Abstract:

Study on effects of planting transgenic cotton on functional diversity in rhizosphere soil microbial community. By the method of Biolog, a comparative study was made on the utilization level of single carbon source by the microbes in the rhizosphere soils of transgenic Bt+CpTI cotton SGK321 and its parental isoline ‘Shiyuan 321’ in different growth stages. The results showed that, the Average Well Color Development (AWCD) changed in the following variation: compared with the parental isoline, AWCD value of transgenic cotton at seedling stage and budding stage were significantly higher (P<0.05) while flower and boll stage and boll-opening stage were significantly lower. The Shannon index (H) and Simpson's Dominance (D) of the soil microbial community varied with the growth stages, whereas the Substrate evenness (E) with no significant difference between transgenic cotton and its parental isoline in the four growth stages. Principal component analysis indicated that the carbon source utilization of soil microbial community was similar among transgenic cotton at seeding stage and flower and boll stage and parental isoline at seeding stage and budding stage, also the same finding among parental at flower and boll stage and transgenic at budding stage. The main carbon sources used by soil microbes were carbohydrates, amino acids, carboxylic acids, polymers.