Investigation on Resources of Nitrogenfixing Leguminous Tree Species and Rhizobia in Jingdong County of Yunnan Province

70 nitrogenfixing leguminous tree species (NfLTS) that are symbiotic with the appropriate rhizobium strains were identified and recorded through the primary investigation on the relevant resources in Jingdong County, Yunnan Province. Among the 70 species, there was only one species of one genus from the family of Caesalpinioideae and there were 20 species of 6 genera from Mimosaideae family and 49 species of 23 genera from Papilionoideae family. The volume and shape of the nodules varied with the leguminous tree species and rhizobia. The shapes of the nodules were usually globose, ellipse, rodlike and coralloid, and the color appearances on the surface of the nodules were light yellow, blackbrown, brown or black. 147 rhizobia strains were isolated, identified and preserved from the living nodules of 38 NfLTS. This investigation showed that there were rich resources of both NfLTS that can be developed as the multipurpose tree species and rhizobia or strains in Jingdong County and in other southsubtropical or tropical regions of Yunnan Province, which could be utilized for both scientific research and development purposes.