在东北三省15个地区采集分离26个玉米弯孢菌菌株,通过鉴别寄主技术与RAPD分子标记技术进行致病性与遗传分化的研究。结果表明,东北地区玉米弯孢菌在致病性与遗传上都存在明显的变异,二者有一定的相关性,未发现变异程度与菌株地理来源有明显的直接关系。26个菌株的致病性分为5种类型,其中中等致病类型分布遍及东北三省,为优势致病类群;强致病类型分布在吉林省的白城市;弱致病类型主要分布在吉林省的白山和梨树。用8个引物对供试菌株进行RAPD扩增,共获得77个RAPD标记,其中多态性标记71个,多态性比例92.2%。供试菌株在相似系数约0.71处共聚为4组,大多数致病性较强的菌株聚在一起,而弱致病株在相似系数相对较低时和其他菌株聚在一起。 Twenty-six strains of Curvularia mazei were collected and collected in 15 regions of Northeast China. Pathogenicity and genetic differentiation were studied by differential host assay and RAPD molecular marker. The results showed that the pathogenicity and heredity of Curvularia lunata in Northeast China were obviously different. There was a certain correlation between the two. There was no obvious direct relationship between the degree of variation and geographical origin of the strain. The pathogenicity of the 26 isolates were divided into five types, of which the distribution of middle pathogenicity was in the three northeastern provinces, which was the predominant pathogenic group. The strong pathogenicity type was located in Baicheng City, Jilin Province. The main pathogenic types were weak in Jilin Province White mountain and pear tree. A total of 77 RAPD markers were obtained by RAPD amplification with 8 primers. Among them, 71 were polymorphic markers with a polymorphism ratio of 92.2%. The tested strains were co-cultured into 4 groups at a similarity coefficient of about 0.71, most of the pathogenic strains were clustered together, while the weak pathogenic strains were clustered with other strains when the similarity coefficient was relatively low.