Rhizoctonia potato disease is widespread in the world and causes substantial yield and quality losses in potato. This study aimed to evaluate the efficacy of entomopathogenic fungi Metarhizium robertsii and Beauveria bassiana in the inhibition of potato Rhizoctonia complex disease. The efficacy of the entomopathogenic fungi M. robertsii and B. bassiana in the defense of potato against Rhizoctonia disease (stem cancer, black scrulf and other forms of manifestation on tubers) was estimated under field conditions in Western Siberia. Preplanting treatment of the tubers with B. bassiana decreased Rhizoctonia disease in the stems and stolons. At the same time, treatment with M. robertsii did not cause a decrease in Rhizoctonia disease in these organs. However, both fungi decreased the sclerotium index on the tubers of new crops. We demonstrated two mechanisms of inhibition of Rhizoctonia solani by M. robertsii and B. bassiana, including (1) direct effect, expressed as inhibition of R. solani sclerotium formation in cocultivation assays, and (2) indirect effect, which is associated with increased peroxidase activity in potato roots under the influence of colonization by entomopathogenic fungi. We suggest that the treatment of seed tubers with B. basiana can effectively manage Rhizoctonia disease during the plant vegetative season and that both fungi significantly improve the quality of the new tuber crop.

中文翻译：

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昆虫病原真菌在田间条件下减少马铃薯丝核菌病

马铃薯丝核菌病在世界范围内普遍存在，并导致马铃薯产量和质量的重大损失。本研究旨在评价昆虫病原真菌罗伯氏绿僵菌和白僵菌对马铃薯丝核菌复合病害的抑制作用。在西西伯利亚的田间条件下，对昆虫病原真菌 M. robertsii 和 B. bassiana 在防御马铃薯丝核菌病（茎癌、黑头巾和其他形式的块茎表现）方面的功效进行了评估。用 B. bassiana 对块茎进行种植前处理减少了茎和匍匐茎中的丝核菌病。同时，用罗伯氏分枝杆菌治疗并没有导致这些器官中丝核菌病的减少。然而，这两种真菌都降低了新作物块茎上的菌核指数。我们证明了 M. robertsii 和 B. bassiana 抑制立枯丝核菌的两种机制，包括 (1) 直接作用，表示为在共培养试验中抑制 R. solani 菌核形成，和 (2) 间接作用，这与增加的在昆虫病原真菌定植影响下马铃薯根部过氧化物酶活性的研究。我们建议用 B. basiana 处理种子块茎可以在植物营养季节有效控制丝核菌病，并且两种真菌都显着提高了新块茎作物的质量。这与在昆虫病原真菌定植的影响下马铃薯根部过氧化物酶活性增加有关。我们建议用 B. basiana 处理种子块茎可以在植物营养季节有效控制丝核菌病，并且两种真菌都显着提高了新块茎作物的质量。这与在昆虫病原真菌定植的影响下马铃薯根部过氧化物酶活性增加有关。我们建议用 B. basiana 处理种子块茎可以在植物营养季节有效控制丝核菌病，并且两种真菌都显着提高了新块茎作物的质量。