Control of Magnaporthe oryzae and Rice Growth Promotion by Bacillus subtilis JN005

Abstract

It is quite important to develop the microorganism resources with biocontrol capacity for rice blast. This study evaluated Bacillus subtilis JN005 for growth promotion and biocontrol efficacy against Magnaporthe oryzae. Results showed that rice seeds treated with 1 × 107 cfu/mL suspension of B. subtilis JN005 had 16% germination energy, 14% germination rate, 15% germination index, and 270% vigor index compared to those treated with sterile water (control). In pot experiments, the JN005 strain-treated rice plants exhibited notable increase in plant height, root length, stem circumference, and fresh weight, as well as higher concentration of chlorophyll a, chlorophyll b, and total chlorophyll in rice leaves. Rice leaves inoculated with the JN005 strain resulted in increased activities of defense-related enzymes, including peroxidase (POD), phenylalanine ammonialyase (PAL), superoxide dismutase (SOD), and catalase (CAT) compared to the water and the M. oryzae-inoculated treatments. In vitro inoculated rice leaves with 1 × 107 cfu/mL bacterial suspension compared to sterile water or control treatment exhibited lower disease incidence in the curative and preventive groups by 79% and 76%, respectively. Field experiment showed that after spraying with 1 × 107 cfu/mL bacterial suspension, efficacy rates on controlling rice blast on plants were (56.82 ± 1.12)% and (58.39 ± 3.05)% at seedling and maturity stages, respectively, and that rice production yield was (524.40 ± 17.88) g/m2. Therefore, B. subtilis JN005 could be a promising biological control agent for rice blast, thereby warranting further investigation of its efficacy.

Potential of Bacillus stercoris B.PNR2 to stimulate growth of rice and waxy corn under atrazine-contaminated soil

“…This phenomenon was observed when B. subtilis JN005 was inoculated into seeds of rice variety Xiangwanxian No 12. The growth of seedlings that received B. subtilis JN005 at a concentration of 1× 10 7 cfu/mL was higher than that of seedlings that received other inoculum sizes (Zhu et al, 2022). This study used seed inoculation methods to inoculate cells of B. stercoris B.PNR2 into the seeds of rice cultivar RD6, rice cultivar Leum Pua, and waxy corn cultivar Muang Tam.…”