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。 The PCR-RFLP method was used to study the population and classification of denitrifying microorganisms in continuous cropping and rotation soybean soils. Results The presence of denitrifying microorganisms could be detected in both soil samples. A total of 268 nirS gene clones and 46 genotypes were obtained from the two soils. Among them, 29 were genotypes in continuous cropping soil and 34 genotypes in crop rotation. The results showed that there were dominant populations in both soil samples , And the dominant microflora of denitrifying bacteria in soil samples was slightly more than that of rotation soil samples. Sequence homology analysis showed that the cloned sequence of nirS gene has a relatively distant relationship with known denitrifying microorganisms. The results indicated that the genetic diversity and composition of denitrifying microorganisms in continuous cropping soybean soil were changed compared with that of rotating soybean, and the structure and composition of the population were easily influenced by the farming methods.