利用PLFA方法研究转Bt基因棉花对土壤微生物群落结构变化的影响

摘要

The experiment was conducted to evaluate the effects of transgenic Bt cotton on soil microbial community in 2006 under the field based on phospholipid fatty acid (PFLA) method.Three transgenic Bt cotton lines ( JM26,JM44 and CCRI41) and one non-Bt cotton line were used.The results showed transgenic Bt cotton increased amount of PFLA for soil microbe.Bt-cotton soils were characterized by the predominance of actinomycetes,fungi and eukaryotes in comparison with non-Bt cotton soil.In contrast,the microbial community was characterized by the predominance of Gram-positive bacteria in non-Bt cotton soil.Soil microbial community were characterized by the predominance of protoza and Gram-negative bacteria for Bt-cotton soils in square growth stage,and for non-Bt cotton soil in the open boll stage.PFLA anlysis was accepted as indicator for risk evaluation of transgenic Bt cotton on soil microbial community.%在大田条件下,用3个转Bt基因棉花品种和一个常规品种,利用磷脂脂肪酸(PLFA)方法研究转Bt基因棉花对土壤微生物群落结构变化的影响.试验结果表明,转基因棉花增加了土壤微生物PLFA的含量.转基因棉花降低了棉田土壤格兰氏阳性细菌的比例,提高棉田土壤的真核生物、真菌和放线菌的比例;转基因棉花在蕾期提高了土壤原生动物比例,在吐絮期比例反而降低;转基因棉花在蕾期提高了棉田土壤格兰氏阴性细菌的比例,吐絮期则降低了格兰氏阴性细菌的比例.主成分分析和聚类分析表明,转Bt基因棉花对土壤微生物群落结构变化有明显影响.PLFA方法可作为转基因生态安全评价的一种方法.