Abstract:[Background] Many Methylobacterium can promote the growth of host plants, which is widely distributed. Screening methylobacterium strains with salt tolerance and growth promoting characteristics can provide basis for the development of microbial fertilizer, which can provide a basis for the development of microbial fertilizer. [Objective] Salt tolerant and plant growth-promoting bacteria were isolated from the saline soil of Wuerhe area in Xinjiang, and the culture medium were optimized after identification, the performance of growth-promoting was preliminarily studied. [Methods] The salt tolerant strains were screened by Ashby medium. The gene sequence analysis, physiological and biochemical determination were carried out on the strains. The effects on the growth of Arabidopsis thaliana were preliminarily studied by plate test. [Results] Moderate salt tolerant strains W-1 screened were identified as Methylobacterium sp. The best inorganic salt for the growth of strain was NaCl, and the optimum concentration was 1%-3%, and the maximum tolerance concentration was 7%. The best nitrogen source was organic nitrogen (acid hydrolyzed casein), with the highest yield of auxin (IAA) up to 33.53 mg/L, The dissolved phosphorus capacity was 28.71 mg/L. Inoculating Arabidopsis thaliana seedlings with the Methylobacterium sp. W-1, The contents of chlorophyll a and chlorophyll b of the Arabidopsis seedlings were higher than control group, the root structure of Arabidopsis thaliana was promoted significantly. [Conclusion] This study provided strain resources for the preparation of biofertilizer candidates.
