Phosphate-dissolving bacteria isolated from rhizosphere of mangrove were characterized by 16S rDNA PCR-RFLP and 16S rDNA sequence to describe the genetic diversity and phylogeny. The dendrogram of 16S rDNA PCR-RFLP revealed the 24 isolated stains were assembled at 59% similarity level. The strains were grouped into 7 subgroups at 80% similarity. Phylogenetic tree of 16S rDNA sequences was constructed with representative strains in reference to the homogenous sequences in Genebank,and the result showed that Bacillus sp. was the dominant member,besides Paenibacillus sp.,Vibrio sp.,Klebsiella sp. and Pseudomonas sp. were also found.The highly genetic diversity was highly revealed by this study.In addition,the phosphate-dissolving capacity to dissolve solubilize the unsolvable inorganic phosphorus of bacteria was tested.All representative strains had the phosphate-dissolving capacity.The pH of liquid media of strains both were reduced to some degree,but the correlations were not found between phosphate-dissolving capacity and pH of the culture solution.
【目的】针对采集自福建、广东的34株黑木相思根瘤菌进行分类研究,进一步确定其分类地位,丰富我国黑木相思根瘤菌种质资源。【方法】对选取的34株菌株测定了16S r RNA基因、持家基因atp D和gln II序列,以14株菌为代表菌株分析其系统发育情况。而且选取了部分菌株进行结瘤实验。【结果】16S r RNA基因以及持家基因atp D和gln II的系统发育分析结果与16S r RNA PCR-RFLP分型结果基本一致,14株代表菌株被分为10个不同的类群,其中有2个群组属于中慢生根瘤菌属(Mesorhizobium),其余群组属于慢生根瘤菌属(Bradyrhizobium)。结瘤试验证明,相关的供试根瘤菌能与黑木相思、银合欢、南洋楹和网脉相思结瘤共生,显示出较广的宿主范围,且对黑木相思和银合欢的促生效果较明显。【结论】研究发现黑木相思根瘤菌具有丰富的遗传多样性和共生多样性。
