侵染北京、宁夏和内蒙古番茄的番茄黄曲叶病毒的鉴定和全基因组分析

Identification and complete genome sequence analysis of tomato yellow leaf curl virus infecting tomato in Beijing,Ningxia,and Inner Mongolia

为明确从北京、宁夏和内蒙古采集的15份疑似病毒感染的番茄样本是否感染番茄黄曲叶病毒(tomato yellow leaf curl virus,TYLCV),利用TYLCV的特异性引物对采集的样本进行检测,结果从8个样本中扩增到TYLCV片段,并获得了8个样本TYLCV的全长序列。序列分析发现,样本NS-1、NS-5、NS-8、NS-9、NS-13和NS-14的全长核苷酸序列与北京分离物TYLCV-BJTZ的相似性最高,达99.03%~99.42%;NS-2与陕西分离物TYLCV-JY-2的相似性最高,为99.60%;NS-7与江苏分离物TYLCV-YZ02的相似性最高,为99.35%。表明这8个TYLCV全基因组均为TYLCV的不同分离物。系统进化树分析发现,这8个TYLCV分离物与2017年鉴定的北京分离物聚成一个单独的分支,说明与北京分离物的亲缘关系最近。研究结果显示,TYLCV已经扩散到宁夏和内蒙古,在我国分布范围不断扩大。

To determine whether 15 tomato samples collected from Beijing,Ningxia,and Inner Mongolia,exhibiting symptoms of viral infection have been infected by tomato yellow leaf curl virus(TYLCV),specific primers were used for TYLCV detection,and fragments of the expected size were amplified from eight samples.The complete genome sequences of TYLCV were further obtained from these eight samples.Sequence analysis revealed that the full-length sequences cloned from NS-1,NS-5,NS-8,NS-9,NS-13,and NS-14 showed the highest identity with the Beijing isolate TYLCV-BJTZ,ranging from 99.03%to 99.42%.NS-2 shared the highest similarity(99.60%)with the Shaanxi isolate TYLCV-JY-2,while NS-7 showed the highest similarity(99.35%)with the Jiangsu isolate TYLCV-YZ02,suggesting that the virus isolated from the eight tomato samples belongs to different isolates of TYLCV.Phylogenetic analysis indicated that the TYLCV sequences were most closely related to the Beijing isolate identified in 2017.This study demonstrates the occurrence of TYLCV in Ningxia and Inner Mongolia,expanding our understanding of the geographic distribution of TYLCV in China.