Application of plant growth regulators on Vitis vinifera L var. Mouchtaro affect berry quality characteristics & associated microbial communities

Abstract

The phenolic profile of the red grapevine varieties berries is a key quality factor and several techniques have been applied to improve it (Perez-Lamela et al., 2007; Singh SK and Sharma, 2010). The last decade the application of resistance elicitors and phytohormones is an innovative viticultural technique (Paladines-Quezada et al., 2021; Alenazi et al., 2019).In the present study, leaves and berries of a Greek red indigenous variety (Mouhtaro) sprayed with two elicitors, benzothiadiazole and chitosan and a plant hormone abscisic acid, during veraison. Physicochemical and phenolic characteristics of the berries and microbial communities of carposphere were analyzed during harvest.Differences in the microbial communities were observed after the application of the plant activators. CHT treatment increased the abundance of the beneficial lactic acid bacteria while the ABA treatment decreased the presence of spoilage fungi on the carposphere. Treatments differentiate total phenolics, anthocyanins and in the chemical characteristics of grape must with chitosan treated grapes had increased anthocyanins and skin-derived phenolics that correlated positively with the microbial taxa that was discriminant by LefSe analysis.In the present research, we investigated the effect of alternative environmentally friendly compounds on grape berry quality characteristics, and how the carposhere communities could be influenced by them, contributing to the establishment of more sustainable viticulture.