连作与轮作大豆土壤反硝化细菌多样性与组成结构(英文)

Molecular Deversity and Characterization of Nitrite Reductase Genes from Continuous and Rotational Cropping Soybean

应用PCR-RFLP方法对连作与轮作大豆土壤中反硝化微生物种群和分类进行研究。结果 2种土壤样品中均可检测到反硝化微生物存在。从2种土壤中获取268个nirS基因克隆,46种基因型,其中连作土壤中有29种基因型,轮作土壤中有34种基因型,分析结果显示2种土壤样品中均有优势菌群存在,并且连作土壤样品中反硝化细菌的优势菌群略多于轮作土壤样品。序列同源性分析显示nirS基因克隆序列与已知反硝化微生物具有较远的亲缘关系。结果提示:与轮作大豆相比,连作大豆土壤中反硝化微生物的遗传多样性和组成有所改变,类群的结构组成易受耕作方式影响。

Gene sequence analysis of nitrite reductases was performed on continuous cropping and rotational cropping soils of soybean to assess their incidence in different bacterial taxa and their taxonomical value.NirS gene fragments could be amplified from both soils.A total of 268 nirS clones were detected by restriction fragment length polymorphism（RFLP） analysis and obtained 29 and 34 distinct nirS clones in continuous cropping and rotational cropping soils respectively.A dominant nirS pattern,a single dominant nirS restriction pattern of rotational cropping,was observed in both samples.Beside above pattern,another two dominant patterns were also detected in continuous cropping soil.Many of the sequences belonged to dominant pattern were not closely related to previously observed genes and some phylogenetically related sequences were obtained from similar samples.The results indicated that the continuous cropping and rotational cropping soils contained novel nirS sequences,functional diversity of nirS genes changed in the two type soils.