转双价基因抗虫棉对土壤微生物群落多样性的影响

Effects of transgenic Bt+CpTI insect-resistant cotton on microbial community diversity in rhizosphere soil

采用Biolog技术,研究了不同生育期(30、60、90和120d)转双价(Bt+CpTI)基因抗虫棉SGK321及其亲本非转基因常规棉石远321根际土壤微生物群落多样性变化。结果表明,反映土壤微生物活性的平均颜色变化率(AWCD)呈现出以下变化规律:与亲本常规棉相比,整个培育过程中转双价基因抗虫棉AWCD值除30d显著高于亲本常规棉(P<0.05),其他3个时期均显著低于亲本常规棉(P<0.05)。两种棉花根际土壤微生物群落丰富度指数和优势度指数随棉花生育期的不同而有所不同,4个时期转双价基因抗虫棉均匀度指数与亲本常规棉无显著差异。主成分分析结果表明,转双价基因抗虫棉30d、亲本常规棉60、120d土壤微生物群落碳源利用方式相似,转双价基因抗虫棉60、90、120d与亲本常规棉30d土壤微生物群落碳源利用方式相似。土壤微生物利用的主要碳源为糖类、氨基酸类、羧酸类和聚合物。

An experiment with transgenic Bt＋CpTI cotton SGK321 and its parental isoline Shiyuan 321 was conducted to examine the effects of planting transgenic Bt＋CpTI cotton on the soil microbial community diversity. Rhizosphere soil was sampled at different growth stages （30, 60, 90, and 120 d） of SGK321 and Shiyuan 321. The Biolog analysis showed that the average well color development （AWCD, reflecting soil microbial activity） of all carbon sources changed in the following patterns. As compared with that for Shiyuan 321, the AWCD for SGK321 was significantly higher （P〈0.05） at the growth stage of 30 d but significantly lower at other growth stages （P〈0.05）. The Shannon richness index and Simpson’s dominance index of the soil microbial community changed differently during the growth of SGK321 and Shiyuan 321, whereas the evenness index had no significant difference at the four growth stages of the two cultivars. Principal component analysis indicated that at the SGK321 growth stage of 30 d and the Shiyuan 321 growth stages of 60 and 120 d, and also, at the SGK321 growth stages of 60, 90, and 120 d and the Shiyuan 321 growth stage of 30 d, the carbon sources utilization of soil microbial community was similar. The main carbon sources utilized by the soil microbes were carbohydrates, amino acids, carboxylic acids, and polymers.