山东小麦纹枯病菌致病性与遗传分化关系的研究

 对山东麦区被鉴定为双核丝核菌的35个菌株进行致病性测定的基础上,选用15个随机引物对上述菌株进行了RAPD分析,共标记出171条DNA片段,其中多态性片段161个,多态率为94.15%。用UPGMA法构建系统树,以遗传距离0.33为阈值,被鉴定为AG-D融合群的33个菌株隶属于同一个RAPD组,而3个未定融合群菌株(WK-6、WK-37和WK-13)均为独立的RAPD组。以遗传距离0.25为阈值,将属于同一个融合群的33个AG-D群菌株划分为7个亚组,说明受试小麦纹枯病菌株间存在丰富的遗传多样性。综合分析受试菌株的致病力测定结果与RAPD分析发现,供试菌株的RAPD组与菌株致病力的强弱无明显的相关性,但少数菌株的致病力强弱与亚RAPD组有一定的相关性。

Genetic and virulence variation of wheat sharp eyespot isolates ( Rhizoctonia cerealis AG-D) from Shandong province

Genetic variation of 35 binucleate Rhizoctonia isolates collected from Shandong province was analyzed with RAPD assay after the test of pathogencity. Fifteen oligonucleotide primers were screened from 140 RAPD primers. A total of 171 RAPD bands were amplified, and 161 were polymorphic. The rate of polymorphism of the isolates was 94.15%. The dendrogram derived from RAPD data by UPGMA suggested that 36 isolates could be divided into 4 RAPD groups with a genetic distance of 0.33. Each of three isolates WK-6, WK-37, and WK-13 made a separate group. The other 33 isolates, the members of AG-D, made the 4th group, and could be further divided into 7 RAPD groups with a genetic distance of 0.25. It proved that the isolates of wheat sharp eyespot had an abundant genetic diversity. No significant correlation was found between the RAPD groups and their virulence, but a few sub-RAPD groups had some correlation with their virulence.