我国水稻条纹病毒RNA3片段序列分析—纤细病毒属重配的又一证据

测定了来源于我国水稻条纹叶枯病常年流行区的辽宁盘锦 (PJ)、云南昆明 (KM)、云南宜良 (YL)及病害暴发区的江苏洪泽 (HZ)的水稻条纹病毒 (RSV) 4个分离物RNA3全长序列 ,其长度分别为 2 480bp、2 5 0 9bp、2 489bp和 2 497bp。与已报道的RSV云南Y、日本T和M分离物RNA3序列进行比较的结果表明 ,这 7个分离物可分为两组 ,其中 ,KM、YL分离物为一组 ,PJ、HZ、Y、T和M分离物为另一组。组与组之间 ,RNA3的毒义链 (vRNA3)及RNA3的毒义互补链 (vcRNA3)上的ORF的核苷酸同源性分别为 97%～ 98%和 93%～ 94% ,但在氨基酸水平上则没有明显差异。结合上述RSV分离物RNA4的核苷酸全序列比较结果 ,推测认为RSV自然种群中存在两个与地理因素相关的不同类型的亚群 ,Y分离物不同片段具有不同来源可能是由重配引起的。

Sequence Analysis of RNA3 of Rice Stripe Virus Isolates Found in China: Evidence for Reassortment in Tenuivirus

The RNA3 segments of four isolates of Rice stripe virus (RSV), isolated from endemic sites at Panjin (PJ), Liaoning Province, Kunming (KM) and Yiliang (YL), Yunnan Province, as well as from outbreak sites at Hongze (HZ), Jiangsu Province, were determined. RNA3 of these four isolates were 2480 bp, 2509 bp, 2489 bp and 2497 bp in length, respectively. Compared with RNA3 of T and M isolates from Japan and Y isolate from Yunnan Province of China, that had been previously reported, these seven isolates could be divided into two groups. KM and YL isolates formed group one, and PJ, HZ, Y, T and M isolates belonged to another group. The two groups shared 97%-98% and 93%-94% sequence homology in viral RNA3 (vRNA3) and viral complementary RNA3 (vcRNA3) at the nucleotide levels, respectively, and there was no significant difference between the two groups at the amino acid levels. In the first group, Y isolate was significantly different from HZ,PJ and two Japan isolates in their RNA4 segment. These results show that there were two subgroups in RSV natural population related with geographical location, and reassorment may be the main factor leading to different segments of Y isolate belonging to different subgroups. The results may provide another evidence for reassortment variation in Tenuivirus.