中国水稻白叶枯病原菌群体的遗传结构

用Rep-PCR和RFLP两种方法分析了143个水稻白叶枯病Xanthomonas oryzae pv.oryzae菌系。这些菌系采集于长江流域,华南,华北和东北的20个省市的96个点。Rap-PCR是利用一些基于细菌的短的重复单位引物(ERIC,BOX和REP)及来自稻白叶枯病原菌的可动重复单位(IS1112和IS1113)引物的DNA扩增特性。在RFLP分析中,以无毒基因家族中的一个成员avrXa10为探针。Rep-PCR分析呈显较高的单元型多样性(H=0.75)。在4个水稻生长地区中,Rep-PCR分析的结果是:华南稻区的遗传多样性最高(H=0.96),随后为长江流域(H=0.93),东北(H=0.77),华北(H=0.69)。根据3个分簇生物统计的共有指纹型,143个菌系被构成3簇。在各簇中都有来自不同水稻产区的菌系,表明菌系的分簇不受地理区域的影响。

Genetic Structure of Rice Bacterial Blight Pathogen Population in China

Rep-PCR and restriction fragment length polymorphism (RFLP) were used to analyze the genetic structure in a population of 143 Xanthomonas oryzae pv. oryzae(X. o. pv. oryzae)strains. The strains were isolated from 96 sites in 20 different provinces of the Yangtze River Region. South, North and Northeast China. Rep-PCR was performed using DNA amplification with primers based on short bacterial repetitive elements (ERIC, BOX and REP primers)and mobile, repetitive elements from X. o. pv. oryzae (IS1112, IS1113). For RFLP analysis, a member of a family of avirulence genes, avrXa10 was used as a probe. Rep-PCR revealed higher haplotypic diversity(H=0. 95). Of the four rice growing regions, the highest genetic diversity (based on rep-PCR)was observed in South China(H=0. 96), followed by the Yangtze River Region(H=0. 93), Northeast China(H = 0. 77), and North China(H=0. 69). On the basis of the consensus of three clustering statistics, the 143 strains constituted three clusters. Strains from each different rice growing regions grouped into all clusters indicating no geographic differentiation.