The rhizosphere of the pioneer plant Dicranopteris dichotoma (Thunb.) Bernh. contains powerful and robust rhizosphere growth-promoting bacteria

Abstract

Rhizosphere microorganisms are important for maintaining soil and plant health and promoting plant growth and development. Screening rhizosphere growth-promoting bacteria with unique habitats, high activity and multiple functions is conducive to exploring the potential stress resistance of growth-promoting bacteria, and further improving the applicability of microbial fertilizers in agricultural production in response to the development concept of green agriculture. The aim of this study was to investigate the physiological activity of the culturable core growth-promoting bacteria of Dicranopteris dichotoma and verify their growth-promoting effect on mung bean (Vigna radiata) growth. A total of 41 bacterial strains were isolated in this study; 21 strains had more than one physiological activity, among which the highest siderophores units (SU) were 97.1%, and the highest IAA yield was 134.46 mg/L. According to morphology and 16S rRNA, three strains of Bacillus sp. and one strain of Pantoea sp. were screened, all of which were predicted to have the functions of phosphorous solubilization, cellulase production, IAA production and siderophores production. In a pot experiment, these four strains were inoculated in the rhizosphere soil every 7 days for a total of 4 times, and the aerial and underground biomass, plant height, root length and leaf number of V. radiata plants increased significantly 30 days after the last inoculation. The strains isolated in this study have excellent plant growth promoting (PGP) properties and were expected to be used as a new biological inoculant in practical production.

Keywords

• Bacillus sp.
• PGPR
• Vigna radiata
• Dicranopteris dichotoma