灰飞虱来源的水稻条纹病毒外壳蛋白基因遗传多样性

 采用单雌产卵法获得来自江苏、云南、山东、河北等地灰飞虱（Laodelphax striatellus Fallén，SBPH）来源的21个水稻条纹病毒（Rice stripe virus，RSV）分离物，提取灰飞虱总RNA，经RT-PCR扩增，获得21个RSV分离物的包含外壳蛋白（cp）基因在内的约1 000 bp左右的DNA片段。测序结果显示，参试分离物的cp由969个核苷酸组成，编码322个氨基酸。采用DNASTAR软件进行分析，21个灰飞虱来源的RSV-cp核苷酸序列和推导出的编码蛋白的氨基酸序列同源性分别为95.7%~100%和96.0%~100%。与已报道水稻来源的32个RSV分离物一起进行序列同源性比较和系统进化树分析结果表明，总体而言RSV-cp较为保守，其遗传多样性首先与地缘相关，从地理位置上可以分成中国云南、中国沿海和日本3个地理种群；其次与寄主相关，在同一地理种群中可以划分为灰飞虱和水稻2个寄主种群。

Genetic diversity of coat protein gene in Rice stripe virus isolated from Laodelphax striatellus

Twenty-one Laodelphax striatellus Fallén isofemale lines infected with Rice stripe virus（RSV） were collected from Jiangsu, Yunnan, Shandong and Hebei Province, China. The RSV coat protein(cp) gene was amplified using RT-PCR, generating a fragment with the size of 1 000 bp. Sequence analysis revealed that the RSV-cp contained 969 bp which encoded 322 amino acids. Further analysis with DNAstar software showed that the identities of cp nucleotide and amino acid sequences among the isolates ranged from 95.7% to 100% and 96.0% to 100%, respectively. The results together with the 32 sequence data published previously suggested that RSV-cp was conserved and had little molecular variation. The results also suggested that the genetic diversity of RSV was strongly associated with its geographical origin and the virus could be grouped into three geographical populations, i.e.Yunnan, China and Coastal areas of China and Japan. The genetic diversity of RSV was also associated with its host origin. Within a geographical location, RSV could be grouped into Laodelphax striatellus Fallén and rice populations.