm) and clone level (vb) varied among 8 observation years. Both As(x) and As(v) were negatively correlated with effective numbers at gamete and clone levels. Averages of female and male strobilus production and estimates of sexual asymmetry were negatively correlated but the correlation was not significant. The correlations among effective number of clone (vb), arithmetic mean of female and male effective numbers (va) and estimate of sexual asymmetry [As(x)] were strong and significant. Relatively larger difference between vb and va were found when higher level of sexual asymmetry were observed.

Keywords

  • sexual asymmetry
  • effective number
  • strobilus production
  • fertility
  • coefficient of variation
Open Access

Genetic Gains of Full-Sib Families from Disconnected Diallels in Loblolly Pine

Published Online: 27 Oct 2017
Page range: 60 - 64

Abstract

Abstract

Breeding values for the 2nd-cycle of the loblolly pine (Pinus taeda L.) breeding program were analyzed with the NCSUIndustry Tree Improvement Cooperative database to estimate genetic gains and compare different strategies for full-sib deployment. In the disconnected half-diallel mating design used for loblolly pine, six parents within each diallel were crossed to generate 15 full-sib families for general combining ability (GCA) and specific combining ability (SCA) estimates. Parents among disconnected diallels were never crossed, and the SCA and full-sib family breeding values cannot be estimated directly. Using the GCA and SCA estimates from 60 diallels in the Atlantic Coastal region of loblolly pine, genetic gains were estimated in this study for full-sib families within the disconnected diallels and then compared with the potential gains that would be expected if we select parents for full-sib families based on GCA values for all parents within a geographic region. As the dominance variance was found to be much less than the additive variance, the SCA contribution to the full-sib genetic gain was relatively small. Higher full-sib genetic gains were obtained by crossing the best GCA parents from different diallels within a geographic region than selecting only those within diallels. The difference increased with increasing number of selected full-sibs. Results from different selection scenarios, with various selection intensities and relatedness managements, suggest that selection based on GCA from all parents within a geographic region would result in a higher genetic gain for full-sib families in loblolly pine. The deployment of full-sib families are very important for achieving higher genetic gains in a loblolly pine breeding program. But they were not due to the SCA contribution, but rather due to high GCA of best parents in creating these full-sib crosses. The strategies for family and clonal deployment are very attractive based on the data from this study.

Keywords

  • Pinus taeda L.
  • full-sib crosses
  • volume gain
  • deployment
  • general combining ability
  • special combining ability
Open Access

The Effect of Inbreeding on Early Growth of Acacia mangium in Vietnam

Published Online: 27 Oct 2017
Page range: 65 - 69

Abstract

Abstract

Seeds were collected from each of twelve parent trees from each of six seed orchards of Acacia mangium in different locations in Vietnam to examine the relationship between growth and inbreeding in this species. Seedlings were raised and planted out in a field trial at Ba Vi in northern Vietnam. The inbreeding status (self-fertilized or outcrossed) of most of the seedlings was determined by DNA analysis. Heights were measured at 12 and 18 months, and diameter at breast height (dbh) at 18 months. There were significant differences in growth between the six orchard sources at 18 months. Progeny from two orchards based primarily on Papua New Guinea (PNG) provenances with high levels of outcrossing displayed the best growth, with mean heights of 3.1 m at 18 months, while an orchard also based primarily on PNG provenances but with predominantly selfed progeny, and another orchard based on Queensland provenances with 51% selfed progeny, displayed the poorest growth (mean heights of 2.0 m and 2.2 m respectively). Analysis of variance established that within the 32 families that included both selfed and outcrossed individuals, self-fertilized individuals were significantly (P< 0.001) slowergrowing than were outcrossed individuals, with selfs on average 15% smaller in mean height and 16% smaller in mean dbh at age 18 months, relative to outcrosses. The results demonstrate the need to minimise selfing in operational seed production for A. mangium plantations.

Keywords

  • Seed orchards
  • self
  • outcross
  • growth
  • inbreeding depression
  • Acacia mangium
Open Access

A Report of Triploid Populus of the Section Aigeiros

Published Online: 27 Oct 2017
Page range: 69 - 75

Abstract

Abstract

This screening study analyzed ploidy levels by counting the chromosome number of 61 Aigeiros cultivars grown in China. Triploid Aigeiros has been found in four of these cultivars: Populus x euramericana (Dode) Guiner cv. Wuhei-1, P. × Liaohenica, P. Langfangensis-3 Wang (P. deltodide Barry cv. “Shanhaiguan” × P. simonii × P. pyramidalis-12 +Ulmus pumila Linn.), and P. × euramericana (Dode) Guinier. cv. “Zhonglin-46”. The karyotype analysis indicates that triploid Aigeiros might be derived from original allotriploid. Because growth of the triploid trees was faster than their respective diploid hybrids or clones in the plantations where we collected the materials, we expect that they will play a significant role in breeding, reforestation and fiber production in China.

Keywords

  • Aigeiros
  • triploid
Open Access

Longitudinal Differences in Scots pine Frost Hardiness

Published Online: 27 Oct 2017
Page range: 76 - 80

Abstract

Abstract

The autumn frost hardiness of Scots pine (Pinus sylvestris L.) populations from Scandinavia (57°28’-68°54’ N, 13°00’-27°00’ E) and the Komi Republic in Russia (61°30’-64°20’ N, 49°10’-54°50’ E), and open pollinated families from a population in Komi (61°43’ N, 51°07’ E) were examined in artificial freezing tests with one-year-old seedlings. The aims were to estimate genetic variation in hardiness between families of Russian origin and to compare populations of Russian (continental) and Scandinavian (maritime) origins. The longitudinal distance between the Scandinavian and Russian seed sources was associated with a significant difference in climatic conditions. At latitude 63°N the degree of continentality (the difference between July and January monthly mean temperatures) was 23.7°C for longitude 15°E in Sweden and 35.2°C for longitude 54°E in Komi. The narrow-sense heritability of frost hardiness calculated for the Russian families was 0.22. This indicates relatively high genetic control of the trait, of similar magnitude as earlier shown for populations of Scandinavian origin. Both Scandinavian and Russian populations showed a strong clinal variation in frost hardiness, northern populations being the hardiest. In addition, Russian populations were more frost hardy than Scandinavian ones from corresponding latitudes and attained the same level of hardiness as Scandinavian populations from 4.1° latitude further north. The results indicate that the longitude or continentality of the origins of Scots pine populations is associated with adaptive pressures that have significant effects on hardiness and are distinct from photoperiodic effects. When enriching breeding or production populations by including populations from remote origins it is essential to recognize not only latitudinal origin, but also longitudinal origin or temperature regime, in order to match material to the planned utilization areas.

Keywords

  • Pinus sylvestris (L.)
  • adaptation
  • freezing tests
  • climatic change
  • continentality
  • heritability
Open Access

Inbreeding in Pinus Radiata – V. The Effects of Inbreeding on Fecundity

Published Online: 27 Oct 2017
Page range: 80 - 88

Abstract

Abstract

A successful inbreeding and hybrid breeding strategy in tree improvement requires that 1) inbreeding (selfing) can produce superior inbred lines (effective purging of deleterious alleles), 2) there is heterosis among crosses of inbred lines, 3) early selection between lines is effective, and 4) inbreeding will not substantially reduce reproductive ability. We have previously reported that inbreeding depression on growth was lower in radiata pine relative to other conifers and segregation in the first two-generations of selfs generated superior inbred trees. In addition, we have observed that early selection among inbred trees (lines) was more effective than in out-crossed populations and there was an apparent heterosis in radiata pine. In this study, the effect of inbreeding on the reproductive ability in young and adult trees of radiata pine has been quantified from five populations of varied inbreeding levels (F =0, 0.125, 0.25, 0.5, and 0.75). It was observed that the effects of inbreeding depression on fecundity was higher at a young age than at older age and inbreeding depression at a young age is due to two factors: 1) a delay of reproductive age (about 8.3, and 8.5% of trees delayed for F =0.5 and F =0.75 populations, respectively) and 2) a true reduction of flowering trees (6.7 and 13.1% more trees having no flowers for F =0.5 and F =0.75 populations than F =0 population, respectively). Despite significant inbreeding depression on the percentage of female reproductive trees and the number of cones on adult trees, overall inbreeding depression on fecundity was low in radiata pine. One founder clone contributed most of the significant inbreeding depression observed for the population of eight founder clones. It was observed that fecundity varied more widely among the eight clones than among the inbreeding level (self and outcross).

Keywords

  • Radiata pine
  • Pinus radiata
  • inbreeding depression
  • reproductive ability
  • fecundity
  • fitness
Open Access

Discordance Between Geographical Distribution and Genetic Relationship Among Populations of Japanese Red Pine in Korea Revealed by Analysis of I-SSR Markers

Published Online: 27 Oct 2017
Page range: 89 - 92

Abstract

Abstract

Level and distribution of genetic diversity in 8 populations of Japanese red pine in Korea were estimated using I-SSR variants. A total of 80 I-SSR variants were observed in the analyzed 150 individuals, which revealed DNA fingerprints-like individual specific amplicon profiles for all of them. Relatively higher level of genetic diversity within populations was observed in 8 populations of Japanese red pine (mean of 0.450) than in other tree species. From the results of AMOVA, majority of genetic diversity was allocated within populations (93.42%) resulting in a moderate degree of population differentiation (ΦST= 0.066). The observed distribution pattern of I-SSR variants among 8 populations was coincided with the typical patterns for the long-lived woody species. Genetic relationships among the populations, reconstructed by UPGMA and Neighbor- Joining methods, revealed 2 genetic groups. The populations of Gangwon-Uljin and Chungnam-Taean turned out to be the most closely related despite a distant location between them. The overall genetic relationships among the 8 populations, reconstructed by both methods, were not coincided with geographic distances. The discrepancy between genetic relationships and geographical distribution among the populations suggests that the analyzed populations might have undergone random changes in genetic composition due to some kinds of disturbances. Results obtained in this study suggests that more careful approach should be made in preparing strategy for gene conservation of Japanese red pine in Korea. More information on countrywide molecular population genetic status of Japanese red pine will be helpful to prepare more reasonable strategy for gene conservation of the species in the country.

Keywords

  • Pinus densiflora
  • Japanese red pine
  • I-SSR markers
  • Genetic diversity
  • AMOVA
  • Population differentiation
  • Genetic relationships
Open Access

Genetic Structure and Variability of Natural Populations of Maritime Pine (Pinus pinaster Aiton) in Morocco

Published Online: 27 Oct 2017
Page range: 93 - 99

Abstract

Abstract

The estimation of genetic diversity using molecular markers is a major component of genetic conservation programs. In its range, Maritime pine has been extensively studied using different molecular markers and quantitative traits. However, Moroccan populations have been usually represented only by a few typical locations in the Middle Atlas (e.g., Tamjout). To describe the genetic structure and variability of maritime pine in Morocco, eleven populations of this species comprising all major geographic regions (Rif, Middle Atlas and High Atlas) were studied using allozyme markers. A total of 471 samples were analyzed using polyacrylamide gel electrophoresis (PAGE) of eight enzyme systems encoded by 19 loci. Genetic variation was lower in Morocco than in other ranges of the species. However, genetic diversity was structured and a high differentiation among populations (θ = 10.44%) and a moderate correlation between genetic and geographic distances were found (0.350). Three main groups of populations can be distinguished based on genetic distances: (i) Mediterranean Coastal, (ii) Occidental Rif and Middle Atlas and (iii) High Atlas. The populations from Middle Atlas presented the lowest values of allelic richness and gene diversity whereas the populations from Rif showed a considerable amount of genetic variability. Human impact and isolation are major factors explaining population genetic structure of maritime pine in Morocco. Overexploitation of the forest by intensive cattle grazing and land speculation are suggested to be active mechanisms currently deploying the genetic resources of this species.

Keywords

  • Pinus pinaster
  • genetic structure
  • genetic diversity
  • genetic conservation
  • allozymes
  • Morocco
  • maritime pine
Open Access

Chloroplast DNA Variation in Some Representatives of the Asian, North American and Mediterranean Firs (Abies spp)

Published Online: 27 Oct 2017
Page range: 99 - 104

Abstract

Abstract

Using PCR-RFLP analysis, a comparative study on the restriction site polymorphism within 8 genes and regions of the Abies chloroplast DNA has been conducted covering 15 Asian, 6 North American and 7 Mediterranean species. A variable degree of divergence was observed among individual species of a given region as well as between geographical groups. A group of the Mediterranean firs, consisting of closely related species, differed profoundly from both Asian and North American representatives. Although a higher level of restriction site variants was detected among the Asian firs, two thirds of them were allocated to the difference between A. mariesii and the other Asian firs. The North American species exhibited the highest level of polymorphism resulting in several subgroups on a cladogram. At the individual species level, the Asian species A. mariesii and the North American species A. lasiocarpa diverged conspicuously from their counterparts in their respective regions. The results of restriction site polymorphism analysis are discussed with ragard to crossability and taxonomic status of individual species.

Keywords

  • Abies
  • chloroplast DNA
  • restriction site variation
  • relationships
  • species differentiation
Open Access

Nuclear Markers (AFLPs) and Chloroplast Microsatellites Differ Between Fagus sylvatica and F. orientalis

Published Online: 27 Oct 2017
Page range: 105 - 110

Abstract

Abstract

Former studies based on chloroplast markers and allozymes suggested that postglacial recolonization of central Europe by Fagus sylvatica L. occurred from one or a few undifferentiated refuges. Here, we examine F. sylvatica from Germany and Greece and different provenances of F. sylvatica ssp. orientalis (Lipsky) Greut & Burd. (F. orientalis Lipsky) with chloroplast microsatellites and AFLP markers. Only such AFLP markers were selected that had shown a differential amplification in F. sylvatica and F. orientalis in a preliminary analysis. UPGMA cluster analysis of AFLP data distinguished one F. sylvatica group and one F. orientalis group from northern Turkey. Low structuring in the neighborjoining analysis and the lack of diagnostic bands for either taxon suggests a relatively recent differentiation in Fagus orientalis and F. sylvatica. High bootstrap values were only found for a separate cluster that comprises F. orientalis from two different forest botanical gardens. Four of these samples have a unique chloroplast type and are genetically very similar (bootstrap value 96) mostly likely due to clonal replication. Only two different chloroplast types (type 1 in Germany, type 1 and type 2 in Greece) could be detected for F. sylvatica. In contrast, F. orientalis from northern Turkey showed different chloroplast types even within one provenance pointing to a glacial refuge in northern Turkey and a bottleneck at the time of postglacial recolonization of central Europe. The classification of ten samples from northern Turkey as F. sylvatica by AFLP data, chloroplast markers and morphology questions the interpretation of F. orientalis and F. sylvatica as two geographically separated (allopatric) taxa.

Keywords

  • Fagus sylvatica
  • Fagus orientalis
  • AFLP
  • cpDNA
Open Access

A Decision Support System Inferring the Genotypes of Seed Trees From Open Pollinated Progenies

Published Online: 27 Oct 2017
Page range: 111 - 116

Abstract

Summary

The knowledge of the genetic background of seed lots used in forestry operations (i.e., afforestations, reforestations) is important for the evaluation of the future potential of forests to survive under changing environments. An approach to infer the genotype of seed trees from their open pollinated progenies is presented. Sampling difficulties of adult tree tissue make the genetic analysis of seed trees often impossible. The present decision support system (TGDSS - Tree Genotype Decision Support System) allows the reconstruction of the genotypes of the parent population (adult trees) through the analysis of only the genotypes of the progeny generation (seeds). The method consists of three steps, each one representing a specific logical test. The system was tested with data obtained from the genetic analysis of tree populations. The genotypes inferred through the TGDSS and the ones observed in the laboratory were identical. The factors defining the effectiveness of the system are discussed.

Keywords

  • Decision Support System
  • genotypes
  • seed trees
  • progeny
  • inheritance
  • C++
Open Access

Seed Source Variation in Cone, Seed and Seedling Characteristic Across the Natural Distribution of Himalayan Low Level Pine Pinus roxburghii Sarg

Published Online: 27 Oct 2017
Page range: 116 - 123

Abstract

Abstract

The wide range of climatic condition in the natural distribution of chir pine is expected to result in high genetic variation within different populations of the species. The present study on the provenance variation of chir pine aims to determine the nature and extent of variation in wide range of populations with respect to 23 morphological traits of cone, seed and seedling, (at nursery stage) of 63 provenances of Pinus roxburghii. Seed sources exhibited a wide range of variability in terms of mean vales for various traits, standard deviation, variance, coefficient of variability, broad sense heritability, genetic advance and genetic gain and offer ample scope for undertaking screening for the desired traits. Genotypic variance (Vg) and genotypic coefficient of variability (GCV) for most of the parameters were found to be higher than corresponding environmental variance (Ve) and environmental coefficient of variability (ECV), except cone fresh weight, survival%, days taken for bud break and collar diameter where Ve and ECV dominated the Vg and GCV, thus indicating influence of environment on the expression of these traits. Moderate to high percentage of heritability coupled with same intensity of gain, was observed for many of the traits studied under laboratory conditions and at nursery stage e.g. for germination percentage, MGT, GV. This signifies that these traits are under strong genetic control and good amount of heritable additive genetic component can be exploited for further selection and improvement of this species.

Keywords

  • Pinus roxburghii Sarg.
  • seed source variation
  • seed and seedling characters
  • bud break
  • genotypic variance (Vg)
  • genotypic coefficient of variability (GCV)
  • environmental variance (Ve) and environmental coefficient of variability (ECV)
  • heritability
  • genetic gain
Open Access

Juvenile – Mature Genetic Correlations in Pinus pinaster Ait. Under Different Nutrient x Water Regimes

Published Online: 27 Oct 2017
Page range: 124 - 129

Abstract

Summary

Juvenile - mature (JM) correlations and selection efficiencies among one-year old Pinus pinaster seedlings and 8-yr field performance were analyzed in order to study the possibilities of early selection in the maritime pine breeding program in Galicia (NW Spain). Twenty four open-pollinated families from a first generation clonal seed orchard were grown in the greenhouse under two nutrient crossed with two water regimes. Several growth and dry mass traits were assessed 30 weeks after sowing and compared with field performance (height, diameter and volume) of four 8-yr-old progeny tests established in the coastal area of Galicia. Family mean correlations and genetic correlations were computed for each greenhouse trait, greenhouse treatment, field test site and field trait combination. Except for a few cases, most of the JM correlations were weak and in many cases negative. There was no detectable pattern of JM correlations regarding to combinations of greenhouse treatments and test site water availability and/or fertility. The large variation in the JM correlations for the same traits in different environments and sites (even changing sign in several cases) suggest a large influence of the genotype x environment interaction in the JM estimations. Other possible causes of the weak JM correlations are discussed. Based on the results of this study it may be concluded that none of the combinations of trait and treatment included in this experiment can be recommended for incorporation into early testing in the Galician Pinus pinaster breeding program. Indications for further research to optimize an early selection procedure are included.

Keywords

  • early selection
  • maritime pine
  • drought
  • nutrient availability
  • retrospective studies
  • greenhouse - field correlations
Open Access

DNA Profiling, Pedigree Lineage Analysis and Monitoring in the Australian Breeding Program of Radiata Pine

Published Online: 27 Oct 2017
Page range: 130 - 134

Abstract

Abstract

Ten microsatellite loci were used to DNA profile 215 first and second generation breeding clones in the Australian radiata pine breeding program. The clones were essentially unique from one another and these DNA profiles were used to examine the sexual and asexual phases in the breeding program. Only 2.6% of ramets from 25 breeding clones were incorrect whereas 8.4% of progeny from 10 families were genetically incorrect. The lineages of second generation clones were checked for DNA profiles that were available for putative parents. Some parents appear to be incorrect on the basis of the DNA profiles and further sampling will be required to confirm these results across the breeding program. Microsatellite markers can now enable most questions to be resolved in breeding programs and also will allow novel breeding strategies to be used in the future.

Keywords

  • DNA fingerprinting
  • microsatellite loci
  • probability of identity
  • paternity
Open Access

Accuracy of Single- and Multiple-Trait REML Evaluation of Data Including Non-Random Missing Records

Published Online: 27 Oct 2017
Page range: 135 - 139

Abstract

Abstract

We examined the accuracy of single- and multiple-trait REML procedures by studying estimates of within-individual genetic correlations between an ordered categorical trait and a continuous trait. The traits were derived from simulated bivariate, normally distributed data including selectively deleted records. Ten thousand data sets were generated for each partially factorial combination of two levels of genetic correlation (0.3 and 0.6), and environmental correlation (0.3 and 0.6), and three levels of narrow-sense individual heritability (0.05, 0.15 and 0.25) and mortality (0, 10, 30 and 50%). All data sets consisted of data on 200 unrelated parents, each with 20 halfsib progenies. The accuracy of the evaluations was illustrated in terms of average bias and variation of derived correlation estimates. The average bias values generated by multiple-trait REML were generally low. In contrast, single-trait REML was sensitive to selective deletion of records and systematically underestimated the genetic correlations. For both methods, especially at low heritabilities, the magnitude of the variation was generally high, showing that there is a substantial probability of obtaining seriously misleading genetic correlation estimates if the analysis is based on a single experiment and data include non-random missing records.

Keywords

  • Genetic correlation
  • Monte Carlo simulation
  • multiple-trait analysis
  • REML
Open Access

Simple PCR Markers for the Study of Chloroplast in Eucalyptus

Published Online: 27 Oct 2017
Page range: 139 - 140

Abstract

Summary

Combined use of two newly designed PCR primers with already described rpl2 and trnH primers, yields amplification of three non-independent products from the hypervariable JLA region of eucalypt chloroplast. Polymorphism analysis of the resulting PCR markers is proved to be a time- and cost-efficient alternative to traditional cpDNA techniques as RFLP or sequencing for Eucalyptus globulus Labill. population genetics studies.

Keywords

  • Eucalyptus
  • chloroplast DNA
  • JLA junction
  • PCR markers
Open Access

Genetic Variation in Picea glauca for Growth and Phenological Traits From Provenance Tests in Ontario

Published Online: 27 Oct 2017
Page range: 141 - 148

Abstract

Abstract

Ecologically based management of white spruce (Picea glauca [Moench] Voss.) requires an understanding of its patterns of adaptive variation. This understanding will become increasingly important under changing climate conditions. Five common garden tests and a greenhouse trial established in 2002 across Ontario were used to assess levels of genetic variation and relate this variation to local climate. Growth and phenological variables, including height, root collar diameter, survival, timing of spring budflush, and timing of fall budset were measured. Intraclass correlation coefficients were calculated for all traits to determine levels of genetic variation. Simple linear regressions were used to relate these differences to local climate conditions. After two growing season’s levels of between-provenance genetic variation ranged from 0 percent for several of the budflush variables to 22 percent for 2003 survival at the Englehart field trial. Overall, growth variables showed higher levels of between-provenance variation than phenological variables. Variation was predominately explained by longitude, a surrogate for precipitation patterns in Ontario, and temperature variables related to the growing season with r2 values ranging from 0.03 to 0.55. Generally, patterns of adaptive variation followed a southeast to northwest trend across Ontario. Northern sources flushed earlier and set bud earlier, while southern sources demonstrated superior growth. Results support previous white spruce genecology studies showing superior growth of sources from the Ottawa valley region of Ontario and Quebec.

Keywords

  • Picea glauca
  • white spruce
  • genetic variation
  • adaptive variation
  • provenance trials
  • intraclass correlation coefficient
  • climate
Open Access

Genetic Variability and Early Growth Performance of Eucalyptus tereticornis Sm. in Provenance cum Progeny Trials in India

Published Online: 27 Oct 2017
Page range: 148 - 153

Abstract

Abstract

Results of provenance cum progeny trials of Eucalyptus tereticornis Sm. laid out in 2002 at three sites viz. FRI Campus (Uttaranchal), Chiryanpur (Uttaranchal) and Midnapore (West Bengal) located in tropical region of India are reported and discussed. Thirteen provenances representing 91 families from Australia and Papua New Guinea (PNG) viz. Oro bay to Emo, PNG; Sirinumu Sogeri Plat, PNG; Warwick, QLD; Yurammie, SF, NSW; Buckenbowra SF, NSW; Selection flat SF559, NSW; Credition SF, QLD; Cardwell, QLD; Mitchell River MT Molloy, QLD; Mill stream archer creek, QLD; Helenvale, QLD; Walsh River, QLD; Burdekin River, QLD were evaluated from nursery stage to field performance (age 21months). As a local seed source open-pollinated seeds collected from selected interspecific Eucalyptus F1 hybrid trees of FRI-4, FRI-5 and Mysore gum (Eucalyptus teretirornis) were used to serve as check material (control). Significant differences between the provenances and families at age 21 months were observed for height, clean stem length, collar diameter and field survival. Significant provenance x site interaction was observed for height. In general the north Queensland provenances performed better and in particular two provenances viz. Walsh River, QLD and Burdekin River, QLD ranked the best in comparison to others at this age. Results indicate that significant genetic differences exist between the families and provenances of E. tereticornis. The growth traits were inter-correlated with each other. Geographic clinal variation pattern was observed in some of the growth traits viz. height, clean stem height and collar diameter. There were fair differences between phenotypic and genotypic coefficient of variability. Heritability (narrow sense) values were fairly good for height and clear stem length in comparison to collar diameter. The relative performance of the provenances was fairly consistent throughout test sites.

Keywords

  • Eucalyptus tereticornis
  • variation
  • provenance
  • genetic improvement
  • productivity
  • heritability
  • progeny
  • provenance x site interaction
Open Access

Use of Belowground Growing Degree Days to Predict Rooting of Dormant Hardwood Cuttings of Populus

Published Online: 27 Oct 2017
Page range: 154 - 160

Abstract

Abstract

Planting Populus cuttings based on calendar days neglects soil temperature extremes and does not promote rooting based on specific genotypes. Our objectives were to: 1) test the biological efficacy of a thermal index based on belowground growing degree days (GDD) across the growing period, 2) test for interactions between belowground GDD and clones, and 3) identify beneficial planting windows based on combinations of genotypes and belowground GDD. We tested two clones of Populus deltoides Bartr. ex Marsh (D133, D134) and four hybrid clones of P. deltoides × P. maximowiczii A. Henry (DM101, DM105, NC14105, NC14107). Cuttings, 20 cm long, were planted in randomized complete blocks at 15- × 15-cm spacing across three planting dates during 1999 at Alexandria, Minnesota, USA (45.9°N, 95.4°W) and Fertile, Minnesota, USA (47.3°N, 96.2°W). Temperatures at 20 cm belowground were converted to GDD with a base temperature of 10°C. We measured root, top, and total dry weight, along with number of roots after 14 d of growth. Relatively warmer and cooler soil temperatures promoted rooting for the cottonwoods and hybrids, respectively. We recommend planting after reaching a threshold of 163 belowground GDD for P. deltoides clones and planting before reaching a threshold of 173 belowground GDD for P. deltoides × P. maximowiczii clones.

Keywords

  • Populus deltoides
  • P. maximowiczii
  • hybrid poplar
  • soil temperature
  • genotype × environment interaction
Open Access

Fertility Variation and Status Number Between a Base Population and a Seed Orchard of Pinus brutia

Published Online: 27 Oct 2017
Page range: 161 - 163

Abstract

Abstract

Female, male and total fertility variations were estimated in a base population and a seed orchard derived from the base population in Pinus brutia. Relative status number for gametes (female and male contribution) and zygotes (average of female and male contribution) were estimated based on the fertility variation. Average female and male strobilus production were 229.1 and 1003.3 in the base population, and 98.9 and 244.9 in the seed orchard for combined years, respectively. Positive and significant correlations were found between female and male strobilus production in both base population and seed orchard. The male fertility variation was higher than female fertility variation in the seed orchard, while female fertility variation was higher than male fertility variation in the base population. Coefficients of variations in female and male strobilus production were 0.721 and 0.696 in the base population, and 0.403 and 1.110 in the seed orchard for combined years, respectively. Total fertility variation was 1.41 in the base population and 1.40 in the seed orchard for combined years. The relative status numbers estimated based on the total fertility were 70% of census number in the base population, and 71% in the seed orchard for combined years.

Keywords

  • Pinus brutia
  • seed orchard
  • base population
  • sibling coefficient
  • status number
Open Access

Fertility and Effective Population Size in Seedling Seed Orchards of Casuarina equisetifolia and C. junghuhniana

Published Online: 27 Oct 2017
Page range: 164 - 168

Abstract

Abstract

Two seedling seed orchards each of C. equisetifolia and C. junghuhniana established by thinning provenance trials in coastal and inland locations in South India were evaluated for sex expression and fertility variation at four years. More than 80% of the trees in C. equisetifolia orchards were fertile in both sites with a similar pattern of more (almost 2 times) female trees and equal proportion of monoecious and non-flowering trees. In C. junghuhniana, the coastal orchard had twice the proportion of fertile trees as that of the inland. Orchards established in coastal environment had less fertility variation and hence maintained lower coancestry values in both species. Coastal site has more trees contributing effectively to seed production than inland locations and the orchards maintain higher (almost two times) effective population sizes. Genetic drift is also 3 times higher in inland locations in both species. Male and female trees in inland orchards of both species however had greater reproductive output than coastal trees. Monoecious Casuarina equisetifolia trees showed a different trend of greater male fertility in coastal site, but seed output was the same in both locations. Gene diversity values of all orchards are high though it is marginally higher in coastal sites. Measures like constrained seed collection from large number of trees and promoting representation of superior provenances with low fertility would be useful in checking diversity loss during domestication.

Keywords

  • breeding population
  • coancestry
  • gene diversity
  • relative status number
  • provenance trial
  • seed orchard
Open Access

Genetic Variation in Turkish Red Pine (Pinus brutia Ten.) Seed Stands as Determined by RAPD Markers

Published Online: 27 Oct 2017
Page range: 169 - 175

Abstract

Summary

Turkish red pine (Pinus brutia Ten.) is one of the important tree species in Turkey. The species has been heavily disturbed by anthropogenic factors and fire, making it important to understand the magnitude of the impact on genetic diversity of areas reserved for seed production. To explore the extent of genetic variation in Turkish red pine seed stands, a random amplified polymorphic DNA (RAPD) marker system was used in the study. The estimated genic diversity for seed stands was found to range from H =0.17 (P, %of polymorphic loci =%58.7) in Çameli-Göldağ to 0.29 (P =%81.7) in Bayramiç-Karaköy seed stand though the lowest polymorphism was observed in Fındıkpınarı seed stand (P =55.8%). The total gene diversity was calculated as HT=0.34, in Turkish red pine. About 65% of the total diversity was within seed stands. No distinct pattern of genetic diversity was found according to the geography, elevation or breeding zones. The highest genetic differentiation was found in the Western Mediterranean geographic region, however, within population genetic diversity was found to be similar among different geographic regions (HS=0.22-0.24). GST value calculated was high (0.35) indicating that genetic differentiation among the studied seed stands was substantial. Dendrogram constructed with genetic distance data did not yield a firm pattern with respect to geography, elevation and breeding zones. In fact, the most of the clusters in the dendrogram had very low bootstrap values, suggesting that the clusters could be refined if more populations and markers are included in the future studies. The implication of the results with respect to in situ conservation of genetic resources of the species was discussed.

Keywords

  • Pinus brutia
  • RAPD markers
  • Seed stands
  • genetic diversity
  • in situ conservation
Open Access

Genotype x Environment Interaction in Maritime Pine Families in Galicia, Northwest Spain

Published Online: 27 Oct 2017
Page range: 175 - 182

Abstract

Summary

The magnitude and practical importance of family x site interactions for growth and form traits in maritime pine (Pinus pinaster Ait.) breeding in the coastal area of Galicia (NW Spain) were analysed using several different techniques. Data were from 58 8-yr-old half-sib families planted across four sites. The analysis of variance and the ratio of interaction to family variance component showed the interactions to be quantitatively important for several traits, especially for volume and straightness. Genetic correlations between the same trait at different sites were moderate and highly variable, especially for certain pairs of sites. The results indicated that interactions are a consequence of few highly interactive families that may be particularly sensitive to environmental variation. The removal of these families from the breeding program appeared as an effective strategy to solve the interactions. Results are discussed in relation to the stability parameter considered to identify the most unstable progenies.

Keywords

  • Stability
  • Pinus pinaster
  • Progeny trial
  • Half-sibs
  • Genetic correlation
Open Access

Seed Source Variation in Growth Performance of Eucalyptus camaldulensis Dehnh. of Australian Origin in India

Published Online: 27 Oct 2017
Page range: 182 - 186

Abstract

Abstract

Results of a provenance trial of Eucalyptus camaldulensis Dehnh. laid out in 2001 at Seothi (30° N Lat., 76° E Long. and 250 m altitude) Haryana, a semi-arid region of India are reported and discussed. Six seed sources from Australia viz. Laura River, Emu Creek, Degrey River, Wiluna, Kennedy River, Morehead River were evaluated from nursery stage (3 months) to field performance (2 year). Two sources viz. E.tereticornis (Helenvele, Qld) and FRI-4 a local seed source were used as control (check material). Significant differences between the seed sources at nursery stage were observed for collar diameter (P < 0.05) and number of leaves (P < 0.01). At age 2 years, significant differences between the seed sources (P < 0.05) were observed for height and field survival. The two seed sources viz. Emu Creek Petford, QLD and Laura river, QLD ranked first and second for height and survival at this age. Results indicate that genetic differences exist between the sources of E. camaldulensis. None of the traits assessed (viz. height, collar diameter, number of leaves, number of branches and survival) was found to correlate with any of the geographical coordinates of the site (latitude, longitude and altitude). There were fair differences between phenotypic and genotypic coefficient of variability. Heritability values were fairly high for height and clear bole length in comparison to collar diameter, number of branches and survival. The relative performance of these provenances was fairly consistent throughout the period of observation. The two sources viz. Laura river, QLD and Emu Creek Petford, QLD are recommended for potential source for plantation programme under semi-arid conditions.

Keywords

  • Eucalyptus camaldulensis
  • variation
  • provenance
  • seed source
  • genetic improvement
  • productivity
  • heritability
Open Access

Seed Source Variation in Growth Performance and Oil Yield of Jatropha curcas Linn. in Central India

Published Online: 27 Oct 2017
Page range: 186 - 192

Abstract

Abstract

Results of a seed source evaluation trial of Jatropha curcas Linn. laid out in 1996 at Jabalpur (M.P), a semi arid region of India are reported and discussed. Seeds collected from ten sources from central India representing the states Madhya Pradesh and Maharashtra viz. Gondia, Bichia, Balaghat, Niwas, Khandwa, Burhanpur, Nasik, Chindwara, Kundam and Jabalpur were evaluated for their growth performance from nursery stage (3 months) to field (two years). Variation in seed oil content of different sources were also studied and reported. Significant differences between the seed sources at age 27 months were observed for height, collar diameter, number of branches leaf area and field survival. Seeds collected from different sources also varied significantly in respect of seed and kernel weight and oil content in seed/kernel. The Chhindwara (M.P.) source performed the best and yielded a maximum oil of 39.12% from whole seed and 58.12% from kernel. The oil content ranged from 33.02 to 39.12% in whole seeds and 47.08 to 58.12% in kernel, across the seed sources. The performance of Kundam (M.P.), Jabalpur (M.P.), Bichia (M.P.), Niwas (M.P.) and Nasik (Maharashtra) sources were also found satisfactory for oil yield. Results indicate that genetic differences exist between the seed sources of J. curcas. The growth traits showed significant positive correlation with each other. Fair differences between phenotypic and genotypic coefficient of variability were observed. Heritability (broad sense) values were fairly good with regard to leaf area, height and collar diameter in comparison to survival percent. The relative performance of these sources was fairly consistent throughout the observation period.

Keywords

  • Jatropha curcas
  • variation
  • provenance
  • genetic improvement
  • productivity
  • heritability
  • oil
  • diesel
Open Access

Intraspecific variation and geographic patterns of Fagus orientalis Lipsky chloroplast DNA

Published Online: 27 Oct 2017
Page range: 193 - 197

Abstract

Abstract

CpDNA variation in Iranian beech, Fagus orientalis Lipsky (Fagaceae) was studied in 14 populations distributed throughout the species range in the Hyrcanain zone. Two cpDNA intergenic regions were analyzed: (i) one in the DT region between trnD (tRNA-Asp) and trnT (tRNA-Thr) genes, and (ii) one in the OA region between the orf184 and petA genes. The restriction fragments of the region DT did not show polymorphism among individuals within any population analyzed. However, among individuals within analyzed populations of Asalem region and Neka-1400 population, polymorphism in the restriction fragments of the OA region were found. A total of 3 different chloroplast (cp) haplotypes were scored. The distribution of the cpDNA haplotypes revealed a geographical structure of the genetic differentiation with Gst = %68.7 and Nst = %70.3. The distribution pattern of F. orientalis cpDNA haplotypes may reflect environmental differences and migration history of beech during historical distribution in Tertiary from Asalem (most polymorphic region) to East of Hyrcanian forests.

Keywords

  • cpDNA
  • Fagus orientalis Lipsky
  • Hyrcanian zone
  • Iranian beech
  • intraspecific diversity
  • genetic patterns
Open Access

Genetic Variation in Growth Traits in a Quercus robur L. Open-Pollinated Progeny Test of the Slavonian Provenance

Published Online: 27 Oct 2017
Page range: 198 - 201

Abstract

Abstract

The study presents evaluation of an open-pollinated progeny test of 21 selected plus trees from Slavonian pedunculate oak provenance in Croatia (in the central part of Drava river valley). The test was established in 1992 with two-year-old seedlings. Heights were measured at 5 to 13 years and diameters at breast height (DBH) at 10 to 13 years after sowing. Variances caused by the population within provenance effect were not significant during the studied period. In contrast, variance components caused by family effect were statistically significant, and ranged from 11.1 to 18.6% and from 2.2 to 10.6% for height and DBH respectively. Statistically significant variances caused by the family effect indicate that most of genetic variation of productive traits was within the studied populations. The estimated family mean narrow sense heritabilities varied from 0.62 to 0.78 and from 0.28 to 0.65, while individual heritabilities ranged from 0.48 to 0.80 and from 0.09 to 0.46 for height and DBH, respectively. Realised gain from the test and expected genetic gains by two possible methods of selection for the measured traits have been calculated for: i.) realised gain i.e. superiority of selected plus trees progenies over control plants (bulks from unselected trees within the provenance) ii.) individual within provenance mass selection of first generation plus trees at the same ages as those represented in studied trial and iii.) backward selection among first generation plus trees after open-pollinated testing. Estimated genetic gains indicate that the highest gain could be expected by backward selection among first generation plus trees after open-pollinated progeny testing (9.7 to 22.3% and 6.8 to 17.3% over control means). These results indicate that due to significant within population variation and high additive variances, improvement for productive traits in the studied oak populations could be achieved by use of seeds and plants from selected plus trees (especially from already established clonal seed orchard), at least in younger ages.

Keywords

  • Quercus robur
  • open-pollinated progeny test
  • genetic variation
  • genetic parameters
  • selection
Open Access

Fertility Variation, Genetic Relatedness, and Their Impacts on Gene Diversity of Seeds From a Seed Orchard of Pinus thunbergii

Published Online: 27 Oct 2017
Page range: 202 - 206

Abstract

Abstract

Clonal differences in the number of male and female strobili were determined for five consecutive years in a clonal seed orchard of Pinus thunbergii in Korea. The effects of relatedness and clonal differences in reproductive development on gene diversity of seed (in terms of accumulated relatedness by status number) were estimated. While clonal differences were found, fertility variation was not large through all studied years. The orchard clones were divided into different regions and locations based on the geographical distribution and distance of natural stands that plus trees were selected from. Assuming that there was no relatedness among regions, locations and clones, the status number (Ns) was varied from 47.6 to 55.5 for five successive years. On average (pooling), Ns was 92% of census number (N). Assumed relatedness among regions, locations and/or clones decreased the status number. Effect of parental selection on relatedness and orchard management was also discussed.

Keywords

  • fertility variation
  • status number
  • gene diversity
  • relatedness
  • Pinus thunbergii
Open Access

Spatial Genetic Structure in Disturbed Populations of Quercus acutissima (Fagaceae)

Published Online: 27 Oct 2017
Page range: 206 - 211

Abstract

Abstract

Quercus acutissima is a large deciduous tree of hillsides ranging from South Korea to Japan. It occurs in many plant communities, often as a pioneer species in monospecific stands which colonized gaps after gap formation. This study used multilocus allozyme genotypes mapped from two disturbed populations near farm houses in southern Korea to compare our results with previous studies conducted on undisturbed populations of trees in southern Korea. Coancestry measures (fij), RIPLEY’s L-statistics, and WRIGHT’s F-statistics were then calculated to examine the distribution of individuals and spatial genetic structure both within and between populations. RIPLEY’s Lstatistics indicated significant aggregation of individuals at interplant distances. A weak but significant positive fine-scale genetic structure at 10 m distance was detected in the two disturbed populations, which is consistent with the structure found in an inland, disturbed population in southern Korea. Estimates of near-distance fij in the two populations (0.020 and 0.036) were considerably lower than that expected for half-sibs (0.125) under random mating, suggesting secondary seed dispersal and substantial overlap of seed shadows. The levels of genetic diversity within the two disturbed populations of Q. acutissima were found to be comparable to the within-mean for populations of other oak species. Significant deficits of heterozygosity were detected in both populations, probably due to several parent-offspring and sib matings. Finally, a significant but low differentiation between the two disturbed populations of Q. acutissima was found, which is likely to be attributable to long-distance pollen movement by wind, which should enhance homogeneity of allele frequencies between adjacent local oak populations.

Keywords

  • allozymes
  • disturbance
  • Fagaceae
  • Quercus acutissima
  • spatial genetic structure
Open Access

Evaluation of Clonal Variability in Shoot Coppicing Ability and in vitro Responses of Dalbergia sissoo Roxb

Published Online: 27 Oct 2017
Page range: 212 - 220

Abstract

Summary

Clonal variations were observed amongst 12 clones of Dalbergia sissoo belonging to four states (U.P, Uttaranchal, Haryana and Rajasthan) of India, representing four different geographical zones in respect of ex vitro shoot coppicing ability and in vitro responses. Coppicing ability of shoot hedges of clones exhibited significant variation which ranged from average of 13.81 coppiced shoots (Clone 40, Uttar Pradesh) to 9.29 (Clone 64, Haryana). Comparative analysis of clones from different regions in respect to their coppicing ability revealed that clones from U.P had higher coppicing ability whereas those from Haryana proved to be least coppicers. Regional variations were also exhibited in the in vitro multiple bud induction ability on nodal explants excised from shoot hedges of clones (mean number of buds induced and percentage of cultures forming multiple buds). Regional as well as inter clonal variations were recorded in the shoot proliferation efficiency as well as rootability of microshoots of these clones as well as their optimal plant growth regulator requirements. BAP alone (2.5 μM) was sufficient for inducing multiple buds on cultured nodal explants of Uttaranchal and Uttar Pradesh region clones. On the contrary, clones from Rajasthan and Haryana had higher optimal requirement of BAP and in addition, they required media to be supplemented with auxin (NAA) for induction of multiple buds on explants. Correlation analysis between shoot coppicing ability of clones and in vitro performances of explants of these clones cultured on 2.5 μM BAP indicates a positive correlation. Observation lays credence to our view that these characters are genetically controlled and shoot coppicing can be used as a marker character in optimizing in vitro performance of clones. Using the information generated by this paper in vitro production of elite planting material can be maximized by ameliorating plant growth regulator requirement in the medium.

Keywords

  • Dalbergia sissoo
  • coppicing ability
  • clonal variation
  • in vitro
  • provenance
  • correlation
  • U. P. (Uttar Pradesh)
Open Access

Identification of Rhus succedanea L. Cultivars Using Elliptic Fourier Descriptors Based on Fruit Shape

Published Online: 27 Oct 2017
Page range: 221 - 226

Abstract

Abstract

We have developed a method to identify cultivars of Rhus succedanea L. based on their fruit contour shape. For this, we collected fruits of five cultivars from three different environments (differing in site and/or year of collection) and the horizontal contour shape of each fruit was expressed by 37 elliptic Fourier descriptors, normalized in terms of size, rotation, shift and starting point of contour tracing. The first six components derived from a principal component analysis of the elliptic Fourier descriptors explained 89% of the variance. The differences among cultivars, environments and the cultivar x environment interaction were significant at the 0.01% probability level for all six principal components according to ANOVA. UPGMA cluster analysis based on the six principal components showed a high degree of clustering and most (but not all) ramets from the same cultivar clustered together. However, results of a UPGMA cluster analysis of Mahalanobis’ generalized distances among cultivars and environments, based on the 37 elliptic Fourier descriptors, showed that samples from the same cultivars clustered together, regardless of the environmental factors. We then applied a ‘similarity probability’ test, based on Mahalanobis’ generalized distances and a randomization test. The similarity probabilities between descriptors in the database and sampled fruits, when the cultivars they represented were included in the database, were >97%. In contrast, for samples representing cultivars that were not included in the database, the probabilities were <46%. These figures also apply to pairs of samples included in the database that represented the same cultivar, and different cultivars, respectively. These results suggest that it is possible to identify R. succedanea cultivars based on fruit contour shape using elliptic Fourier descriptors and similarity probability analysis.

Keywords

  • Rhus succedanea L.
  • cultivar identification
  • fruit shape
  • elliptic Fourier descriptor
  • Mahalanobis’ generalized distance
  • randomization test
Open Access

A Comparison of Isozyme and Morphological Markers to Assess the Within Population Variation in Small Populations of European aspen (Populus tremula L.) in Spain

Published Online: 27 Oct 2017
Page range: 227 - 233

Abstract

Summary

European aspen (Populus tremula L.) has been traditionally thought to establish new stands by vegetative propagation through root suckers produced by very few individuals (often only one). Morphological traits and isozyme patterns were studied in five small stands in northern Spain. Both isozyme and morphological approaches showed variation within and between stands. Estimated intrapopulational variation was higher than the expected, and clusters of individuals with the same isozyme multilocus patterns within each population have been identified. In order to check to what extent morphological markers are affected by the genotypes or clones, comparisons between leaf parameters and isozyme patterns were performed by hierarchical ANOVA and tests of hypothesis were constructed from the components of variance. Leaf shape parameters show a good correlation with the isozyme multilocus patterns. On the other hand, leaf size parameters, were more influenced by environmental factors. These traits may be useful as tools for the definition of in situ conservation units in endangered European aspen stands.

Keywords

  • Populus tremula
  • isozyme multilocus patterns
  • leaf morphology
  • within population variation
Open Access

RAPD Analysis of Genetic Variation Within and Among Four Natural Populations of Betula maximowicziana

Published Online: 27 Oct 2017
Page range: 234 - 239

Abstract

Summary

Betula maximowicziana is a long-lived pioneer tree species in cool temperate forests that plays an important role in the forest ecosystem and has high economic value. Random amplified polymorphic DNA (RAPD) markers were used to evaluate the genetic variation of four natural populations of B. maximowicziana (three in central Honshu and the other in Hokkaido) to obtain fundamental information on this natural resource. Sixty-one reproductive amplified bands were obtained with 23 primers. Of these 61 bands, 22 were monomorphic and 39 were polymorphic. The level of genetic variation within each population may be very similar, because the population rankings according to number of polymorphic loci, Shannon’s indices and intra-population genetic variance revealed no definite patterns. Global analysis of AMOVA (analysis of molecular variance) showed that genetic variation among populations accounted for 15.6% of the total variation, with the remainder (84.4%) occurring within population. These results demonstrate that genetic differentiation among the four populations is moderate. Hierarchical AMOVA analysis showed that variation among regions (Hokkaido and central Honshu) accounted for 10.4% of the total genetic variation, suggesting that regional genetic differentiation is relatively high. Significant correlations between pairwise ΦPT values and geographic distance were detected, and results of both a neighbor-joining dendrogram based on pairwise ΦPT values, and principal coordinate analysis (PCO) based on a Euclidean metric revealed that the Furano population in Hokkaido was genetically different from the three populations in central Honshu. The data obtained in this study should have important implications for the conservation and management of regional genetic variation of B. maximowicziana.

Keywords

  • Betula maximowicziana
  • natural resource
  • RAPD
  • regional genetic variation
Open Access

SSR Markers for Analysing South American Nothofagus Species

Published Online: 27 Oct 2017
Page range: 240 - 243

Abstract

Summary

11 newly discovered microsatellites were used to identify SSR markers for characterising South American Nothofagus species. This was carried out in six species. The sample sizes used were between four and six individuals per species. The cross-genera transferability of 34 Quercus SSRs was also essayed. Out of the 11 new microsatellite markers, three proved to be polymorphic (NnBIO 11, NgBIO 13 and NgBIO 14). The qualitative confirmation of the inheritance of these markers could also be verified. Polymorphism was also observed in five of the cross-genera transferred SSRs (QrBIO7, quru-GA-0A01, quru-GA-0C11, quru-GA-0I01, quru-GA-0M07). The number of alleles per locus found range between 1 and 6 per species. The eight polymorphic SSRs identified in this study will constitute a valuable tool in the gene flow studies that are currently being carried out in natural populations of South American Nothofagus species. The confirmation of crossspecies and cross-genera transferability opens the way for the use of SSRs as bridge markers in genetic mapping.

Keywords

  • microsatellites
  • Nothofagus
  • transferability
  • Quercus
Open Access

Sexual Symmetry in Natural Populations of the Patagonian Cypress (Austrocedrus chilensis)

Published Online: 27 Oct 2017
Page range: 244 - 246

Abstract

Abstract

Sexual symmetry, defined as equal allelic frequencies among reproduction effective gametes of both sexes, was analysed by means of 10 isozyme loci in three natural populations of Austrocedrus chilensis (dioecious and wind pollinated tree species). Haplotypes of effective gametes were inferred by analysing side-by-side both the embryo and the endosperm of seeds collected from 20 to 27 trees per population. The allelic frequencies of effective ovules and pollen were compared in each of the three populations. The hypothesis of sexual symmetry could only be rejected in case of one locus in two out of three analysed populations. That is, most of the loci surveyed turned out to be symmetric in the three sampled populations in spite of their contrasting environmental conditions. Therefore, sexual symmetry in A. chilensis seems to be mainly uninfluenced by the environment. On the other hand, all loci showed Hardy- Weinberg (HW) proportions in the three populations, even those that resulted asymmetric. HW structure is usually considered as enough evidence of panmixia, what implies sexual symmetry, and consequently this result gives an example of the low reliability of indirect methods of testing genetic processes, such as the classical HW test.

Keywords

  • reproductive system
  • Austrocedrus
  • isozymes
  • Cupressaceae
Open Access

PCR-Multiplex of Six Chloroplast Microsatellites for Population Studies and Genetic Typing in Pinus sylvestris

Published Online: 27 Oct 2017
Page range: 246 - 248

Abstract

Abstract

The major drawback of microsatellites analysis is that they are expensive to develop, labor-intensive and demand skilled personnel. However, such studies might be still simplified and accelerated by multiplexing of the markers and the use of highthroughput systems for genotyping DNA fragments. In this paper we present a single, simple and highly effective PCRmultiplex reaction composed of six chloroplast microsatellites widely used for population studies in pines but here applied to Pinus sylvestris. The reaction allows for rapid genotyping of large sample sizes.

Keywords

  • chloroplast microsatellites
  • PCR-multiplex
  • Pinus sylvestris
  • polymorphism
  • haplotypes
Open Access

An assessment of family variation of Norway spruce (Picea abies (L.) Karst.) of the Kolonowskie provenance from a reconstitution seed orchard

Published Online: 27 Oct 2017
Page range: 249 - 253

Abstract

Abstract

Variation in spring bud break dates and growth traits was studied among 183 half-sib families developed from Norway spruce grafts on a reconstitution seed orchard. The grafts were derived from maternal trees (ortets), which were selected on the IUFRO 1964/68 experimental plots in 11 countries. All maternal trees belong to the same provenance Kolonowskie, which should be reconstituted as a population by a seed orchard because its exact location was not documented, and thus seed of this provenance was not available. Analyses of variance of the data collected in the first six years of the experiment revealed a very high variation between families in general and between families within clones. Differences between the clones were observed in some traits (plant height after the first growing season, spring flushing in the sixth growing season), but differences between families within clones proved to be more significant. A positive correlation was found between bud break dates of grafts in the seed orchard and their generative progeny on the family experimental plot. The correlation was significant both at the family (graft) level (p = 0.01) and at the clonal level (p = 0.05). The substantial variation between open pollinated families from the reconstitution seed orchard cannot entirely be interpreted but it indicates a high selective potential of Norway spruce at the family level.

Keywords

  • Norway spruce
  • reconstitution seed orchard
  • half-sib families
  • genetic variation
  • growth traits
  • spring flushing
Open Access

Genetic Analysis of Growth and Susceptibility to Bacterial Wilt (Ralstonia solanacearum) in Eucalyptus by Interspecific Factorial Crossing

Published Online: 27 Oct 2017
Page range: 254 - 258

Abstract

Summary

Factorial mating crosses of Eucalyptus urophylla × E. tereticornis (3 x 5), E. urophylla × E. camaldulensis (3 x 3) and E. urophylla × E. exserta (3 x 3) were used for genetic analysis of growth traits and susceptibility to bacterial wilt (Ralstonia solanacearum). Genetic effects including female, male and female × male interaction were examined for height (H) and diameter at breast height (DBH) at age five as well as final bacterial wilt index (BWI) in both nursery inoculation and field assessment by five years of age. Female, male and female x male variances appeared to have a significant role in growth traits H and DBH though their magnitude varied for the factorials studied. For the trait BWI additive (male) and dominant (female x male) effects were both involved in the genetics of bacterial wilt susceptibility, and additive was the major. Estimates of narrow-sense heritability (h2) for H, DBH and BWI ranged from 0.11 ± 0.06 to 0.70 ± 0.09, varying with either trait or factorial. Growth traits (H and DBH) had low and non-significant phenotypic and genetic correlations with BWI in all the three factorials, ranging from -0.10 ± 0.08 to 0.17 ± 0.14 in coefficient of correlation. This indicates that it may be possible to select superior trees with both fast growth and high resistance to bacterial wilt in eucalypt hybrid populations in operational breeding programs.

Keywords

  • Eucalyptus
  • growth
  • bacterial wilt (Ralstonia solanacearum)
  • genetic parameters
Open Access

Patterns of Pollen Flow and Genetic Differentiation Among Pollen Pools in Quercus salicina in a Warm Temperate Old–growth Evergreen Broad-leaved Forest

Published Online: 27 Oct 2017
Page range: 258 - 264

Abstract

Abstract

Paternity analysis and analysis of molecular variance were used to determine patterns of pollen flow and genetic differentiation among pollen pools in Quercus salicina in an 11.56-ha plot in a temperate old-growth evergreen broad-leaved forest. The genotypes at seven microsatellite loci were determined for 111 adult trees and 276 seeds collected from under eight seed parents. The proportion of pollen flow from outside the plot (further than 100 m) was 52.2%, indicating that long-distance pollen flow occurred frequently in this species, as observed in other Quercus species. The pollen pools from inside and outside the plot differed genetically, and genetic structure was detected in the population of adult trees within the plot. Therefore, longdistance pollen flow from outside the plot may introduce new or low-frequent alleles, and increase genetic diversity in this population. However, the actual average distance of pollen flow within the plot was significantly shorter than the average potential distance, and negative exponential curves explained well the frequencies of matings as functions of the distance between parents, as found in other Quercus species. The genetic composition of pollen pools differed among the eight seed parents. The genetic differentiation of pollen pools between the seed parents showed significant positive correlation with the spatial distance between them, indicating that neighboring seed parents tend to accept similar pollen pools, probably because matings are frequently mediated by pollen transported over short distances

Keywords

  • AMOVA
  • gene flow
  • microsatellite
  • paternity analysis
  • pollen
  • Quercus
Open Access

Variation in Growth Performance of Acacia nilotica Willd. ex Del. Provenances of Wide Geographical Origin : Six Year Results

Published Online: 27 Oct 2017
Page range: 264 - 269

Abstract

Abstract

Results of a provenance trial of Acacia nilotica Willd. ex Del. laid out in 1993 at Tropical Forest Research Institute Campus, Jabalpur (23°N lat., 79°E long. and 400 m altitude) Madhya Pradesh, a semi-arid region of India are reported and discussed. Nineteen provenances from India, Pakistan, Sudan, Senegal and Yemen were evaluated in the field at age three and six years. Local source of A. nilotica (S.F.R.I., Jabalpur) was used as check material for comparison. Significant differences between the provenances (P < 0.05) were observed for height, diameter at breast height (DBH), number of branches and field survival. The provenances from Gujrat (Punjab), Pakistan, ranked first for growth traits namely height, DBH and survival. The next superior provenance was from Beihan, Yemen, which scored second highest values of height and DBH and had good survival at age six years. Results indicate that genetic differences exist between the provenances of A.nilotica. None of the traits assessed (viz. height, DBH, number of branches, inter-nodal length and survival) were found to correlate with any of the geographical coordinates of the provenances (latitude, longitude and altitude). Height, DBH and number of branches showed significant and positive correlation with each other. Fair differences between phenotypic and genotypic coefficient of variability were observed. Heritability values were found fairly good for height, DBH and number of branches as compared to inter-nodal length. The relative performance of these provenances was fairly consistent throughout the period of observation at three and six year. The two sources viz. Gujrat (Punjab), Pakistan and Beihan, Yemen, are recommended for plantation programme under semi-arid conditions.

Keywords

  • Acacia nilotica
  • variation
  • provenance
  • seed source
  • genetic improvement
  • productivity
  • heritability
Open Access

Correlation and Path Analysis Studies Between Biomass and Other Characters in Bombax ceiba L.

Published Online: 27 Oct 2017
Page range: 269 - 272

Abstract

Abstract

The genotypic and phenotypic correlation and path analysis of plant biomass, plant height, stem diameter and other biomass component traits were analyzed in thirty provenances of Bombax ceiba. In general, the magnitude of genotypic correlations was higher than phenotypic correlations. Stem diameter and plant biomass showed highly significant genotypic correlations with all the traits except the number of secondary branches and plant biomass with leaf biomass. Plant height had the highest positive direct effect on plant biomass followed by the number of primary branches/plant and the number of leaves/plant. On the basis of this study, a higher plant biomass would be achieved through direct selection based on plant height, the number of primary branches and the number of leaves/plant. Therefore, the study is important in selection of traits of economic importance based on other characters, whose direct effect is not visible.

Keywords

  • Bombax ceiba L.
  • provenance
  • plant biomass
  • biomass characters
  • genotypic and phenotypic correlation
  • path coefficient
50 Articles
Open Access

Population Genetics of Heterosis: Effects of Hardy-Weinberg Disequilibrium

Published Online: 27 Oct 2017
Page range: 1 - 6

Abstract

Summary

The mechanistic explanation of heterosis has been traditionally based on quantitative differences of gene effects. However, for outcrossing populations, heterosis is also a property of populations. In this paper, the effects of the deviation of a population from Hardy-Weinberg equilibrium (HWE) on the magnitude of heterosis have been examined numerically. The mating of two populations in HWE may generate directions and magnitudes of heterosis different from the mating of two populations in Hardy-Weinberg disequilibrium (HWD). Such differences of heterosis between these two types of population mating may be due to the release of vigor restored in the parental populations during the process of HWD. Results from this study can provide guidance on the selection of parental populations for the effective exploitation of heterosis and the prediction of genetic structure and organization for hybrid zones in nature.

Keywords

  • Hardy-Weinberg disequilibrium
  • heterosis
  • hybrid population
  • outcrossing population
  • population genetics
Open Access

Studies on the Pollination Characteristics and Pollination Level of Chinese fir Seed Orchard

Published Online: 27 Oct 2017
Page range: 7 - 11

Abstract

Abstract

Data from three seed orchards (Chongyang, Zhangle and Laoshan) and Lintian forest were used to study pollination characteristics, pollination level, pollen and ovule production in Chinese fir. The results show that male and female cones have their own distribution patterns within crowns. Male cones are located in the middle to top and female cones the middle to bottom part of the crown. Because of lower density of trees in seed orchard than that in a stand, female cones are distributed over the entire crown in seed orchard trees. Chinese fir male and female cones appear to be very well adapted for wind as the pollination mechanism. There is no difference in the number of pollen grains produced by one pollen sac among trees in the same clone, but there are differences between clones. There are differences between both clones and years in female cone number, male cone number and their ratio. The pollen accumulation rate during pollination should be 3 to 5 pollen grains/mm2 to ensure fertilization. The Chinese fir seed orchards in this study produced too much pollen and could be improved by stimulation of more female flowers in order to produce more seeds.

Keywords

  • Cunninghamia lanceolata (Lamb.) Hook
  • Chinese fir
  • seed orchard
  • clones
  • pollen
  • ovules
Open Access

Variation and Population Structure at Enzyme Gene Loci in Araucaria angustifolia (Bert.) O. Ktze

Published Online: 27 Oct 2017
Page range: 12 - 19

Abstract

Abstract

We describe alloenzyme variation in A. angustifolia populations of three separate geographical areas in southern Brazil. The genetic structure of populations was examined in seedtrees, embryos and effective pollen. Seven out of 24 enzyme loci were polymorphic. The average number of alleles per locus (24 loci) was 1.54, with 2.44 alleles per polymorphic locus. Mean expected and observed heterozygosities at the polymorphic loci were He = 0.128 and Ho = 0.132 for seed-trees, and He = 0.142 and Ho = 0.161 for embryos. All measures of genetic variability were highest in the most northern populations. Differences among localities explained 84.14% and 92.06% of the total genetic diversity in embryos and seed trees, respectively. Sex ratio was 1:1 in almost all populations. Female and male gene pools differed in allele frequencies, most significantly at loci 6- Pgdh-B and Skdh-B. This explains the excess of heterozygotes detected among embryos. No inbreeding or excess of heterozygotes was detected among adult seed trees. Genetic variation in A. angustifolia revealed a latitudinal gradient.

Keywords

  • Paraná pine
  • alloenzymes
  • genetic variation
  • differentiation of populations
  • paleohistory
Open Access

Progeny Testing Preceded by Phenotypic Pre-selection – Timing Considerations

Published Online: 27 Oct 2017
Page range: 20 - 26

Abstract

Abstract

Progeny-testing is a common element in tree breeding. It takes long time until trees reach the sexual maturity. That time could be used for field testing followed by progeny-test of the selected phenotypes (two-stage strategy), or the time until mating could be reduced by forcing early flowering (singlestage strategy). Benefit of phenotypic pre-selection followed by progeny testing in long-term breeding was assessed as a function of the age at the pre-selection by the aid of a deterministic tree breeding simulator. As a criterion of goodness of a breeding program, annual progress in group merit (GM/Y-refers to the rate of change in the average of genetic gain and gene diversity) at a total budget constraint was used. For simplicity, a long-term program with balanced selection was studied. Scenarios with different genetic parameters, cost and time components were evaluated and optimised for resource allocation. At the optimum age of mating for progeny test, two-stage Phenotype/ Progeny strategy generated higher GM/Y than singlestage Progeny strategy at the age of mating for progeny test equal to three years, except for a typical scenario with weak JM correlation, low heritability and long rotation time. High heritability, short rotation and strong J-M genetic correlation favoured phenotypic pre-selection. Optimum age for phenotypic pre-selection varied from 6 to 17 years and the percentage of GM/Y lost in comparison to the maximum due to delay of mating for the progeny test until age 15 and 25 years ranged from 0 to 14% and from 1 to 29%, respectively. In the case of low heritability, long rotation, low J-M correlation, high cost for cycling and low budget, early mating age would bring little benefit if compared to mating at the optimum age. We suggest that, in long-term breeding based on progeny testing, investment in phenotypic pre-selection is more beneficial than investment to achieve early flowering to initiate the progeny test early.

Keywords

  • annual gain
  • juvenile-mature correlation
  • gene diversity
  • group merit
  • optimisation
  • two-stage selection
  • stage-wise selection
  • flowering induction
Open Access

Retrospective Evaluation of Parental Selection in Nursery Tests of Juglans regia L. Using a Mixed Model Analysis

Published Online: 27 Oct 2017
Page range: 26 - 33

Abstract

Summary

Results of early testing in Juglans regia performed over the period 1993-2002 are presented. A total of 37 progenies were evaluated for establishment, growth traits, and phenology at ages one and two during two or more sowing years in the nursery. Independent culling selection was applied on parental trees to the family-mean values using specific truncation points for establishment, diameter and total height. In addition, parental selection was performed on unbiased predictions (BLUPs) of parental breeding values using a multivariate mixed model analysis in order to account for the unbalanced nature of the entire data set. Genetic parameters (heritabilities, correlations) of juvenile traits were also estimated. Except for second year growth traits, the genetic control of most characters was quite high, with heritability estimates ranging from 0.51 (establishment) to 0.93 (flushing date). Growth performance and establishment did not bear a common genetic control according to non-significant genetic correlations, but a higher growth was typical of early flushing families. Changes in parental ranking for growth after comparison of familymean and BLUP-based estimates of parental performance were considerable. This observation, together with the larger proportion of culled progenies in the former method (about 70%), suggests a sizeable loss of genetic gain by using unadjusted parental means. It is concluded that current evaluation and selection schemes using family-mean values should be reconsidered by i) relaxing truncation points for selection on establishment and growth traits and ii) re-evaluating progeny test data using a mixed model framework to unveil valuable material otherwise neglected due to unaccounted environmental influence on family performance.

Keywords

  • Juglans regia
  • early selection
  • genetic parameters
  • BLUP
  • mixed model
Open Access

Genetic Variation in Growth and Blister-Rust Resistance in a Pinus strobus x P. wallichiana Hybrid Population

Published Online: 27 Oct 2017
Page range: 33 - 41

Abstract

Summary

This experiment consists in a controlled crossing according to a factorial design performed between 7 female trees of P. strobus and 4 male trees of P. wallichiana to combine the rapid growth of former species with high resistance to Cronartium ribicola of the latter one. The hybrid families were artificially inoculated at age 2, and field planted at age 6. Blister rust resistance (BRR), tree survival (TS), total height growth, (H) annual height growth (h), diameter (D), basal area (BA), stem volume (V), stems straightness (SS) and branch thickness (BT) were the traits measured at age 17. Statistical analysis produced the results presented below. Significant (p<0.05) and highly significant (p<0.01; p<0.001) differences were found among hybrid families. Differences among female effects were highly significant (p<0.001) for all tested traits including BRR, suggesting that nuclear additive genes controlled these traits. Significant differences were found among male parents for H but no significant differences for BRR; therefore, all four male parents transmitted a similar level of resistance. The ratio σ2GCA2SCA variance accounted for 8.1 for BRR, 8.5 for H, 3.5 for V, 9.3 for SS and 1.9 for BT. Similarly, the ratios of σ2GCA-F2GCA-M variance due to female parents were 70.5 for BRR, 23.6 for H, 1.0 for V, 0.4 for SS and 1.0 for BT, were found. Narrow-sense heritabilities, at individual level, were low to moderately high, ranging between 0.085 for BT and 0.421 for BRR. By comparison with the mean of P. strobus parent species, the BRR heterosis was highly positive, but negative for all growth traits. If the hybrids will be used in operational planting programs, a significant genetic gain for BRR and growth traits could be achieved.

Keywords

  • Pinus strobus
  • P. wallichiana
  • Cronartium ribicola
  • hybrid
  • heterosis
  • additive variance
  • heritability
  • genetic correlation
  • genetic gain
Open Access

Stability of Outcrossing Rates in Eucalyptus globulus Seedlots

Published Online: 27 Oct 2017
Page range: 42 - 44b

Abstract

Summary

Eucalyptus globulus has a mixed mating system and selfing leads to severe inbreeding depression. Thus, outcrossing rate is an important measure of seed quality in this species. Outcrossing rates were estimated on the frequency of a rare recessive chlorophyll deficient mutant in open pollinated seed. Variation of outcrossing rates across different flowering seasons, seed sizes and storage times was assessed in E. globulus seedlots. Although there was a significant difference between the trees studied, outcrossing rates within a tree were found to be stable across four flowering seasons and three seed sizes. Storage either on the tree or in the laboratory did not alter the outcrossing rate in a consistent manner. The stability of outcrossing rates with season of pollination, age and size of seed is noteworthy as these factors may vary widely in multi-tree seedlots used for plantation establishment.

Keywords

  • Selfing
  • seed size
  • seed age
Open Access

Identification of Molecular Markers for Selected Wood Properties of Norway Spruce Picea abies L. (Karst.) I. Wood Density

Published Online: 27 Oct 2017
Page range: 45 - 50

Abstract

Abstract

The identification of AFLP markers and their subsequent conversion to SCAR-markers linked to wood density of Norway Spruce (Picea abies L [Karst.]) is described for the first time. In AFLP-analyses, 102 different primer enzyme combinations were screened in a bulked segregant approach comparing individuals with high and low wood density. A total of 107 polymorphic AFLP fragments were obtained between the DNA-pools. Twenty-three markers were selected for further analyses to verify their linkage to wood density based on individuals used for pool constitution and additional unrelated clonal material. For 15 markers, a significant linkage to wood density was confirmed by a two-sided Fisher’s-exact test. Four markers were converted into SCAR markers and validated for plant material assayed for wood density by X-ray microdensitometry. For each marker a monomorphic band was obtained using sets of nested primers or restriction site-specific primers (RSS), which include the AFLP-restriction recognition sites. For two markers that are linked to high wood density, a separation from unlinked size homologous marker-alleles was realized by a PCR-restriction approach. Validation of these markers in different full-sib families confirmed their usability to separate the classes for low and high wood density of Picea abies.

Keywords

  • AFLP
  • Bulked segregant analysis
  • Marker assisted selection (MAS)
  • Molecular markers
  • Wood properties
Open Access

Clonal Propagation of Dalbergia sissoo Roxb. by Softwood Nodal Cuttings: Effects of Genotypes, Application of IBA and Position of Cuttings on Shoots

Published Online: 27 Oct 2017
Page range: 50 - 55

Abstract

Summary

Softwood nodal shoot cuttings were collected from the hedge garden at New Forest campus of Forest Research Institute, Dehra Dun. The cuttings were rooted in mist chamber to investigate the effect of IBA application and position of cuttings on shoots on rooting ability in different clones of Dalbergia sissoo Roxb. As compared to the 0% (control) and 0.1%; 0.2% IBA showed maximum adventitious root formation. Overall percent rooting, percent sprouting, mean number of shoots and their length, mean number of roots and their length increased with increasing concentration of IBA. Among different positions of cuttings within the shoots, the best rooting response was recorded in the middle part followed lower and upper part. The findings exhibited significant interclonal variation regarding adventitious rooting and maximum response was observed in C42 (Gonda, Uttar Pradesh) clone. Interactive effect of clone C42 and middle position significantly increased percent sprouting while; interactive effects of middle position and 0.2% IBA treatment significantly increased percent rooting. It is concluded that the selection of genotypes with good rooting ability with respect to shoot position in hedged plants and concentration of IBA can be made to produce high quality planting stock material to start clonal forestry programme of D. sissoo.

Keywords

  • Dalbergia sissoo
  • IBA
  • position on shoots
  • clone
  • nodal cuttings
  • rooting
Open Access

Sexual Asymmetry based on Flowering Assessment in a Clonal Seed Orchard of Pinus densiflora

Published Online: 27 Oct 2017
Page range: 55 - 59

Abstract

Abstract

Two equations were formulated in order to estimate the degree of sexual asymmetry for monoecious species. The concepts of the equations were formulated on the basis of the effective population numbers of female and male parents [i.e, As(v)], and the differences of relative frequency between genders [i.e., As(x)]. These equations were applied to estimate the degree of sexual asymmetry based on the empirical data of flowering assessment in a clonal seed orchard of Pinus densiflora. The yearly variation in the production of female and male strobili was found. The effective population numbers at gamete levels (vf and vm) and clone level (vb) varied among 8 observation years. Both As(x) and As(v) were negatively correlated with effective numbers at gamete and clone levels. Averages of female and male strobilus production and estimates of sexual asymmetry were negatively correlated but the correlation was not significant. The correlations among effective number of clone (vb), arithmetic mean of female and male effective numbers (va) and estimate of sexual asymmetry [As(x)] were strong and significant. Relatively larger difference between vb and va were found when higher level of sexual asymmetry were observed.

Keywords

  • sexual asymmetry
  • effective number
  • strobilus production
  • fertility
  • coefficient of variation
Open Access

Genetic Gains of Full-Sib Families from Disconnected Diallels in Loblolly Pine

Published Online: 27 Oct 2017
Page range: 60 - 64

Abstract

Abstract

Breeding values for the 2nd-cycle of the loblolly pine (Pinus taeda L.) breeding program were analyzed with the NCSUIndustry Tree Improvement Cooperative database to estimate genetic gains and compare different strategies for full-sib deployment. In the disconnected half-diallel mating design used for loblolly pine, six parents within each diallel were crossed to generate 15 full-sib families for general combining ability (GCA) and specific combining ability (SCA) estimates. Parents among disconnected diallels were never crossed, and the SCA and full-sib family breeding values cannot be estimated directly. Using the GCA and SCA estimates from 60 diallels in the Atlantic Coastal region of loblolly pine, genetic gains were estimated in this study for full-sib families within the disconnected diallels and then compared with the potential gains that would be expected if we select parents for full-sib families based on GCA values for all parents within a geographic region. As the dominance variance was found to be much less than the additive variance, the SCA contribution to the full-sib genetic gain was relatively small. Higher full-sib genetic gains were obtained by crossing the best GCA parents from different diallels within a geographic region than selecting only those within diallels. The difference increased with increasing number of selected full-sibs. Results from different selection scenarios, with various selection intensities and relatedness managements, suggest that selection based on GCA from all parents within a geographic region would result in a higher genetic gain for full-sib families in loblolly pine. The deployment of full-sib families are very important for achieving higher genetic gains in a loblolly pine breeding program. But they were not due to the SCA contribution, but rather due to high GCA of best parents in creating these full-sib crosses. The strategies for family and clonal deployment are very attractive based on the data from this study.

Keywords

  • Pinus taeda L.
  • full-sib crosses
  • volume gain
  • deployment
  • general combining ability
  • special combining ability
Open Access

The Effect of Inbreeding on Early Growth of Acacia mangium in Vietnam

Published Online: 27 Oct 2017
Page range: 65 - 69

Abstract

Abstract

Seeds were collected from each of twelve parent trees from each of six seed orchards of Acacia mangium in different locations in Vietnam to examine the relationship between growth and inbreeding in this species. Seedlings were raised and planted out in a field trial at Ba Vi in northern Vietnam. The inbreeding status (self-fertilized or outcrossed) of most of the seedlings was determined by DNA analysis. Heights were measured at 12 and 18 months, and diameter at breast height (dbh) at 18 months. There were significant differences in growth between the six orchard sources at 18 months. Progeny from two orchards based primarily on Papua New Guinea (PNG) provenances with high levels of outcrossing displayed the best growth, with mean heights of 3.1 m at 18 months, while an orchard also based primarily on PNG provenances but with predominantly selfed progeny, and another orchard based on Queensland provenances with 51% selfed progeny, displayed the poorest growth (mean heights of 2.0 m and 2.2 m respectively). Analysis of variance established that within the 32 families that included both selfed and outcrossed individuals, self-fertilized individuals were significantly (P< 0.001) slowergrowing than were outcrossed individuals, with selfs on average 15% smaller in mean height and 16% smaller in mean dbh at age 18 months, relative to outcrosses. The results demonstrate the need to minimise selfing in operational seed production for A. mangium plantations.

Keywords

  • Seed orchards
  • self
  • outcross
  • growth
  • inbreeding depression
  • Acacia mangium
Open Access

A Report of Triploid Populus of the Section Aigeiros

Published Online: 27 Oct 2017
Page range: 69 - 75

Abstract

Abstract

This screening study analyzed ploidy levels by counting the chromosome number of 61 Aigeiros cultivars grown in China. Triploid Aigeiros has been found in four of these cultivars: Populus x euramericana (Dode) Guiner cv. Wuhei-1, P. × Liaohenica, P. Langfangensis-3 Wang (P. deltodide Barry cv. “Shanhaiguan” × P. simonii × P. pyramidalis-12 +Ulmus pumila Linn.), and P. × euramericana (Dode) Guinier. cv. “Zhonglin-46”. The karyotype analysis indicates that triploid Aigeiros might be derived from original allotriploid. Because growth of the triploid trees was faster than their respective diploid hybrids or clones in the plantations where we collected the materials, we expect that they will play a significant role in breeding, reforestation and fiber production in China.

Keywords

  • Aigeiros
  • triploid
Open Access

Longitudinal Differences in Scots pine Frost Hardiness

Published Online: 27 Oct 2017
Page range: 76 - 80

Abstract

Abstract

The autumn frost hardiness of Scots pine (Pinus sylvestris L.) populations from Scandinavia (57°28’-68°54’ N, 13°00’-27°00’ E) and the Komi Republic in Russia (61°30’-64°20’ N, 49°10’-54°50’ E), and open pollinated families from a population in Komi (61°43’ N, 51°07’ E) were examined in artificial freezing tests with one-year-old seedlings. The aims were to estimate genetic variation in hardiness between families of Russian origin and to compare populations of Russian (continental) and Scandinavian (maritime) origins. The longitudinal distance between the Scandinavian and Russian seed sources was associated with a significant difference in climatic conditions. At latitude 63°N the degree of continentality (the difference between July and January monthly mean temperatures) was 23.7°C for longitude 15°E in Sweden and 35.2°C for longitude 54°E in Komi. The narrow-sense heritability of frost hardiness calculated for the Russian families was 0.22. This indicates relatively high genetic control of the trait, of similar magnitude as earlier shown for populations of Scandinavian origin. Both Scandinavian and Russian populations showed a strong clinal variation in frost hardiness, northern populations being the hardiest. In addition, Russian populations were more frost hardy than Scandinavian ones from corresponding latitudes and attained the same level of hardiness as Scandinavian populations from 4.1° latitude further north. The results indicate that the longitude or continentality of the origins of Scots pine populations is associated with adaptive pressures that have significant effects on hardiness and are distinct from photoperiodic effects. When enriching breeding or production populations by including populations from remote origins it is essential to recognize not only latitudinal origin, but also longitudinal origin or temperature regime, in order to match material to the planned utilization areas.

Keywords

  • Pinus sylvestris (L.)
  • adaptation
  • freezing tests
  • climatic change
  • continentality
  • heritability
Open Access

Inbreeding in Pinus Radiata – V. The Effects of Inbreeding on Fecundity

Published Online: 27 Oct 2017
Page range: 80 - 88

Abstract

Abstract

A successful inbreeding and hybrid breeding strategy in tree improvement requires that 1) inbreeding (selfing) can produce superior inbred lines (effective purging of deleterious alleles), 2) there is heterosis among crosses of inbred lines, 3) early selection between lines is effective, and 4) inbreeding will not substantially reduce reproductive ability. We have previously reported that inbreeding depression on growth was lower in radiata pine relative to other conifers and segregation in the first two-generations of selfs generated superior inbred trees. In addition, we have observed that early selection among inbred trees (lines) was more effective than in out-crossed populations and there was an apparent heterosis in radiata pine. In this study, the effect of inbreeding on the reproductive ability in young and adult trees of radiata pine has been quantified from five populations of varied inbreeding levels (F =0, 0.125, 0.25, 0.5, and 0.75). It was observed that the effects of inbreeding depression on fecundity was higher at a young age than at older age and inbreeding depression at a young age is due to two factors: 1) a delay of reproductive age (about 8.3, and 8.5% of trees delayed for F =0.5 and F =0.75 populations, respectively) and 2) a true reduction of flowering trees (6.7 and 13.1% more trees having no flowers for F =0.5 and F =0.75 populations than F =0 population, respectively). Despite significant inbreeding depression on the percentage of female reproductive trees and the number of cones on adult trees, overall inbreeding depression on fecundity was low in radiata pine. One founder clone contributed most of the significant inbreeding depression observed for the population of eight founder clones. It was observed that fecundity varied more widely among the eight clones than among the inbreeding level (self and outcross).

Keywords

  • Radiata pine
  • Pinus radiata
  • inbreeding depression
  • reproductive ability
  • fecundity
  • fitness
Open Access

Discordance Between Geographical Distribution and Genetic Relationship Among Populations of Japanese Red Pine in Korea Revealed by Analysis of I-SSR Markers

Published Online: 27 Oct 2017
Page range: 89 - 92

Abstract

Abstract

Level and distribution of genetic diversity in 8 populations of Japanese red pine in Korea were estimated using I-SSR variants. A total of 80 I-SSR variants were observed in the analyzed 150 individuals, which revealed DNA fingerprints-like individual specific amplicon profiles for all of them. Relatively higher level of genetic diversity within populations was observed in 8 populations of Japanese red pine (mean of 0.450) than in other tree species. From the results of AMOVA, majority of genetic diversity was allocated within populations (93.42%) resulting in a moderate degree of population differentiation (ΦST= 0.066). The observed distribution pattern of I-SSR variants among 8 populations was coincided with the typical patterns for the long-lived woody species. Genetic relationships among the populations, reconstructed by UPGMA and Neighbor- Joining methods, revealed 2 genetic groups. The populations of Gangwon-Uljin and Chungnam-Taean turned out to be the most closely related despite a distant location between them. The overall genetic relationships among the 8 populations, reconstructed by both methods, were not coincided with geographic distances. The discrepancy between genetic relationships and geographical distribution among the populations suggests that the analyzed populations might have undergone random changes in genetic composition due to some kinds of disturbances. Results obtained in this study suggests that more careful approach should be made in preparing strategy for gene conservation of Japanese red pine in Korea. More information on countrywide molecular population genetic status of Japanese red pine will be helpful to prepare more reasonable strategy for gene conservation of the species in the country.

Keywords

  • Pinus densiflora
  • Japanese red pine
  • I-SSR markers
  • Genetic diversity
  • AMOVA
  • Population differentiation
  • Genetic relationships
Open Access

Genetic Structure and Variability of Natural Populations of Maritime Pine (Pinus pinaster Aiton) in Morocco

Published Online: 27 Oct 2017
Page range: 93 - 99

Abstract

Abstract

The estimation of genetic diversity using molecular markers is a major component of genetic conservation programs. In its range, Maritime pine has been extensively studied using different molecular markers and quantitative traits. However, Moroccan populations have been usually represented only by a few typical locations in the Middle Atlas (e.g., Tamjout). To describe the genetic structure and variability of maritime pine in Morocco, eleven populations of this species comprising all major geographic regions (Rif, Middle Atlas and High Atlas) were studied using allozyme markers. A total of 471 samples were analyzed using polyacrylamide gel electrophoresis (PAGE) of eight enzyme systems encoded by 19 loci. Genetic variation was lower in Morocco than in other ranges of the species. However, genetic diversity was structured and a high differentiation among populations (θ = 10.44%) and a moderate correlation between genetic and geographic distances were found (0.350). Three main groups of populations can be distinguished based on genetic distances: (i) Mediterranean Coastal, (ii) Occidental Rif and Middle Atlas and (iii) High Atlas. The populations from Middle Atlas presented the lowest values of allelic richness and gene diversity whereas the populations from Rif showed a considerable amount of genetic variability. Human impact and isolation are major factors explaining population genetic structure of maritime pine in Morocco. Overexploitation of the forest by intensive cattle grazing and land speculation are suggested to be active mechanisms currently deploying the genetic resources of this species.

Keywords

  • Pinus pinaster
  • genetic structure
  • genetic diversity
  • genetic conservation
  • allozymes
  • Morocco
  • maritime pine
Open Access

Chloroplast DNA Variation in Some Representatives of the Asian, North American and Mediterranean Firs (Abies spp)

Published Online: 27 Oct 2017
Page range: 99 - 104

Abstract

Abstract

Using PCR-RFLP analysis, a comparative study on the restriction site polymorphism within 8 genes and regions of the Abies chloroplast DNA has been conducted covering 15 Asian, 6 North American and 7 Mediterranean species. A variable degree of divergence was observed among individual species of a given region as well as between geographical groups. A group of the Mediterranean firs, consisting of closely related species, differed profoundly from both Asian and North American representatives. Although a higher level of restriction site variants was detected among the Asian firs, two thirds of them were allocated to the difference between A. mariesii and the other Asian firs. The North American species exhibited the highest level of polymorphism resulting in several subgroups on a cladogram. At the individual species level, the Asian species A. mariesii and the North American species A. lasiocarpa diverged conspicuously from their counterparts in their respective regions. The results of restriction site polymorphism analysis are discussed with ragard to crossability and taxonomic status of individual species.

Keywords

  • Abies
  • chloroplast DNA
  • restriction site variation
  • relationships
  • species differentiation
Open Access

Nuclear Markers (AFLPs) and Chloroplast Microsatellites Differ Between Fagus sylvatica and F. orientalis

Published Online: 27 Oct 2017
Page range: 105 - 110

Abstract

Abstract

Former studies based on chloroplast markers and allozymes suggested that postglacial recolonization of central Europe by Fagus sylvatica L. occurred from one or a few undifferentiated refuges. Here, we examine F. sylvatica from Germany and Greece and different provenances of F. sylvatica ssp. orientalis (Lipsky) Greut & Burd. (F. orientalis Lipsky) with chloroplast microsatellites and AFLP markers. Only such AFLP markers were selected that had shown a differential amplification in F. sylvatica and F. orientalis in a preliminary analysis. UPGMA cluster analysis of AFLP data distinguished one F. sylvatica group and one F. orientalis group from northern Turkey. Low structuring in the neighborjoining analysis and the lack of diagnostic bands for either taxon suggests a relatively recent differentiation in Fagus orientalis and F. sylvatica. High bootstrap values were only found for a separate cluster that comprises F. orientalis from two different forest botanical gardens. Four of these samples have a unique chloroplast type and are genetically very similar (bootstrap value 96) mostly likely due to clonal replication. Only two different chloroplast types (type 1 in Germany, type 1 and type 2 in Greece) could be detected for F. sylvatica. In contrast, F. orientalis from northern Turkey showed different chloroplast types even within one provenance pointing to a glacial refuge in northern Turkey and a bottleneck at the time of postglacial recolonization of central Europe. The classification of ten samples from northern Turkey as F. sylvatica by AFLP data, chloroplast markers and morphology questions the interpretation of F. orientalis and F. sylvatica as two geographically separated (allopatric) taxa.

Keywords

  • Fagus sylvatica
  • Fagus orientalis
  • AFLP
  • cpDNA
Open Access

A Decision Support System Inferring the Genotypes of Seed Trees From Open Pollinated Progenies

Published Online: 27 Oct 2017
Page range: 111 - 116

Abstract

Summary

The knowledge of the genetic background of seed lots used in forestry operations (i.e., afforestations, reforestations) is important for the evaluation of the future potential of forests to survive under changing environments. An approach to infer the genotype of seed trees from their open pollinated progenies is presented. Sampling difficulties of adult tree tissue make the genetic analysis of seed trees often impossible. The present decision support system (TGDSS - Tree Genotype Decision Support System) allows the reconstruction of the genotypes of the parent population (adult trees) through the analysis of only the genotypes of the progeny generation (seeds). The method consists of three steps, each one representing a specific logical test. The system was tested with data obtained from the genetic analysis of tree populations. The genotypes inferred through the TGDSS and the ones observed in the laboratory were identical. The factors defining the effectiveness of the system are discussed.

Keywords

  • Decision Support System
  • genotypes
  • seed trees
  • progeny
  • inheritance
  • C++
Open Access

Seed Source Variation in Cone, Seed and Seedling Characteristic Across the Natural Distribution of Himalayan Low Level Pine Pinus roxburghii Sarg

Published Online: 27 Oct 2017
Page range: 116 - 123

Abstract

Abstract

The wide range of climatic condition in the natural distribution of chir pine is expected to result in high genetic variation within different populations of the species. The present study on the provenance variation of chir pine aims to determine the nature and extent of variation in wide range of populations with respect to 23 morphological traits of cone, seed and seedling, (at nursery stage) of 63 provenances of Pinus roxburghii. Seed sources exhibited a wide range of variability in terms of mean vales for various traits, standard deviation, variance, coefficient of variability, broad sense heritability, genetic advance and genetic gain and offer ample scope for undertaking screening for the desired traits. Genotypic variance (Vg) and genotypic coefficient of variability (GCV) for most of the parameters were found to be higher than corresponding environmental variance (Ve) and environmental coefficient of variability (ECV), except cone fresh weight, survival%, days taken for bud break and collar diameter where Ve and ECV dominated the Vg and GCV, thus indicating influence of environment on the expression of these traits. Moderate to high percentage of heritability coupled with same intensity of gain, was observed for many of the traits studied under laboratory conditions and at nursery stage e.g. for germination percentage, MGT, GV. This signifies that these traits are under strong genetic control and good amount of heritable additive genetic component can be exploited for further selection and improvement of this species.

Keywords

  • Pinus roxburghii Sarg.
  • seed source variation
  • seed and seedling characters
  • bud break
  • genotypic variance (Vg)
  • genotypic coefficient of variability (GCV)
  • environmental variance (Ve) and environmental coefficient of variability (ECV)
  • heritability
  • genetic gain
Open Access

Juvenile – Mature Genetic Correlations in Pinus pinaster Ait. Under Different Nutrient x Water Regimes

Published Online: 27 Oct 2017
Page range: 124 - 129

Abstract

Summary

Juvenile - mature (JM) correlations and selection efficiencies among one-year old Pinus pinaster seedlings and 8-yr field performance were analyzed in order to study the possibilities of early selection in the maritime pine breeding program in Galicia (NW Spain). Twenty four open-pollinated families from a first generation clonal seed orchard were grown in the greenhouse under two nutrient crossed with two water regimes. Several growth and dry mass traits were assessed 30 weeks after sowing and compared with field performance (height, diameter and volume) of four 8-yr-old progeny tests established in the coastal area of Galicia. Family mean correlations and genetic correlations were computed for each greenhouse trait, greenhouse treatment, field test site and field trait combination. Except for a few cases, most of the JM correlations were weak and in many cases negative. There was no detectable pattern of JM correlations regarding to combinations of greenhouse treatments and test site water availability and/or fertility. The large variation in the JM correlations for the same traits in different environments and sites (even changing sign in several cases) suggest a large influence of the genotype x environment interaction in the JM estimations. Other possible causes of the weak JM correlations are discussed. Based on the results of this study it may be concluded that none of the combinations of trait and treatment included in this experiment can be recommended for incorporation into early testing in the Galician Pinus pinaster breeding program. Indications for further research to optimize an early selection procedure are included.

Keywords

  • early selection
  • maritime pine
  • drought
  • nutrient availability
  • retrospective studies
  • greenhouse - field correlations
Open Access

DNA Profiling, Pedigree Lineage Analysis and Monitoring in the Australian Breeding Program of Radiata Pine

Published Online: 27 Oct 2017
Page range: 130 - 134

Abstract

Abstract

Ten microsatellite loci were used to DNA profile 215 first and second generation breeding clones in the Australian radiata pine breeding program. The clones were essentially unique from one another and these DNA profiles were used to examine the sexual and asexual phases in the breeding program. Only 2.6% of ramets from 25 breeding clones were incorrect whereas 8.4% of progeny from 10 families were genetically incorrect. The lineages of second generation clones were checked for DNA profiles that were available for putative parents. Some parents appear to be incorrect on the basis of the DNA profiles and further sampling will be required to confirm these results across the breeding program. Microsatellite markers can now enable most questions to be resolved in breeding programs and also will allow novel breeding strategies to be used in the future.

Keywords

  • DNA fingerprinting
  • microsatellite loci
  • probability of identity
  • paternity
Open Access

Accuracy of Single- and Multiple-Trait REML Evaluation of Data Including Non-Random Missing Records

Published Online: 27 Oct 2017
Page range: 135 - 139

Abstract

Abstract

We examined the accuracy of single- and multiple-trait REML procedures by studying estimates of within-individual genetic correlations between an ordered categorical trait and a continuous trait. The traits were derived from simulated bivariate, normally distributed data including selectively deleted records. Ten thousand data sets were generated for each partially factorial combination of two levels of genetic correlation (0.3 and 0.6), and environmental correlation (0.3 and 0.6), and three levels of narrow-sense individual heritability (0.05, 0.15 and 0.25) and mortality (0, 10, 30 and 50%). All data sets consisted of data on 200 unrelated parents, each with 20 halfsib progenies. The accuracy of the evaluations was illustrated in terms of average bias and variation of derived correlation estimates. The average bias values generated by multiple-trait REML were generally low. In contrast, single-trait REML was sensitive to selective deletion of records and systematically underestimated the genetic correlations. For both methods, especially at low heritabilities, the magnitude of the variation was generally high, showing that there is a substantial probability of obtaining seriously misleading genetic correlation estimates if the analysis is based on a single experiment and data include non-random missing records.

Keywords

  • Genetic correlation
  • Monte Carlo simulation
  • multiple-trait analysis
  • REML
Open Access

Simple PCR Markers for the Study of Chloroplast in Eucalyptus

Published Online: 27 Oct 2017
Page range: 139 - 140

Abstract

Summary

Combined use of two newly designed PCR primers with already described rpl2 and trnH primers, yields amplification of three non-independent products from the hypervariable JLA region of eucalypt chloroplast. Polymorphism analysis of the resulting PCR markers is proved to be a time- and cost-efficient alternative to traditional cpDNA techniques as RFLP or sequencing for Eucalyptus globulus Labill. population genetics studies.

Keywords

  • Eucalyptus
  • chloroplast DNA
  • JLA junction
  • PCR markers
Open Access

Genetic Variation in Picea glauca for Growth and Phenological Traits From Provenance Tests in Ontario

Published Online: 27 Oct 2017
Page range: 141 - 148

Abstract

Abstract

Ecologically based management of white spruce (Picea glauca [Moench] Voss.) requires an understanding of its patterns of adaptive variation. This understanding will become increasingly important under changing climate conditions. Five common garden tests and a greenhouse trial established in 2002 across Ontario were used to assess levels of genetic variation and relate this variation to local climate. Growth and phenological variables, including height, root collar diameter, survival, timing of spring budflush, and timing of fall budset were measured. Intraclass correlation coefficients were calculated for all traits to determine levels of genetic variation. Simple linear regressions were used to relate these differences to local climate conditions. After two growing season’s levels of between-provenance genetic variation ranged from 0 percent for several of the budflush variables to 22 percent for 2003 survival at the Englehart field trial. Overall, growth variables showed higher levels of between-provenance variation than phenological variables. Variation was predominately explained by longitude, a surrogate for precipitation patterns in Ontario, and temperature variables related to the growing season with r2 values ranging from 0.03 to 0.55. Generally, patterns of adaptive variation followed a southeast to northwest trend across Ontario. Northern sources flushed earlier and set bud earlier, while southern sources demonstrated superior growth. Results support previous white spruce genecology studies showing superior growth of sources from the Ottawa valley region of Ontario and Quebec.

Keywords

  • Picea glauca
  • white spruce
  • genetic variation
  • adaptive variation
  • provenance trials
  • intraclass correlation coefficient
  • climate
Open Access

Genetic Variability and Early Growth Performance of Eucalyptus tereticornis Sm. in Provenance cum Progeny Trials in India

Published Online: 27 Oct 2017
Page range: 148 - 153

Abstract

Abstract

Results of provenance cum progeny trials of Eucalyptus tereticornis Sm. laid out in 2002 at three sites viz. FRI Campus (Uttaranchal), Chiryanpur (Uttaranchal) and Midnapore (West Bengal) located in tropical region of India are reported and discussed. Thirteen provenances representing 91 families from Australia and Papua New Guinea (PNG) viz. Oro bay to Emo, PNG; Sirinumu Sogeri Plat, PNG; Warwick, QLD; Yurammie, SF, NSW; Buckenbowra SF, NSW; Selection flat SF559, NSW; Credition SF, QLD; Cardwell, QLD; Mitchell River MT Molloy, QLD; Mill stream archer creek, QLD; Helenvale, QLD; Walsh River, QLD; Burdekin River, QLD were evaluated from nursery stage to field performance (age 21months). As a local seed source open-pollinated seeds collected from selected interspecific Eucalyptus F1 hybrid trees of FRI-4, FRI-5 and Mysore gum (Eucalyptus teretirornis) were used to serve as check material (control). Significant differences between the provenances and families at age 21 months were observed for height, clean stem length, collar diameter and field survival. Significant provenance x site interaction was observed for height. In general the north Queensland provenances performed better and in particular two provenances viz. Walsh River, QLD and Burdekin River, QLD ranked the best in comparison to others at this age. Results indicate that significant genetic differences exist between the families and provenances of E. tereticornis. The growth traits were inter-correlated with each other. Geographic clinal variation pattern was observed in some of the growth traits viz. height, clean stem height and collar diameter. There were fair differences between phenotypic and genotypic coefficient of variability. Heritability (narrow sense) values were fairly good for height and clear stem length in comparison to collar diameter. The relative performance of the provenances was fairly consistent throughout test sites.

Keywords

  • Eucalyptus tereticornis
  • variation
  • provenance
  • genetic improvement
  • productivity
  • heritability
  • progeny
  • provenance x site interaction
Open Access

Use of Belowground Growing Degree Days to Predict Rooting of Dormant Hardwood Cuttings of Populus

Published Online: 27 Oct 2017
Page range: 154 - 160

Abstract

Abstract

Planting Populus cuttings based on calendar days neglects soil temperature extremes and does not promote rooting based on specific genotypes. Our objectives were to: 1) test the biological efficacy of a thermal index based on belowground growing degree days (GDD) across the growing period, 2) test for interactions between belowground GDD and clones, and 3) identify beneficial planting windows based on combinations of genotypes and belowground GDD. We tested two clones of Populus deltoides Bartr. ex Marsh (D133, D134) and four hybrid clones of P. deltoides × P. maximowiczii A. Henry (DM101, DM105, NC14105, NC14107). Cuttings, 20 cm long, were planted in randomized complete blocks at 15- × 15-cm spacing across three planting dates during 1999 at Alexandria, Minnesota, USA (45.9°N, 95.4°W) and Fertile, Minnesota, USA (47.3°N, 96.2°W). Temperatures at 20 cm belowground were converted to GDD with a base temperature of 10°C. We measured root, top, and total dry weight, along with number of roots after 14 d of growth. Relatively warmer and cooler soil temperatures promoted rooting for the cottonwoods and hybrids, respectively. We recommend planting after reaching a threshold of 163 belowground GDD for P. deltoides clones and planting before reaching a threshold of 173 belowground GDD for P. deltoides × P. maximowiczii clones.

Keywords

  • Populus deltoides
  • P. maximowiczii
  • hybrid poplar
  • soil temperature
  • genotype × environment interaction
Open Access

Fertility Variation and Status Number Between a Base Population and a Seed Orchard of Pinus brutia

Published Online: 27 Oct 2017
Page range: 161 - 163

Abstract

Abstract

Female, male and total fertility variations were estimated in a base population and a seed orchard derived from the base population in Pinus brutia. Relative status number for gametes (female and male contribution) and zygotes (average of female and male contribution) were estimated based on the fertility variation. Average female and male strobilus production were 229.1 and 1003.3 in the base population, and 98.9 and 244.9 in the seed orchard for combined years, respectively. Positive and significant correlations were found between female and male strobilus production in both base population and seed orchard. The male fertility variation was higher than female fertility variation in the seed orchard, while female fertility variation was higher than male fertility variation in the base population. Coefficients of variations in female and male strobilus production were 0.721 and 0.696 in the base population, and 0.403 and 1.110 in the seed orchard for combined years, respectively. Total fertility variation was 1.41 in the base population and 1.40 in the seed orchard for combined years. The relative status numbers estimated based on the total fertility were 70% of census number in the base population, and 71% in the seed orchard for combined years.

Keywords

  • Pinus brutia
  • seed orchard
  • base population
  • sibling coefficient
  • status number
Open Access

Fertility and Effective Population Size in Seedling Seed Orchards of Casuarina equisetifolia and C. junghuhniana

Published Online: 27 Oct 2017
Page range: 164 - 168

Abstract

Abstract

Two seedling seed orchards each of C. equisetifolia and C. junghuhniana established by thinning provenance trials in coastal and inland locations in South India were evaluated for sex expression and fertility variation at four years. More than 80% of the trees in C. equisetifolia orchards were fertile in both sites with a similar pattern of more (almost 2 times) female trees and equal proportion of monoecious and non-flowering trees. In C. junghuhniana, the coastal orchard had twice the proportion of fertile trees as that of the inland. Orchards established in coastal environment had less fertility variation and hence maintained lower coancestry values in both species. Coastal site has more trees contributing effectively to seed production than inland locations and the orchards maintain higher (almost two times) effective population sizes. Genetic drift is also 3 times higher in inland locations in both species. Male and female trees in inland orchards of both species however had greater reproductive output than coastal trees. Monoecious Casuarina equisetifolia trees showed a different trend of greater male fertility in coastal site, but seed output was the same in both locations. Gene diversity values of all orchards are high though it is marginally higher in coastal sites. Measures like constrained seed collection from large number of trees and promoting representation of superior provenances with low fertility would be useful in checking diversity loss during domestication.

Keywords

  • breeding population
  • coancestry
  • gene diversity
  • relative status number
  • provenance trial
  • seed orchard
Open Access

Genetic Variation in Turkish Red Pine (Pinus brutia Ten.) Seed Stands as Determined by RAPD Markers

Published Online: 27 Oct 2017
Page range: 169 - 175

Abstract

Summary

Turkish red pine (Pinus brutia Ten.) is one of the important tree species in Turkey. The species has been heavily disturbed by anthropogenic factors and fire, making it important to understand the magnitude of the impact on genetic diversity of areas reserved for seed production. To explore the extent of genetic variation in Turkish red pine seed stands, a random amplified polymorphic DNA (RAPD) marker system was used in the study. The estimated genic diversity for seed stands was found to range from H =0.17 (P, %of polymorphic loci =%58.7) in Çameli-Göldağ to 0.29 (P =%81.7) in Bayramiç-Karaköy seed stand though the lowest polymorphism was observed in Fındıkpınarı seed stand (P =55.8%). The total gene diversity was calculated as HT=0.34, in Turkish red pine. About 65% of the total diversity was within seed stands. No distinct pattern of genetic diversity was found according to the geography, elevation or breeding zones. The highest genetic differentiation was found in the Western Mediterranean geographic region, however, within population genetic diversity was found to be similar among different geographic regions (HS=0.22-0.24). GST value calculated was high (0.35) indicating that genetic differentiation among the studied seed stands was substantial. Dendrogram constructed with genetic distance data did not yield a firm pattern with respect to geography, elevation and breeding zones. In fact, the most of the clusters in the dendrogram had very low bootstrap values, suggesting that the clusters could be refined if more populations and markers are included in the future studies. The implication of the results with respect to in situ conservation of genetic resources of the species was discussed.

Keywords

  • Pinus brutia
  • RAPD markers
  • Seed stands
  • genetic diversity
  • in situ conservation
Open Access

Genotype x Environment Interaction in Maritime Pine Families in Galicia, Northwest Spain

Published Online: 27 Oct 2017
Page range: 175 - 182

Abstract

Summary

The magnitude and practical importance of family x site interactions for growth and form traits in maritime pine (Pinus pinaster Ait.) breeding in the coastal area of Galicia (NW Spain) were analysed using several different techniques. Data were from 58 8-yr-old half-sib families planted across four sites. The analysis of variance and the ratio of interaction to family variance component showed the interactions to be quantitatively important for several traits, especially for volume and straightness. Genetic correlations between the same trait at different sites were moderate and highly variable, especially for certain pairs of sites. The results indicated that interactions are a consequence of few highly interactive families that may be particularly sensitive to environmental variation. The removal of these families from the breeding program appeared as an effective strategy to solve the interactions. Results are discussed in relation to the stability parameter considered to identify the most unstable progenies.

Keywords

  • Stability
  • Pinus pinaster
  • Progeny trial
  • Half-sibs
  • Genetic correlation
Open Access

Seed Source Variation in Growth Performance of Eucalyptus camaldulensis Dehnh. of Australian Origin in India

Published Online: 27 Oct 2017
Page range: 182 - 186

Abstract

Abstract

Results of a provenance trial of Eucalyptus camaldulensis Dehnh. laid out in 2001 at Seothi (30° N Lat., 76° E Long. and 250 m altitude) Haryana, a semi-arid region of India are reported and discussed. Six seed sources from Australia viz. Laura River, Emu Creek, Degrey River, Wiluna, Kennedy River, Morehead River were evaluated from nursery stage (3 months) to field performance (2 year). Two sources viz. E.tereticornis (Helenvele, Qld) and FRI-4 a local seed source were used as control (check material). Significant differences between the seed sources at nursery stage were observed for collar diameter (P < 0.05) and number of leaves (P < 0.01). At age 2 years, significant differences between the seed sources (P < 0.05) were observed for height and field survival. The two seed sources viz. Emu Creek Petford, QLD and Laura river, QLD ranked first and second for height and survival at this age. Results indicate that genetic differences exist between the sources of E. camaldulensis. None of the traits assessed (viz. height, collar diameter, number of leaves, number of branches and survival) was found to correlate with any of the geographical coordinates of the site (latitude, longitude and altitude). There were fair differences between phenotypic and genotypic coefficient of variability. Heritability values were fairly high for height and clear bole length in comparison to collar diameter, number of branches and survival. The relative performance of these provenances was fairly consistent throughout the period of observation. The two sources viz. Laura river, QLD and Emu Creek Petford, QLD are recommended for potential source for plantation programme under semi-arid conditions.

Keywords

  • Eucalyptus camaldulensis
  • variation
  • provenance
  • seed source
  • genetic improvement
  • productivity
  • heritability
Open Access

Seed Source Variation in Growth Performance and Oil Yield of Jatropha curcas Linn. in Central India

Published Online: 27 Oct 2017
Page range: 186 - 192

Abstract

Abstract

Results of a seed source evaluation trial of Jatropha curcas Linn. laid out in 1996 at Jabalpur (M.P), a semi arid region of India are reported and discussed. Seeds collected from ten sources from central India representing the states Madhya Pradesh and Maharashtra viz. Gondia, Bichia, Balaghat, Niwas, Khandwa, Burhanpur, Nasik, Chindwara, Kundam and Jabalpur were evaluated for their growth performance from nursery stage (3 months) to field (two years). Variation in seed oil content of different sources were also studied and reported. Significant differences between the seed sources at age 27 months were observed for height, collar diameter, number of branches leaf area and field survival. Seeds collected from different sources also varied significantly in respect of seed and kernel weight and oil content in seed/kernel. The Chhindwara (M.P.) source performed the best and yielded a maximum oil of 39.12% from whole seed and 58.12% from kernel. The oil content ranged from 33.02 to 39.12% in whole seeds and 47.08 to 58.12% in kernel, across the seed sources. The performance of Kundam (M.P.), Jabalpur (M.P.), Bichia (M.P.), Niwas (M.P.) and Nasik (Maharashtra) sources were also found satisfactory for oil yield. Results indicate that genetic differences exist between the seed sources of J. curcas. The growth traits showed significant positive correlation with each other. Fair differences between phenotypic and genotypic coefficient of variability were observed. Heritability (broad sense) values were fairly good with regard to leaf area, height and collar diameter in comparison to survival percent. The relative performance of these sources was fairly consistent throughout the observation period.

Keywords

  • Jatropha curcas
  • variation
  • provenance
  • genetic improvement
  • productivity
  • heritability
  • oil
  • diesel
Open Access

Intraspecific variation and geographic patterns of Fagus orientalis Lipsky chloroplast DNA

Published Online: 27 Oct 2017
Page range: 193 - 197

Abstract

Abstract

CpDNA variation in Iranian beech, Fagus orientalis Lipsky (Fagaceae) was studied in 14 populations distributed throughout the species range in the Hyrcanain zone. Two cpDNA intergenic regions were analyzed: (i) one in the DT region between trnD (tRNA-Asp) and trnT (tRNA-Thr) genes, and (ii) one in the OA region between the orf184 and petA genes. The restriction fragments of the region DT did not show polymorphism among individuals within any population analyzed. However, among individuals within analyzed populations of Asalem region and Neka-1400 population, polymorphism in the restriction fragments of the OA region were found. A total of 3 different chloroplast (cp) haplotypes were scored. The distribution of the cpDNA haplotypes revealed a geographical structure of the genetic differentiation with Gst = %68.7 and Nst = %70.3. The distribution pattern of F. orientalis cpDNA haplotypes may reflect environmental differences and migration history of beech during historical distribution in Tertiary from Asalem (most polymorphic region) to East of Hyrcanian forests.

Keywords

  • cpDNA
  • Fagus orientalis Lipsky
  • Hyrcanian zone
  • Iranian beech
  • intraspecific diversity
  • genetic patterns
Open Access

Genetic Variation in Growth Traits in a Quercus robur L. Open-Pollinated Progeny Test of the Slavonian Provenance

Published Online: 27 Oct 2017
Page range: 198 - 201

Abstract

Abstract

The study presents evaluation of an open-pollinated progeny test of 21 selected plus trees from Slavonian pedunculate oak provenance in Croatia (in the central part of Drava river valley). The test was established in 1992 with two-year-old seedlings. Heights were measured at 5 to 13 years and diameters at breast height (DBH) at 10 to 13 years after sowing. Variances caused by the population within provenance effect were not significant during the studied period. In contrast, variance components caused by family effect were statistically significant, and ranged from 11.1 to 18.6% and from 2.2 to 10.6% for height and DBH respectively. Statistically significant variances caused by the family effect indicate that most of genetic variation of productive traits was within the studied populations. The estimated family mean narrow sense heritabilities varied from 0.62 to 0.78 and from 0.28 to 0.65, while individual heritabilities ranged from 0.48 to 0.80 and from 0.09 to 0.46 for height and DBH, respectively. Realised gain from the test and expected genetic gains by two possible methods of selection for the measured traits have been calculated for: i.) realised gain i.e. superiority of selected plus trees progenies over control plants (bulks from unselected trees within the provenance) ii.) individual within provenance mass selection of first generation plus trees at the same ages as those represented in studied trial and iii.) backward selection among first generation plus trees after open-pollinated testing. Estimated genetic gains indicate that the highest gain could be expected by backward selection among first generation plus trees after open-pollinated progeny testing (9.7 to 22.3% and 6.8 to 17.3% over control means). These results indicate that due to significant within population variation and high additive variances, improvement for productive traits in the studied oak populations could be achieved by use of seeds and plants from selected plus trees (especially from already established clonal seed orchard), at least in younger ages.

Keywords

  • Quercus robur
  • open-pollinated progeny test
  • genetic variation
  • genetic parameters
  • selection
Open Access

Fertility Variation, Genetic Relatedness, and Their Impacts on Gene Diversity of Seeds From a Seed Orchard of Pinus thunbergii

Published Online: 27 Oct 2017
Page range: 202 - 206

Abstract

Abstract

Clonal differences in the number of male and female strobili were determined for five consecutive years in a clonal seed orchard of Pinus thunbergii in Korea. The effects of relatedness and clonal differences in reproductive development on gene diversity of seed (in terms of accumulated relatedness by status number) were estimated. While clonal differences were found, fertility variation was not large through all studied years. The orchard clones were divided into different regions and locations based on the geographical distribution and distance of natural stands that plus trees were selected from. Assuming that there was no relatedness among regions, locations and clones, the status number (Ns) was varied from 47.6 to 55.5 for five successive years. On average (pooling), Ns was 92% of census number (N). Assumed relatedness among regions, locations and/or clones decreased the status number. Effect of parental selection on relatedness and orchard management was also discussed.

Keywords

  • fertility variation
  • status number
  • gene diversity
  • relatedness
  • Pinus thunbergii
Open Access

Spatial Genetic Structure in Disturbed Populations of Quercus acutissima (Fagaceae)

Published Online: 27 Oct 2017
Page range: 206 - 211

Abstract

Abstract

Quercus acutissima is a large deciduous tree of hillsides ranging from South Korea to Japan. It occurs in many plant communities, often as a pioneer species in monospecific stands which colonized gaps after gap formation. This study used multilocus allozyme genotypes mapped from two disturbed populations near farm houses in southern Korea to compare our results with previous studies conducted on undisturbed populations of trees in southern Korea. Coancestry measures (fij), RIPLEY’s L-statistics, and WRIGHT’s F-statistics were then calculated to examine the distribution of individuals and spatial genetic structure both within and between populations. RIPLEY’s Lstatistics indicated significant aggregation of individuals at interplant distances. A weak but significant positive fine-scale genetic structure at 10 m distance was detected in the two disturbed populations, which is consistent with the structure found in an inland, disturbed population in southern Korea. Estimates of near-distance fij in the two populations (0.020 and 0.036) were considerably lower than that expected for half-sibs (0.125) under random mating, suggesting secondary seed dispersal and substantial overlap of seed shadows. The levels of genetic diversity within the two disturbed populations of Q. acutissima were found to be comparable to the within-mean for populations of other oak species. Significant deficits of heterozygosity were detected in both populations, probably due to several parent-offspring and sib matings. Finally, a significant but low differentiation between the two disturbed populations of Q. acutissima was found, which is likely to be attributable to long-distance pollen movement by wind, which should enhance homogeneity of allele frequencies between adjacent local oak populations.

Keywords

  • allozymes
  • disturbance
  • Fagaceae
  • Quercus acutissima
  • spatial genetic structure
Open Access

Evaluation of Clonal Variability in Shoot Coppicing Ability and in vitro Responses of Dalbergia sissoo Roxb

Published Online: 27 Oct 2017
Page range: 212 - 220

Abstract

Summary

Clonal variations were observed amongst 12 clones of Dalbergia sissoo belonging to four states (U.P, Uttaranchal, Haryana and Rajasthan) of India, representing four different geographical zones in respect of ex vitro shoot coppicing ability and in vitro responses. Coppicing ability of shoot hedges of clones exhibited significant variation which ranged from average of 13.81 coppiced shoots (Clone 40, Uttar Pradesh) to 9.29 (Clone 64, Haryana). Comparative analysis of clones from different regions in respect to their coppicing ability revealed that clones from U.P had higher coppicing ability whereas those from Haryana proved to be least coppicers. Regional variations were also exhibited in the in vitro multiple bud induction ability on nodal explants excised from shoot hedges of clones (mean number of buds induced and percentage of cultures forming multiple buds). Regional as well as inter clonal variations were recorded in the shoot proliferation efficiency as well as rootability of microshoots of these clones as well as their optimal plant growth regulator requirements. BAP alone (2.5 μM) was sufficient for inducing multiple buds on cultured nodal explants of Uttaranchal and Uttar Pradesh region clones. On the contrary, clones from Rajasthan and Haryana had higher optimal requirement of BAP and in addition, they required media to be supplemented with auxin (NAA) for induction of multiple buds on explants. Correlation analysis between shoot coppicing ability of clones and in vitro performances of explants of these clones cultured on 2.5 μM BAP indicates a positive correlation. Observation lays credence to our view that these characters are genetically controlled and shoot coppicing can be used as a marker character in optimizing in vitro performance of clones. Using the information generated by this paper in vitro production of elite planting material can be maximized by ameliorating plant growth regulator requirement in the medium.

Keywords

  • Dalbergia sissoo
  • coppicing ability
  • clonal variation
  • in vitro
  • provenance
  • correlation
  • U. P. (Uttar Pradesh)
Open Access

Identification of Rhus succedanea L. Cultivars Using Elliptic Fourier Descriptors Based on Fruit Shape

Published Online: 27 Oct 2017
Page range: 221 - 226

Abstract

Abstract

We have developed a method to identify cultivars of Rhus succedanea L. based on their fruit contour shape. For this, we collected fruits of five cultivars from three different environments (differing in site and/or year of collection) and the horizontal contour shape of each fruit was expressed by 37 elliptic Fourier descriptors, normalized in terms of size, rotation, shift and starting point of contour tracing. The first six components derived from a principal component analysis of the elliptic Fourier descriptors explained 89% of the variance. The differences among cultivars, environments and the cultivar x environment interaction were significant at the 0.01% probability level for all six principal components according to ANOVA. UPGMA cluster analysis based on the six principal components showed a high degree of clustering and most (but not all) ramets from the same cultivar clustered together. However, results of a UPGMA cluster analysis of Mahalanobis’ generalized distances among cultivars and environments, based on the 37 elliptic Fourier descriptors, showed that samples from the same cultivars clustered together, regardless of the environmental factors. We then applied a ‘similarity probability’ test, based on Mahalanobis’ generalized distances and a randomization test. The similarity probabilities between descriptors in the database and sampled fruits, when the cultivars they represented were included in the database, were >97%. In contrast, for samples representing cultivars that were not included in the database, the probabilities were <46%. These figures also apply to pairs of samples included in the database that represented the same cultivar, and different cultivars, respectively. These results suggest that it is possible to identify R. succedanea cultivars based on fruit contour shape using elliptic Fourier descriptors and similarity probability analysis.

Keywords

  • Rhus succedanea L.
  • cultivar identification
  • fruit shape
  • elliptic Fourier descriptor
  • Mahalanobis’ generalized distance
  • randomization test
Open Access

A Comparison of Isozyme and Morphological Markers to Assess the Within Population Variation in Small Populations of European aspen (Populus tremula L.) in Spain

Published Online: 27 Oct 2017
Page range: 227 - 233

Abstract

Summary

European aspen (Populus tremula L.) has been traditionally thought to establish new stands by vegetative propagation through root suckers produced by very few individuals (often only one). Morphological traits and isozyme patterns were studied in five small stands in northern Spain. Both isozyme and morphological approaches showed variation within and between stands. Estimated intrapopulational variation was higher than the expected, and clusters of individuals with the same isozyme multilocus patterns within each population have been identified. In order to check to what extent morphological markers are affected by the genotypes or clones, comparisons between leaf parameters and isozyme patterns were performed by hierarchical ANOVA and tests of hypothesis were constructed from the components of variance. Leaf shape parameters show a good correlation with the isozyme multilocus patterns. On the other hand, leaf size parameters, were more influenced by environmental factors. These traits may be useful as tools for the definition of in situ conservation units in endangered European aspen stands.

Keywords

  • Populus tremula
  • isozyme multilocus patterns
  • leaf morphology
  • within population variation
Open Access

RAPD Analysis of Genetic Variation Within and Among Four Natural Populations of Betula maximowicziana

Published Online: 27 Oct 2017
Page range: 234 - 239

Abstract

Summary

Betula maximowicziana is a long-lived pioneer tree species in cool temperate forests that plays an important role in the forest ecosystem and has high economic value. Random amplified polymorphic DNA (RAPD) markers were used to evaluate the genetic variation of four natural populations of B. maximowicziana (three in central Honshu and the other in Hokkaido) to obtain fundamental information on this natural resource. Sixty-one reproductive amplified bands were obtained with 23 primers. Of these 61 bands, 22 were monomorphic and 39 were polymorphic. The level of genetic variation within each population may be very similar, because the population rankings according to number of polymorphic loci, Shannon’s indices and intra-population genetic variance revealed no definite patterns. Global analysis of AMOVA (analysis of molecular variance) showed that genetic variation among populations accounted for 15.6% of the total variation, with the remainder (84.4%) occurring within population. These results demonstrate that genetic differentiation among the four populations is moderate. Hierarchical AMOVA analysis showed that variation among regions (Hokkaido and central Honshu) accounted for 10.4% of the total genetic variation, suggesting that regional genetic differentiation is relatively high. Significant correlations between pairwise ΦPT values and geographic distance were detected, and results of both a neighbor-joining dendrogram based on pairwise ΦPT values, and principal coordinate analysis (PCO) based on a Euclidean metric revealed that the Furano population in Hokkaido was genetically different from the three populations in central Honshu. The data obtained in this study should have important implications for the conservation and management of regional genetic variation of B. maximowicziana.

Keywords

  • Betula maximowicziana
  • natural resource
  • RAPD
  • regional genetic variation
Open Access

SSR Markers for Analysing South American Nothofagus Species

Published Online: 27 Oct 2017
Page range: 240 - 243

Abstract

Summary

11 newly discovered microsatellites were used to identify SSR markers for characterising South American Nothofagus species. This was carried out in six species. The sample sizes used were between four and six individuals per species. The cross-genera transferability of 34 Quercus SSRs was also essayed. Out of the 11 new microsatellite markers, three proved to be polymorphic (NnBIO 11, NgBIO 13 and NgBIO 14). The qualitative confirmation of the inheritance of these markers could also be verified. Polymorphism was also observed in five of the cross-genera transferred SSRs (QrBIO7, quru-GA-0A01, quru-GA-0C11, quru-GA-0I01, quru-GA-0M07). The number of alleles per locus found range between 1 and 6 per species. The eight polymorphic SSRs identified in this study will constitute a valuable tool in the gene flow studies that are currently being carried out in natural populations of South American Nothofagus species. The confirmation of crossspecies and cross-genera transferability opens the way for the use of SSRs as bridge markers in genetic mapping.

Keywords

  • microsatellites
  • Nothofagus
  • transferability
  • Quercus
Open Access

Sexual Symmetry in Natural Populations of the Patagonian Cypress (Austrocedrus chilensis)

Published Online: 27 Oct 2017
Page range: 244 - 246

Abstract

Abstract

Sexual symmetry, defined as equal allelic frequencies among reproduction effective gametes of both sexes, was analysed by means of 10 isozyme loci in three natural populations of Austrocedrus chilensis (dioecious and wind pollinated tree species). Haplotypes of effective gametes were inferred by analysing side-by-side both the embryo and the endosperm of seeds collected from 20 to 27 trees per population. The allelic frequencies of effective ovules and pollen were compared in each of the three populations. The hypothesis of sexual symmetry could only be rejected in case of one locus in two out of three analysed populations. That is, most of the loci surveyed turned out to be symmetric in the three sampled populations in spite of their contrasting environmental conditions. Therefore, sexual symmetry in A. chilensis seems to be mainly uninfluenced by the environment. On the other hand, all loci showed Hardy- Weinberg (HW) proportions in the three populations, even those that resulted asymmetric. HW structure is usually considered as enough evidence of panmixia, what implies sexual symmetry, and consequently this result gives an example of the low reliability of indirect methods of testing genetic processes, such as the classical HW test.

Keywords

  • reproductive system
  • Austrocedrus
  • isozymes
  • Cupressaceae
Open Access

PCR-Multiplex of Six Chloroplast Microsatellites for Population Studies and Genetic Typing in Pinus sylvestris

Published Online: 27 Oct 2017
Page range: 246 - 248

Abstract

Abstract

The major drawback of microsatellites analysis is that they are expensive to develop, labor-intensive and demand skilled personnel. However, such studies might be still simplified and accelerated by multiplexing of the markers and the use of highthroughput systems for genotyping DNA fragments. In this paper we present a single, simple and highly effective PCRmultiplex reaction composed of six chloroplast microsatellites widely used for population studies in pines but here applied to Pinus sylvestris. The reaction allows for rapid genotyping of large sample sizes.

Keywords

  • chloroplast microsatellites
  • PCR-multiplex
  • Pinus sylvestris
  • polymorphism
  • haplotypes
Open Access

An assessment of family variation of Norway spruce (Picea abies (L.) Karst.) of the Kolonowskie provenance from a reconstitution seed orchard

Published Online: 27 Oct 2017
Page range: 249 - 253

Abstract

Abstract

Variation in spring bud break dates and growth traits was studied among 183 half-sib families developed from Norway spruce grafts on a reconstitution seed orchard. The grafts were derived from maternal trees (ortets), which were selected on the IUFRO 1964/68 experimental plots in 11 countries. All maternal trees belong to the same provenance Kolonowskie, which should be reconstituted as a population by a seed orchard because its exact location was not documented, and thus seed of this provenance was not available. Analyses of variance of the data collected in the first six years of the experiment revealed a very high variation between families in general and between families within clones. Differences between the clones were observed in some traits (plant height after the first growing season, spring flushing in the sixth growing season), but differences between families within clones proved to be more significant. A positive correlation was found between bud break dates of grafts in the seed orchard and their generative progeny on the family experimental plot. The correlation was significant both at the family (graft) level (p = 0.01) and at the clonal level (p = 0.05). The substantial variation between open pollinated families from the reconstitution seed orchard cannot entirely be interpreted but it indicates a high selective potential of Norway spruce at the family level.

Keywords

  • Norway spruce
  • reconstitution seed orchard
  • half-sib families
  • genetic variation
  • growth traits
  • spring flushing
Open Access

Genetic Analysis of Growth and Susceptibility to Bacterial Wilt (Ralstonia solanacearum) in Eucalyptus by Interspecific Factorial Crossing

Published Online: 27 Oct 2017
Page range: 254 - 258

Abstract

Summary

Factorial mating crosses of Eucalyptus urophylla × E. tereticornis (3 x 5), E. urophylla × E. camaldulensis (3 x 3) and E. urophylla × E. exserta (3 x 3) were used for genetic analysis of growth traits and susceptibility to bacterial wilt (Ralstonia solanacearum). Genetic effects including female, male and female × male interaction were examined for height (H) and diameter at breast height (DBH) at age five as well as final bacterial wilt index (BWI) in both nursery inoculation and field assessment by five years of age. Female, male and female x male variances appeared to have a significant role in growth traits H and DBH though their magnitude varied for the factorials studied. For the trait BWI additive (male) and dominant (female x male) effects were both involved in the genetics of bacterial wilt susceptibility, and additive was the major. Estimates of narrow-sense heritability (h2) for H, DBH and BWI ranged from 0.11 ± 0.06 to 0.70 ± 0.09, varying with either trait or factorial. Growth traits (H and DBH) had low and non-significant phenotypic and genetic correlations with BWI in all the three factorials, ranging from -0.10 ± 0.08 to 0.17 ± 0.14 in coefficient of correlation. This indicates that it may be possible to select superior trees with both fast growth and high resistance to bacterial wilt in eucalypt hybrid populations in operational breeding programs.

Keywords

  • Eucalyptus
  • growth
  • bacterial wilt (Ralstonia solanacearum)
  • genetic parameters
Open Access

Patterns of Pollen Flow and Genetic Differentiation Among Pollen Pools in Quercus salicina in a Warm Temperate Old–growth Evergreen Broad-leaved Forest

Published Online: 27 Oct 2017
Page range: 258 - 264

Abstract

Abstract

Paternity analysis and analysis of molecular variance were used to determine patterns of pollen flow and genetic differentiation among pollen pools in Quercus salicina in an 11.56-ha plot in a temperate old-growth evergreen broad-leaved forest. The genotypes at seven microsatellite loci were determined for 111 adult trees and 276 seeds collected from under eight seed parents. The proportion of pollen flow from outside the plot (further than 100 m) was 52.2%, indicating that long-distance pollen flow occurred frequently in this species, as observed in other Quercus species. The pollen pools from inside and outside the plot differed genetically, and genetic structure was detected in the population of adult trees within the plot. Therefore, longdistance pollen flow from outside the plot may introduce new or low-frequent alleles, and increase genetic diversity in this population. However, the actual average distance of pollen flow within the plot was significantly shorter than the average potential distance, and negative exponential curves explained well the frequencies of matings as functions of the distance between parents, as found in other Quercus species. The genetic composition of pollen pools differed among the eight seed parents. The genetic differentiation of pollen pools between the seed parents showed significant positive correlation with the spatial distance between them, indicating that neighboring seed parents tend to accept similar pollen pools, probably because matings are frequently mediated by pollen transported over short distances

Keywords

  • AMOVA
  • gene flow
  • microsatellite
  • paternity analysis
  • pollen
  • Quercus
Open Access

Variation in Growth Performance of Acacia nilotica Willd. ex Del. Provenances of Wide Geographical Origin : Six Year Results

Published Online: 27 Oct 2017
Page range: 264 - 269

Abstract

Abstract

Results of a provenance trial of Acacia nilotica Willd. ex Del. laid out in 1993 at Tropical Forest Research Institute Campus, Jabalpur (23°N lat., 79°E long. and 400 m altitude) Madhya Pradesh, a semi-arid region of India are reported and discussed. Nineteen provenances from India, Pakistan, Sudan, Senegal and Yemen were evaluated in the field at age three and six years. Local source of A. nilotica (S.F.R.I., Jabalpur) was used as check material for comparison. Significant differences between the provenances (P < 0.05) were observed for height, diameter at breast height (DBH), number of branches and field survival. The provenances from Gujrat (Punjab), Pakistan, ranked first for growth traits namely height, DBH and survival. The next superior provenance was from Beihan, Yemen, which scored second highest values of height and DBH and had good survival at age six years. Results indicate that genetic differences exist between the provenances of A.nilotica. None of the traits assessed (viz. height, DBH, number of branches, inter-nodal length and survival) were found to correlate with any of the geographical coordinates of the provenances (latitude, longitude and altitude). Height, DBH and number of branches showed significant and positive correlation with each other. Fair differences between phenotypic and genotypic coefficient of variability were observed. Heritability values were found fairly good for height, DBH and number of branches as compared to inter-nodal length. The relative performance of these provenances was fairly consistent throughout the period of observation at three and six year. The two sources viz. Gujrat (Punjab), Pakistan and Beihan, Yemen, are recommended for plantation programme under semi-arid conditions.

Keywords

  • Acacia nilotica
  • variation
  • provenance
  • seed source
  • genetic improvement
  • productivity
  • heritability
Open Access

Correlation and Path Analysis Studies Between Biomass and Other Characters in Bombax ceiba L.

Published Online: 27 Oct 2017
Page range: 269 - 272

Abstract

Abstract

The genotypic and phenotypic correlation and path analysis of plant biomass, plant height, stem diameter and other biomass component traits were analyzed in thirty provenances of Bombax ceiba. In general, the magnitude of genotypic correlations was higher than phenotypic correlations. Stem diameter and plant biomass showed highly significant genotypic correlations with all the traits except the number of secondary branches and plant biomass with leaf biomass. Plant height had the highest positive direct effect on plant biomass followed by the number of primary branches/plant and the number of leaves/plant. On the basis of this study, a higher plant biomass would be achieved through direct selection based on plant height, the number of primary branches and the number of leaves/plant. Therefore, the study is important in selection of traits of economic importance based on other characters, whose direct effect is not visible.

Keywords

  • Bombax ceiba L.
  • provenance
  • plant biomass
  • biomass characters
  • genotypic and phenotypic correlation
  • path coefficient

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