将采集自甘肃、新疆、宁夏等地区的苦马豆根瘤,经分离、纯化获得48株未知菌株,并选取7株参比菌株,进行唯一碳、氮源利用、对抗生素及染料抗性、耐盐性、初始pH生长、生长温度范围及酶活性等共113项生理生化测定;采用数值分类方法对未知根瘤菌进行表型多样性分析。结果表明:供试菌株在碳氮源利用、抗生素敏感性、抗逆性等方面存在着差异。该地区苦马豆根瘤菌具有较强的耐盐、耐碱能力,所有菌株均能在初始pH9~12的YMA培养基上生长,35%菌株可耐受6%的NaCl。从数值分类树状图可见,未知供试菌株在56%的相似水平上聚在一起,在72%的相似水平上分为5个表观群。群Ⅰ有39株菌,在74.6%相似水平聚合,中心菌株为CCNWGS0215;群Ⅱ有5株菌,在76%的相似水平聚合,中心菌株为CCNWGS0228;群Ⅳ有2株菌,在81.5%的相似水平聚合,群Ⅲ和群Ⅴ分别只有1株菌,它们与模式株分离,可能为潜在的新种。
Forty-eight unknown Rhizobium strains isolated and purified from Sphaerophysa salsula(RSS) in northwest China and 7 selected reference strains were analyzed by 113 tests included unique carbon and nitrogen sources utilization,resistance against antibiotics,stain,salt,initial pH of growth,growth temperature,enzymatic activity,physiological and biochemical items and numerical taxonomy for phenotypic diversities.The results revealed that there were differences on their carbon and nitrogen sources utilization,sensitivity to antibiotics,resistances and other aspects.RSS from the area had the resistance against salt and base,all the RSS strains could grow on YMA medium at initial pH at 9~12,35% of the strains could resist 6% NaCl.The dendrogram of numerical taxonomy showed that the unknown tested strains gathered in the similarity level at 56%.They formed five new phenotypic clusters at the similarity level of 72%.ClusterⅠhad 39 strains,they gathered in the similarity level at 74.6%,the central strain was CCNWGS0215;ClusterⅡhad 5 strains,they gathered in the similarity level at 76%,the central strain was CCNWGS0228;Cluster Ⅳ had 2 strains,they gathered at the similarity level of 81.5%.Clusters Ⅲ and V had only one strain respectively,and they segregated from model strains,indicated that they may be potential new species.