Bacillus-derived consortium enhances Ginkgo biloba's health and resistance to Alternaria tenuissima.

Abstract

Bacillus, as a plant-growth-promoting rhizobacteria, can enhance the resistance of plants to phytopathogens. So, in our study, the excellent biocontrol Bacillus strains were screened and used to control ginkgo leaf blight (Alternaria tenuissima). Four biocontrol Bacillus strains-Bsa537, Bam337, Bso544, and Bsu503-were selected from 286 isolates based on their capacity to inhibit pathogens and promote plant growth. They significantly improved the resistance of ginkgo to leaf blight, especially the mixture of four Bacillus strains, which contributed to the decrease in lesion areas by more than 40%. Hence, a mixture of Bacillus strains was used to control ginkgo leaf blight in the field. Treatment efficiency varied from 30% to 100% (average 81.5%) and was higher than that of the control (from -2% to -18%, average - 8.5%), the antioxidant capacity of the treated ginkgo was also stronger. Additionally, ginkgo biomass rose as a result of treatment with the Bacillus mixture, including leaf weight, area, thickness, number of lateral roots, and root weight. Furthermore, the Bacillus mixture improved the ginkgo rhizosphere soil by boosting the number of beneficial microorganisms, lowering the number of pathogens, and quickening soil catabolism. The Bacillus mixture improved the health status of ginkgo by protecting it from pathogen attack, promoting its growth, improving microorganism community in rhizosphere. This work closes a technological gap in biological control of ginkgo leaf blight, investigates the application methods of compound Bacillus biofertilizers, and establishes a framework for the population and commercialization of these products. This article is protected by copyright. All rights reserved.