Effects of Transgenic Bt ＋ CpTI Cotton Cultivation on Functional Diversity of Microbial Communities in Rhizo- sphere Soils

摘要

[Objective] This study aimed to investigation the effects of transgenic Bt+CpTI cotton cultivation on functional diversity of microbial communities in rhizosphere soils.[Method] By using the Biolog method, a comparative study was conducted on the utilization level of single carbon source by microbes in the rhizosphere soils of transgenic Bt+CpTI cotton SGK321 and its parental conventional cotton 'Shiyuan 321' at different growth stages.[Result] The results showed that, compared with the parental conventional cotton, the average well-color development (AWCD) value of microbial communities in rhizosphere soils of transgenic Bt+CpTI cotton were significantly higher (P<0.05) at seedling stage and budding stage while significantly lower at flower and boll stage and boll opening stage.Shannon-Wiener diversity index (H) and Simpson dominance index (D) of microbial communities in rhizosphere soils of transgenic cotton and conventional cotton varied with the different growth stages, whereas the Shannon-Wiener evenness index (E) showed no significant difference between transgenic cotton and conventional cotton at four growth stages.Principal component analysis indicated that the patterns of carbon source utilization by microbial communities in rhizosphere soils were similar among transgenic cotton at seeding stage and flower and boll stage and parental conventional cotton at seeding stage and budding stage, which were also similar between transgenic cotton at budding stage and parental conventional cotton at flower and boll stage.[Conclusion]Analysis of different carbon sources indicated that the main carbon sources utilized by soil microbes were carbohydrates, amino acids, carboxylic acids and polymers.