河北省番茄黄化卷叶病毒的分子鉴定及序列分析

本研究旨在对河北省发生的番茄黄化卷叶病毒病的病原进行分子鉴定，并对其病原分子的变异和进化情况进行分析。根据已知的番茄黄化卷叶病毒（Tomato yellow leaf curl virus, TYLCV）基因组序列设计特异引物进行PCR扩增，对获得的特异片段进行回收、克隆和测序，而后根据测定序列重新设计引物扩增病毒样品DNA-A的近全长序列，并进行同源性比较及分子系统进化分析。结果显示利用PA1-F/R引物从采集的4个病毒样品中均扩增得到大小约为645bp的特异片段，DNA-A全长序列测定和分析发现4个病毒样品的全长为2781-2782个核苷酸，共编码6个ORFs。基因组比较发现，4个样品DNA-A与山东、上海、浙江、安徽以及日本、澳大利亚报道的TYLCV的同源性最高，均达99.0%以上，并与美洲、非洲及欧洲报道的TYLCV同属一个大的分支。研究结果表明在河北省采集的4个病株样本均为感染了番茄黄化卷叶病毒所致，而且极有可能同属于TYLCV-Israel株系的分离物。

Molecular Identification and Sequence Analysis of Tomato Yellow Leaf Curl Virus from Hebei Province

This study was designed to conduct molecular identification of tomato yellow leaf curl virus （TYLCV） in Hebei Province, and analyze their variation and phylogenetic relationships. In the study, a pair of specific primers PA1-F/R was designed according to known genome sequence of TYLCV to conduct PCR detection, and then the generated specific segments were collected, cloned and sequenced. Next, a new pair of primers PA2-F/R was redesigned according to the sequence to amplify the near whole sequence of virus sample, and conducting homology comparison and molecular evolution analyzing. The result indicated that all specific segments attained from the 4 virus samples by PA1-F/R primers were approximate 645 bp. Also, by sequencing and analyzing on DNA-A, it discovered that total length of the 4 virus samples were 2781-2782 nucleotides, coding 6 ORFs in all. Through comparison of genomes, it found that the 4 sample DNA-A had the highest probability in homology with TYLCV reported in Shandong, Shanghai, Zhejiang, Anhui, Japan and Australia at above 99.0%, and belonged to the same large branch with TYLCV reported in America, Africa and Europe. This study demonstrated that the 4 samples were infected with TYLCV, and highly probable that they were isolates of TYLCV-Israel strain.