The microbiome structure of disease-escape grapevines in New Zealand

Abstract

Grapevine trunk diseases (GTDs), caused by a complex of fungi, continue to be one of the most devastating grapevine diseases worldwide. Grapevine trunk diseases cause yield loss and reduce the longevity of vineyards. There is no approved fungicide for eradicating GTDs, and this has influenced research efforts geared towards identifying sustainable control methods for GTDs management. Therefore, the primary goal of this study was to determine the microbial contribution to grapevine health. In some New Zealand vineyards, there have been anecdotal reports of grapevines that remain healthy within a background of trunk diseases. This research aimed to investigate the occurrence of such grapevines, referred to here as disease-escape grapevines, in the context of GTDs and to explore their microbiome. First, vineyards in Hawke's Bay and Canterbury were surveyed for the presence of grapevines escaping GTDs. Following that, grapevine trunk samples were taken from the putative disease-escape grapevines and the symptomatic grapevines in their vicinity. The grapevine trunks' total fungal and bacterial communities were then identified by culturing and DNA metabarcoding. The DNA metabarcoding revealed microbial taxa differentially abundant in disease-escape grapevines and the ones which correlated negatively with GTDs pathogens. Future work will involve manipulating young grapevines' microbiome with a consortium designed from the taxa of interest, and then monitoring their proliferation, persistence, and ability to suppress GTDs in planta.