3个黑龙江烟区烟草花叶病毒分离物的全基因组序列测定与分析

为明确黑龙江烟区烟草花叶病毒（Tobacco mosaic virus，TMV）分子株系和进化特征，从哈尔滨和牡丹江感病烟草采集到HEB1、HEB2和MDJ三个样品，通过RT-PCR扩增了其全基因组序列，并进行了一致率、重组、系统发育和选择压力等分析。结果表明，3个分离物全长均为6395核苷酸（GenBank登录号分别为MH595919、MH595920和MH595921）。HEB1和MDJ与辽宁分离物Beipiao（HE818412）一致率最高，分别为98.9%和99.6%；HEB2与云南分离物Chuxiong1（HE818417）一致率最高，为97.1%。HEB1是MDJ和HEB2的重组体。在根据全基因组序列构建的系统进化树中，TMV分为3个组，其中HEB1和MDJ均属I（U1）组，HEB2属Ⅱ（Rakkyo）组。TMV的4个基因均处于负选择，其中衣壳蛋白基因的选择压力最大。 

Determination and analysis of complete genomic sequence of three TMV isolates from tobacco producing areas in Heilongjiang

To elucidate the molecular strains and evolution characteristics of Tobacco mosaic virus (TMV) from tobacco plants in Heilongjiang producing area, three samples from Harbin and Mudanjiang tobacco fields were collected and designated as HEB1, HEB2 and MDJ. Their complete genomic fragments were amplified via RT-PCR.Sequence identities, recombination, phylogenetic relationship and selection pressure were analyzed. Results showed that the full-length genome of isolates HEB1, HEB2 and MDJ were 6395 nucleotides(nt) (GenBank accession numbers MH595919, MH595920 and MH595921). HEB1 and MDJ had the highest identities of 98.9% and 99.6%, respectively, with isolate Beipiao (HE818412) from Liaoning province, while MDJ had the highest identity of 97.1% with isolate Chuxiong1 (HE818417) from Chuxiong of Yunnan province. HEB1 was a recombinant of isoaltes MDJ and HEB2.In the phylogenetic tree constructed with the complete genomic sequence, TMV was divided into three groups, among which HEB1 and MDJ belong to group I (U1)while HEB2 belong to group II (Rakkyo). All four proteins of TMV were under negative selection, with CP gene under the highest selection pressure.