华东地区豆科树种根瘤菌多样性的研究

华东地区５１个豆科树种（含羞草亚科５属，蝶形花亚科１８属）根瘤中分离获得的６６个菌株经形态、生理生化、抗逆性等性状测定，对４２个性状进行了聚类分析，除９２７８２菌株外，６５个菌株在０７５的相似水平上可划分为６个菌群。根据菌株的生长速度，６个菌群可以分为快生和慢生两个类群，但两类群的某些性状与目前根瘤菌分类系统中的分属辨别特征不完全符合，如部分菌株能利用其淀粉。聚类分析结果还表明，菌群划分的主要依据是表型特征，与寄主的种类、来源没有相关性。６６个菌株在形态、生理生化、抗逆性以及交叉结瘤试验结果存在明显差异，表明了豆科树种根瘤菌的多样性。

DIVERSITY OF NODULE BACTERIA ISOLATED FROM THE ROOT NODULES OF LEGUMINOUS TREES IN EAST CHINA

Sixty six rhizobial strains, isolated from root nodules of fifty one species of woody legumes (five genera in subfamily Mimosoideae and eighteen genera in subfamily Papilionoideae) in East China, were studied by performing a fuzzy analysis of 42 phenotypic characteristics. Six clusters were formed below the boundary level of 0.75 average distance except 92 78 2 strain. We consider that six clusters should belong to the fast growers and slow growers. However, the properties of the two growers are correspond incompletely with the differential characters of the 4 genera in the rhizobial taxonomic system, for example, some strains can utilize starch as the sole carbon source. The results of numerical analysis also suggest that the primary basis of the division of the clusters is the phenotypic characteristics, and has nothing to do with the category and origin of the hosts. Our results indicate that tree rhizobia are very diverse with respect to their physiological and biochemical properties.