TY - JOUR AU - Rozhkova, T. O. PY - 2022/07/21 Y2 - 2024/03/28 TI - HARMFULNESS FUSARIUM SP. FROM MYCOBIOTA OF WINTER WHEAT SEEDS JF - Bulletin of Sumy National Agrarian University. The series: Agronomy and Biology JA - ab VL - 47 IS - 1 SE - Articles DO - 10.32845/agrobio.2022.1.16 UR - https://snaubulletin.com.ua/index.php/ab/article/view/644 SP - 119-124 AB - Fusarium sp. on wheat cause spots and fusarium head blight. The main source of their infection is seeds. They are part of the seed mycobiota together with other fungi. The species composition of Fusarium determines the range of mycotoxins and other secondary metabolites in seeds that affect its germination and plant development. Therefore, the aim of our research was to establish the Fusarium species composition in the mycobiota of wheat seeds from the North-East of Ukraine and the influence of species on seed germination and seedling development. Samples of wheat seeds were obtained from farms in Sumy and Kharkiv regions. Fusarium sp. were identified by macro- and micromorphological characteristics. They were isolated during the analysis of mycobiota of winter wheat seeds on potato-glucose agar. The nature of the harmful effect was established by observing the development of colonies of Fusarium fungi on the PGA, noting the impact on seed germination and development of seedlings and roots. Seedling length was measured on the 7th and 14th day, determining the average. In the mycobiota of winter wheat seeds in the North-East of Ukraine during 2015–2020, 7 species of Fusarium were identified, which belong to 5 sections: F. culmorum and F. graminearum (Discolor section), F. oxysporum (Elegans), F. verticillioides (Liseola), F. sporotrichioides and F. poae (Sporotrichiella). Calculation of the frequency of occurrence showed the dominance of two species: F. sporotrichioides and F. poae. Seeds with Fusarium had no characteristic signs of damage, except for wrinkles. Some species have affected the germination of wheat in different ways: from complete suppression to the formation of seedlings that are not inferior in length to others. Most often, observations showed thinning, deformation, reduction in length and necrotic spots on seedlings. Necrotization was also noted on the roots, which were also often suppressed. According to our observations, F. culmorum was the most harmful for the germination of wheat on a nutrient medium. He was the fastest to form a plaque. Most seeds under the influence of its toxins were unable to germinate. Some seedlings were completely necrotized. F. sporotrichioides and F. poae could form inconspicuous plaques and have no obvious symptoms of plant oppression. Measurement of seedlings demonstrated how F. sporotrichioides and F. poae reduce the length of wheat seedlings. Seedling length comparisons were made with Alternaria sp., as they did not have phytotoxic effects during all years of research, and even stimulated seed germination. F. poae reduced the length of seedlings in the presence of an average of 51.3%, and F. sporotrichioides – by 45.5%. Fusarium sp. from mycobota wheat seeds had a negative effect on its germination and plant development. ER -