Zhang Yong Fa, Wang En Tao, Tian Chang Fu, Wang Feng Qin, Han Li Li, Chen Wen Feng, Chen Wen Xin
The Key Laboratory of Agro-Microbial Resource and Application (Ministry of Agriculture), College of Biological Sciences, China Agricultural University, Beijing, China.
FEMS Microbiol Lett. 2008 Aug;285(2):146-54. doi: 10.1111/j.1574-6968.2008.01169.x. Epub 2008 Jun 28.
Cowpea (Vigna unguiculata) and mung bean (Vigna radiata) are important legume crops yet their rhizobia have not been well characterized. In the present study, 62 rhizobial strains isolated from the root nodules of these plants grown in the subtropical region of China were analyzed via a polyphasic approach. The results showed that 90% of the analyzed strains belonged to or were related to Bradyrhizobium japonicum, Bradyrhizobium liaoningense, Bradyrhizobium yuanmingense and Bradyrhizobium elkanii, while the remaining represented Rhizobium leguminosarum, Rhizobium etli and Sinorhizobium fredii. Diverse nifH and nodC genes were found in these strains and their symbiotic genes were mainly coevolved with the housekeeping genes, indicating that the symbiotic genes were mainly maintained by vertical transfer in the studied rhizobial populations.
豇豆（Vigna unguiculata）和绿豆（Vigna radiata）是重要的豆科作物，但其根瘤菌尚未得到很好的表征。在本研究中，通过多相方法分析了从生长在中国亚热带地区的这些植物根瘤中分离出的62株根瘤菌菌株。结果表明，90%的分析菌株属于或与日本慢生根瘤菌（Bradyrhizobium japonicum）、辽宁慢生根瘤菌（Bradyrhizobium liaoningense）、圆明慢生根瘤菌（Bradyrhizobium yuanmingense）和埃氏慢生根瘤菌（Bradyrhizobium elkanii）相关，而其余的代表豌豆根瘤菌（Rhizobium leguminosarum）、菜豆根瘤菌（Rhizobium etli）和费氏中华根瘤菌（Sinorhizobium fredii）。在这些菌株中发现了不同的nifH和nodC基因，并且它们的共生基因主要与管家基因共同进化，这表明共生基因在研究的根瘤菌群体中主要通过垂直传递得以维持。
