刺槐根瘤菌的表型多样性研究

从杨陵地区采集豆科树种刺槐的根瘤，经分离、纯化，获得40株未知菌株，并选取35株参比菌株，进行唯一碳源、氮源利用、对抗生素和染料的抗性、耐盐性、初始pH生长、生长温度范围及石蕊牛奶反应等共105项生理生化测定。结果表明：供试的刺槐根瘤菌在碳、氮源利用、抗生素敏感性、对染料的抗性程度等方面存在着差异。部分菌株具有较强的耐盐碱能力，其中42．5％的菌株能耐受3.0％的NaCl，17．5％的菌株可在初始pH12的YMA培养基上生长。从数值分类树状图可见，在86％的相似水平上未知菌株构成了3个新的类群，其中第1、2类群各有10株菌，中心菌株分别为NWYC113和NWYCl29，第3类群有7株菌，中心菌株为NWYC147。其分类地位需进一步研究和确定。

Study on phenotypic feature diversity of rhizobia isolated from Robinia pseudoacacia

40 unknown strains of rhizobia isolated from Robinia pseudoacacia in Yangling, Shaanxi province and 34 reference strains were analyzed with 105 phenotypic features and numerically classified. The result showed that there was difference in the features of carbon and nitrogen source, resistance to antibiotics and chemical dye, endurance to salt alkali among strains isolated from Robinia pseudoacacia. 42.5% strains had properties resistant to 3.0% NaCl, 17.5% of strains can grow in YMA medium with pH12. Unknown strains were clustered into three new clusters different from known species at the similarity of 86%. Both cluster 1 and cluster 2 had 10 strains, NWYC113 was the central strain of cluster 1, and NWYC129 was the central strain of cluster 2. Cluster 3 had 7 strains and NWYC147 was the central strain.