饭豆(Vignaumbellata L.)根瘤菌的分离及多样性

DIVERSITY OF RHIZOBIA ISOLATED FROM RICE BEAN (VIGNA UMBELLATE L.)

从生长在湖北省几种不同土壤中两类饭豆 (VignaumbellataL .)的根瘤中分离、纯化并通过结瘤试验筛选出2 6株饭豆根瘤菌 ;对这些菌株和来自其它种属的 8个参比菌株的培养特性、生长速度、耐酸碱性、生长最终 pH值、耐盐性、天然抗药性、碳源和氮源的利用及部分快生型菌株质粒图谱进行了系统的比较研究 ,并通过聚类分析得到数值分类树状图谱 .结果发现 ,分离自不同类型土壤中的饭豆根瘤菌具有较大的多样性 ,在 77%的相似水平上 ,形成了三大类群 ,群Ⅰ为慢生型菌群 ,群Ⅱ与群Ⅲ为快生型菌群 ,在 80 %相似水平上各群又可进一步划分为不同亚群 ,而且亚群中部分菌株的相似性与地理来源有相关性 .图 2表 4参

Twenty-six rhizobia strains were isolated and purified from the nodules of 2 cultivars of rice bean (Vigna umbellata L.) collected from different soils located at various ecological sites in Hubei, China. These strains and 8 reference strains of other genus and species of rhizobia were comparatively studied by determining their biological characteristics including growth rate, acid-alkali endurance, salt stress, resistance of intrinsic antibiotics, utilization of carbon and nitrogen sources and plasmid profiles. The dendrogram was described by using cluster analyses, and the biodiversity of rhizobia isolated from rice bean was shown. At the similarity of 77%, all strains could be divided into 3 groups. GroupⅠ consisted of slow-growing strains. Fast-growing strains fell into groups Ⅱ and Ⅲ. The 3 groups were further divided into different subgroups at the similarity of 80%. Similarities of some strains clustered into a subgroup were related with geographical sampling sites. Fig 2, Tab 4, Ref 13