Isolation and evaluation ofBacillus velezensisZW-10 as a potential biological control agent againstMagnaporthe oryzae

Rice blast is one of the most destructive diseases of rice and is caused by the infection with rice blast fungus,Magnaporthe oryzae.In the present study, we obtained 12 bacterial isolates from Sichuan basin neutral purplish soil. Among them, the strain named ZW-10 showed significant activity againstM. oryzae. Morphological and biochemical studies, along with 16SrDNAsequencing analysis, proved that the strain belongs toBacillus velezensis. The cell-free culture filtrate of ZW-10 inhibited the growth ofM. oryzae, suggesting the presence of active enzymes and secondary metabolites. The experimental results showed that ZW-10 produced cellulase, protease, and peroxidase. The temperature experiment indicated that the secondary metabolisms of ZW-10 remained active at high temperature. In addition, this strain had good acidity resistance. As shown in leaf experimentsin vitroas well as field trials, the liquid culture and the cell-free culture filtrate of ZW-10 had significant inhibitory effects on rice blast. In conclusion, ZW-10 can be used as a potential biological agent in the control of rice blast.