甜菜坏死黄脉病毒不同分离物三联基因区及RNA3的序列分析

以来自于我国内蒙古、黑龙江和宁夏的3个甜菜坏死黄脉病毒（BNYVV）分离物为材料,采用反转录－PCR方法扩增不同RNA组分的基因片段,经cDNA克隆和序列测定后,与国外报道的BNYVV不同株系和来自于我国不同地区的BNYVV分离物之间进行比较分析。结果表明,BNYVV内蒙呼和浩特分离物（HU）RNA2中的42kD至3'端蛋白编码区长度为2435个核苷酸（nt),与法国F2分离物、德国G1分离物、日本S分离物的一致性分别为97．7％,94．9％;而黑龙江（HEI）、宁夏（NIN）和内蒙古包头分离物（BAO）RNA3的25kD蛋白编码区则与以往报道的内蒙呼和浩特分离物（HU）相应片段分别具有95．4％,93．4％和94．0％4的一致性,这些差异进一步证明了在BNYVV分离物之间广泛存在的分子变异,并可能与它们的致病能力相关。

Sequence Analysis of BNYVV RNA2 "Triple Block" and RNA3 Sequence Variation of Different Isolates

The RNA was extracted from purified beet necrotic yellow vein virus (BNYVV) isolated from Inner Mongolia. Heilongjiang and Ningxia. cDNA fragments corresponding to different RNA genome were cloned and sequenced with RT-PCR, Then compared the sequences between the different strain of overseas and the isolates of different region in China. The results showed that the "the triple block" of RNA2 between HU and F2, G1, S shares 97. 7%, 94. 9%, 96. 2%; and the 25 kD code region of RNA3 between HEI, NIN, BAO and HU shares 95. 4%, 93. 4%, 94. 0%. These sequence data demonstrated that RNA3 variants were widely existed (distributed) in the isolates of BNYVV which may be related with their pathogenicity.