兰坪铅锌尾矿区豆科植物根瘤菌的多样性及抗性研究

对兰坪铅锌尾矿区自然发生的植物进行调查,共发现18种植物,分属于10科。对野豇豆（Vigna vexiauata（Linn.）Bench.）、长波叶山蚂蝗（Desmodium sequax Wall.）、三叶草（Trifolium pratense Linn.）、白刺花（Sophora davii（franch.）Skeels）、密花序黄芪（Astragalus forrestii Simpson.）、美丽胡枝子（Lespedeza Formosa（Vog.）Koehne.）6种8株豆科植物根瘤进行根瘤菌的分离纯化,共得到419株细菌,经镜检初步确定有94株为根瘤菌。对其中31株根瘤菌的淀粉水解、糖发酵等12项生理生化指标进行测定,并以平均连锁法进行聚类分析。结果表明,兰坪铅锌尾矿区31株根瘤菌在50%的相似水平上可分为6个类群,其表型特性存在明显差异,同一种植物中可能存在不同代谢类型的根瘤菌,同一种代谢类型的根瘤菌也可与不同植物共生。抗逆性测定结果表明,菌株（4G.7、5.4.3、7.4.3）对温度、（4A.12、4G.7、4G.10、5.4.3）对pH、（3.7.9、5.4.3）对盐、（3.7.19、4A.12、6.1.2、6.1.13）对抗生素有较强耐受性或抗性,大多数菌株能在较宽的温度、盐度和pH范围内生长。

Diversity and resistance of rhizobia from legumes in Lanping lead and zinc mine tailings

Eighteen wild species plants founded in Lanping lead and zinc mine tailings were classified into 10 family.419 bacteria were isolated from root nodules of 8 legumes,which belong to Vigna vexiauata（Linn.）Bench.,Desmodium sequax Wall.,Trifolium pratense Linn.,Sophora davii（franch.）Skeels.,Astragalus forrestii Simpson.,Lespedeza Formosa（Vog.） Koehne.,and 94 strains were identified as rhizobia by Gram’s method and microscopy.The physiological and biochemical characters of 31 rhizobia were detected.The matrix was computed to construct an average linkage analysis（UPGMA） dendrogram.The cluster results showed that 31 rhizobia were divided into 6 groups at 50% similarity,which existed remarkable differences in the phenotypic traits.Different metabolism types of rhizobia could exist in the same plant,and the same rhizobia could also grow symbiotically with different plants.The resistance test results showed that strains（4G.7,5.4.3,7.4.3） were of strong tolerance or resistance to temperature,and strains（4A.12,4G.7,4G.10,5.4.3） were of strong tolerance or resistance to pH,NO.3.7.9,5.4.3 strains were of strong tolerance or resistance to NaCl,and other strains,such as No.3.7.19,4A.12,6.1.2,6.1.13,were of strong tolerance or resistance to antibiotic.Most of strains grew well in a wide range of temperature,pH,NaCl.