从3龄思茅松毛虫(Dendrolimus kikuchii)幼虫肠道样品中分离得到11株好氧细菌。以细菌基因组DNA为模板,扩增16 S rDNA,并用4种限制性内切酶HaeⅢ和HindⅢ、HinfⅠ和TaqⅠ对PCR扩增产物进行ARDRA多态性分析。对聚类图谱的分析结果发现11株好氧细菌在70%的遗传相似度水平上聚成4个不同分类操作单元(OTU),表明3龄松毛虫中肠道内好氧细菌的遗传多样性水平偏低。
[ Objective ] The paper was to screen intestinal aerobic bacteria from 2nd instar larvae of Dendrolimu kikuchii and determine its toxicity. [ Method ] The intestinal samples of 2nd instar larvae of D. kikuchii were diluted in gredient and coated on plates to isolate strains, and a total of 5 strains of aerobic bacteria were isolated. With bacterial genomic DNA as template, the universal primers of bacterial 16S rDNA （27f and 1 492r） were used to amplify the template, 4 restriction enzymes Hae Ⅲ and Hind Ⅲ, Hinf Ⅰ and Taq Ⅰ were used to carry out ARDRA polymorphism analysis on PCR products. [ Result] Clustering map analysis showed that 5 strains of aerobic bacteria clustered into two different taxonomic operating units （OTU） in 95% similarity level, this indicated that the genetic diversity level of intestinal aerobic bacteria in 2nd instar larvae of D. kikuchii was relatively low. The indoor toxicity test showed that the death peaks of insects killed by intestinal bacteria were during 4 - 10 d, the insecticidal effect of strain 4 was the best with corrected mortality rate of 53.57% at 12 d. [ Conclusion] The paper provided reference for control of D. kikuchii.
