Distribution of Fusarium dry rot of potato tubersin Russian Federation

Fusarium dry rot of tubers (FDR), caused by Fusarium fungi, is a widespread potato disease that reduces seed quality both during planting and storage. The aim of the study was to establish the distribution of FDR in Russia and to reveal the species diversity of fungi causing this disease. In 2018–2024, tuber analysis of 342 potato batches obtained from various regions of 5 Federal Districts of the Russia was carried out. The share of batches with FDR and the occurrence of the tubers with disease symptoms were assessed, and Fusarium fungi were isolated from these tubers, followed by identification of them based on the morphological and cultural characteristics. It was found that 82.7 % of the analyzed potato batches contained tubers infected with Fusarium fungi, the proportion of which varied from 5.7 to 13.5 %. Potato yield of 2020, 2021, 2023 and 2024 can be characterized as a relatively low-infected by FDR, the frequency occurrence of tubers with disease symptoms did not exceed 6.5 % on average, whereas in 2018 and 2019, high potato infestation was noted – 15.3–20.5 % of tubers. According to the results of the dispersion analysis, a reliable effect of the factors “origin”, “year”, “cultivar” and “reproduction” on the FSGC occurrence in potato batches was established. Fusarium fungi isolated from tubers were represented by members of seven species complexes: F. sambucinum (FSAMSC), F. oxysporum (FOSC), F. tricinctum, F. incarnatum-equiseti, F. redolens (FRSC), F. solani and F. nisikadoi. In the Siberian, Central and Northwestern Federal Districts, FSAMSC isolates were the most common in the tuber with FDR symptoms (34.2–66.7 % of all isolated Fusarium fungi), and F. sambucinum dominated among them. xIn the North Caucasian Federal District, FOSC isolates prevailed – 68.8 % of all isolated Fusarium fungi. In the Volga Federal District, the F. redolens from the FRSC was detected with a high frequency (33.3 %). Understanding the key factors facilitating on FDR and the species composition of pathogens will make it possible to justify the control of this potato disease.