Biocontrol and Plant Growth Promoting Potential of Strain Streptomyces sp. A537 isolated form Suaeda salsa non-rhizosphere soil

Henan Agricultural University, Zhengzhou 450046, China

^a* Corresponding author: lzpzxx@126.com; b* lzpbio@126.com

Abstract

Fusarium oxysporum is a serious pathogenic fungus that can cause peanut root rot, leading to reduced peanut yield, plant death, and severely hindering the development of agriculture and economy in peanut cultivation region. This study isolated a large number of bacterial strains from soil samples of wild plants such as Suaeda salsa, Tamarix, and Phragmites australis in the Aydingkol Lake area of Xinjiang, and evaluated their biocontrol and capability of promote plant growth. Finally, an actinomycete strain A537 was isolated and screened from the non-rhizosphere soil of Suaeda salsa. The sequencing results of 16s RNA indicate that A537 belongs to the genus Streptomyces. The plate confrontation assay showed that strain A537 has a wide antifungal spectrum and has certain antagonistic activities to various plant pathogens such as Fusarium oxysporum, Fusarium solani, Diplodia gossypina, Fusarium equiseti, Fusarium acuminatum, Verticillium dahlia, Rhizoctonia cerealis, Fusarium pseudograminearum and Fusarium graminearum. In addition, in vitro evaluation of PGP traits showed that strain A537 has the capability of phosphate solubilization, IAA production, siderophore production, ACC deaminase production and cellulases production. Different concentrations of culture filtrate of strain A537 have a certain antagonistic activities on Fusarium oxysporum, with an inhibition rate of 76.54 ± 6.79%. The results indicate that strain Streptomyces sp. A537 has the potential for biological control and growth promotion, and can be used as a novel biocontrol agent against peanut root rot.