Influência de Trichoderma spp. na estrutura e funcionalidade da comunidade microbiana edáfica e endofítica em cultivo de feijão comum (Phaseolus vulgaris L.) inoculado com Sclerotinia sclerotiorum (LIB.) de Bary

Abstract

The control of agricultural pathogens can be obtained by biological control agents, but information about their impacts on the native microbiota of the Cerrado is scarce. Biocontrolling agents Trichoderma harzianum ESALQ-1306, Trichoderma asperellum BRM29104 and sclerotia of the phytopathogen Sclerotinia sclerotiorum (Lib.) de Bary were selected to determine the effects of biocontrol agents on the edaphic, endophytic microbial community and on the functional traits in bean crop (Phaseolus vulgaris L.) in the Cerrado. Soil samples were collected before planting and after 90 days of cultivation. Parameters of abundance and alpha diversity of fungi and edaphic bacteria were evaluated by cultivation-dependent methods and by new generation sequencing (NGS), while endophytic communities were evaluated exclusively by NGS sequencing. Arbuscular mycorrhizal fungi (AMF) spores were quantified, identified and the root colonization rate was estimated. The disease severity and bean yield were evaluated. Functional parameters of metabolic diversity, glomalin mass, synthesis of hydrolytic enzymes, respiration and microbial carbon biomass were quantified. There was a significant increase in some alpha diversity parameters, in the abundance of predominant taxa and changes in edaphic microbial community composition. These changes occurred regardless of the presence of biocontrol agents, suggesting that they were stimulated by the development of common bean. Changes observed in the composition of endophytic communities are related to the type of plant organ. Bean productivity and functional parameters did not change significantly in relation to the control. Thus, we determined that Trichoderma harzianum ESALQ-1306 and Trichoderma asperellum BRM-29104 do not change functional parameters and the alpha diversity of the native microbial communities analyzed and promote the biological control of S. sclerotiorum, maintaining bean productivity.