重庆地区侵染抱子芥和茎瘤芥的病毒及其株系的分子鉴定

为了明确当前重庆地区抱子芥和茎瘤芥病毒病的病原种类和株系,在重庆13个区县的18个乡镇采集疑似病毒感染的样品进行病毒RT-PCR检测和株系分析。结果表明:在57份抱子芥样品中,黄瓜花叶病毒(Cucumber mosaic virus,CMV)、芜菁花叶病毒(Turnip mosaic virus,TuMV)、烟草花叶病毒(Tobacco mosaic virus,TMV)、马铃薯X病毒(Potato virus X,PVX)和芸薹黄化病毒(Brassica yellows virus,BrYV)的检出率分别为31.58%、85.86%、49.12%、59.65%和77.19%,其中87.72%的样品受两种及以上病毒的复合侵染,45.61%的样品受3种病毒的复合侵染;在41份茎瘤芥样品中,CMV、TuMV、PVX和BrYV的检出率分别为36.59%、73.17%、75.61%和70.73%,其中80.49%的样品受两种及以上病毒的复合侵染,51.22%的样品受3种病毒的复合侵染。对各检出病毒分离物CP基因进行扩增、序列测定和系统发育分析,明确抱子芥和茎瘤芥中TuMV分离物归属于TuMV的World-B组;CMV分离物归属于CMV亚组Ⅰ;PVX分离物归属于PVX的X3株系;BrYV和TMV与已报道的病毒株系CP基因核苷酸序列具有很高的相似性,存在一定的地域相关性,BrYV为重庆地区首次报道。

Molecular Identification of Pathogens of Brassica juncea var. gemmifera and Brassica juncea var. tumida Virus Disease in Chongqing

In order to determine the viral species and strains of the Brassica juncea var. gemmifera Lee et Lin（B. jg）and Brassica juncea var. tumida Tsen et Lee（B. jt）virus disease in Chongqing，RT-PCR and sequences analysis were used to detect and identify virus species and strains in the samples collected from 18 towns of 13 counties in Chongqing area. The results showed that in the 57 B. jg samples，31.58%，85.86%，49.12%，59.65% and 77.19% were infected by Cucumber mosaic virus（CMV），Turnip mosaic virus（TuMV），Tobacco mosaic virus（TMV），Potato virus X（PVX）and Brassica yellows virus（BrYV），respectively. Among the virus infected B. jg samples，87.72% were mix-infected by more than two viral species，and 45.61% samples were mix-infected by three viral species. While，in the 41 B. jt samples，36.59%，73.17%，75.61% and 70.73% were infected by CMV，TuMV，PVX and BrYV，respectively. Among the virus infected B.jt samples，80.49% were mix-infected by more than two viral species，and 51.22% were mix-infected by three viral species. Based on the amplification，sequencing，and phylogenetic analysis of the CP gene of each virus，TuMV in B. jg and B. jt was clustered into the World-B group，CMV was clustered into subgroup Ⅰ，and PVX was identified to be the X3 strain. Although BrYV and TMV had high sequence homology in CP gene with each of their previously reported strains，there was correlation between the isolates and geographic regions. Furthermore，this is the first report of the occurrence of BrYV in Chongqing.