水稻条叶枯病毒NS2基因遗传多样性分析

应用单链构象多态性 (SSCP)和序列分析方法研究了来自我国 9个省份的水稻条叶枯病毒(RSV) 80个田间分离物的NS2基因遗传结构特征 .SSCP分析结果表明 ,我国RSVNS2基因遗传结构符合准种 (quasispecies)结构特征 .部分分离物的序列分析结果表明 ,RSV上述分离物和已报道的日本 2个分离物可以归入 2个组 :云南的部分分离物划分为 1个组 ;其它分离物及日本T、O的 2个分离物为另 1组 .组与组之间 ,NS2蛋白基因核苷酸同源性为 94 %～ 95 % ,氨基酸同源性为 95 %～ 97% .遗传多样性分析结果表明 ,RSV种群存在地理隔离但在种群间可能发生了基因漂移 (geneflow) .NS2蛋白可能的运动蛋白功能所造成的负选择压力和介体传播引起的奠基者效应可能是RSV种群内和种群间遗传多样性差别的主要因素

Analysis of Genetic Diversity of Rice Stripe Virus in the NS2 Gene

The population structure and genetic variation of rice stripe virus (RSV) isolates were estimated by single strand conformation polymorphism (SSCP) and sequence analysis of the RSV NS2 gene. SSCP analysis of 80 isolates collected from 9 provinces in China showed that these isolates had a quasi species structure. Sequence analysis showed that these isolates and two Japan isolates could be divided into two diverged groups. A part of Yunnan isolates formed one group and the other group contained the rest of the RSV isolates. The two groups shared 94%—95% and 95%—97% sequence identities at the nucleotide and amino acid levels, respectively. Phylogenetic studies based on the sequences confirmed the geographical isolation of RSV virus population, but showed that gene flow may occur between populations. Negative selection caused by NS2 protein possible movement protein function and founder effect due to vector transmission were proposed to explain the intra and inter population diversity observed.