海南橡胶树暹罗刺盘孢菌群体遗传结构分析

暹罗刺盘孢菌Colletotrichum siamense是引起海南橡胶树炭疽病的重要病原之一,为了明确海南橡胶树暹罗刺盘孢菌群体的遗传结构,本研究对海南5个市(县)的橡胶树暹罗刺盘孢菌的ITS序列进行分析。结果表明,58个病菌样品可推导出11种单倍型,其中单倍型H11包含样品数最多且在5个市(县)均有分布,其次为单倍型H4,在4个市(县)有分布。遗传分化指数(Fst)表明保亭种群与其他种群的遗传分化较大。AMOVA分析显示,遗传变异主要发生在种群内,占总变异的93.9%。对所有地理种群病原菌ITS序列的核苷酸不配对进行分析,表明病菌未经历过大规模的种群扩张。系统发育分析表明,来自相同地区的病菌单倍型并没有聚在一起。研究结果表明海南橡胶树暹罗刺盘孢菌种群具有丰富的遗传多样性。

Population genetic structure of Colletotrichum siamense from rubber tree in Hainan Province

Colletotrichum siamense is one of the main anthracnose pathogen of rubber tree in Hainan. To clarify the population genetic structure of C. siamense from rubber tree in Hainan Province, ITS sequences of 58 C. siamense strains from rubber tree in five counties were analyzed in this study. The results showed that 11 haplotypes were identified. The haplotype 11 was the most one and distributed in all sampled counties, and the next was haplotype 4 distributed in 4 of 5 sampled counties. The genetic differentiation index, Fst, revealed significant genetic differentiation between Baoting populations and the others. AMOVA test showed that the genetic differentiation was mainly occurred within population which accounted for 93.9% of the total genetic differentiation. Mismatch distribution analysis suggested there is no population expansion for C. siamense from rubber tree. Phylogenetic analysis showed that the haplotypes from the same counties were not clustered together. The results showed that the natural population of C. siamense from rubber tree in Hainan had rich genetic diversity.