Control of White Rot Caused by Sclerotinia sclerotiorum in Strawberry Using Arbuscular Mycorrhizae and Plant-Growth-Promoting Bacteria

Abstract

Sclerotinia sclerotiorum is a phytopathogenic fungus that causes wilting and white rot in several species such as strawberry. The overuse of agrochemicals has caused environmental pollution and plant resistance to phytopathogens. Inoculation of crops with beneficial microorganisms such as arbuscular mycorrhizae (AM), plant-growth-promoting rhizobacteria (PGPR), and their metabolites is considered as an alternative to agrochemicals. B.halotolerans IcBac2.1 (BM) and Bacillus TrujBac2.32 (B), native from Peruvian soils, produce antifungal compounds and are plant-growth-promoting rhizobacteria (PGPR). B. halotolerans IcBac2.1 and Bacillus TrujBac2 with or without G. intraradices mycorrhizal fungi (M) are capable of controlling S. sclerotiorum disease in strawberries. Inoculation of mycorrhiza alone decreases disease incidence as well. Treatments with chitosan (Ch), which is used to elicit plant defense responses against fungal pathogens, were used for comparison, as well as non-inoculated plants (C). Co-inoculation of mycorrhiza and bacteria increases plant shoot and root biomass. Our results show that the inoculation of arbuscular mycorrhiza and antifungal Bacillus are good biocontrols of S. sclerotiorum in strawberry.