Fungal pathogens of mold of winter wheat grains in Rostov region

Long-term monitoring of the colonization of winter wheat grain by fungal mold pathogens that negatively affect the quality of grain during storage, reducing the quality of seed material, food grains and forage, showed that a high level of occurrence on the grain of Rostov winter wheat samples for the period 2014–2021 was manifested by mold fungi Mucor spp., Aspergillus niger, Aspergillus glaucus, Aspergillus flavus, species of the genus Penicillium. Relatively low occurrence was observed in Rhizopus nigricans and Cladosporium herbarum species. Mold pathogens are producers of the most dangerous mycotoxins: ochratoxin A (species of Penicillium, Aspergillus niger, A. glaucus), aflotoxin B1 (A. flavus), rhizonins (Rhizopus spp.), etc. In the regions of Southern Russia, with severe drought in the soil and on the lower parts of plants, the accumulation of the fungus Penicillium purpureogenum is often noted, for some time it could become dominant. When restoring the level of moisture supply, a decrease in the occurrence of P. purpureogenum was observed, often to zero, and an increase in the occurrence of mucor fungi (Fusarium solani, F. semitectum), non-circulating Mycelia sterilia fungi, etc., a noticeable increase in the total density of fungal colonies. The highest level of external infection of grain was due to colonization of grain by fungi from the Penicillium group, as well as A. glaucus and A. niger, the highest level of internal infection was caused by the Penicillium group, Rhizopus nigricans, A. niger. The dominance of external infection over internal infection was observed during colonization by penicilli and aspergillus, the dominance of internal over external infection by rhizopus and cladosporium.