Volume 30 (2018): Issue 1 (June 2018)

Bacterial blight (BB) caused by Xanthomonas axonopodis pv. dieffenbachiae (Xad) is the most destructive disease of ornamental anthurium. In the present study, foliar resistance of 21 anthurium cultivars were assessed under shaded field and laboratory conditions by injection inoculation of 3 × 10⁸ cfu/ml Xad; disease severity was evaluated using a pretransformed rating scale after symptoms survey. Then six selected cultivars with different resistance levels were evaluated for the induced activities of six defence-related enzymes. The obtained results indicated that the same cultivar shared identical resistance under both conditions, but there was a great variation among the cultivars. Anthurium cv. Pink Champion and Manaka showed the highest resistance, and five other cultivars were highly susceptible. The activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD) and phenylalanine ammonia-lyase (PAL) in the resistant cultivars increased much faster and reached much higher peak levels than those in susceptible cultivars. Further analyses revealed that the relative resistance index (RRI) significantly positively correlated with the activities of SOD, APX, POD and PAL, but not with catalase (CAT) and polyphenol oxidase (PPO), suggesting that early rapid accumulation of SOD, APX, PAL and POD might be an important mechanism of defence against Xad and could serve as one of the valuable physiological indices for the prediction of BB resistance in anthurium germplasm. Consequently, the identified resistant cultivars and the induced defence enzymes will facilitate the phytopathological research and enhance blight resistance selection in future breeding.

Strawberry trees (Arbutus unedo L.) are naturally grown in particular Black Sea and Mediterranean regions of Turkey with great diversity due to continuous seed propagation for centuries. The trees differ in terms of most of the horticultural characteristics. We investigated the phenolic compounds and the biochemical and pomological characteristics of the fruits of eight strawberry tree selections naturally grown in the western part of Turkey. Significant differences were found among the genotypes in terms of their phenolic compounds and their biochemical and pomological characteristics. Among soluble sugars, fructose (11.63 g 100 g⁻¹) was the dominant sugar, followed by glucose (6.10 g 100 g⁻¹) and sucrose (1.44 g 100 g⁻¹) for all the genotypes. Positive correlation was found between fruit weight and soluble sugar content. Malic acid was the major organic acid (0.67-2.33 g 100 g⁻¹), and the second major organic acid in strawberry tree fruits was citric acid (0.25-0.87 g 100 g⁻¹). Vitamin C content was an average of 56.22 g 100 g⁻¹ for the eight genotypes. Among phenolic compounds, gallic acid was dominant (1.62-7.29 mg 100 g⁻¹), followed by chlorogenic acid (1.23-3.14 mg 100 g⁻¹), on an average basis.

The effect of post-harvest irrigation and genotype on the quality components of white asparagus spears was investigated. The field experiment was conducted in 2003-2008 on a very light soil in the Bydgoszcz region. The research was based on a two-factorial split-plot design with randomly selected sub-main blocks. The first studied factor was irrigation applied as two treatments: drip irrigation and microsprinkler irrigation. Non-irrigated plants were tested as the control. The second factor considered was genotype represented by three male cultivars of the garden asparagus: ‘Gijnlim’, ‘Ramos’ and ‘Vulkan’. The irrigation started after the harvest of the spears, while the concentrations of chemical ingredients were measured in the white spears collected in the next growing period. The level of the tested components was significantly influenced by both factors studied. The average amounts of dry matter, potassium, iron and nitrates measured in the white spears were 6.37%, 268.9 mg 100 g⁻¹ f.m., 0.29 mg 100 g⁻¹ f.m. and 62.1 mg kg⁻¹ f.m., respectively. Compared to the control, both irrigation treatments considerably increased the dry matter and potassium contents. The irrigation reduced the amount of nitrates, although the microsprinkler irrigation gave better results than the drip irrigation. The highest concentrations of potassium and iron were measured in the spears of ‘Ramos’, especially in the case of drip-irrigated (potassium) and non-irrigated (iron) plants. The amount of dry matter was high in the spears of ‘Ramos’, while ‘Vulkan’ presented a low tendency to accumulate nitrates.

Melatonin, as an indoleamine molecule, regulates a wide range of physiological functions during the growth, morphogenesis and response of plants to biotic and abiotic stresses. In this research, the effect of exogenous application of melatonin (0 (distilled water), 50, 100 and 150 µM) to the leaves of Moldavian balm plants grown under different levels of drought stress (100% (control), 80%, 60% and 40% of field water capacity) was investigated. The results indicate that plants which were treated with 100 µM melatonin showed the greatest leaf surface area, lateral branching, flower length and activities of antioxidant enzymes (superoxide dismutase, guaiacol peroxidase and ascorbate peroxidase). Foliar application of 100 µM melatonin had no significant difference in catalase activity in comparison with the control and other concentrations of melatonin under normal, moderate and severe drought stress conditions. The lowest H₂O₂ content and lipid peroxidation (electrolyte leakage, concentrations of malondialdehyde and other aldehydes) were obtained at the concentration of 100 µM melatonin under severe drought stress. This concentration also significantly increased the chlorophyll content and enhanced the relative water content; however, foliar application of 100 µM melatonin had no significant effect on leaf length and proline content compared with the control under normal and stress conditions. The obtained results suggested that foliar application of 100 µM melatonin was more effective than the concentrations of 50 and 150 µM melatonin in reducing the adverse effects of moderate and severe drought stress.

Some important physical, chemical and sensory characteristics of raw and processed olives (processed by the same scratched table olive process) were investigated. In the study, six candidate cultivars obtained by cross-breeding and one standard cultivar (‘Domat’) grown together in an olive breeding and observation plot in the Ataturk Central Horticultural Research Institute in Turkey were investigated. Fruit weight and flesh-to-seed ratio of fresh raw olives ranged from 5.18 to 7.65 g and 4.8 to 6.3, respectively. LT011 had the highest fruit weight, whereas LT001 and LE001 had the highest flesh-to-seed ratio. Total phenolic content and antioxidant activity of the produced table olives were estimated between 102 and 141 mg gallic acid equivalents per 100 g⁻¹fresh weight, and 13.4 and 14.9 µmol Trolox 100 g⁻¹, respectively. Fruits of LT001 had higher appearance, taste, bitterness and general appreciation scores than the others. LT001 showed a lesser loss of oleuropein absorbance and antioxidant activity than the others during processing. The results of this study revealed that LE001, LT001 and LT011 had superior characteristics for the production of scratched green table olives.

The aim of the study was to determine the influence of jasmonic acid added to culture medium on the growth of plants and antioxidant properties of dry plant material, as well as on the antimicrobial properties of essential oils produced by the narrow-leaved lavender. For plant propagation, MS media supplemented with JA at concentrations of 0.2-1.5 mg dm⁻³ were used. The use of the lower JA concentrations did not influenced the growth parameters measured, whereas at the higher concentrations (1 and 1.5 mg dm⁻³) JA caused growth inhibition and a decrease in plant weight. With increasing JA concentration, the number of secretory trichomes decreased. Addition of 0.5 mg dm⁻³ JA caused an increase in secretory trichome diameter on both the adaxial and abaxial surface of leaves (83.3 and 73.2 μm, respectively). The antioxidant activity of the lavender plants propagated on media with the addition of JA (regardless of the concentration used) was higher than that of the control plants. The plants from JA-supplemented media were used to isolate essential oils, the antimicrobial activity of which was tested using the disc diffusion method at the concentrations of 10 and 50%. All the oils tested exhibited activity towards Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis and Candida albicans. The essential oils isolated from the plants propagated on the medium with 1 mg dm⁻³ JA were characterized by the highest antimicrobial activity against the majority of the tested microorganisms.

Symptoms of discoloration and necrosis of the leaves/needles and shoots of plants are an increasingly common phenomenon in nurseries. They necessitate the withdrawal of the affected plants from sale, which has significant economic consequences. In 2010-2011, observations were conducted of the health of shrubs in nurseries of the Małopolska province. Disease symptoms were mostly found in juniper (Juniperus horizontalis ‘Wiltonii’), rose (ground-cover rose ‘Star Profusion’), yew (Taxus × media ‘Hillii’) and highbush blueberry (Vaccinium corymbosum ‘Patriot’). These species were selected for further study. The affected shrubs represented more than 46% of the population of a given species. Fragments of the diseased organs: the leaves or needles, the base of the shoots, and the roots, were collected from the borderline between healthy and diseased tissue, and used to isolate and identify the microorganisms colonizing the diseased parts. The affected organs were found to be inhabited to the largest extent by the fungus Alternaria alternata (Fr.) Keissl., which accounted for 19.7 to 47.5% of the isolates from the tested species of shrubs. There were also large populations of fungi of the genera: Botrytis (up to 9.82%), Cladosporium (up to 5.66%), Colletotrichum (up to 5.13%), Fusarium (up to 18.38%), Mortierella (up to 7.26%), Pestalotia (up to 5.36%), Rhizoctonia (up to 5.36%), Sclerotinia (up to 6.99%), and Trichoderma (up to 17.09%). The fungus A. alternata, being by far the dominant pathogen, was tested for its pathogenicity for the shoots of the chosen species of shrubs. The test was conducted for 14 days in a chamber with parameters so programmed that they reflected the natural conditions at the height of the growing season. The fungus A. alternata exhibited pathogenicity for all of the tested species of shrubs. Necrosis developed on all the inoculated fragments of shoots. The surface area of necrotic lesions was larger on the shoots of juniper and blueberry.

The complex relationship between water and grapevine has been examined in several studies. The aim of this study was to understand the impact of water stress on photosynthesis, carbon-13 discrimination in leaves in different positions on the shoot, and the capacity of vines to recover from different levels of water stress intensity. The vine physiological responses to a water stress regimen followed by re-watering for two consecutive cycles was evaluated using potted ‘Sangiovese’ grapevines. The intensity and the duration of the water limitation affected the emergence and development of new leaves, but did not significantly affect leaf water potential. Leaf stomatal conductance and carbon assimilation during the first water-stress phase were reduced respectively by about 61% and 20%, while after the second water stress cycle both were lower than the initial values by 77% and 21%, respectively. After 1 day of re-watering, only the leaves located in the medial positions on the shoot showed a partial recovery of photosynthesis. After at least 2 days post-re-watering, the leaves located in the distal portion of the shoot showed a recovery of photosynthetic capacity. The results indicated that leaf position along the shoot, i.e., an indicator of leaf age, is an important variable in developing grapevine strategies in response to conditions of limited water availability.

The present study evaluated the effects of five species of arbuscular mycorrhizal fungi (AMF) on vegetative development parameters and nutrient uptake of persimmon (Diospyros kaki L.) seedlings. The experiment was carried out in a completely randomized experimental design with six treatments involving AMF inoculation (non-inoculated; Dentiscutata heterogama, Claroideoglomus etunicatum, Rhizophagus clarus, Acaulospora scrobiculata and A. morrowiae), in sterile soil (Oxisol – Dystrophic Red Latosol) under greenhouse conditions. Persimmon seeds were germinated in sterile sand and the seedlings were transplanted to the sterile soil and received AMF inocula. After 360 days, the following vegetative parameters were analyzed: plant height, number of leaves, leaf surface area, stem diameter, shoot and root dry mass, percentage of root colonization and nutrient accumulation in shoot and root biomass. We observed different responses to the AMF species tested. Seedling height and leaf surface area were promoted by inoculation with D. heterogama and A. morrowiae, and these species also promoted a higher percentage of root colonization. Plants inoculated with D. heterogama and C. etunicatum presented a greater number of leaves, but only D. heterogama promoted significant increases in stem diameter. Shoot dry mass was improved by inoculation with D. heterogama, A. morrowiae and C. etunicatum, while the first two species and R. clarus increased root dry mass. Nutrient accumulation in shoot and root biomass was stimulated by AMF inoculation, especially by D. heterogama and A. morrowiae. Therefore, the effects on early vegetative development were more pronounced in the persimmon seedlings inoculated with D. heterogama.

The aim of the study was to estimate the effect of' tree pruning intensity on the content of nutrients in leaves of the ‘Łutówka’ sour cherry cultivar (Prunus cerasus L.). Between 2006 and 2010 an experiment with different tree pruning intensity was carried out. The study material consisted of first- class one-year old budded plants of the ‘Łutówka’ cultivar IR2 type, on Prunus mahaleb rootstock. The plants were planted in the spring of 2001 (orchard 1) and 2002 (orchard 2) and spaced at 4.0 × 1.3 m², giving a total of 1.920 trees ha⁻¹. Three pruning regimes were applied in the plantation: 1) no pruning; (only sanitation felling was applied), 2) moderate traditional pruning - branches were shortened, 3) intensive pruning by removing branches older than three years. The cherry tree pruning intensity significantly influenced the content of mineral components in leaves. The content of N increased, whereas the content of Ca and Mg decreased. The maximum temperatures at the beginning of the growth period had particularly beneficial effect on the P and K content. Chilly and dry spring limited the P and K content in the plants. The content of minerals in sour cherry leaves depended on the age of trees.

Protocols leading to the development of doubled haploid (DH) lines by microspore culture are widely used in white cabbage (Brassica oleracea var. capitata L.), but efficiency varies according to the cultivar and induction procedure. Forty different genotypes consisting of F1 cultivars and their crosses with responsive doubled haploid lines were tested to evaluate the androgenic response. In total, 20,032 embryos were produced. On average, the haploid induction response of F1 cultivars was 7.0 embryos/Petri dish, but the average of these hybrids crossed to responsive DH lines was 26.6 embryos/Petri dish. In seven reciprocal crosses, a difference was observed in just one, meaning that the maternal effect probably has a minor influence on haploid embryogenesis in cabbage. Addition of 0.02% activated charcoal (AC) to the induction media increased embryo formation in several low-responsive genotypes, but its effect on embryo formation of high-responsive genotypes was predominantly negative, although larger embryos were formed on media containing AC than without AC. Further development into plantlets was tested by two procedures. Formed embryos were either transferred directly to regeneration medium or treated with abscisic acid and desiccated for 4 weeks. Regrowth and further development reached on average 15.5 and 57.6%, for the first and second procedures, respectively. Plantlets developed by direct transfer often exhibited abnormal development or hyperhydricity, unlike the desiccated embryos. Spontaneous diploidisation of embryos reached 42.5% in total and was not affected by AC added to the induction media.

This study was performed to explore the efficacy of combining more than one postharvest treatment in maintaining some quality attributes and reducing fungal pathogenicity in cold-stored guava fruits. The investigated postharvest treatments included the control, CaCl₂ (4%), lemongrass oil (2 dm³ kg⁻¹), gamma (γ) irradiation (0.2, 0.4 and 0.6 kGy), 0.4 kGy γ irradiation + CaCl₂ (4%), and 0.4 kGy γ irradiation + lemongrass oil (2 dm³ kg⁻¹). The studied physiochemical attributes included weight loss, decay percentage, fruit firmness, total soluble solids (TSS), titratable acidity (TA), and vitamin C content. Different fungal species were also isolated from decayed fruits and were identified as Alternaria alternata, Alternaria solani, Aspergillus niger, Botrytis cinerea, Fusarium solani and Rhizopus stolonifer. The severity of infection for the different fungi was determined, and an in vitro antifungal assay was conducted for lemongrass oil. All the investigated treatments generally reduced decay and water loss percentages, and controlled TSS, TA and vitamin C decrements that occurred during cold storage. On the other hand, higher irradiation doses generally increased fruit softness, and the 0.4 kGy γ dose did not contribute to the overall fruit quality when coupled with CaCl₂ and lemongrass oil, compared to CaCl₂ and lemongrass oil treatments alone.

Plant enzymes, growth regulators and organic acids are the main groups of plant biostimulants (PBs), and their combined use in the final formulation may be important for increasing the quantitative and qualitative composition of plant products. This study aimed to determine the effects of a multienzymatic biostimulant (MB), indole-3-butyric acid (IBA), and citric acid (CA) on the morphological and phytochemical traits of bladder cherry (Physalis alkekengi L.). The treatments included different concentrations of MB (0, 0.5 and 1.0%), IBA (0, 25, and 50 ppm), and CA (0, and 500 mg dm⁻³), which were sprayed four times during the vegetative stage, at 12-day intervals, 35 days after planting. The results showed that the treatments had a significant effect on plant height, stem number, diameter and weight, leaf number and weight, fruit number, diameter and weight, the amounts of total phenols, alkaloids and flavonoids, and on the radical scavenging activity. The most effective formulation for improving the fruit yield of bladder cherry was 1% MB with 50 ppm IBA and 500 ppm CA. However, the best treatment for increasing the total phenolic and alkaloid contents, and radical scavenging activity was 0.5% MB. In general, the maximum values of most traits were obtained by spraying the plants with 0.5 and 1% MB combined with IBA and CA. The concentration of alkaloids, the main pharmaceutical metabolites of bladder cherry, increased as a result of the application of the multienzymatic biostimulant.

Turkey is one of the most important centres of mulberry genetic resources and mulberries grow naturally almost everywhere in Turkey. This study was carried out to determine the most important phenolic compounds and phytochemical properties of mulberry (Morus nigra L.) genotypes collected from natural resources in 2016-2017 in the province of Uşak (Turkey). The investigated biochemical characteristics included: total soluble solids content (TSS), pH, titratable acidity, total phenolic content, vitamin C and antioxidant capacity (DPPH). The highest values of phenolic compounds, i.e. ellagic acid, rutin, quercetin, gallic acid, catechin, chlorogenic acid and caffeic acid, were as follows: 5.89, 133.60, 11.25, 40.90, 10.54, 97.59 and 21.93 g 100 g⁻¹, respectively. The highest values of total phenolics, vitamin C content and antioxidant capacity determined in the investigated mulberry genotypes were 2977.30 mg GAE g⁻¹, 31.34 mg 100 g⁻¹ and 26.80%, respectively. The genotypes 64USA08, 64USA06 and 64USA10 can be recommended in terms of the most valuable chemical composition and used for future breeding purposes. It is desirable to take steps to implement an intensive programme for the preservation of Morus nigra L. biodiversity in Turkey.

Flow cytometry (FCM) has been used for plant DNA content estimation since the 1980s; however, presently, the number of laboratories equipped with flow cytometers has significantly increased and these are used extensively not only for research but also in plant breeding (especially polyploid and hybrid breeding) and seed production and technology to establish seed maturity, quality and advancement of germination. A broad spectrum of horticultural and medicinal species has been analyzed using this technique, and various FCM applications are presented in the present review. The most common application is genome size and ploidy estimation, but FCM is also very convenient for establishing cell cycle activity and endoreduplication intensity in different plant organs and tissues. It can be used to analyze plant material grown in a greenhouse/field as well as in vitro. Due to somaclonal variation, plant material grown in tissue culture is especially unstable in its DNA content and, therefore, FCM analysis is strongly recommended. Horticultural species are often used as internal standards in genome size estimation and as models for cytometrically studied cytotoxic/anticancer/allelopathic effects of different compounds. With the growing interest in genome modification, increased application of FCM is foreseen.