Volume 25 (2013): Issue 2 (December 2013)

During a three-year field experiment, the possibilities of cultivating the ‘Performer’ cultivar of Japanese bunching onion for early harvest bunching were assessed through the use of autumn and spring planting terms. The seedlings, produced in multi-pots, were planted in the open field on 8-10 September, 9-10 October and 6-12 April, and covered with a perforated foil and agrotextile in mid-November or directly following the spring planting. The covers were removed at the end of April, and the harvest of Japanese bunching onion was conducted at the end of May. The percentage of plants that survived the winter, how many produced flowering stems and the height of the total and marketable yield of plants with a pseudostem diameter >10 mm were determined. We evaluated the content of selected components with a nutritional value in samples of edible plant parts.

The results of the study showed that it is possible to obtain a high yield of plants harvested for bunches following an early spring term seedling planting. The majority of plants planted in the autumn froze during the winter, while those that were overwintered produced flower stems, especially if planted in September. The application of flat covers increased the percentage of plants that survived the winter, though in spite of this fact, the obtained marketable yield of Japanese bunching onion planted in the autumn was very low. Plants from the spring planting were characterised by a lower content of dry matter, chlorophyll a+b and volatile oils, while their content of K, Ca and Mg showed enhanced levels. Covering plants with a perforated foil positively influenced the content of total sugars and volatile oils, while negatively influencing the amounts of vitamin C, potassium and calcium as compared to those cultivated without covers.

The study was conducted in the years 2007-2012 at the Didactic and Experimental Station of the University of Warmia and Mazury in Olsztyn in order to select plum cultivars suitable for growing on ‘Wangenheim Prune’ rootstock in northeastern Poland. The study encompassed the following plum cultivars: ‘Herman’, ‘Čačanska Rana’, ‘Dąbrowicka Prune’, ‘Promis’, ‘Elena’ ‘Tolar’, ‘Bluefre’, ‘Top’, ‘President’ and ‘Valor’. The measurements taken included: trunk growth, yield, weight of one fruit, size of fruit, the content of dry matter, ascorbic acid, total and simple sugars and organic acids. We found that the ‘Valor’ and ‘Herman’ trees grew the best and ‘Top’ grew the most poorly. The highest yields were gathered from the ‘President’, ‘Valor’ and ‘Bluefre’ trees. ‘Bluefre’ had the largest fruit size. The highest content of dry matter was found in the fruit of ‘Tolar’, ‘Valor’ and ‘Promis’. The fruit of ‘Bluefre’, ‘Tolar’ and ‘Top’ had the highest concentration of ascorbic acid. The highest content of total sugars and simple sugars was detected in the fruit of ‘Tolar’, while the highest concentrations of organic acids were found in the fruit of ‘Čačanska Rana’, ‘Dąbrowicka Prune’ and ‘Top’. ‘Promis’, ‘Herman’, ‘Valor’, ‘Top’ and ‘Tolar’ had the highest sugar/acid indexes.

Milk thistle (Silybum marianum (L.) Gaertn.) is one of the most important medicinal plants. The fungi infesting its seeds may negatively influence their germination and health-promoting properties. However, there is no standard method for S. marianum seed health testing. The aim of this study was to find a suitable method for the detection and identification of fungi in/on milk thistle seeds. The following tests were used: deep-freeze blotter test, blotter test with an addition of mannitol, blotter test with an addition of polyethylene glycol, agar test on potato-dextrose agar (PDA), agar test on PDA after seed disinfection, agar test on reduced PDA and an agar test on reduced PDA after seed disinfection. Seeds were incubated for 10 and 14 days. The most prevalent fungi were: Alternaria alternata, Botrytis cinerea, Cladosporium spp., Fusarium spp., Penicillium spp., Rhizopus nigricans and Verticillium spp. A deep-freeze blotter test followed by a blotter test with an addition of mannitol and a blotter test with an addition of polyethylene glycol performed for 14 days could be recommended for the further study of milk thistle seed health testing, as they favoured the growth of the most important fungi.

The aim of the study was to determine the effect of mycorrhisation and mulching on the colonisation of the roots of ‘Gold Milennium’ apple trees and ‘Ojebyn’ and ‘Tiben’ blackcurrant bushes by arbuscular mycorrhizal fungi. In order to assess mycorrhizal frequency, samples of roots were collected in the 2012 season from all of the experimental combinations (control, peat substrate, bark, sawdust, manure, compost, mycorrhizal substrate and straw). The results of the analyses showed that all of the different mulches had a positive effect on increasing the degree of mycorrhizal association. In apple, the highest mycorrhizal frequency (F% - mycorrhizal frequency for the entire sample) and mycorrhizal intensity (M% - relative mycorrhizal frequency for the entire sample) were observed in the roots of trees inoculated with the mycorrhizal substrate (F = 24.40%, M = 0.24%) and those mulched with compost (F = 16.67%, M = 0.17%). In blackcurrant, the highest values of mycorrhizal frequency and mycorrhizal intensity were recorded in the roots of ‘Tiben’ bushes inoculated with the mycorrhizal substrate (F = 37.78%, M = 0.38%) and those mulched with sawdust (F = 21.11%, M = 0.21%).

The antagonistic activity of 52 isolates of Trichoderma spp. against Botrytis cinerea was tested in in vitro conditions using the dual culture technique. The results revealed that all of the Trichoderma isolates had the ability to inhibit the mycelial growth of grey mould. The percentage reduction in the growth of Botrytis cinerea after six days of incubation at 25ºC varied between 45-78%. The isolates Tr43 and Tr52 showed the highest antagonistic activity (Tr43 - 76%; Tr52 - 78%). Biochemical and molecular identification indicated that both isolates were T. atroviride. The isolates showed differences in the utilisation of 11 to 96 different carbon sources. Additional biochemical tests revealed the ability of Tr43 and Tr52 to produce siderophores, indole-3-acetic acid and chitinases. Neither of the isolates gave positive results regarding phosphate solubilisation on Pikovskaya’s medium.

Chrysanthemums are amongst the most economically important flowers in the world. The protection and storage of these valuable genetic resources is of great importance. Today, cryopreservation, or the storage of biological material at the temperature of liquid nitrogen (-196°C), is believed to be the most promising long-term storage method. To optimise the cryopreservation protocol, the shoot tips of Chrysanthemum × grandiflorum /Ramat./ Kitam. ‘Lady Orange’ and ‘Lady Salmon’ mutants were cryopreserved using the encapsulation-dehydration technique. During the experiment, the influence of sucrose concentration (2, 3 and 6%) during preculture and the concentration of kinetin (0.25, 0.5, 0.75 and 1.0 mg dm-3) in the regrowth medium were tested. A higher survival rate was observed for ‘Lady Salmon’. In general, the media with higher sucrose levels provided the best survival and recovery rates (35-40%). Kinetin had no influence on the survival rate; however, it influenced the morphogenesis of the plants. The lowest number of explants forming multiple shoots was observed on the medium with the lowest sucrose (during preculture) and kinetin (in the recovery medium) concentration. On the other hand, the best rhizogenesis efficiency was observed when 0.25 mg dm-3 kinetin was added. In conclusion, the composition of both preculture and recovery media need to be adjusted to single cultivars. The use of 3% sucrose (preculture) and 0.25 mg dm-3 kinetin (recovery) seems reasonable, since it guarantees a satisfying recovery rate of the explants and at the same time prevents the formation of callus and multiple shoots, stimulating the rooting instead.

The effects of different concentrations of copper ions (Cu²⁺ in the form of CuSO₄ × 5H₂O) on in vivo cucumber (Cucumis sativus L. ‘Edinstvo’) seedlings as well as on in vitro hypocotyl-derived callus were considered. Callus induction from hypocotyls was more prolific than from roots or cotyledons. Thus, callus obtained from hypocotyls of 7-day-old cucumber plants was cultured for 5 weeks on Murashige and Skoog medium containing 4 mg dm-3 2,4-D + 1 mg dm-3 BA supplemented with 0.01 mM, 0.1 mM or 1.0 mM of Cu²⁺. Biochemical indices related to oxidative stress were assessed. Cu²⁺ at 0.01 mM stimulated callus induction but 1.0 mM Cu²⁺ negatively affected callus formation and growth. LPO intensity was significantly lower than the control at all concentrations of Cu²⁺ but significantly higher than the control in plants exposed to 0.01 or 0.1 mM Cu²⁺. A similar trend was observed for the generation of the superoxide radical in both callus and plantlets. Superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APOX) activity increased in both callus and plantlets, but the level of increase in these antioxidant enzyme systems depended on the Cu²⁺ concentration. Cu²⁺ ions had a stronger (i.e., more negative) influence on oxidative stress in cucumber seedlings than on cucumber callus.

Light is one of the basic factors needed by plants for their development. The aim of this study was to measure the effect of supplementary lighting of tomato plants with HPS and LED lamps on the chosen physiological parameters and yielding of autumn-winter cultivation crops. Two tomato cultivars (‘Komeett’ F1 and ‘Starbuck’ F1 by De Ruiter Seeds) were used in this experiment. After the plants were planted, LED and HPS lamps of 100 μmol m-2 s-1 light intensity were installed. The results show that the introduction of a supplementary light source to tomato cultivation caused an increase in the intensity of photosynthesis, transpiration, stomatal conductance and chlorophyll by 57.7%, 17.1%, 39.3% and 24.4% on average, respectively. Higher values of those parameters were obtained with HPS lamps than with LED lamps. The amount of marketable crops, number of fruits and mean fruit weight were higher in both combinations in which supplementary lighting was applied, and the values of these traits were higher when the cultivation was supplementary lighted with HPS lamps than with LED lamps. Due to the overhead light configuration and continued low light output, there was no increase of efficiency when using LED lamps compared to HPS lamps despite better focusing and spectral distribution.

This review summarises the research projects that have been conducted with the goal of mapping the apple (Malus × domestica) genome. The generation of apple linkage and physical maps, which was started at the end of the 20th century by many scientific teams, has resulted in rich data useful for further fundamental and applied studies. The mapping efforts mainly contained the choice of mapping populations as well as the choice of types and number of markers. Over the years, scientists have achieved major successes and faced major obstacles. Many economically important traits have been mapped in the apple genome, which has a total length of 2000 cM. The recently published integrated genetic and physical maps summarise the data and will be helpful to modern breeding programs, with a special focus on resistance to various diseases, as well as on fruit quality and other desired apple traits.