Are Epiphytic Microbial Communities in the Carposphere of Ripening Grape Clusters (Vitis vinifera L.) Different between Conventional, Organic, and Biodynamic Grapes?

Abstract

Using barcoded pyrosequencing fungal and bacterial communities associated with grape berry clusters (Vitis vinifera L.) obtained from conventional, organic and biodynamic vineyard plots were investigated in two subsequent years at different stages during berry ripening. The four most abundant operational taxonomic units (OTUs) based on fungal ITS data were Botrytis cinerea, Cladosporium spp., Aureobasidium pullulans and Alternaria alternata which represented 57% and 47% of the total reads in 2010 and 2011, respectively. Members of the genera Sphingomonas, Gluconobacter, Pseudomonas, Erwinia, and Massilia constituted 67% of the total number of bacterial 16S DNA reads in 2010 samples and 78% in 2011 samples. Viticultural management system had no significant effect on abundance of fungi or bacteria in both years and at all three sampling dates. Exceptions were A. alternata and Pseudomonas spp. which were more abundant in the carposphere of conventional compared to biodynamic berries, as well as Sphingomonas spp. which was significantly less abundant on conventional compared to organic berries at an early ripening stage in 2011. In general, there were no significant differences in fungal and bacterial diversity indices or richness evident between management systems. No distinct fungal or bacterial communities were associated with the different maturation stages or management systems, respectively. An exception was the last stage of berry maturation in 2011, where the Simpson diversity index was significantly higher for fungal communities on biodynamic compared to conventional grapes. Our study highlights the existence of complex and dynamic microbial communities in the grape cluster carposphere including both phytopathogenic and potentially antagonistic microorganisms that can have a significant impact on grape production. Such knowledge is particularly relevant for development, selection and application of effective control measures against economically important pathogens present in the grape carposphere.

Shared and unique features of bacterial communities in native forest and vineyard phyllosphere

“…In contrast to grape leaves, grape berries were less affected by agricultural management. This result supports previous studies indicating that the natural phyllosphere bacteria of the grape berry are likely to be highly resilient to agricultural treatment (Kecskeméti et al, ). Additionally, our study suggests that the sensitivity to agricultural management differs between leaf‐associated and berry‐associated bacterial communities.…”

“…It is also important to the wine industry to understand how agricultural management affects the microbial community of grapevines because grapevine microorganisms can affect the production of healthy grapes (Barata, Malfeito-Ferreira, & Loureiro, 2012;Pinto & Gomes, 2016) and wine quality (Bokulich et al, 2016;Knight, Klaere, Fedrizzi, & Goddard, 2015;Mezzasalma et al, 2017). The natural phyllosphere bacteria of the grapevine are likely to be highly resilient to agricultural treatments; studies have shown that differences in management, including chemical fungicides (Perazzolli et al, 2014), biological control (Perazzolli et al, 2014), and conventional, organic and biodynamic systems (Kecskeméti, Berkelmann-Löhnertz, & Reineke, 2016), do not affect bacterial diversity indices. On the other hand, the composition of bacterial communities found on wine grapes has been shown to be affected by agricultural practices, as differences in dominant taxonomic groups between organic and conventionally managed grapes have been observed (Pinto & Gomes, 2016).…”

Phyllospheric Microbiomes: Diversity, Ecological Significance, and Biotechnological Applications

“…Durand et al (2018) characterized the bacterial genera such as Methylobacterium, Kineococcus, Sphingomonas, and Hymenobacter of the phylum Firmicutes from the leaf surface. The phyllosphere of the grapevine contains Acinetobacter, Bacillus, Citrobacter, Curtobacterium, Enterobacter, Erwinia, Frigoribacterium, Methylobacterium, Pantoea, Pseudomonas, and Sphingomonas as dominant genera (Kecskeméti et al 2016). Steven et al (2018) characterized Pseudomonas and Enterobacteriaceae as predominant taxa from apple.…”

“…Steven et al (2018) characterized Pseudomonas and Enterobacteriaceae as predominant taxa from apple. Several studies revealed Pseudomonas as the most abundant genus of phyllosphere region (Aleklett et al 2014;Kecskeméti et al 2016;Steven et al 2018). Seed coat associated bacteria that have been reported in phyllosphere are mainly Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria (Johnston-Monje and Raizada 2011;Rodríguez-Escobar et al 2018).…”

An indigenousSaccharomyces uvarumpopulation with high genetic diversity dominates uninoculated Chardonnay fermentations at a Canadian winery

“…Alternaria sp. are plant pathogens that are also commonly identified on grapes and in grape must [44,64,65]. M. tassiana , also known as Davidiella tassiana , is a common grape symbiont that has been previously isolated from vineyards [12,44,66,67], and has been identified as the most abundant fungal species isolated on grapes in one study [65].…”