Black point of winter wheat seeds

Abstract

Goal. To study infection of seeds of winter wheat varieties by «black point» and to establish the phytopathogenic composition of pathogens in the Right Bank Forest-Steppe of Ukraine. Methods. Laboratory — macroscopic analysis was performed according to DSTU 4138-2002, phytopathogenic composition was identified using nutrient medium, statistical analysis of the obtained data — calculation of the degree of pathogen severity, LSD. Results. A collection of 27 varieties of soft winter wheat was studied to determine the degree of seed infection. The highest percentage of infection was found in varieties Vodogray Bilotserkivsky (Ukraine), Adele (Russia), Balitus (Austria), Viglanka (Slovakia), Sefeg-2 (Azerbaijan). The least susceptible to the disease are varieties Daria (Croatia), Bodycek (France), Gratsia Bilotserkivska (Ukraine, Bila Tserkva DSS), Azano (Sweden), Gospodarka (Ukraine), Kozyr (Ukraine), Morozko (Russia), the number of grains with signs of darkening in the embryonic zone for these varieties did not exceed 1%. The sowing qualities of the diseased seeds were determined. The species composition of phytopathogens that cause the disease has been established. The phytopathogenic complex of seeds with the «black point» included fungi of the genera Alternaria, Fusarium, Curvularia, Bipolaris, Aspergillus, Acremoniella, Stemphillium, Sordaria and Epicoccum. Most often, the seeds were colonized by fungi of the genus Alternaria Nees. Their share in the years of research was 76.6—83.1%. Conclusions. The infection of seeds of winter wheat varieties by black point under conditions of the Right-Bank Forest-Steppe of Ukraine in 2018—2019 ranged from 0 to 19.8% depending on the variety and year of research. The phytopathogenic complex included 13 species of fungi from 9 genera: Alternaria, Fusarium, Curvularia, Bipolaris, Aspergillus, Acremoniella, Stemphillium, Sordaria, Epicoccum. The part of Alternaria spp. in the years of research was over 75%, the most common species were A. tenuissima and A. infectoria. The percentage of species from other genera was insignificant and did not exceed 4.6%.