摘要： 利用致病性测定及Pot2-rep-PCR技术对2007、2008年采集自江苏省五大稻区的稻瘟病菌株进行多样性分析,这2年的菌株被划分为10个小种和14个系谱,其中ZG1为优势小种,JSL5为优势系谱,研究结果表明:江苏稻瘟病菌具有丰富的多样性,但与1999-2002年的群体结构比较时发现,群体结构趋于简单;对病原菌的时空分布分析发现,不同的年份、不同的地区之间稻瘟菌的群体结构差异明显;结合致病型与遗传系谱分析时发现,致病类型与遗传系谱并没有一一对应的关系,但致病性和遗传系谱的地区变化有一定的相似性,这说明致病性和DNA分子水平上多态性检测在宏观上具有共同点,在一定程度上都能反映稻瘟病菌的多样性。

关键词: 稻瘟病菌, 致病性, 群体结构, 多样性

Abstract: In order to investigate the characteristics for separation and identification of the antifungal substance produced by antagonistic Streptomyce lydicus A02,the methods of pH paper chromatography,paper electrophoresis,organic solvent extraction,silica gel TLC,Doskochilova solvent system paper chromatography,ultraviolet spectrum scan,functional group and proteinase test were respectively used to determine the ion property,the polarity,the ultraviolet absorption character,the main functional groups and the sensitivity to proteinases of the bioactive substance of strain A02.The results showed that the antifungal substance were electrically neutral and highly polar in solutions,which enabled it to be efficiently extracted with n-butyl alcohol as the extractant and separated by TLC with ethanol + aqua ammonia + water(8∶ 1∶ 1,V/V) as the solvent combination.Its antifungal activity was not affected by proteinase K and trypsase.There were functional groups of unsaturated alkyl,saccharide or glycoside,amino acid and aldehyde in its structure according to the chemical reactions.Doskochilova paper chromatographic pattern and ultraviolet absorption spectrum of the antifungal substance were in accordance with the characters of tetar-alkene macrolide antibiotic.The combination of the information referred to above reveal a new biological function for S.lydicus to produce tetar-alkene macrolide antibiotics.

Key words: Magnaporthe grisea, Pathogenicity, Population structure, Variation

中图分类号: 

• S435．111． 4 + 1