van Berkum P, Beyene D, Eardly B D
Soybean and Alfalfa Research Laboratory, BARC-West, U.S. Department of Agriculture, Beltsville, Maryland 20705, USA.
Int J Syst Bacteriol. 1996 Jan;46(1):240-4. doi: 10.1099/00207713-46-1-240.
The phylogenetic relationships among Rhizobium species that nodulate Phaseolus vulgaris (common bean) were determined by directly sequencing the amplified 16S ribosomal DNA genes of these organisms. The bean strains formed four separate clusters. One cluster was composed of Rhizobium leguminosarum bv. trifolii, R. leguminosarum bv. viciae, and R. leguminosarum bv. phaseoli. Two other clusters comprised Rhizobium etli and Rhizobium tropici, and the fourth cluster contained a single bean-nodulating strain. Data for species identification were obtained from DNA-DNA reassociation experiments. The levels of DNA relatedness among strains belonging to the three biovars of R. leguminosarum ranged from 58 to 67%. The levels of DNA relatedness between R. leguminosarum bv. phaseoli and R. etli and R. tropici ranged from 43 to 45% and 13 to 16%, respectively. The levels of DNA relatedness between the strain belonging to the fourth cluster and strains of the other three Rhizobium species that nodulate beans were less than 10%.
通过直接对能使菜豆（普通豆）结瘤的根瘤菌属物种的16S核糖体DNA基因进行扩增测序，确定了这些根瘤菌属物种之间的系统发育关系。菜豆菌株形成了四个独立的簇。一个簇由豌豆根瘤菌三叶生物型、豌豆根瘤菌蚕豆生物型和豌豆根瘤菌菜豆生物型组成。另外两个簇包含埃氏根瘤菌和热带根瘤菌，第四个簇包含一个单一的菜豆结瘤菌株。物种鉴定数据来自DNA-DNA重联实验。豌豆根瘤菌三个生物型的菌株之间的DNA相关性水平在58%至67%之间。豌豆根瘤菌菜豆生物型与埃氏根瘤菌和热带根瘤菌之间的DNA相关性水平分别在43%至45%和13%至16%之间。属于第四个簇的菌株与其他三种能使菜豆结瘤的根瘤菌属物种的菌株之间的DNA相关性水平低于10%。
