Bacillus velezensis BM21, a potential and efficient biocontrol agent in control of corn stalk rot caused by Fusarium graminearum

Abstract

The present work was conducted to screen and identify biocontrol bacteria that effectively reduce the severity of corn stalk rot (CSR) and clarify the antifungal activity of secondary metabolites. The bacterial strain (BM21) was isolated from corn rhizosphere soil that effectively reduced CSR in pot experiments. On the basis of phylogenetic reconstructions, 16S rRNA sequence analysis, and biochemical and physiological reactions, BM21 was identified as Bacillus velezensis. The strain exhibited remarkable antifungal activity against Fusarium graminearum, a pathogenic fungus that causes CSR. Extracellular antifungal substances (10%) isolated from BM21 inhibited F. graminearum mycelial growth by 79.2%, conidial germination by 84.0%, and conidial production by 78.1%. In addition, the extracellular antifungal substances caused mycelial malformation and ultra-structural changes. The extracellular antifungal substances were sensitive to heat and showed a degree of resistance to ultraviolet radiation. The optimum pH for antifungal activity was 6-8. In pot experiments, irrigation with aqueous extracts from BM21 (1.0 mL/plant) reduced CSR incidence by 72.4-77.4%. B. velezensis BM21 effectively reduced CSR incidence and showed a potential as a biocontrol agent to control CSR.

Comparative Management Studies on Banded Leaf and Sheath Blight of Maize Caused by <i>Rhizoctonia Solani F.</i><i>SP</i><i>. Sasakii</i>

“…Similar findings were observed that Bacillus velezensis, the strain exhibited remarkable antifungal activity against Fusarium graminearum, a pathogenic fungus that causes Corn Stalk Rot [12] and Bacillus subtilis BR23 strain controlled BLSB, when applied as Seed Treatment and Soil Application on corn crop [17]. As per the findings of McMullen and Lamey [18], B.subtilis used as seed treatment colonize the developing root system, suppressing disease organisms such as Fusarium and Rhizoctonia.…”

“…Trichoderma harzianum, showed 68% of inhibition of the mycelia of R. solani, under in vitro conditions [11]. Bacterial strains from the corn rhizosphere soil were isolated and screened in vitro for antagonistic activity against F. graminearum [12]. Among biocontrol microbes, Bacillus spp.…”

Isolation, Identification, and Complete Genome Assembly of an Endophytic Bacillus velezensis YB-130, Potential Biocontrol Agent Against Fusarium graminearum

“…Other Bacillus isolates, such as B. subtilis , B. amyloliquefaciens , and B. velezensis had been found to inhibit spore morphology or mycelial growth of F. graminearum ( Zhao et al, 2015 ; Jamal et al, 2017 ; Lee et al, 2017 ; Chen et al, 2018 ; Wang et al, 2020 ). Abnormally swollen spores and hyphae of plant pathogens were previously reported in dual cultures with endophytic bacteria ( Lee et al, 2017 ; Saechow et al, 2018 ; He et al, 2019 ).…”

Crop Protection against Botrytis cinerea by Rhizhosphere Biological Control Agent Bacillus velezensis XT1

“…Antagonistic activity against the pathogens Monilinia fructicola [ 61 ] and B. cinerea (60%) reached maximum levels of > 80% and 60%, respectively, mainly due to the large amount of lipopeptides produced (10 g/L) [ 67 ]. Many studies of olive, tomato, corn, peanut, pepper, maize and rice crop yields have also described the biocontrol activity of B. velezensis strains against phytopathogens such as Verticillium dahliae , Fusarium graminerarum , Sclerotium rolfsii , Phytophthora and B. cinerea [ 68 , 69 , 70 , 71 , 72 , 73 , 74 ]. Our results are in line with the findings of Lee et al (2006) [ 75 ] who investigated the effect of radicular applications of B. subtilis WXCDD105 on B. cinerea in tomato plants.…”