山西草莓斑驳病毒cp基因克隆及遗传多样性分析

旨在研究草莓斑驳病毒（SMoV）在山西省的分布、结构变异及遗传多样性。从山西省7个主要草莓种植区随机采取159份草莓叶片进行RT-PCR病毒检测，结合在线数据库，使用MEGA5构建系统发育树，采用SDTv 1.2软件进行序列相似性分析，运用DnaSP v5.10软件分析cp基因的遗传多样性，采用RDP v.4.31 软件检测SMoV中的重组事件。RT-PCR检测后发现，从山西省各地区收集的159份草莓叶片中有65份样品呈阳性，检出率为38.46%。这些阳性样品经过分离、测序、克隆，获得16个SMoV分离物。结合在线的19个SMoV分离物系统进化树分析显示，35个SMoV分离物被分成两组，组1包含28个分离物，均来自中国；组2包含7个分离物，分别来自加拿大、日本和美国。经选择压分析和中性检验，组1和组2 SMoV分离物之间存在显著的遗传差异，且中性检验均为负值，SMoV种群呈扩张状态。序列相似性分析表明，35株分离物的核苷酸同一性为81.34%~100%，氨基酸的一致性为94.77%~100%，呈现出较高的相似性。可见：SMoV存在较高的遗传变异，负选择压力可能是导致SMoV遗传多样性的原因。

Genetic Diversity of Strawberry Mottle Virus Based On cp Gene

A systematic study of the distribution,structural variation and genetic diversity of SMoV in Shanxi will lay a theoretical foundation for the prevention and control of strawberry virus diseases.In this study,159 strawberry leaves were randomly collected from 7 major strawberry cultivation areas in Shanxi and constructed RT-PCR detection.The cp genes of positive samples were sequenced and analyzed through MEGA5,SDTv 1.2,DnaSP v5.10 and RDP v.4.31,RT-PCR detection showed that 65 samples of the 159 strawberry leaves were positive with a detection rate of 38.46%.The 65 positive samples were isolated,sequenced,and cloned to obtain 16 SMoV isolates.The phylogenetic tree analysis,using a dataset that included 19 online SMoV isolates,showed two distinct groups:Group 1,consisting of 28 isolates from China,and Group 2,comprising 7 isolates from Canada,Japan,and the United States.Selective pressure analysis and neutrality testing indicated significant genetic differences between these groups,with negative neutrality test results suggesting SMoV population expansion.Sequence similarity analysis displayed that the nucleotide identity range and the consistency range of amino acids was 81.34%-100% and 94.77%-100% respectively,which showed high similarity.This study demonstrated that SMoV has high genetic variation,and the negative selection pressure may be the cause of SMoV genetic diversity,which provides a theoretical guidance for SMoV in Shanxi.