Genetic diversity of groundnut rhizosphere antagonistic bacteria and biological control of groundnut wilted diseases in central Vietnam

Abstract

Stem rot of groundnut caused by Sclerotium rolfsii, seriously damages groundnut production in central Vietnam. Biological control is a promising strategy for sustainable groundnut cultivation. In this study, indigenous bacteria were isolated from the rhizosphere of groundnut and tested for fungal inhibition against S. rolfsii in vitro and disease control under net house condition. Genetic diversity of isolated bacterial population was evaluated by BOX-PCR and 16S rDNA sequences. Bacterial strains that showed high disease control in net house were evaluated under natural conditions in farmer fields. The antifungal mechanism of the best bacterial strain was identified. Results of the study showed that the antagonistic bacterial population in groundnut rhizosphere is separated in three bacterial genera including Bacillus, Pseudomonas and Burkholderia. One bacterial strain which produces 2,4-DAPG reduced stem rot of groundnut caused by S. rolfsii and increased yield from 20.3 to 26.3% compared to the control.