Diversity And Plant-growth Promotion Functions Of The Culturable Bacteria In The Roots Of Moso Bamboo (phyllostachys Edulis) Plants

The diversity of culturable endophytic bacteria in the roots of greenhouse moso bamboo (Phyllostachys edulis) plants was investigated by culture-dependent methods. The endophytic bacterial strains isolated from the roots of wild plants are less than that of the space mutant plants. 126 strains with different colony characteristics were isolated with Luria-Bertani and King′s B media. Amplified ribosomal DNA restriction analysis (ARDRA) and partial sequence analysis of 16S rDNA gene indicated that the population diversity of culturable endophytic bacteria was abundant in the roots of greenhouse moso bamboo plants. 66 strains isolated from wild plants were grouped into six groups and fifteen genera, while 60 strains isolated form mutant plants were clustered into five groups and eight genera. The members of Alphaproteobacteria, Gammaproteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes were found both in the roots of wild and mutant plants. The majority of root endophytic bacteria were the members of Alphaproteobacteria, while the most dominant genera was Rhizobium. The members of Betaproteobacteria were only found in the roots of space mutant plants. Several potential novel strains were found at the same time.A novel endophytic strain AK43 6.1T was studied on the basis of morphological, phylogenetic and chemotaxonomic data, for which the name Parapedobacter phyllostachys sp. nov. is proposed.Plant-growth promotion fuctions of 387 bacterial strains isolated from the roots of moso bamboo plants were analyzed. Results showed that there were 36 strains with phosphate-solubilizing activity, 58 strains with IAA producing activity, and 78 strains with siderophore-producing activity. The strain with highest phosphate-solubilizing activity was BK24, 369.06 mg/L; the strain with maximal IAA concentration was AP5-2, 4.08μg/mL; the strain with highest siderophore producing activity was H87.