贺兰山地区油松根际固氮菌的多样性研究

对贺兰山北寺自然保护区油松(Pinus tabulaeformis)的根际土壤固氮菌多样性和群落结构进行研究。采用阿须贝培养基对土壤中的固氮菌进行分离和纯化,用通用引物27f/1492r对固氮菌进行16S r DNA扩增并测序,应用DNAMAN 6.0软件进行多序列比对,用MEGA 4.0软件构建聚类树。结果表明:从贺兰山北寺油松根际土壤中分离出的固氮菌属于假单胞菌属(Pseudomonas)、芽孢杆菌属(Bacillus)、叶杆菌属(Phyllobacterium)、节杆菌属(Arthrobacter)、根瘤菌属(Rhizobium)、类芽孢杆菌属(Paenibacillus)、鞘氨醇单胞菌属(Sphingomonas)、柄细菌属(Caulobacter)、土地杆菌属(Pedobacter)等9个不同的类群,其中假单胞菌属(Pseudomonas)、芽孢杆菌属(Bacillus)、叶杆菌属(Phyllobacterium)、节杆菌属(Arthrobacter)是优势类群。这表明贺兰山北寺地区油松根际土壤中固氮菌具有较丰富的多样性。

Diversity of nitrogen-fixing bacteria isolated from Pinus tabulaeformis in Helan Mountains

The diversity and community structure of nitrogen-fixing bacteria isolated from Pinus tabulaeformis rhizosphere in Helan Mountains was studied. Nitrogen-fixing bacteria from rhizosphere soil were isolated and purified by Ashby’ s Medium,the 16S rDNA gene of nitrogen-fixing bacteria was amplified using primers 27f/1492r and sequenced,the align-ment of 16S rDNA sequences was conducted by DNAMAN 6.0,and the neighbor-joining phylogenetic tree was construc-ted by MEGA 4.0 software. The results showed that nitrogen-fixing bacteria isolated from P. tabulaeformis belonged to nine groups,which were Pseudomonas,Bacillus,Phyllobacterium,Arthrobacter,Rhizobium,Paenibacillus,Sphin-gomonas,Caulobacter,Pedobacter,and Pseudomonas,Bacillus,Phyllobacterium,Arthrobacter were dominant groups.The results indicated that nitrogen-fixing bacteria from P. tabulaeformis in Helan Mountains have rich diversity.