分离自杭子梢等3个宿主的根瘤菌的表型分析*

对86株分离自杭子梢、决明和菜豆的根瘤菌及20株已知参比菌进行了数值分类和全细胞蛋白SDS-PAGE的表型分析。在数值分类聚类中，所有供试菌在68％的相似性水平上分为两群。群I为快生和中侵生根瘤菌，群Ⅱ为慢生根瘤菌。群I在85％的相似性水平上又可分为3个亚群，群Ⅱ在76％的相似性水平上分为3个亚群。蛋白电泳结果表明，群I在68％的相似性水平上，分为4个亚群，其中亚群1和亚群2相当于数值分类中的亚群1，亚群3和亚群4与数值分类中的亚群2和亚群3相对应；群Ⅱ在59％的相似性水平上分为3个亚群，分别与数值分类中的亚群3、亚群1和亚群2大致对应。这说明两种方法在分类上得到的结果比较接近。正在通过进一步的实验确定两种方法一致的未与已知菌株聚在一起的亚群的分类地位。研究结果还表明，三种宿主的根瘤菌存在着多样性。

PHENOTYPIC ANALYSIS OF RHIZOBIA ISOLATED FROM THREE HOSTS

strains of rhizobia isolated from root nodules of Campylotropis, Cassia and Phaseolus were classified by numerical taxonomy and SDS PAGE of whole cell proteins. 20 reference strains were included for comparison. The strains formed 2 groups by numerical taxonomy at 68% similarity. Group I contained all of fast and medium slow growing strains and group II slow growing strains. Group I and II were divided into three subgroups at 85% and 76% similarity respectively. The result of SDS PAGE of whole cell proteins indicated that group I might be divided into four subgroups and group II three subgroups at 68% and 59% similarity respectively. In group I, subgroup 1 and 2 corresponded to subgroup 1 of numerical taxonomy, subgroup 3 and 4 to the other two subgroups 2 and 3 of numerical taxonomy respectively. In group II, three subgroups corresponded basically to subgroup 3, 1 and 2 of numerical taxonomy. It showed that we could get close results by these two methods. The common subgroups of the two methods, which did not cluster with the established, were being identified by further study. The results also suggested that diversity existed among the rhizobia of the three hosts.