Diverse, novel mycoviruses co-infecting the phytopathogenic fungus Corynespora cassiicola from Sesamum indicum

Mingming Liu¹Yunxia Ni^1*Jing Wang¹Xintao Liu¹Hui Zhao¹Xinbei Zhao¹Wenqing Yan¹Hongyan Liu¹Baoming Tian^2*Hongmei Miao^3*

• ¹Key Laboratory of Integrated Pest Management on Crops in Southern Region of North China, Henan Key Laboratory of Agricultural Pest Monitoring and Control, China, Postgraduate T&R Base of Zhengzhou University, Henan Academy of Agricultural Sciences Institute of Plant Protection, Zhengzhou, China
• ²School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
• ³Henan Sesame Research Center, Henan Academy of Agricultural Sciences, Zhengzhou, China

Corynespora leaf spot caused by Corynespora cassiicola is one of the most serious foliar diseases of sesame. Mycoviruses can infect various groups of fungi, and have certain potential biocontrol value. However, the number of mycovirus reported in C. cassiicola is relatively scarce. In this study, a metatranscriptomic analysis was performed on 7 strains of C. cassiicola isolated from Sesamum indicum, and the diversity of virus species was analyzed combined with detection and verification by RT-qPCR. Based on sequence alignment and phylogenetic analysis, 7 strains contain 19 viruses belonging to 12 families. +ssRNA viruses were identified, belonging to Botourmiaviridae (4 viruses), Deltaflexiviridae (1 virus), Fusariviridae (2 viruses), Narnaviridae (2 viruses), Ambiguiviridae (2 viruses) and Potyviridae (1 virus). -ssRNA viruses were assigned to Mymonaviridae (2 viruses), and Mycophioviridae (1 virus). dsRNA viruses were found, including Chrysoviridae (1 virus), Partitiviridae (1 virus), Totiviridae (1 virus) and Polymycoviridae (1 virus). This study uses metatranscriptome technology to expand our understanding of the diversity of mycoviruses in C. cassiicola and provides a rich resource for future studies on mycovirus diversity and taxonomy.