Biological control of important fungal diseases of potato and raspberry by two Bacillus velezensis strains

Abstract

Stem canker and black scurf caused by Rhizoctonia solani are the important diseases in potato, while spur blight caused by Didymella applanata is a major disease in red raspberry. In Western Siberia, both crops are grown predominantly in small-scale farming that requires maximal usage of biological products for plant protection instead of chemicals. We evaluated two promising Bacillus velezensis strains BZR 336 g and BZR 517 isolated in the south of Russia (45°1′N, 38°59′E) for their biological control potentials against the potato and red raspberry diseases under the more severe weather conditions of Western Siberia (55°1′N, 82°55′ E). We tested two techniques to apply biocontrol agents: (1) coating the seeds (potato tubers) and (2) spraying over the plants (raspberry canes). In each case, we estimated B. velezensis strains on two plant cultivars differed by the disease resistance. The degree of B. velezensis influence on disease incidence and severity depended on the bacterial strain, the protected plant, and its cultivar. We also demonstrated that two B. velezensis strains significantly stimulated plant growth of potato, which contributed to the plant productivity on both cultivars. The BZR 336 g strain affected the potato productivity more than the BZR 517 strain. Under the influence of both bacterial strains, raspberry yield was significantly higher compared to the control on the susceptible cultivar. These findings indicated that two southern B. velezensis strains had proved their efficacy as biological control agents in the control of the serious fungal infection of potato and raspberry plants under the more severe ecological conditions of Western Siberia. For the first time, we demonstrated B. velezensis strains potential for use as biological control agents against R. solani on potato, and against D. applanata on red raspberry.

Deciphering core microbiota in rhizosphere soil and roots of healthy and Rhizoctonia solani-infected potato plants from various locations

“…Simultaneously, the plant roots may recruit beneficial microbes to counteract pathogenic fungi (Zhang et al, 2022). Key species identified, such as Streptomyces, Lysobacter, Bacillus, Pseudomonas, Ensifer, Enterobacter, the Rhizobium group (Allorhizobium, Neorhizobium, Pararhizobium, Rhizobium), Aspergillus, Penicillium, Purpureocillium, and Gibberella moniliformis, are recognized for enhancing plant growth and disease resistance (Ma et al, 2018;Schreiter et al, 2018;Wu et al, 2020;Zhang J. et al, 2020;Asaturova et al, 2021;Wei et al, 2021;Abdelaziz et al, 2023;Rashad et al, 2023).…”

“…Currently, biological control involving specific endophytes and rhizosphere microbiome like Aspergillus, Bacillus, Pseudomonas, Streptomyces, and Lysobacter is a viable method for managing various soilborne diseases and this approach works through mechanisms such as antagonism, altering rhizospheric microbial diversity, and metabolite production (Ma et al, 2018;Schreiter et al, 2018;Wu et al, 2020;Zhang J. et al, 2020;Asaturova et al, 2021;Wei et al, 2021;Abdelaziz et al, 2023;Rashad et al, 2023). In recent years, there have been successive reports on the biological control of potato black scurf.…”

Potato Microbiome: Relationship with Environmental Factors and Approaches for Microbiome Modulation

“…Potato plants are vulnerable to a wide range of diseases related to the proliferation of pathogenic microorganisms. At the same time, some bacteria and fungi associated with the potato microbiome may demonstrate an antagonistic nature towards diverse pathogenic bacteria, fungi and oomycetes [74][75][76]. In addition, a number of potato symbiotic microorganisms are involved in the defense systems of plants and help them to resist pathogens by triggering the induced systemic resistance or systemic acquired resistance [77][78][79].…”

Efficacy of New Local Bacterial Agents against Pyrenophora tritici-repentis in Kuban Region, Russia

“…The bacteria have been proven to be effective on various crops and in different climate regions. B. velezensis showed great antagonist activity in the south of Russia [18], as well as in the extreme weather of Western Siberia [19,20]. These microorganisms promote plant growth [21], making them excellent candidates for the development of the new bioproducts.…”