Bacterial community in different wine appellations – biotic and abiotic interaction in grape berry and its impact on Botrytis cinerea development

Abstract

An in-depth knowledge on the conditions that trigger Botrytis disease and the microbial community associated with the susceptibility/resistance to it could led to the anticipation and response to the Botrytis emergence and severity. Therefore, the present study pretends to establish links between biotic and abiotic factors and the presence/abundance of B. cinerea. Several grape varieties from 4 different wine appellations in France and Spain have been studied at different maturity stages to analyse: 1) B. cinerea abundance (established by qPCR), 2) grape composition parameters (comprising water activity measuring, exudates composition, phenologic stage, gluconic acid, calcium, etc), and 3) grape berries microbial community diversity and composition (using 16S rRNA and ITS amplicon sequencing).Preliminary analysis of the results obtained through 16S rRNA Next Generation Sequencing revealed differences in microbial richness and bacterial composition between the vineyards. Both alpha and beta diversities correlated with fruit maturity, where grapes at harvest stage showed significantly higher richness and a dissimilar bacterial composition. In addition, bacterial community structure differed between wine appellations. The study will increase significantly our understanding of the ecology of microbial associated to different grape varieties and viticulture areas. Additionally, it will generate knowledge about the factors.