我国北方稻区水稻条纹病毒分子变异和水稻品种抗病性分析

Molecular variation of the population of Rice stripe virus and the resistance of rice varieties in northern China

为了明确我国北方稻区水稻条纹病毒（Rice stripe virus，RSV）群体的分子变异和水稻品种的抗性情况，测定了2004年和2005年从我国6省9个地区采集的34个RSV分离物的外壳蛋白（coat protein，CP）基因的序列，并对其进行了分析，同时用强致病性江苏分离物（RSV-JS）对河南、安徽、山东、河北等省的25个推广品种进行了抗性研究。结果表明，供试RSV分离物间的核苷酸序列一致性和氨基酸序列的一致性分别在93．9％～100％和96．3％～100．0％之间。根据CP基因核苷酸序列一致性，所有分离物可以分为2组。云南4个分离物为一组，其余为一组。在第2组中各分离物CP基因的核苷酸序列和氨基酸序列的一致性与地域无必然联系。且在2年之内，RSV CP基因变异不大。抗病性鉴定表明同一分离物在不同水稻品种上表现不同症状。表现高抗（HR）的品种占供试品种的24％；60％以上的品种表现为感病，且不同水稻品种上表现不同症状。因此，我国北方稻区RSV的CP基因非常保守，但同一分离物在不同水稻品种上可能表现不同症状，不同水稻品种对RSV抗性有显著差异。这些结果为我国北方稻区水稻条纹叶枯病防治和抗病毒基因工程提供了理论依据。

Rice stripe disease, caused by Rice stripe virus （RSV）, is one of the most serious rice diseases in temperate and subtropical regions of the world. In recent years, this disease has become increasingly severe and brought great yield losses in northern China due to climatic changes, adjustment of cultivation structure and loss of varieties resistance. The molecular variability of CP gene of RSV isolates collected from northern China, as well as the resistance of twenty five local japonica varieties to RSV was studied. The result indicated that the CP genes of thirty-four isolates were composed of 969 nts and 322 deduced amino acids. The similarity of nucleotides and deduced amino acides sequences of CP gene in these isolates and 4 isolates from Yunnan Province and T isolate from Japan reached 93. 9%-100% and 96.8%-100%, respectively. All RSV isolates could be divided into two groups., isolates from Yunnan Province constituted one group and others shared the second group. The results of the resistant identification for twenty-five rice varieties indicated that the varieties ‘ Yangj ing9538 ’ , ‘ Shuijing3 ’ , ‘ Kendao95-4 ’ , ‘ Nuhe0218 ’ , ‘ 04G886’ and ‘ 04G1020’ are highly resistant to RSV, while ‘ 04G824’, ‘ Luhe301 ’, ‘ Zhendao88 ’ and ‘ V6 ’ are moderately resistant. The others （above 60%） are susceptible. The different symptoms displaying on rice by inocu- lating the same isolate （RSV-JS） to 25 rice entries showed that the leaf-folded and leaf-unfolded symptoms were closely related to the resistance of rice varieties.