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胶孢炭疽菌是引起油茶炭疽病的主要病原之一。目前对于该病原菌种群的遗传结构尚未见报道。研究病菌种群的遗传结构对制定科学的防治方法具有重要意义。本研究比较中国6个省12个不同地区的126个胶孢炭疽菌的ITS序列的差异,以期研究各不同群体的单倍体型多样性,不同地区群体之间的遗传关系,以及遗传距离与地理距离的线性关系。遗传分析发现,得到的126个胶孢炭疽菌样品ITS序列可定义为27种单倍体型。27种单倍体型中,一个主要的单倍体型(Haplotype12)含有78个样品,且基本上每个样品采集地都有分布。遗传分化指数(Fst)表明病菌不同地理种群间的遗传分化较大。AMOVA分析显示,种群间的遗传变异占总变异的6%,种群内部变异占总变异的94%。Mantel测试显示地理距离与遗传距离没有显著的线性关系。对所有地理种群病原菌ITS序列的核苷酸不配对进行分析,发现油茶炭疽病菌未经历过大规模的种群扩张过程。系统发育分析表明,来自不同地区的油茶炭疽病菌散乱的分布在系统树中。研究结果表明油茶炭疽病菌种群具有丰富的遗传多样性。
Colletotrichum gloeosporioides is one of the major pathogens causing anthrax in Camellia oleifera. At present, the genetic structure of the pathogen population has not been reported yet. Studying the genetic structure of the germ-line population is of great importance to formulating scientific methods of prevention and treatment. In this study, we compared the ITS sequences of 126 isolates of Colletotrichum gloeosporioides in 12 different regions of six provinces in China in order to study the haplotype diversity of different populations, the genetic relationship among populations in different regions, The linear relationship of distance. Genetic analysis found that 126 isolates of Colletotrichum gloeosporioides ITS sequences can be defined as 27 haplotypes. Of 27 haplotypes, one major haplotype (Haplotype 12) contains 78 samples and is distributed essentially every sample is collected. The genetic differentiation index (Fst) indicated that the genetic differentiation among different geographical populations of germs was larger. AMOVA analysis showed that genetic variation among the populations accounted for 6% of the total variance and intraspecific variation accounted for 94% of the total variation. Mantel tests showed no significant linear relationship between geographic distance and genetic distance. An unpaired nucleotide analysis of ITS sequences of all geographic population pathogens showed that C. oleae had not undergone a large population expansion process. Phylogenetic analysis showed that C. anthracnose from different regions scattered in the system tree. The results show that the anthrax of Camellia oleifera is rich in genetic diversity.