Biocontrol Potential of Grapevine Endophytic and Rhizospheric Fungi Against Trunk Pathogens.

Isidora Silva-Valderrama,Alvaro Castro,Dario Cantu,Diana Toapanta,Maria De Los Angeles Miccono,Mauricio Lolas,Gonzalo A Díaz

doi:10.3389/fmicb.2020.614620

Isidora Silva-Valderrama, Alvaro Castro + Show 5 more

Open Access

https://doi.org/10.3389/fmicb.2020.614620

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Abstract

Grapevine Trunk Diseases (GTDs) are a major challenge to the grape industry worldwide. GTDs are responsible for considerable loss of quality, production, and vineyard longevity. Seventy-five percent of Chilean vineyards are estimated to be affected by GTDs. GTDs are complex diseases caused by several fungi species, including members of the Botryosphaeriaceae family and Phaeomoniella chlamydospora, considered some of the most important causal agents for these diseases in Chile. In this study, we isolated 169 endophytic and 209 rhizospheric fungi from grapevines grown under organic and conventional farming in Chile. Multiple isolates of Chaetomium sp., Cladosporium sp., Clonostachys rosea, Epicoccum nigrum, Purpureocillium lilacinum, and Trichoderma sp. were evaluated for their potential of biocontrol activity against Diplodia seriata, Neofusicoccum parvum, and Pa. chlamydospora. Tests of antagonism were carried out using two dual-culture-plate methods with multiple media types, including agar containing grapevine wood extract to simulate in planta nutrient conditions. Significant pathogen growth inhibition was observed by all isolates tested. Clonostachys rosea showed 98.2% inhibition of all pathogens in the presence of grapevine wood extract. We observed 100% pathogen growth inhibition when autoclaved lignified grapevine shoots were pre-inoculated with either C. rosea strains or Trichoderma sp. Overall, these results show that C. rosea strains isolated from grapevines are promising biocontrol agents against GTDs.

Highlights

Grapevine trunk diseases (GTDs) are a major challenge to viticulture worldwide because they compromise the productivity and longevity of grapevines (Vitis vinifera L.) and increase production costs (Munkvold et al, 1994; Bertsch et al, 2013; Kaplan et al, 2016; Gramaje et al, 2018)
GTDs can spread during plant propagation (Aroca et al, 2010; Gramaje and Armengol, 2011), with infections found in dormant wood cuttings and young grafted plants (Waite and Morton, 2007; Gramaje and Armengol, 2011; Billones-Baaijens et al, 2013)
In Chile, as in other viticulture areas, the most common microorganisms isolated from arms and trunks of grapevines with symptoms of GTDs are ascomycetous fungi and include Phaeomoniella (Pa.) chlamydospora, Diplodia seriata De Not., and Neofusicoccum parvum (Auger et al, 2004; Díaz et al, 2011a; Besoain et al, 2013; Díaz and Latorre, 2013; Díaz and Latorre, 2014)

Summary

Introduction

Grapevine trunk diseases (GTDs) are a major challenge to viticulture worldwide because they compromise the productivity and longevity of grapevines (Vitis vinifera L.) and increase production costs (Munkvold et al, 1994; Bertsch et al, 2013; Kaplan et al, 2016; Gramaje et al, 2018). GTDs are a group of diseases affecting the grapevine trunk and internal tissue (Mugnai, 2011), resulting in foliar symptoms, cankers, and dieback of the plant (Gramaje et al, 2018). These diseases are caused by a wide range of fungi (Trouillas et al, 2010; Gramaje and Armengol, 2011; ÚrbezTorres, 2011; Augusti-Brisach and Armengol, 2013; Lombard et al, 2014; Gramaje et al, 2018) that often infect established grapevines through wounds produced during winter pruning (Rolshausen et al, 2010). In Chile, as in other viticulture areas, the most common microorganisms isolated from arms and trunks of grapevines with symptoms of GTDs are ascomycetous fungi and include Phaeomoniella (Pa.) chlamydospora, Diplodia seriata De Not., and Neofusicoccum parvum (Auger et al, 2004; Díaz et al, 2011a; Besoain et al, 2013; Díaz and Latorre, 2013; Díaz and Latorre, 2014)

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