水稻细菌性条斑病菌DNA多态性与致病性研究

利用６０个随机引物对来自我国不同稻区的水稻细菌性条斑病菌株基因组ＤＮＡ进行ＰＣＲ扩增，其中２０个引物均出现清晰和重复性的ＤＮＡ扩增片段，扩增片段大小在０．５ｋｂ至３．５ｋｂ；应用Ｓｔａｔｉｓｔｉｃｓ软件ＵＰＧＭＡ程序进行树状聚类分析，聚类结果表明，我国水稻细菌性条斑病菌具有明显的遗传分化，在遗传距离为０．３０时，供试菌株可划分为７个遗传相似组（谱系）。其中第１、第２和第５组为优势组群，分别由７、８、６个菌株组成。根据菌株在１２个已知基因品种上的抗感反应，将供试菌株分为１３个致病型，在遗传距离为０．５０水平上聚类归属于６个簇。菌株的致病类群与其ＤＮＡ的遗传变异具有弱相关性。

Analysis of DNA Polymorphism and Virulence in China Strains of Xanthomonas oryzae pv. oryzicola

RAPD was used to analyze the genetic diversity and virulence phenotypes of Xanthomonas oryzae pv. oryzicola , the bacterial leaf streak pathogen of rice in China. Twenty of 60 used random primers produced consistent and clear banding patterns that generated a set of products from 0.5 kb to 3.5 kb in size. Cluster analysis was conducted using UPGMA. The result showed that genetic variation existed obviously among isolates of rice bacterial leaf streak (BLS) from different regions,isolates tested could be divided into 7 lineages (groups) .Lineages 1,2 and 5 were the most frequently detected,including 7,8 and 6 strains respectively. Thirteen pathotypes(virulence phenotypes) of X.oryzae pv. oryzicola were identified according to resistant and susceptible react of 12 genotypes to the strains using 12 rice near iso lines, each containing a single gene for resistance.The 13 pathotypes grouped into six clusters. There was a weak correlation between RAPD groups and virulence phenotypes.