陕西杨凌番茄褪绿病毒的分子检测

Molecular detection of Tomato chlorosis virus in Yangling,Shaanxi

近年来在陕西番茄生产区出现了一种新病害,病株表现为叶片褪绿,叶脉颜色变深及叶片增厚,果实变小发白,严重影响番茄产量及经济效益,2016年发病极为严重,部分产区甚至绝收。该病疑似由番茄褪绿病毒Tomato chlorosis virus(ToCV)引起。利用ToCV特异引物对感病番茄样品进行RT-PCR检测,结果从所采集的4份病样中均检测到ToCV预期大小的特异片段。对ToCV外壳蛋白CP基因和类热激蛋白HSP70h基因进行克隆与序列分析,ToCV-YL1 CP基因774个核苷酸序列与已报道的ToCVCP基因有较高的一致性,与山东青岛和山西晋中分离物同源性为100%。ToCV-YL1 HSP70h基因1 665个核苷酸序列与已报道的ToCV HSP70h基因有较高的同源性,与中国、韩国、日本、美国、希腊分离物同源性达到99%以上。研究表明ToCV已传播至陕西地区。

In recent years,a new disease on tomato has occurred in tomato production area of Shaanxi Province.The diseased tomato plants showed chlorotic leaves,dark greening veins and leaf thickening occurred in the diseased tomato plants,and the fruits became partial white and small,which seriously affected the yield and economic benefits.The disease is extremely serious,leading to total yield loss in part of the producing areas in 2016.The symptom of infected tomatoes is similar to Tomato chlorosis virus(ToCV).The expected DNA fragments were amplified from all 4 infected samples with specific markers of ToCV by RT-PCR.The coat protein gene(CP)and heat shock protein 70(HSP70h)gene of ToCV were cloned and analyzed,respectively.The nucleotide sequence of the CP gene of ToCV-YL1 was the same as those of the previously reported ToCV isolates in Qingdao and Jinzhong.The nucleotide sequence of the HSP70h gene of ToCV-YL1 shared the highest identity(up to 99%)with those of the ToCV isolates from China,South Korea,Japan,USA and Greece.These results confirmed that ToCV had spread to Shaanxi.