云南球孢白僵菌的遗传多样性研究

Study on the Genetic Diversity of Beauveria bassiana (Bals.) Vuill.in Yunnan

球孢白僵菌是一种广谱性虫生真菌,在害虫种群的自然控制中发挥着重要作用。为弄清云南省球孢白僵菌种群的遗传多样性,丰富云南虫生真菌多样性内容,本研究采用ISSR分子标记技术对云南不同地区及不同寄主来源的39个球孢白僵菌菌株的遗传多样性进行了分析。结果表明,有11个ISSRs可用于39个球孢白僵菌菌株群体PCR扩增,每个引物扩增5～15条DNA带。供试39个球孢白僵菌菌株群体的多态位点百分率(PPL)达99.09%,不同寄主来源亚种的Nei基因多样性(He)为0.347 8,居群间的基因分化系数(Gst)为0.072 4,总基因多样性(Ht)为0.351 8,亚种群内基因多样性(Hs)为0.326 3,不同寄主亚种群间的基因流(Nm)为6.404 4;不同地理来源白僵菌种群Nei基因多样性指数He为0.344 4,Shannon指数I为0.515 2;总基因多样性Ht为0.347 3,亚种群内基因多样性Hs为0.213 1,亚种群间的基因分化系数Gst为0.386 2。综合遗传多样性结果,云南省球孢白僵菌种群遗传结构复杂、遗传异质性明显,从寄主来源来看,居群间遗传变异较小,居群内遗传分化较大;从地理来源来看,居群间遗传变异较大,居群内表现遗传变异较小。

Beauveria bassiana is a broad spectrum of entomopathogenic fungi, it has played an important role in the natural control on pest population. To verify the genetic diversity of B. bassiana strains and enrich the diversity content of B. bassiana in Yunnan, the genetic diversity of 39 B. bassiana strains from different locations and different insect hosts in Yunnan Province was evaluated using the inter-simple sequence repeat （ISSR） markers. Eleven ISSR primers were selected for higher reproducibility and polymorphism. The average of 10 fragments was amplified, and the polymorphic was 99.09%. Nei＇s genetic diversity （He） of those strains from different host insects was 0. 347 8, the total genetic diversity （ Ht ） was 0. 351 8, the genetic diversity （ Hs ） from intra-populations was 0. 326 3, the genetic differentiation （ Gst ） was 0. 072 4 ; The gene flow （ Nm ） was 6. 404 4 for the sub-population isolates, and it showed that genetic differentation caused by the genetic drift. Nei＇s genetic diversity （ He） of those strains from different host insects was 0. 344 4 and Shannon genetic diversity index （I） was 0. 515 2, the total genetic diversity Ht was 0. 347 3, the genetic diversity Hs from intra-populations was 0. 213 1, the genetic differentiation Gst was 0. 386 2. Overall, all the above re- sults indicated that there was an complicated genetic diversity and higher genetic heterogeneity, and a low degree of genetic differentiation was in the B. bassiana among populations.