运用RAPD技术分析玉溪市烟草黑胫病菌遗传多样性

Genetic Diversity of Tobacco Black-Shank Pathogen in Yuxi City by RAPD

为了分析玉溪市典型烟区烟草黑胫病的发生动态与烟草疫霉遗传分化的关系,选用6条具有多态性的RAPD随机引物对玉溪市新平县和澄江市不同地理来源、海拔高度、寄主品种的164株烟草疫霉菌进行PCR扩增,利用NTSYS软件以UPGMA对扩增结果进行聚类分析,构建遗传系统树状图谱。结果表明:在0.84相似水平上,这些菌株可分为6组,其中146个菌株聚集在Ⅰ组,占89.02%,其他5组总和仅占10.98%,这说明新平县和澄江市的烟草疫霉在遗传上具有高度同源性,分化差异较小;供试菌株的群体基因型划分与地理来源没有直接关系,但与海拔高度、烟草品种有一定的关联。因此,通过种苗或其他工具使内部病菌频繁交流可能是导致少数病菌分化差异较大的原因之一。

In order to detect the relationship between the occurrence dynamics of tobacco black-shank and the genetic differentiation of Phytophthora nicotianae in typical tobacco areas of Yuxi City,the genomic DNA of 164 strains of Phytophthora nicotianae from different geographical origins,altitudes and tobacco varieties in Xinping County and Chengjiang City were amplified by using 6 polymorphic RAPD random primers.The results of amplification were analyzed by unweighted pair group method with arithmetic means (UPGMA) with NTSYS software,and the tree map of the genetic system was constructed.The results showed that at a similar level of 0.84,these strains were divided into 6 groups,among which 146 strains clustered in groupⅠ,accounting for 89.02%,and the sum of the other 5 groups was only 10.98%.These results indicated that Phytophthora nicotianae from Xinping County and Chengjiang City had high genetic homology and little differentiation difference.The population genotype of tested strains was not directly related to geographical origin,but was related to altitude and distribution of tobacco varieties.Therefore,the frequent communication of pathogens through seedlings or other tools may be one of the reasons for the large differences in differentiation of a few pathogens.