Lactarius fungi belong to the Russulaceae family and have an important ecological role as ectomycorrhizal symbionts of coniferous and deciduous trees. Two Lactarius species, L. tabidus and L. rufus have been shown to harbor bisegmented dsRNA viruses belonging to an unclassified virus group including the mutualistic Curvularia thermal tolerance virus (CThTV). In this study, we characterized the first complete genome sequences of these viruses designated as Lactarius tabidus RNA virus 1 (LtRV1) and Lactarius rufus RNA virus 1 (LrRV1), both of which included two genome segments of 2241 and 2049 bp. We also analyzed spatial distribution and sequence diversity of the viruses in sixty host strains at two forest sites, and showed that the viruses are species-specific at sites where both host species co-occur. We also found that single virus isolates inhabited several different conspecific host strains, and were involved in persistent infections during up to eight years.

中文翻译：

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芬兰南部两个森​​林地点的外生菌根真菌 Lactarius rufus 和 L. tabidus 中的病毒种群结构。

Lactarius真菌属于红菇科，作为针叶树和落叶树的外生菌根共生体具有重要的生态作用。两种 Lactarius 物种，L. tabidus 和 L. rufus 已被证明含有属于未分类病毒组的双段 dsRNA 病毒，包括互惠弯曲菌热耐受病毒 (CThTV)。在这项研究中，我们表征了这些病毒的第一个完整基因组序列，称为 Lactarius tabidus RNA 病毒 1 (LtRV1) 和 Lactarius rufus RNA 病毒 1 (LrRV1)，它们都包括两个 2241 和 2049 bp 的基因组片段。我们还分析了两个森林地点 60 种宿主菌株中病毒的空间分布和序列多样性，并表明病毒在两种宿主物种共存的地点具有物种特异性。