Gu Chun Tao, Wang En Tao, Sui Xin Hua, Chen Wen Feng, Chen Wen Xin
Key Laboratory of Agro-Microbial Resource and Application, Ministry of Agriculture/Department of Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100094, China.
Arch Microbiol. 2007 Oct;188(4):355-65. doi: 10.1007/s00203-007-0256-3. Epub 2007 May 26.
Eighty-eight root-nodule isolates from Lespedeza spp. grown in temperate and subtropical regions of China were characterized by a polyphasic approach. Nine clusters were defined in numerical taxonomy and SDS-PAGE analysis of whole cell proteins. Based upon further characterizations of amplified 16S rDNA restriction analysis (ARDRA), PCR-based restriction fragment length polymorphism of ribosomal IGS, 16S rDNA sequence analysis and DNA-DNA hybridization, these isolates were identified as Bradyrhizobium japonicum, B. elkanii, B. yuanmingense, Mesorhizobium amorphae, M. huakuii, Sinorhizobium meliloti and three genomic species related to B. yuanmingense, Rhizobium gallicum and R. tropici. The Bradyrhizobium species and R. tropici-related rhizobia were mainly isolated from the subtropical region and the species of Mesorhizobium, S. meliloti and R. gallicum-related species were all isolated from the temperate region. Phylogenetic analyses of nifH and nodC indicated that the symbiotic genes of distinct rhizobial species associated with Lespedeza spp. might have different origins and there was no evidence for lateral gene transfer of symbiotic genes. The results obtained in the present study and in a previous report demonstrated that Lespedeza spp. are nodulated by rhizobia with diverse genomic backgrounds and these Lespedeza-nodulating rhizobia were not specific to the host species, but specific to their geographic origins.
采用多相分类方法对从中国温带和亚热带地区生长的胡枝子属植物中分离得到的88株根瘤菌进行了鉴定。通过数值分类和全细胞蛋白的SDS-PAGE分析确定了9个聚类。基于对扩增的16S rDNA限制性分析（ARDRA）、核糖体IGS的基于PCR的限制性片段长度多态性、16S rDNA序列分析和DNA-DNA杂交的进一步鉴定，这些分离物被鉴定为日本慢生根瘤菌、埃氏慢生根瘤菌、圆明慢生根瘤菌、无叶中生根瘤菌、华癸中生根瘤菌、苜蓿中华根瘤菌以及与圆明慢生根瘤菌、加里根瘤菌和热带根瘤菌相关的三个基因组种。慢生根瘤菌属物种和与热带根瘤菌相关的根瘤菌主要从亚热带地区分离得到，而中生根瘤菌属、苜蓿中华根瘤菌和与加里根瘤菌相关的物种均从温带地区分离得到。对nifH和nodC的系统发育分析表明，与胡枝子属植物共生的不同根瘤菌物种的共生基因可能有不同的起源，并且没有证据表明共生基因发生了横向基因转移。本研究和之前一份报告中获得的结果表明，胡枝子属植物被具有不同基因组背景的根瘤菌结瘤，这些结瘤的根瘤菌不是宿主物种特异性的，而是地理起源特异性的。
