双价转基因抗虫棉花对土壤氨氧化细菌和氨氧化古菌群落结构及丰度的影响

采用末端片段多态性分析(T-RFLP)和实时定量PCR(Quantitative real-time PCR,qPCR)方法,研究了不同生长时期双价转基因抗虫棉花和亲本非转基因棉花(对照)土壤氨氧化细菌(Ammonia-oxidizing bacteria,AOB)和氨氧化古菌(Ammonia-oxidizing archaea,AOA)群落结构和丰度的变化,以探讨双价转基因抗虫棉花种植对土壤氨氧化微生物的影响。结果表明,双价转基因抗虫棉花土壤中AOB和AOA优势种群与对照相同,且随生长时期无显著变化,但在各自样品中所占比例不同。不同生长时期双价转基因抗虫棉花土壤AOB的Shannon指数和Evenness指数均与对照无显著差异,AOA的Shannon指数与对照也无显著差异,而苗期时Evenness指数显著低于对照(P0.05),其他3个生长时期差异均不显著。qPCR分析表明,除花铃期双价转基因抗虫棉花土壤AOB丰度高于对照外,其他3个生长时期均低于对照,而AOA丰度在4个生长时期均低于对照。吐絮期时,双价转基因抗虫棉花与对照土壤AOB和AOA丰度均差异显著(P0.05)。双价转基因抗虫棉花对土壤AOB和AOA群落结构组成无显著影响,但降低了AOB和AOA的数量,双价转基因抗虫棉花对土壤微生物的某些类群可能存在潜在影响。

Community Structure and Abundance of Soil Ammonia-oxidizing Bacteria and Ammonia-oxidizing Archea as Influenced by Insect-resistant Bivalent Transgenic Cotton

The cultivation area of genetically modified(GM) crops has expanded significantly in recent years. However, concerns have been raised over impacts of GM crops on soil ecosystem, especially soil microorganisms. Here, we examined the influence of insect-resistant bivalent transgenic cotton on soil ammonia-oxidizing bacteria(AOB) and ammonia-oxidizing archaea(AOA). Terminal restriction fragment length polymorphism(T-RFLP) was used to evaluate community structure change and qPCR to detect abundance difference. Compared to the control, the population of dominant AOB and AOA did not show significant difference in insect-resistant bivalent transgenic cotton soil, with no changes over the growth season though the ratio of each dominant species population varied in different varieties and at different growth stages of cotton. The Shannon index and Evenness index of AOB had no significant difference between the transgenic cotton soil and its control during the whole growth period. The Shannon index of AOA had similar results, but Evenness index of AOA was significantly lower in the transgenic cotton soil than in the control at the seedling stage(P<0.05), with no difference found at the other growth stages. The abundance of AOB in the transgenic cotton soil was higher at the blooming stage, whereas lower at the other stages, as compared with the control soil. However, AOA had lower abundance in the GM cotton than in the control soil throughout the growing season. Therefore, the insect-resistant bivalent transgenic cotton had no significant impact on the community structure of soil AOB and AOA, but reduced the abundance of AOB and AOA, suggesting potential impacts of transgenic cotton on soil ammonia-oxidizing microorganisms.