A novel virus infecting yams (Dioscorea spp.), tentatively named "yam asymptomatic virus 1" (YaV1), was characterized and sequenced from an asymptomatic D. alata plant from Vanuatu. Sequence comparisons and phylogenetic analysis showed that YaV1 is a novel ampelovirus and has the smallest genome among "subgroup 1" members. RT-PCR-based screening of a yam germplasm collection conserved in Guadeloupe showed that YaV1 is prevalent in D. alata, D. bulbifera, D. cayennensis subsp. rotundata, D. esculenta and D. trifida accessions but causes no apparent symptoms. Additional phylogenetic analysis revealed a low variability of YaV1 in Guadeloupe in a limited part of the genome, and suggested the occurrence of plant-to-plant transmission.

中文翻译：

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山药无症状病毒1，一种新型病毒，感染山药（Dioscorea spp。）的种质收集率很高。

从瓦努阿图的无症状D. alata植物中定性并测序了一种新型感染山药的病毒（Dioscorea spp。），暂定名为“山药无症状病毒1”（YaV1）。序列比较和系统发育分析表明，YaV1是一种新型的两栖病毒，在“亚组1”成员中具有最小的基因组。基于RT-PCR的瓜德罗普岛保存的山药种质资源收集筛选显示YaV1在D. alata，D。bulbifera，D.cayennensis亚种中普遍存在。rotundata，D。esculenta和D. trifida加入，但没有引起明显的症状。进一步的系统发育分析表明，瓜德罗普岛Yav1在基因组有限部分的变异性较低，并暗示了植物之间的传播。