Title Bradyrhizobium spp. and Sinorhizobium fredii are Predominant in Root Nodules of Vigna angularis, a Native Legume Crop in the Subtropical Region of China
Author Li Li Han1, En Tao Wang1,2, Yang Li Lu1, Yong Fa Zhang1,3, Xin Hua Sui1, Wen Feng Chen1, and Wen Xin Chen1*
Address 1State Key Laboratory for Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, P. R. China, 2Departamento de Microbiologia, Escuela Nacional de Ciencias Biol?icas, Instituto Politecnico Nacional, M?ico D. F. 11340, Mexico, 3Department of Food and Bioengineering Science, Henan University of Science & Technology, Luoyang 471003, P. R. China
Bibliography Journal of Microbiology, 47(3),287-296, 2009,
Key Words phylogeny, adzuki bean, rhizobia, diversity
Abstract Adzuki bean (Vigna angularis) is an important legume crop native to China, but its rhizobia have not been well characterized. In the present study, a total of 60 rhizobial strains isolated from eight provinces of China were analyzed with amplified 16S rRNA gene RFLP, IGS-RFLP, and sequencing analyses of 16S rRNA, atpD, recA, and nodC genes. These strains were identified as genomic species within Rhizobium, Sinorhizobium, Mesorhizobium, Bradyrhizobium, and Ochrobactrum. The most abundant groups were Bradyrhizobium species and Sinorhizobium fredii. Diverse nodC genes were found in these strains, which were mainly co-evolved with the housekeeping genes, but a possible lateral transfer of nodC from Sinorhizobium to Rhizobium was found. Analyses of the genomic and symbiotic gene backgrounds showed that adzuki bean shared the same rhizobial gene pool with soybean (legume native to China) and the exotic Vigna species. All of these data demonstrated that nodule formation is the interaction of rhizobia, host plants, and environment characters.