江苏与云南稻瘟病菌群体遗传结构多样性比较

利用10对SRAP引物对来自江苏和云南的共82个稻瘟病菌(Magnaporthe grisea)菌株构成的试验群体进行了遗传结构分析,并进一步分别对2省的群体遗传结构进行详细的比较研究。试验结果表明,82个供试菌株在相似性系数为0.83时共被划出28个遗传宗谱;其中江苏群体分布于其中的13个宗谱,其宗谱频率和遗传多样性指数分别为31%和0.74。云南群体则分布于其余的15个宗谱,其宗谱频率和遗传多样性指数依次为37.5%和0.89。由此可见,江苏群体的遗传多样性远不及云南群体的丰富。值得关注的是,在28个宗谱中并没有一个宗谱是由2个群体共同组成的。由此推测,江苏与云南2个群体之间存在显著的遗传特异性或异质性。换言之,从两个群体的进化的角度来说,它们是2个相互独立进化而来的群体。这就意味着,在两省之间开展抗性育种以及品种交流等具有很大的潜力。

Comparison of Genetic Structures of Two Rice Blast Fungus Populations Originated from Jiangsu and Yunnan Provinces, China

Forty two and forty monoconidial isolates of Magnaporthe grisea collected respectively from Jiangsu (JS) and Yunnan (YN) in China were cultured for DNA extraction. They were characterized by using the SRAP (sequence-related amplified polymorphism) marker-based DNA fingerprinting and studied by cluster analysis of UPGMA. A total of 82 isolates were clustered into 28 genetic lineages at the similarity coefficient of 0.83. Among the 28 lineages, 13 and 15 lineages were detected in populations respectively from JS and YN, whose genetic diversity indexes were 0.74 and 0.89 separately, indicating that genetic diversity of the population from YN is certainly higher than that from JS. There is no any common lineage to both populations, indicating that there is a high genetic specificity/heterogeneity between these two populations. Therefore, there is a great potential for these two provinces to exchange their resistance breeding programs.