豆科树种刺槐、黄檀、合欢根瘤菌的数值分类及16S rDNA-PCR RFLP研究

NUMERICAL TAXONOMY AND 16S rDNA-PCR RFLP OF NODULEBACTERIA ISOLATED FROM ROOT NODULES OF LEGUMINOUSTREES, ROBINIA SP.,DALBERGIA SPP.,AND ALBIZIA SPP.

测定了从豆科树种刺槐、黄檀、合欢根瘤中分离获得的 5 1个菌株与 18株参比菌株的唯一碳源、氮源利用 ,抗生素抗性 ,耐逆性和酶活性等 132个表型性状 ,并用MINTS软件进行聚类分析 .结果表明 ,全部供试菌株在 5 9%的相似性水平上分为两大群 :一个群为慢生菌群 ,另一群为快生和中慢生菌群 .在 85 .1%的相似性水平上分为 5个亚群 ,其中亚群 4不与任何已知参比菌株聚在一起 ,可能为新种 .同时 ,表型性状测定结果发现某些菌株对抗生素 (30 0 μg/mL)、温度 (40℃ )有较强抗性 ,大多数菌株能在较宽的pH值范围内生长 (pH 5～ 12 ) .这些具有抗逆特性的菌株为我国西部大开发中种植豆科植物接种适宜的根瘤菌提供了宝贵的种质资源 .在数值分类的基础上 ,又对 47株菌进行了 16SrDNA PCRRFLP分析 ,经SPSS软件聚类后 ,划分为 7个亚群 .在较大类群的划分上 ,与数值分类的结果有较好的一致性 .16SrDNA PCRRFLP遗传图谱共有 30种类型 .表型及遗传型分析结果表明 ,豆科树种根瘤菌具有极大的多样性 .图 2表 2参

Fifty-one rhizobial strains, isolated from root nodules of woody legumes (Robinia spp.,Dalbergia spp. and Albizia sp.),were studied by a fuzzy analysis of 132 phenotypic characteristics. All the strains were clustered into 2 groups at the similarity level of 59%.At the similarity level of 85.1%, there were 5 subgroups could be further clustered. One of them, subgroup 4,including 9 strains, maybe one new species. Some strains can grow under severe environment such as high concentration of antibiotics(300 μg/mL) and high temperature(40 ℃). The results indicated that tree rhizobia were very diverse with respect to their physiological and biochemical properties. It should be noted that strains from different geographical origins but belonging to the same taxon were, as a rule, grouped with one another. 16S rDNA-PCR RFLP were used to 37 strains (among the 51 strains) and 10 reference strains. Results were analyzed by SPSS software. All the 51 strains were grouped into 7 subgroups. There are 30 genotypes of 16S rDNA-PCR RFLP. Overall, the results demonstrated a high phenotypic and phylogenetic diversity of rhizobial strains nodulting tree regumes. Fig 2, Tab 2, Ref 14