The effect of culture filtrates of fungal isolates of species Alternaria, Bipolaris, Ulocladium on the seed germination and seedling growth of sunflower

The article presents the study of the toxigenicity of fungi of genus Alternaria, Bipolaris spp. and Ulocladium sp. according to the influence of culture filtrates of their isolates on the germinating seeds of sunflower hybrids Kubansky 930 and Mercury. The fungi isolates were obtained from the leaves, stems and seeds of sunflower of the Krasnodar and Stavropol regions. The high toxicity for sunflower seedlings had the isolates of B. australiensis, Bipolaris sp., one isolate of A. tenuissima, and the specimen of the species complex A. infectoria: the number of seedlings with the abnormal development or absence of roots ranged from 58 to 100 %. The culture filtrates of A. helianthi, A. helianthiinficiens, Ulocladium sp. and the most isolates of A. tenuissima did not affect the growth and development of seedlings of both hybrids.