Isolation,Identification and Studies on Plant Growth-Promoting Properties of a Saline-Alkaline Tolerant Bacterium
XU Yan
LIANG Zhenpu
ZHANG Guozhi
YANG Xinping
ZHANG Xiaoxia
Abstract：To provide microbial resources for the research and development of functional microbial fertilizers and the improvement of saline-alkaline soil,saline-alkaline tolerant plant growth-promoting rhizobacteria were isolated from the rhizosphere soil of Phragmites australis in the saline-alkaline soil of Bachu County,Xinjiang Uygur Autonomous Region.Saline-tolerant and alkaline-tolerant microorganisms were enriched and cultivated using high-saline and high-alkali LB medium.Their taxonomic status was determined through morphological observation and 16S rRNA gene sequencing.The saline and alkaline tolerance and alkali reduction ability of the strains were measured using LB medium with different NaCl contents and pH values.The plant growth-promoting related characteristics of the strains,including nitrogen fixation,organic phosphorus solubilization,inorganic phosphorus solubilization,1-aminocyclopropane-1-carboxylate(ACC)deaminase production,siderophore production,and indole-3-acetic acid(IAA)production,were detected using different functional identification mediums and the Salkowski colorimetric method.The growth-promoting ability of the strains were evaluated through plate and pot experiments.The results indicated that one strain of Aidingimonas was screened out and named Aidingimonas sp.Bachu42,with a patent deposit number of CGMCC No.26952.The strain Bachu42 could grow under the conditions of NaCl content ranging from 20 to 200 g/L and pH value ranging from 7.0 to 11.0.This strain had the functions of nitrogen fixation,organic phosphorus solubilization,inorganic phosphorus solubilization,and could produce siderophores,ACC deaminase and IAA(with the highest yield reaching 12.39 μg/mL).Under the conditions of initial pH 8.0,9.0,and 10.0 of LB medium,the strain Bachu42 could reduce the pH value of the medium by 8.75％,12.78％and 20.10％,respectively.The growth promotion effect was most significant under the condition of pH 8.0+2.0 mmol/L NaHCO3 in the tomato plate growth-promotion test.Compared with the control,the aerial fresh weight,underground fresh weight,total fresh weight,lateral root number and leaf number of tomato inoculated with Bachu42 increased by 81.26％,160.04％,96.37％,144.88％and 26.40％,respectively.In the pot experiment of maize,the strain Bachu42 had the best growth promotion effect under 15 g/kg saline-alkaline stress.Compared with the control group,the growth rates of aerial fresh weight,underground fresh weight,total fresh weight and plant height were 95.77％,56.27％,76.99％and 38.16％,respectively,after inoculating the strain Bachu42.In conclusion,the strain Aidingimonas sp.Bachu42 isolated and screened in this study is a strain with saline-tolerance,alkali reduction and growth-promoting functions,and could be utilized as a microbial fertilizer strain resource for saline-alkaline soil.
Keywords：Plant growth-promoting rhizobacteria(PGPR)Saline-alkaline soilAidingimonasGrowth-promotingIsolation and identification
Publication Date：2025-10-15
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：11( 91-101 )