A double-stranded RNA (dsRNA) segment was identified in Rhizoctonia solani anastomosis group (AG)-2-2IIIB, the primary causal agent of Rhizoctonia crown and root rot of sugar beet. The dsRNA segment represented the genome replication intermediate of a new mitovirus that was tentatively designated as "Rhizoctonia solani mitovirus 39" (RsMV-39). The complete sequence of the dsRNA was 2805 bp in length with 61.9% A+U content. Using either the fungal mitochondrial or universal genetic code, a protein of 840 amino acids containing an RNA-dependent RNA polymerase (RdRp) domain was predicted with a molecular mass of 94.46 kDa. BLASTp analysis revealed that the RdRp domain of RsMV-39 had 43.55% to 72.96% sequence identity to viruses in the genus Mitovirus, and was the most similar (72.96% identical) to that of Ceratobasidium mitovirus A (CbMV-A). Phylogenetic analysis based on RdRp domains clearly showed that RsMV-39 is a member of a distinct species in the genus Mitovirus of the family Mitoviridae. This is the first full genome sequence of a mycovirus associated with R. solani AG-2-2IIIB.

在立枯丝核菌吻合群 (AG)-2-2IIIB中鉴定出双链 RNA (dsRNA) 片段，该群是甜菜丝核菌冠腐病和根腐病的主要致病因子。dsRNA片段代表了一种新的线粒体病毒的基因组复制中间体，该病毒暂时被命名为“立枯丝核菌线粒体病毒39”(RsMV-39)。dsRNA完整序列长度为2805 bp，A+U含量为61.9%。使用真菌线粒体或通用遗传密码，预测含有 RNA 依赖性 RNA 聚合酶 (RdRp) 结构域的 840 个氨基酸的蛋白质，其分子量为 94.46 kDa。BLASTp分析显示，RsMV-39的RdRp结构域与线粒体病毒属病毒具有43.55%至72.96%的序列同一性，并且与Ceratobasidium线粒体病毒A（CbMV-A）的RdRp结构域最为相似（72.96%同一性）。基于 RdRp 结构域的系统发育分析清楚地表明，RsMV-39 是线粒体病毒科线粒体病毒属的一个独特物种的成员。这是与立枯丝核菌AG-2-2IIIB相关的真菌病毒的第一个完整基因组序列。