水稻白叶枯病原菌遗传和致病型多样性分析

Analysis of genotypic and pathotypic diversity in Xanthomonas oryzae pv.oryzae by Rep-PCR

采用Rep PCR分子指纹技术对国内已知致病型和云南省各水稻产区采集的5 6个白叶枯病代表菌株进行分析.用ERIC、J3等引物对其DNA进行Rep PCR特异性扩增,扩增结果经综合聚类分析,在70 %的相似水平上,可将测试菌株划分为10个组群,其中4、5、8、9、10为主要组群;来自云南省的菌株分属于6个组群中,遗传分群与菌株的地理来源关系密切.根据菌株在已知抗性基因的近等基因系的反应,菌株可分为18个致病型,云南省的水稻白叶枯病菌株致病型复杂多样。

Fifty-six strains of Xanthomonas oryzae pv. oryzae (Xoo) were analysed by using short bacterial repetitive elements(REP,ERIC and BOX primers) and the repetitive DNA element IS1113 from X. oryzae pv.oryzae. Dendrograms were generated from the combination data sets of primers ERIC and J3 by using UPGMA analysis. The results indicated that extensive genetic variability and genetic diversity existed within the population of X. oryzae pv. oryzae strains tested. All strains could be divided into 10 groups at level of 70% similarity. Group 4, 5, 8, 9 and 10 were predominant. Strains collected from Yunnan Province were divided into 6 groups, and each group was partially associated with the regional origin of pathogen population. Eighteen pathotypes (virulence phenotype) were identified bg using 16 near-iso-genic rice lines, each containing a single gene for resistance. The pathotype diversity and complicity of strains tested from Yunnan Province were higher than those from other provinces in China. The results would be facilitated for further understanding of the population structure of X.oryzae pv.oryzae in China.