Isolation,Identification And Functional Characterization Of Multifunctional PGPR Associated With Eremophytes

Plant growth promoting rhizobacteria(PGPR)is a kind of beneficial rhizospheric bacteria that can enhance and protect plant growth.It can promote the plants to adapt to the harsh desert ecological environment and can be applied to the ecological agriculture.However,little research is performed on PGPR associated with eremophytes,and the related taxa composition and function are remained unclear.In this research,rhizosphere soil were collected associtated with Haloxylon ammodendron,Ammopiptanthus mongolicus and Nitraria tangutorum in deserts of Badain Jaran,Jilantai,Tengger and Balagong of the Inner Mogolia;the pure culture method applied was to isolat and screen PGPR with biological nitrogen fixation,phosphate solubilization,siderophore production,IAA and ACC production from the rhizospheric soil and the isolates were primarily classified based on 16S rRNA.Isolate and identify.The results showed that totally 472 strains of PGPR were obtained.Among them,191 strains of nitrogen fixing bacteria screened by Ashby medium,the dominant bacteria was Proteobacteria accounted for 85.8%,149 strains of nitrogen fixing bacteria screened by AZO medium,the dominant bacteria was Actinobacteria accounted for 43.7%,53 strains of organic phosphate solubilization bacteria screened by organophosphorus medium,the dominant bacteria was Actinobacteria accounted for 69.8%,79 strains of inorganic phosphate solubilization bacteria screened by NBRIP medium,the dominant bacteria was Actinobacteria accounted for 59.5%.The obtained strains were analyzed for their promoting growth ability,and finally,we had are 9 strains,with have the ability of nitrogen fixation,phosphate solubilizing,siderophore production,IAA and ACC production that the number is 1,58,B58,B70,W64,Y16-1,Y18,Y34,Y43.We isolated 16S rDNA gene sequence analysis showed that the strain 1 was most closely related to Arthrobacter nitroguajacolicus G2-1T(100%),the strain 58 was most closely related to Pseudomonas brassicacearum ATCC 49054T(99.7%),the strain B58 was most closely related to Rhizobium radiobacter ATCC 19358T(100%),the strain B70 was most closely related to Pantoea conspicua LMG 24534T(100%),the strain W64 was most closely related to Rhodococcus marinonascens DSM 43752T(99%),the strain Y16-1 was most closely related to Gordonia terrae NBRC 100016T(100%),the strain Y18 was most closely related to Arthrobacter nicotianae DSM 20123T(98.4%),the strain Y34 was most closely related to Bacillus cereus ATCC 14579T(100%),the strain Y43 was most closely related to Gordonia effusa IFM 10200T(99.2%).