Centre for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, QLD 4072, Australia.
Centre for Australian National Biodiversity Research, National Facilities and Collections, Commonwealth Scientific and Industrial Research Organisation, Canberra, ACT 2601, Australia.
Viruses. 2022 Feb 10;14(2):365. doi: 10.3390/v14020365.
The Australasian biogeographic realm is a major centre of diversity for orchids, with every subfamily of the Orchidaceae represented and high levels of endemism at the species rank. It is hypothesised that there is a commensurate diversity of viruses infecting this group of plants. In this study, we have utilised high-throughput sequencing to survey for viruses infecting greenhood orchids (Pterostylidinae) in New South Wales and the Australian Capital Territory. The main aim of this study was to characterise Pterostylis blotch virus (PtBV), a previously reported but uncharacterised virus that had been tentatively classified in the genus . This classification was confirmed by genome sequencing, and phylogenetic analyses suggested that PtBV is representative of a new species that is possibly indigenous to Australia as it does not belong to either the American or Eurasian clades of orthotospoviruses. Apart from PtBV, putative new viruses in the genera , , and were discovered, and complete genome sequences were obtained for each virus. It is concluded that the polerovirus is likely an example of an introduced virus infecting a native plant species in its natural habitat, as this virus is probably vectored by an aphid, and Australia has a depauperate native aphid fauna that does not include any species that are host-adapted to orchids.
澳大拉西亚生物地理区系是兰花多样性的主要中心，代表了兰科的每一个亚科，并且在物种等级上具有高水平的特有性。据推测，感染这些植物的病毒也具有相应的多样性。在这项研究中，我们利用高通量测序技术调查了新南威尔士州和澳大利亚首都领地的绿叶兜兰（Pterostylidinae）感染的病毒。本研究的主要目的是描述 Pterostylis blotch virus（PtBV），这是一种先前报道但未被描述的病毒，曾被暂时归类为 属。通过基因组测序证实了这一分类，系统发育分析表明 PtBV 代表了一种新的可能是澳大利亚本土的病毒，因为它既不属于美洲或欧亚大陆的正呼肠孤病毒群。除了 PtBV 之外，还发现了 属、属、属和 属中的推定新病毒，并获得了每种病毒的完整基因组序列。结论是，极细病毒很可能是一种感染本地植物物种的外来病毒的例子，因为这种病毒可能是由蚜虫传播的，而澳大利亚的本地蚜虫区系贫乏，不包括任何适应兰花的蚜虫物种。
