关中地区温室越冬茬番茄黄化曲叶病毒病分子鉴定及流行规律

为了明确关中地区越冬茬番茄黄化曲叶病毒病发生和流行规律,通过分析该病发生与番茄品种、定植期及传播介体烟粉虱之间的关系,并采用PCR技术对田间病原进行分子鉴定。结果表明,番茄黄化曲叶病毒病在8月中下旬至11月上中旬开始侵染,翌年3月中下旬发生再侵染,秋季病情减轻;烟粉虱种群数量与病害发生程度呈线性正相关;不同番茄品种对番茄黄化曲叶病毒(Tomato yellow leaf curl virus,TYLCV)的抗性差异显著,其中大番茄品种布鲁尼1288和DRW7728,小番茄品种千禧和美红对该病表现为免疫;分子检测结果表明,4个样品中均扩增出543 bp的特异片段,与NCBI数据库Gen Bank的TYLCV序列(登录号为GU084381、KC138544.1、KC138543.1和JX456642.1)的相似性达99%。研究表明,关中地区番茄病毒病为番茄黄化曲叶病毒病,番茄品种、定植期及烟粉虱发生动态是影响该病发生的主要因素。

Molecular identification and epidemic mechanism of Tomato yellow leaf curl virus (TYLCV) in overwintering tomato in greenhouse in Guanzhong region of Shaanxi Province

In order to investigate Tomato yellow leaf curl virus (TYLCV) occurrence and epidemic mechanism in overwintering tomato in greenhouse, the relationships among disease epidemic and tomato cultivars (cv.), seeding date, spreading vector Bemisia tabaci were analyzed, and the disease was identified with the PCR method. The results indicated that TYLCV initial infection in overwintering tomato in greenhouse in Guanzhong region of Shaanxi Province occurred on middle/late August to early/middle November, and the reinfection emerged on middle/late March of next year and decreased gradually in autumn. The population of B. tabaci on susceptible tomato cultivars had a positive linear correlation with the disease occurrence and epidemic. In addition, the resistance of various tomato cultivars to TYLCV showed significant difference. The resistance to TYLCV of different cultivars had significant differences. The Bruni 1288, DRW 7228, Qianxi and Meihong were immune to the disease. Molecular identification results suggested that a 543 bp specific fragment could be amplified from all the four TYLCV samples, which shared high identity of 99% with sequences of TYLCV submitted to GenBank at NCBI database (Accession Nos. GU084381, KC138544.1, KC138543.1 and JX456642.1). The disease on overwin-tering tomato in Guanzhong region was caused by TYLCV, and tomato cultivar, seeding date and the population dynamic of B. tabaci were the major factors influencing disease occurrence and epidemic.