Department of Plant Protection, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran.
Emeritus Faculty, Australian National University, Canberra, Australia.
Virol J. 2023 May 26;20(1):105. doi: 10.1186/s12985-023-02075-2.
Apple stem grooving virus (ASGV) has a wide host range, notably including apples, pears, prunes and citrus. It is found worldwide.
In this study, two near complete genomes, and seven coat protein (CP) sequences of Iranian isolates from apple were determined. Sequences added from GenBank provided alignments of 120 genomic sequences (54 of which were recombinant), and 276 coat protein genes (none of them recombinant).
The non-recombinant genomes gave a well supported phylogeny with isolates from diverse hosts in China forming the base of the phylogeny, and a monophyletic clade of at least seven clusters of isolates from around the world with no host or provenace groupings among them, and all but one including isolates from China. The six regions of the ASGV genome (five in one frame, one - 2 overlapping) gave significantly correlated phylogenies, but individually had less statistical support. The largest cluster of isolates contained those from Iran and had isolates with worldwide provenances, and came from a wide range of mono- and dicotyledonous hosts. Population genetic comparisons of the six regions of the ASGV genome showed that four were under strong negative selection, but two of unknown function were under positive selection.
ASGV most likely originated and spread in East Asia in one or more of various plant species, but not in Eurasia; the ASGV population of China had the greatest overall nucleotide diversity and largest number of segregating sites.
苹果茎沟病毒（ASGV）宿主范围广泛，包括苹果、梨、李和柑橘等多种植物。该病毒在全球范围内均有分布。
本研究共测定了来自伊朗的两个近全长基因组序列和 7 个苹果分离物的外壳蛋白（CP）序列。从 GenBank 添加的序列提供了 120 个基因组序列（其中 54 个为重组序列）和 276 个外壳蛋白基因（均无重组序列）的比对。
非重组基因组的系统发育树得到了很好的支持，中国不同宿主来源的分离物构成了系统发育树的基础，来自世界各地的至少 7 个分离物聚类形成单系分支，其中没有按宿主或起源地进行分组，除一个外，其余均包含来自中国的分离物。ASGV 基因组的六个区域（一个在一个框架内，一个 -2 重叠）的系统发育相关性显著，但各自的统计支持度较低。最大的分离物聚类包含来自伊朗的分离物，以及来自世界各地的分离物，且这些分离物来自广泛的单子叶和双子叶宿主。ASGV 基因组六个区域的种群遗传比较表明，四个区域受到强烈的负选择，但两个未知功能的区域受到正选择。
ASGV 很可能起源于东亚的一种或多种植物，并在东亚传播，而不是在欧亚大陆；中国的 ASGV 种群具有最大的核苷酸多样性和最大数量的分离位点。
