中文摘要：

以水稻品种IRBB4、IRBB5、IRBB14、IRBB18、IRBB21和IR24为鉴别品种，在孕穗期，采用针刺接种的方法，将水稻条斑病菌接种在水稻剑叶上，根据病菌与品种互作反应和亲和性的类型差异，将供试的75株条斑病菌菌株区分为13个小种群．大多数水稻条斑病菌株在鉴别品种上的互作反应表现为弱互作模式．云南、贵州、四川3省菌株小种组成的比较表明：以小种C9为目前3省的共同优势种群；云南省小种组成多样，所有的小种均有分布，贵州小种类型有6、9、11、13，四川种类型有3、4、6、7、9、11、12、13，小种的分布受地理区域的影响．

英文摘要：

Based on strain-cultivar reaction the pathogenicity of 75 Xanthomonas oryzae pv. oryzicola （Xooc） strains collected from different areas in southwest China was identified. The virulence against the differential varieties of IRBB4, IRBB5, IRBB14, IRBB18, IRBB21 and IR24 were inoculated into flag leaves office by using leaf needling for lesion length measurement. It showed that the virulence of these strains was differentiated distinctly; It also suggested that the 75 Xooc strains can be classified into 13 race groups： （1） RRRRRR, （2） RRRSRS, （3） RRSRSS, （4） RRSSSS, （5） RSRRSS, （6） RSRSSS,（7） RSSRSS,（8）RSSSRS, （9）RSSSSS,（10）SRSSSS, （11） SSRSSS, （12） SSSRSS, （13） SSSSSS, which was designated as C1-C13, respectively. Weak reaction patterns were proved mainly between pathogens and dee varieties and some strong interaction was discovered. The results further indicated that the predominant race C9 was distributed in all three provinces, and all 13 race groups were distributed in Yunnan, race 6,11,13 in Guizhou, race 3,4,6,7, 11,12,13 in Shichuan. The race distribution of Xooc in 3 different provinces is affected by geographic differentiation.