神木地区耐旱灌木和草本豆科植物根瘤菌遗传多样性  

Genetic diversity of rhizobia isolated from shrubby and herbaceous legumes in Shenmu arid area,Shaanxi,China

作　　者：聂刚[1] 陈卫民[1] 韦革宏[1] 

机构地区：[1]西北农林科技大学,陕西杨凌712100

出　　处：《应用生态学报》2014年第6期1674-1680,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(31125007)资助

摘　　要：豆科植物具有抗逆性强、耐瘠薄的特性,许多豆科植物是荒漠地区的先锋植物,在生态环境保护中起重要作用.以神木地区主要的灌木和草本豆科植物-根瘤菌共生体系为材料,采用16S rRNA PCR-RFLP和序列分析等方法,对分离得到的55株菌进行多样性分析,其中,30株菌分离自灌木豆科植物紫穗槐和柠条,25株菌分离自草本豆科植物斜茎黄芪、苜蓿、草木樨黄芪等.结果表明:这些菌株共有11种16S rRNA PCR-RFLP遗传图谱类型,分离自草本豆科植物的菌株主要归属于中慢生根瘤菌属、剑菌属、根瘤菌属、叶瘤杆菌属和土壤杆菌属5个属,分别与华癸中慢生根瘤菌、地中海中慢生根瘤菌、刺槐中慢生根瘤菌、费氏剑菌、草木樨剑菌、木兰根瘤菌、放射根瘤菌、突尼斯叶杆菌和根癌土壤杆菌系统发育关系最近.分离自灌木豆科植物的菌株仅归属于中慢生根瘤菌属,分别与华癸中慢生根瘤菌和地中海中慢生根瘤菌系统发育关系最近.华癸中慢生根瘤菌和地中海中慢生根瘤菌是两类豆科植物的共生菌种,表明在干旱地区,根瘤菌对两种类型豆科植物的选择共生存在差异,这与豆科植物种类有关,还可能与其所处生态环境有关.Legume, with a strong resistance to the adverse environmental conditions, is one of pio- neer plants in the desert region and plays an important role in the protection of the ecological envi- ronment. In this study, the symbiosis of rhizobia associating with shrubby and herbaceous legumes in Shenmu area, Shaanxi, China was characterized by the 16S rRNA PCR-RFLP and sequence analysis of involved genes. A total of 55 strains were isolated and purified, including 30 strains from the shrubby legume Amorpha fruticosa and Caragana microphylla, and 25 strains from herbaceous plants Astragalus adsurgens , Medicago sativa and Astragalus melilotoides. Results showed that there were 11 16S rRNA genotypes. The strains isolated from herbaceous legumes belonged to five genus including Mesorhizobium , Ensifer , Rhizobium , Phyllobacterium and Agrobacterium , which were very close related to M. huakuii, M. mediterraneum, M. robiniae, E. fredii, E. meliloti, R. indigoferae, R. radiobacter, P. ifriqiyense and Ag. tumefaciens through the phylogenetic analy- sis. The strains isolated from shrubby legumes belonged to Mesorhizobium, and they were very close related to M. huakuii and M. mediterraneum which were shared simultaneously by shrubby and her- baceous legumes. All of these indicated the choice of rhizobia by the two types of legumes in the arid area was different, and it might depend on the species of host plant and environmental factors.

关 键 词：耐旱植物根瘤菌16S RRNA PCR-RFLP多样性 

分 类 号：Q939.114[生物学—微生物学]