Isolation and identification of Bacillus spp. controlling Neocosmospora pod rot of peanut

Abstract:

[Objective] To isolate and identify Bacillus spp. to control Neocosmospora pod rot of peanut (NPRP).[Methods] Bacillus spp. of peanut rhizosphere soil were isolated to inhibit Neocosmospora vasinfecta by plate confrontation method, and further classified by multiphase classification method. The lipopeptide synthesis gene type of biocontrol bacteria was detected by PCR. The control effect of Bacillus spp. on NPRP was tested in field trial.[Results] Twenty-eight Bacillus spp. strains were isolated and eight obviously inhibited N. vasinfecta. Two were identified as B. subtilis and the others were B. amyloliquefaciens. The biocontrol bacteria harbored one type of lipopeptide synthesis genes at least and all harbored FenB gene. We speculated that the inhibitory mechanism of the Bacillus spp. may be related to the synthesis of lipopeptide antibiotics. B. amyloliquefaciens GF-3 and GF-22 both could effectively reduce the disease index of NPRP and increase the yield of peanut in field trial.[Conclusion] Two strains B. amyloliquefaciens were isolated and identified to control NPRP. This study could provide strains to make biocontrol agents for prevention and control NPRP.