东北地区小麦赤霉病菌DNA随机扩增多态性分析*

利用RAPD对我国东北地区引致小麦赤霉病的2种镰刀菌进行种群分析,并与江苏和西北的菌株进行了比较。共筛选出16个引物用于扩增反应,其扩增图谱显示供试菌株在种间和种内均具多态性。多数引物扩增出了种的特征性谱带,可用作种的鉴定。综合所有谱带系统聚类所得树状图明显地将Fusarium graminearum的34个菌株和F.avenaceum的5个菌株各聚为一类,每一类又可区分为不同组,以前者分为3组,后者分为2组差异显著,表明种内存在不同的菌系类型;组的划分与菌株致病力及其寄主品种间没有必然的相关性,但与菌株分布的大区域生态气候类型似有联系,供试的东北地区F.graminearum大多数菌株与西北的菌系有较大的遗传相似性,与江苏的菌系相距甚远。

RAPD ANALYSIS OF ISOLATES FROM FUSARIUM SPP. CAUSING WHEAT HEAD BLIGHT IN NORTHEAST CHINA

isolates of Fusarium graminearum and F. avenaceum which caused wheat head blight in Northeast China, with 3 isolates from the Northwest and Jiangsu Province, were analysed by using RAPD. 16 random decamer primers selected from 60 ones from Operon Technologies were used for DNA amplification. The DNA polymorphisms were obtained from both of interspecific and intraspecific isolates. Specific characteristic bands were produced by most of the 16 primers. The dendrogram resulted from hierarchical cluster analysis based on all bands amplified by the 16 primers showed that the isolates were distinctly classified into two large categories which were composed of 34 isolates of F. graminearum and 5 isolates of F. avenaceum respectively. Each categories could be subdivided into different groups. It抯 suggested that the isolates of F. graminearum should be divided into 3 groups and the ones of F. avenaceum into 2 groups. The isolate grouping was not bound up with the pathogenicity and host cultivars, but was seemingly related to the climatological zones from where the isolates were collected. There was considerable genetic resemblance between isolates from the Northeast and from the Northwest. The strong pathogenic isolate from Jiangsu Province, JF-12, was distantly related to all the other isolates. Because of the instability in morphology, pathogenicity, culture property and other characters of the Fusarium isolates, RAPD technique should be of importance for the identification of species, subdivision of intraspecific strains and analysis of population composition of the pathogen.