摘要
对分离自中国14个不同省（自治区）的79株豇豆和绿豆根瘤菌及12株参比菌株进行了唯一碳、氮源利用，抗生素抗性，抗逆性和酶活性等128个表型性状的测定，并用MINTS软件进行聚类分析。表型性状测定结果发现，所有菌株都有极其广泛的碳、氮源利用谱，大多数菌株可在较宽的pH（pH5．0-11．0）值范围内生长，大部分菌株能在37℃高温条件下生长，个别菌株能耐受60℃高温较长时间（20-45min）的热激。聚类分析结果表明，全部供试菌株在63．5％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79％的相似性水平上分为7个亚群。在数值分类的基础上，又将参比菌株增加到22株，对79株待测菌株进行了16S rDNA PCR-RFLP分析，16S rDNA PCR产物经Hae Ⅲ、HinfⅠ、MspⅠ和AluⅠ4种内切酶酶切共产生34种遗传图谱类型，经GelComparⅡ软件聚类后，在79％的相似性水平上也可划分为7个亚群，与数值分类的结果有很好的一致性。
Seventy-nine rhizobial strains, isolated from root nodules of cowpea （ Vigna unguiculata ） and mung bean （Vigna radiata ） grown in different regions of China, were studied by a fuzzy cluster analysis of 128 phenotypic characteristics. The phenotypic characterization of these strains showed that most of these strains had high stress resistance. For instance, most of them could grow from pH 5.0 to pH 11.0. Over 85 % of these strains could grow well on YMA plate at 37 ℃ and several of them even could grow after a 45 minutes hot shock at 60℃. Some strains had a tolerance to high concentration of Bacitracin （400μg/mL）. The result of the fuzzy cluster analysis showed that all the strains were clustered into 2 groups, slow growers and fast growers, at the similarity level of 63.5 %. At the similarity level of 79 %, there were 7 subgroups further separated.
Based upon the result of the numerical taxonomy, these strains together with 22 reference stains were analyzed by the 16S rDNA PCR-RFLP. Thirty-four genotype profiles were obtained from the fingerprinting of the 16S rDNA PCR- RFLP. These strains were analyzed by GelCompare Ⅱ software and clustered into 7 groups at the similarity level of 91%, which were consonant with the 7 subgroups clustered at the similarity level of 79% in numerical taxonomy.
The results of numerical taxonomy and 16S rDNA PCR-RFLP analysis showed that all of the seventy-nine rhizobial strains isolated from root nodules of cowpea and mung bean were clustered into four genera： Bradyrhizobium, Agrobacterium, Rhizobium and Sinorhizobium, respectively.
An individual clade without any reference stains, which was composed of CCBAU 45071, CCBAU 45111-1 and CCBAU 45248, might be a new species of Rhizobium. Overall, the study results demonstrated a high phenotypic and phylogenetic diversity of rhizobial strains nodulating cowpea and mung bean grown in different geographic regions of China.
出处
《微生物学报》
CAS
CSCD
北大核心
2006年第6期861-868,共8页
Acta Microbiologica Sinica
基金
高等学校博士学科点专项科研基金(20050019017)~~
作者简介
张勇法（1974-），男，河南濮阳人，博士研究生，主要从事根瘤菌多相分类及其系统发育研究。E-mail：zyf_1001@163．com
通讯作者。Tel：86-10-62731854；Fax：86-10-62734008：E-mail：wenxin_chen@263．net
