山西苹果茎痘病毒遗传多样性分析

Genetic diversity analysis of apple stem pitting virus isolated in Shanxi based on coat protein

苹果茎痘病毒是苹果安全生产的巨大威胁,严重影响苹果产量和质量。探讨苹果茎痘病毒(Apple stem pitting virus, ASPV)在山西省的分布、变异和多样性,可为制定可持续的病毒管理策略提供理论依据。从山西省11个地区采集苹果叶片样品进行RT-PCR检测。结合在线数据库,利用相关软件对文中研究获得的序列进行系统发育、遗传多样性、重组以及种群遗传分化等分析。RT-PCR检测结果显示从山西省11个地区采集的409份苹果叶片样品中,ASPV的检出率为36.33%(临漪)至55.37%(平遥)。选择15个ASPV检测为阳性的样品,分别克隆其CP基因并与22个不同的ASPV分离物进行核苷酸和氨基酸一致性分析,发现37个ASPV分离物的核酸一致率为70.27~96.31%,氨基酸一致率为37.04~96.64%,其中,Shanxi-2与JX673826.1的核酸一致率最高,为90.86%, Shanxi-2与MN617853.1的核酸一致率最低,为70.40%。基于CP的进化树分析结果显示37个ASPV分离物被划分为2个进化群体。遗传多样性分析结果表明ASPV种群发生了收缩,且在两个群体之间呈现较大的遗传差异。ASPV-CP基因受负选择压力影响。该研究结果将为评估山西省ASPV的流行病学特征提供重要线索。

apple stem pitting virus is a great threat to apple production, which seriously affects apple yield and quality. To explore the distribution, variation and diversity of apple stem pitting virus(ASPV) in Shanxi province can provide a theoretical basis for formulating sustainable virus management strategies. Apple leaf samples were collected from 11 areas of Shanxi province for RT-PCR detection. Combined with the online database, the phylogeny, genetic diversity, recombination and population genetic differentiation of the sequences obtained in this study were analyzed by using relevant software. RT-PCR results showed that among 409 apple leaf samples, the detection rate of ASPV was 36.33%(Linyi) to 55.37%(Pingyao). Fifteen ASPV positive samples were selected, their CP genes were cloned and analyzed for nucleotide and amino acid consistency with 22 different ASPV isolates. It was found that the nucleic acid consistency rate of 37 ASPV isolates was 70.27%-96.31%, and the amino acid consistency rate was 37.04%-96.64%. Among them, Shanxi-2 and JX673826.1 had the highest nucleic acid consistency rate of 90.86%, the nucleic acid consistency rate of Shanxi-2 and MN617853.1 was the lowest, 70.40%. The results of evolutionary tree analysis based on CP showed that 37 ASPV isolates were divided into 2 evolutionary groups. The results of genetic diversity analysis showed that the ASPV population contracted, and there were large genetic differences between the two populations. ASPV-CP gene is affected by negative selection pressure. The results of this study will provide important clues for evaluating the epidemiological characteristics of ASPV in Shanxi province.