基于外壳蛋白基因的湖南烟草黄瓜花叶病毒遗传多样性分析

Genetic diversity of CP gene of Cucumber mosaic virus isolates from tobacco plants in Hunan province

为探明湖南烟草上发生的黄瓜花叶病毒Cucumber mosaic virus(CMV)的遗传多样性及分子进化特征,对来自湖南烟区的303份疑似感染病毒的烟草样品进行检测,分析CMV系统发育、遗传变异和群体结构等特征。结果表明:部分分离物的外壳蛋白(coat protein,CP)基因与NCBI上登录的CMV分离物的一致性为86.34%~98.42%;系统发育分析发现湖南烟草CMV分离物属ⅠB组,不同组间的分离物地理特征不明显,无重组现象,进化的主要驱动力是负选择;组间遗传变异比较明显,基因交流频率较低,受到遗传漂变影响,遗传多样性高,群体趋于扩张。研究结果为烟草抗CMV育种提供了理论依据,对病害防治具有重要意义。

In order to investigate the genetic diversity and molecular evolution of Cucumber mosaic virus(CMV)on tobacco in Hunan province,303 suspected diseased samples from tobacco-growing areas in Hunan were detected,and the phylogeny,genetic variation and population structure of CMV were analyzed.The coat protein(CP)genes of some samples were cloned and compared with CMV isolates registered on NCBI.The results showed that the sequence of CP from Hunan isolates shared identity of 86.34%-98.42%with isolate from NCBI.Phylogenetic analysis showed that CMV isolates from Hunan tobacco plants belonged toⅠB group.The geographical characteristics of these isolates were not distinct among different populations,and there was no recombination phenomenon.The main driving force for evolution was negative selection.The genetic variation among groups was obvious;the frequency of gene flow was low;the genetic diversity was high,and the population tended to expand.These results provide a theoretical basis for breeding tobacco for disease resistance to CMV and are of great significance for disease control.