Determination of vc and mating types of Cryphonectria parasitica isolates by multiplex PCR and their genetic diversity in 13 chestnut-growing provinces of Turkey

Vegetative compatibility (vc) and mating types and genetic diversity of Cryphonectria parasitica isolates were determined using 183 isolates obtained from 215 infected chestnut trees growing in 13 provinces of Turkey. Based on the cultural aspects, 143 of these isolates were evaluated as virulent whereas the remaining 40 isolates were hypovirulent. When vc types of 183 isolates were classically differentiated, 135 of them matched to EU-1 (82.3%), 29 of them to EU-12 (17.6%) vc type, whereas 19 of them did not match to the two. When molecular vic markers were used, all the isolates were assigned to two EU vc types; 149 to EU-1 (81.4%) and 34 (18.5%) to EU-12. Of the majority of the isolates, 134 (73.2%) had mating-type MAT-1, while 44 (24%) isolates had MAT-2 and 5 (2.8%) isolates had both mating types. The population analysis based on two DNA marker systems, Inter-Primer Binding Site and Start Codon Targeted Polymorphism, showed no intraspecific genetic variation among the C. parasitica isolates. The prevalence of two dominant vc types revealed by this study shows that biological control with hypovirulent EU-1 and EU-12 isolates will be significant for the country. The results might be helpful to chestnut breeders carrying out resistance breeding studies to manage this disease based on hypovirulence attributed to Cryphonectria hypovirus 1.     

Effects of Natural and Artificial Colorants on Hot Smoked Garfish—Belone belone (Linnaeus, 1761)—Stored at 4 ± 1ºC

In this study, the effects of natural and artificial colorants on the shelf life of hot smoked garfish were investigated in terms of its chemical, microbiological, and sensory quality. Turmeric and Sunset Yellow FCF were used as the natural and artificial colorants, respectively. The amount of total volatile basic nitrogen (TVB-N) and thiobarbituric acid (TBA), counts of total mesophilic aerobic bacteria, total psychrophilic aerobic bacteria, total yeast and molds increased during the storage (p < 0.05). The results showed that turmeric and Sunset Yellow FCF had a significant effect on pH value and salt content of hot smoked garfish samples during storage (p < 0.05). According to the sensory analysis results, the shelf life of hot smoked garfish stored at 4 ± 1ºC was determined as 17 days.     

Effect of Pregnancy and Foetal Number on Diameter of Corpus Luteum,Maternal Progesterone Concentration and Oxidant/Antioxidant Balance in Ewes

The aim of this study was to determine the changes in diameter of corpus luteum (CL), maternal progesterone (P) concentration, lipid peroxidation and non‐enzymatic antioxidant levels along with enzymatic antioxidant activities in pregnant ewes bearing single and twin foetuses. The ewes were selected from healthy animals that were brought to the abattoir for slaughtering. The ewes were divided into three groups: Group 1 (non‐pregnant, non‐oestrous, n = 30), Group 2 (pregnant bearing a single foetus, n = 30) and Group 3 (pregnant bearing twin foetuses, n = 12) after they were slaughtered. Pregnant ewes were in the first half of the pregnancy. The diameter of CL and P concentration of pregnant ewes bearing a single foetus or twin foetuses were found higher than that found in non‐pregnant ewes. Similarly, the P concentration of pregnant ewes bearing twin foetuses was higher than that found in pregnant ewes bearing a single foetus. Malondialdehyde (MDA) level in pregnant ewes bearing twin foetuses was higher than that found in both non‐pregnant and pregnant ewes bearing a single foetus. The serum glutathione (GSH) level and glutathione‐peroxidase (GSH‐Px) activity of pregnant ewes bearing twin foetuses were found lower than that found in non‐pregnant ewes. Additionally, the GSH‐Px activity of pregnant ewes bearing twin foetuses was found lower than that found in pregnant ewes bearing a single foetus. No significant difference was found between pregnant ewes bearing female and male foetus with respect to diameter of CL, P concentration and oxidative stress parameters. There were significant positive correlations between foetal number (0, 1, 2) and diameter of CL, P concentration, MDA level, and between P concentration and diameter of CL, MDA level. However, significant negative correlations were found between foetal number (0, 1, 2) and GSH level, GSH‐Px activity, and between P concentration and GSH‐Px activity. In conclusion, the diameter of CL enlarges, P production increases and oxidant/antioxidant balance impairs because of the gestation stress in ewes during pregnancy.     

Population structure of Phytophthora infestans in Turkey reveals expansion and spread of dominant clonal lineages and virulence

Late blight, caused by the oomycete Phytophthora infestans, is considered the most important and destructive disease of potato in Turkey. In this study, characterization of 367 isolates of P. infestans obtained from the potato-growing areas of the country was carried out to evaluate the pathogen population structure over the 2017–2019 production seasons. The isolates were characterized by numerous features including mating type, in vitro mefenoxam sensitivity, simple-sequence repeat (SSR) markers, and virulence against a set of potato differential lines. Most isolates were A2 mating type (353 isolates). Also, 68% of isolates were resistant to mefenoxam; the remainder were intermediate in their sensitivity and there were no sensitive isolates. SSR-based genotypic analysis of P. infestans populations showed a low genetic diversity. The 13_A2 clonal lineage predominated with a frequency of 92.1%, followed by 34_A1 (3.3%) and 37_A2 (2.7%). Genotypes 34_A1 and 37_A2 were detected only in 2019. This is the first report of 34_A1 and 37_A2 clonal lineages causing late blight disease of potato in Turkey. The most abundant virulence type was one overcoming resistance genes R1, R2, R3, R4, R6, R7, R10, and R11. These results emphasized that the migration of individuals and the asexual generation of subclonal differences were the main factors driving the population structure of P. infestans in Turkey.     

The utility of Trichoderma spp. isolates to control of Xylosandrus germanus Blandford (Coleoptera: Curculionidae: Scolytinae)

Journal of Plant Diseases and Protection - The invasive ambrosia beetle, Xylosandrus germanus Blandford (Coleoptera: Curculionidae: Scolytinae), is a serious pest of hazelnut in Turkey, which is...     

Effect of some organic amendments on onion bulb rot

The effect of soil amended with stalks of sunflower (Helianthus annuus L.), alfalfa (Medicago sativa L.) and Hungarian vetch (Vicia pannonica Crantz) on onion bulb rot caused byFusarium oxysporum Schlecht. f.sp.cepae (Hanz.) Snyder Hansen andAspergillus niger v. Tieghem was tested in a soil naturally infested with the pathogens under field conditions. All treatments significantly reduced bulb rot incidence. The fungal and antibacterial populations varied among all of the amended tested soils. Heterotrophic fungal populations were more effective than heterotrophic bacterial populations in the suppression of disease. The highest population of fungal microflora was found in plots amended with sunflower stalks. The carbon-to-nitrogen ratio and available moisture content of amended soils have an indirect suppressive role on disease, by increasing the heterotrophic fungal population. http://www.phytoparasitica.org posting June 18, 2002.     

Seed treatments to overcome salt and drought stress during germination in sunflower (Helianthus annuus L.)

The treated seeds (control, KNO₃ and hydropriming) of sunflower (Helianthus annuus L.) cultivar Sanbro were evaluated at germination and seedling growth for tolerance to salt (NaCl) and drought conditions induced by PEG-6000 at the same water potentials of 0.0, −0.3, −0.6, −0.9 and −1.2 MPa. Electrical conductivity (EC) values of the NaCl solutions were 0.0, 6.5, 12.7, 18.4 and 23.5 dS m⁻¹, respectively. The objective of the study was to determine factors responsible for germination and early seedling growth due to salt toxicity or osmotic effect and to optimize the best priming treatment for these stress conditions.

Results revealed that germination delayed in both solutions, having variable germination with different priming treatments. Germination, root and shoot length were higher but mean germination time and abnormal germination percentage were lower in NaCl than PEG at the same water potential. Seeds were able to germinate at all concentrations of NaCl but no seed germination was observed at −1.2 MPa of PEG treatments. NaCl had less inhibitor effect on seedling growth than the germination. It was concluded that inhibition of germination at the same water potential of NaCl and PEG resulted from osmotic effect rather than salt toxicity. Hydropriming increased germination and seedling growth under salt and drought stresses.     

Resistance sources and reactions of common bean (Phaseolus vulgaris L.) cultivars in Turkey to anthracnose disease

Anthracnose caused by Colletotrichum lindemuthianum is one of the major diseases of common bean (Phaseolus vulgaris L.) worldwide. The aim of this study was to analyze common bean cultivars in Turkey for Co resistance genes using different molecular markers (SC08, SBB14, OPAZ04, SF10, OPF10, OPA18, SB12, TGA1, SAB3, SCAreoli, SZ04, and OPV20) linked with anthracnose resistance genes and evaluate the reaction of these cultivars to the pathogen isolates. The results showed the presence of Co-1, Co-1⁴, Co-1⁵, Co-2, Co-4, Co-4², Co-6, Co-10, Co-11, and Co-13 resistance genes, alone or combination except for Co-3³ and Co-5, in common bean cultivars. These cultivars carried predominantly Co-6 and Co-4 genes for anthracnose resistance. Five cultivar (Sazova, Zülbiye, Ak?n, Önceler and Karaca?ehir 90), carrying Co-1, Co-1⁴, Co-1⁵, Co-2, Co-10, Co-13, Co-4, and Co-6 resistance genes were resistant to the pathogen isolates. These cultivars, showing a high level of resistance to the pathogen can be used as resistance sources in common bean breeding programs for resistance to anthracnose disease. These markers will provide significant benefit in breeding strategies.

     

Morphometric traits and iPBS based molecular characterizations of walnut (Juglans regia L.) genotypes

Genetic Resources and Crop Evolution - In this study, walnut genotypes that were selected during two growing seasons among thousands of seedlings were analyzed in terms of detailed morphometric,...     

In vivo anti-mildew activity of essential oils against downy mildew of sunflower caused by PLASMOPARA HALSTEDII

European Journal of Plant Pathology - Commercial essential oils (EO) obtained from different parts of black cumin (N. sativa), mustard (S. nigra), St. John’s wort (H. perforatum), garlic (A....