论文部分内容阅读
于2013-2014连续两年对云南主要水稻种植区的水稻病毒病进行了调查,发现当前为害云南水稻的病毒病主要有水稻条纹叶枯病、南方水稻黑条矮缩病、水稻矮缩病和水稻齿叶矮缩病。其中,条纹叶枯病是当前为害云南水稻最严重的病毒病,部分田块最高发病率可达15.0%;其次是水稻矮缩病,调查田块最高发病率达10.0%;南方水稻黑条矮缩病的平均发病率达5.3%;水稻齿叶矮缩病只在局部地区发生且发病率都不高。对云南当前发生较普遍的RSV不同分离物RNA3基因间隔区(IR3)及RNA4基因间隔区(IR4)开展了分子变异分析。根据不同RSV分离物IR3、IR4核苷酸序列构建系统进化树,所分析的RSV分离物均可被划分为两个组,部分云南分离物和云南以外的中国、日本、韩国分离物聚在Ⅰ组,其余绝大多数云南分离物单独聚在Ⅱ组。不同RSV分离物的IR3和IR4长度差异较大,按每10个核苷酸的长度差异进行划分,均可划分为A、B、C三种不同的类型。部分RSV云南分离物IR3、IR4中有17-21nt的序列与其水稻、小麦和大麦等寄主的部分序列相同,这可能是病毒在进化过程中与寄主植物发生了重组。云南RSV分离物的IR3、IR4分子变异较大,可能与其特殊的地理、生态条件有一定的相关性。
In 2013-2014, two consecutive years of rice virus disease in Yunnan’s major rice-growing areas were investigated and found that the current damage to Yunnan rice diseases are mainly rice stripe virus, southern rice black-streaked dwarf, rice dwarf and Rice leaf dwarf disease. Among them, stripe virus is the most serious viral disease in Yunnan rice currently, and the highest incidence rate is 15.0% in some plots. The next is rice dwarf disease. The highest incidence rate of the survey plots is 10.0% The average incidence rate of shrinkage is up to 5.3%. Rice leaf-dwarf disease occurs only in some areas and the incidence is not high. Molecular variance analysis of the RNA3 intergenic region (IR3) and RNA4 intergenic region (IR4) of the different RSV isolates currently occurring in Yunnan was carried out. According to the nucleotide sequences of IR3 and IR4 of different RSV isolates, phylogenetic tree was constructed. The RSV isolates analyzed could be divided into two groups. Part of Yunnan isolates and China, Japan and South Korea except Yunnan were clustered in Ⅰ Group, the rest of the vast majority of Yunnan isolates gathered in group Ⅱ alone. Different RSV isolates have different lengths of IR3 and IR4, and they can be divided into three different types of A, B and C according to the length difference of every 10 nucleotides. The partial sequence of 17-21nt in some RSV Yunnan isolates IR3 and IR4 was the same as that of some hosts such as rice, wheat and barley, which may be that the virus reorganized with the host plant during its evolution. The variation of IR3 and IR4 in Yunnan RSV isolates is quite large, which may be related to their special geographical and ecological conditions.