玉米新月弯孢菌(Curvularia lunata)的RAPD分析

 对分离自玉米弯孢菌叶斑病标样中的77株新月弯孢菌和1株来自水稻的新月弯孢菌进行RAPD分析表明,菌株间具有丰富的遗传多样性,在相似系数约0.60处,所有菌株被聚为3个组,但88.0%的菌株聚入第Ⅰ组内,其余菌株被聚入另外2个组内。第Ⅰ组内共有69个菌株,包含来自不同区域的致病性较强的菌株,是玉米弯孢菌叶斑病的优势类群,其余2个类群主要是一些致病能力较弱或不致病的菌株。结果表明,新月弯孢菌种内菌株的遗传多样性与致病性相关,但与菌株地理来源无明显的直接关系。

RAPD analysis among Isolates of Curvularia lunata collected from corn in China

78 isolates of Curvularia lunata, mainly Collected from corn Curvularia leaf spot in different geographic regions in China, were characterized by random amplified polymorphic DNA (RAPD) with 8 arbitrarily primers. There was extensive genetic diversity within these isolates. At similar level of 0. 60, all isolates were clustered into three distinct groups. 88. 0% isolates were assigned to groupl, the dominant group, whereas 12.0% isolates to the other two groups. The dominant group included most of the virulent isolates from different corn-growing areas, exhibited high similarity in RAPD patterns and low genetic diversity. However, two prevalent subgroups were distinguished within the dominant group that encompassed 68 isolates (only one isolate not to any of two subgroups). The other two groups, which mainly contained very low virulent and nonpathogenic isolates, displayed high variation in RAPD patterns compared with the first group. No close correlation was found between genetic diversity and geographic origins of isolates within C. lunata population.