【作者】 徐广惠；

【导师】 王宏燕；

【作者基本信息】 东北农业大学 ， 生态学， 2010， 硕士

【摘要】 抗草甘膦转基因大豆(Roundup Ready Soybean简称RRS)是美国孟山都公司通过转基因技术培育而成的转基因作物新品种,其释放到农田后的风险与安全性备受国内外关注。本论文以RRS、亲本(RRS-S)、栽培大豆(D-46)和野生大豆(W-S)四种不同基因型大豆为实验材料,进行对比分析。试验采用PCR-DGGE结合amoA基因测序的方法,研究转基因大豆对根际土壤中与氮素转化有关的功能性菌类——氨氧化细菌(AOB)和氨氧化古菌(AOA)群落多样性的影响。对氨氧化细菌(AOB)群落研究结论如下:RRS根际土壤氨氧化细菌(AOB)的多样性指数(Dsh)及均匀度指数(Jsh)均要低于其亲本RRS-S、W-S与D-46;主成分分析显示,RRS与其他基因型大豆根际土壤氨氧化细菌群落结构差异较大,尤其与亲本RRS-S有很大差异;amoA基因测序与系统发育树的构建进一步证实了不同基因型大豆根际土壤的氨氧化细菌群落中,大多数属于cluster 3a,cluster 9和cluster 1类群,其中Nitrosospira类氨氧化细菌(Nitrosospira-like AOB)是不同基因型大豆根际土壤中AOB优势类群。另外,有一部分已检测的AOB在文献中并无记录和归类,这其中包括RRS的特有条带10。RRS的种植抑制了根际土壤中氨氧化细菌某些类群的生长(如条带1、8、12、20所代表的AOB类群),同时也促进了某些类群的生长(如条带10和19所代表的AOB类群)。研究结果表明在一定程度上RRS的种植减少了根际土壤中氨氧化细菌群落的多样性,改变了氨氧化细菌群落的结构,并且影响了某些氨氧化细菌类群的生长与分布。对氨氧化古菌(AOA)群落研究结论如下:RRS根际土壤氨氧化古菌(AOA)的多样性指数(Dsh)和均匀度指数(Jsh)与其亲本(RRS-S)及其他基因型大豆相比差异均不显著;主成分分析结果显示RRS与其他品种大豆(W-S和D-46)根际土壤氨氧化古菌群落结构差异较大,但与亲本(RRS-S)差异不明显;amoA基因测序与系统发育树的构建证实了不同基因型大豆根际土壤中的AOA一部分属于已有文献中记录的土壤AOA类群(soil/sediment),一部分在现有文献中没有记录(soil),但这其中没有AOA属于水生环境(water)或海洋底泥(sediment)中的AOA类群,此外,不同基因型大豆根际土壤样品中的AOA主要属于amoA基因的cluster 6、cluster 7和cluster 8,其中cluster 6类群的AOA是不同基因型大豆根际土壤中AOA优势类群。另外,有众多已检测的AOA在文献中并无记录和归类,这其中包括RRS的缺失条带1、20及25和特有条带3。试验证明了RRS的种植可能抑制了根际土壤中氨氧化古菌某些类群的生长(如条带1、20和25所代表的AOA类群),同时也促进了某些类群的生长(如条带3所代表的AOA类群)。这些研究结果表明RRS的种植对根际土壤中氨氧化古菌群落的多样性没有影响或只有微小影响,同时对氨氧化古菌群落的结构也只产生较弱的影响,但影响了某些氨氧化古菌类群的生长与分布。更多还原

【Abstract】 Roundup Ready Soybean (RRS) [Glycine max (L.) Merr.] was one of genetically modified crops and produced by the Monsanto company in the United States. The release of GM plants to agricultural ecosystems has raised a number of questions, including the ecological impact of these plants on soil ecosystems. Recently, the impact of GM crops on communities of microorganisms, microbe-mediated processes and functions in soil ecosystem was becoming more and more concerned in the world.As materials of the experiment, four genotypes’soybean including RRS, the parent of RRS (RRS-S), the cultivated soybean variety Dongnong 46 (D-46) and the wild soybean (W-S) were compared in the study. The experiment were conducted in this study in order to investigate effects of Roundup Ready Soybean (RRS) on the diversity of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) in rhizospheric soils using molecular techniques polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and DNA sequencing targeting ammonia monooxygenase (amoA) gene.The conclusion about effects of RRS on AOB communities in the study: the diversity analysis indicated that Shannon-Wiener diversity indexes (Dsh) and evenness indexes (Jsh) related to ammonia-oxidizing bacteria (AOB) in RRS rhizospheric soils were all lower than those of near-isogenic counterparts (RRS-S), W-S and D-46; the principal component analysis demonstrated that the compositions of ammonia oxidizing bacterial communities in RRS rhizospheric soils were different from those of its parent RRS-S and other soybeans (D-46 and W-S); sequencing of DGGE bands and phylogenetic analysis revealed that Nitrosospira-like AOB were the most dominant AOB inhabiting in the rhizospheric soils of different genotypes’soybeans, the amoA sequences associated with the soil samples mostly grouped within the amoA cluster 3a, cluster 9 and cluster 1, RRS promoted some groups of ammonia oxidizing bacterial communities, such as groups represented by bands 10 and 19, however, inhibited the other groups, such as groups represented by band 1, 8, 12 and 20. Our results indicated that RRS reduced the diversity of AOB, changed ammonia-oxidizing bacterial community structure and affected the growth and distribution of some groups of AOB in rhizospheric soil to some extent.The conclusion about effects of RRS on AOA communities in the study: the diversity analysis indicated that Shannon-Wiener diversity indexes (Dsh) and evenness indexes (Jsh) related to ammonia-oxidizing archaea (AOA) in RRS rhizospheric soils were similar to those of near-isogenic counterparts (RRS-S), W-S and D-46, and the difference was not significant among them; the principal component analysis demonstrated that the compositions of ammonia oxidizing archaeal communities in RRS rhizospheric soils were different from those of the other soybeans (D-46 and W-S), but not significantly different from its parent RRS-S; AOA amoA gene sequencing of DGGE bands and phylogenetic analysis revealed that parts of AOA in the rhizospheric soils of different genotypes’soybeans belonged to clusters which had presented in the present references in the soils, others belonged to unknown clusters or groups in the present references,but none of AOA identified belonged to water-like AOA or sediment-like AOA. In addition, the AOA amoA sequences associated with the soil samples mostly grouped within the amoA cluster 6, cluster 7 and cluster 8, and cluster 6 AOA were the most dominant AOA inhabiting in the rhizospheric soils of different genotypes’soybeans. RRS promoted some groups of ammonia oxidizing archaeal communities, such as groups represented by bands 3, however, inhibited the other groups, such as groups represented by band 1, 20 and 25. Our results indicated that RRS didn’t affect the diversity of AOA or there were only a smaller impact on the diversity and the community structure of AOA ,but RRS affected the growth and distribution of some groups of AOA in rhizospheric soils to some extent.更多还原