One vine, two diseases: Interactions of different grapevine trunk disease pathogens within vines

Summary

Objective

This research aims to determine the mechanisms for any antagonistic or synergistic interactions between the two GTD pathogen groups. The role of secondary metabolites to suppress or enhance the growth of the pathogens will be assessed. These investigations focusing on the interaction of GTD pathogens, and the impact of mixed infection will provide critical data to assist in the understanding of the disease epidemiology. This knowledge is required for the development of improved management strategies for these diseases and therefore vineyard longevity and sustainability.

Background

Grapevine trunk diseases (GTDs) pose threats to grapevines. Individual vines containing more than one GTD pathogen are common in the field; however, the interaction of these pathogens within a single host is unknown. 

Recent studies in Australia using microbial profiling demonstrated that the pathogens associated with two significant GTDs [Botryosphaeria dieback (BD) and Petri disease] were present together in individual vines with Petri disease pathogens being the most abundant species detected in both symptomatic and asymptomatic vines and nurseries (Niem et al., 2020; Sosnowski et al., 2022). 

The incidence and role of Petri disease; however, have not beencomprehensively studied in Australia although it is considered a serious disease in Europe. Interestingly, both Petri disease and BD pathogens have been found associated with young vine decline (YVD) in Australia (Edwards and Pascoe, 2004; Billones-Baaijens and Savocchia, 2018).

Sector benefits

The outcome of this research will support Wine Australia’s Strategic Plan 2020-2025 in achieving improved practices for sustainable disease management in grapevines. In addition, the objectives of this study are aligned with the on-going Wine Australia funded project at Charles Sturt University on the management and diagnosis of GTDs in vineyards and nurseries in Australia. Interactions between pathogens are some of the main forces that shape pathogen community structures and could significantly affect the dynamics of diseases in the field, its severity and yield impact (Le May etal., 2019). Characterisation of the pathogen community is an important first step towards developing effective control practices.