我国棉枯萎镰刀菌小种间的营养体亲和性

采用不能还原利用硝酸盐作唯一氮源生长的突变体(nit突变体),对我国棉枯萎镰刀菌的3、7、8号小种的61个菌株作了营养亲和性研究。结果表明,第3号小种7个菌株和第7号小种42个菌株各属一个不同的营养体亲和群,第8号小种的8个菌株则属6个不同亲和群,不同小种的菌株间没有亲和性。营养体亲和性试验结果与致病性测定结果吻合,能从遗传学角度区分棉枯萎菌不同小种,用它作为鉴定手段,结果更能反映出不同菌系间的本质联系,并可克服致病力测定工作中费时、费力及结果不稳定等缺点。

VEGETATIVE COMPATIBILITY AMONG STRAINS OF DIFFERENT RACES OF FUSARIUM OXYSPORUM F. SP. VASINFECTUM IN CHINA

A collection of cotton-wilt pathogen, Fusarium oxysporum f. sp. vasinfectum(FOV) from twelve provinces and autonomous regions in China was identified into FOV races 3,7, and 8 based on pathogenicity tests. Sixty-one isolates representing these three races were tested for their vegetative compatibility by pairing their complementary nitrate non-utilizing mutants. All seven isolates of race 3 belonged to one vegetative compatibility group (VCG). Forty-two isolates of race 7 belonged to a second VCG. Eight isolates of race 8 fell into six distinct VCGs, yet no compatibility was found among isolates of diff erent races. The results of vegetative compatibility tests were in accordance with those of pathogenicity tests and could reflect the genetic differences of different FOV races. Vegeta tive compatibility testing is a better method than pathogenicity testing for identifying FOV races by saving much time and labour, and in overcoming unstable factors.