Virus communities of uncultivated fungi stay largely unknown. In the current study, we characterized a new partitivirus species detected in the basidiomycetous, saprobic mushroom Leucocybe candicans, named “Leucocybe candicans partitivirus 1” (LcPV1). The full-length genome of LcPV1, determined using deep sequencing and RLM-RACE approaches, consists of two dsRNA segments with each having the same size of 1984 bp. Both dsRNA genome segments comprise a single open reading frame (ORF), encoding an RNA-dependent RNA polymerase (RdRp), and a capsid protein (CP), respectively. Based on BLASTp search, the sequences of the RdRp and CP show the highest identity (50.09% and 35.71% similarity, respectively) to those of partitiviruses reported from an oomycetous, plant pathogenic, stramenopile algae Plasmopara viticola and basidiomycetous, plant pathogenic fungus Ceratobasidium sp., respectively. Phylogenetic analyses performed based on the RdRp and CP sequences revealed that LcPV1 falls within a cluster that includes different alphapartitivirus species from the family Partitiviridae. In this study, we propose that LcPV1 is a new member of a species belonging to the genus Alphapartitivirus. To our knowledge, this is the first study reporting on a new fungal virus (mycovirus) identified in the basidiomycetous, saprobic mushroom Leucocybe candicans.

未培养真菌的病毒群落在很大程度上仍然未知。在当前的研究中，我们鉴定了一种在担子菌、腐生蘑菇Leucocybe candicans中检测到的新的 partitivirus 物种，命名为“Leucocybe candicans partitivirus 1” (LcPV1)。使用深度测序和 RLM-RACE 方法确定的 LcPV1 的全长基因组由两个 dsRNA 片段组成，每个片段具有相同的 1984 bp 大小。两个 dsRNA 基因组片段均包含单个开放阅读框 (ORF)，分别编码 RNA 依赖性 RNA 聚合酶 (RdRp) 和衣壳蛋白 (CP)。基于 BLASTp 搜索，RdRp 和 CP 的序列与从卵菌、植物致病性原生藻菌中报道的部分病毒的序列显示出最高的同一性（分别为 50.09% 和 35.71% 的相似性）分别为Plasmopara viticola和担子菌属植物病原真菌Ceratobasidium sp.。基于 RdRp 和 CP 序列进行的系统发育分析表明，LcPV1 属于一个簇，该簇包括来自Partitiviridae科的不同 alphapartitivirus 物种。在这项研究中，我们提出 LcPV1 是属于Alphapartitivirus属的一个物种的新成员。据我们所知，这是第一项关于在担子菌、腐生蘑菇Leucocybe candicans中发现的新型真菌病毒（真菌病毒）的研究报告。