Muscodor spp. controls tomato wilt disease by Ralstonia solanacearum and increases yield and total soluble solids content in tomatoes

Abstract

Tomato is one of the most economically important crops in Brazil. However, several diseases limit tomato production, among which phytobacterial diseases are responsible for the greatest losses, such Ralstonia solanacearum, the pathogen most relevant to the crop. Endophytic fungi of the genus Muscodor are well known for the bioactivity of their volatile organic compounds (VOCs) against phytopathogens and also have the potential to promote plant growth, as in commum beans. Thus, in this study, we hypothesized that isolates of Muscodor spp. can be used for Ralstonia solanacearum control, and to increase tomato yield and total soluble solids content. To test our hypothesis, seven Muscodor coffeanum and two Muscodor sp. isolates associated with Coffea arabica were screened in vitro and in vivo. In vitro, using divided Petri dishes to evaluate the effect of VOCs, it was shown that the isolate of M. coffeanum CML 4009 promoted greater inhibitory effects on the growth of R. solanacearum race 3. In vivo, we inoculated seeds with Muscodor spp. isolates and later transplanted tomato seedlings into soil infested with R. solanacearum, and observed that the isolate CML 4009 reduced the severity of bacterial wilt. Muscodor isolates promoted an increase in fruit production and total soluble solids in tomatoes. Inoculation with Muscodor spp. is a plausible strategy for tomato seed treatment to control R. solanacearum diseases and increase tomato yield. The future of the M. coffeanum CML 4009 isolate as a biocontrol agent and plant growth promoter is promising.