Cultivar Susceptibility to Natural Infections Caused by Fungal Grapevine Trunk Pathogens in La Mancha Designation of Origin (Spain)

Abstract

Grapevine trunk diseases (GTDs) are one of the main biotic stress factors affecting this crop. The use of tolerant grapevine cultivars would be an interesting and sustainable alternative strategy to control GTDs. To date, most studies about cultivar susceptibility have been conducted under controlled conditions, and little information is available about tolerance to natural infections caused by GTD fungi. The objectives of this study were: (i) to identify tolerant cultivars to GTD fungi within a Spanish germplasm collection, based on external symptoms observed in the vineyard; and (ii) to characterize the pathogenic mycoflora associated with symptomatic vines. For this purpose, a grapevine germplasm collection including 22 white and 25 red cultivars was monitored along three growing seasons, and their susceptibility for esca foliar symptoms was assessed. Fungi were identified by using morphological and molecular methods. Cultivars such as, ‘Monastrell’, ‘Graciano’, ‘Cabernet Franc’, ‘Cabernet Sauvignon’, ‘Syrah’, ‘Moscatel de Alejandría’, ‘Sauvignon Blanc’, and ‘Airén’ displayed high susceptibility to GTDs, whereas others such as ‘Petit Verdot’, ‘Pinot Noir’, ‘Chardonnay’, and ‘Riesling’ were considered as tolerant. The prevalent fungal species isolated from symptomatic vines were Phaeomoniella chlamydospora (27.9% of the fungal isolates), Cryptovalsa ampelina (24.6%), and Dothiorella sarmentorum (21.3%).

Variation in Fungal Community in Grapevine (Vitis vinifera) Nursery Stock Depends on Nursery, Variety and Rootstock

“…These conclusions were drawn with full knowledge that "the term fungal community or mycota that were isolated represented only part of the culturable fungi and missed uncultivable fungal species". Since there was no significant difference in the systematic structure of the mycota associated with asymptomatic and Esca-symptomatic plants, it was suggested that they are part of the normal mycota associated with adult grapevine plants [144,145].…”

Biotechnologies and Strategies for Grapevine Improvement

“…Grapevine cultivars are susceptible to biotic (bacteria, fungi, viruses, and insects) and abiotic stressors (drought, extreme temperatures, and salinity) that reduce both the yield and lifespan of vineyards, causing substantial economic losses to grape production and the wine industry [10]. Vegetative propagation and growth on rootstocks ensure the grapevine tolerance to phylloxera, an insect pest that almost destroyed European viticulture in the late nineteenth century [11].…”

Screening of Vitis vinifera cultivars from the Grapevine Germplasm Bank of Aragon for susceptibility to Botryosphaeria dieback fungi

“…Concerning the most frequent GTDs affecting young plants (i.e., those less than 8 years old), those are black-foot disease, Petri disease, and Botryosphaeria dieback, respectively. The latter is one of the most damaging and widespread diseases affecting vineyards in the main wine-producing regions (Chacon et al 2020;Chacon-Vozmediano et al 2021), and-among the different Botryosphaeriaceae species involved (belonging to the Botryosphaeria, Neofusicoccum, Diplodia, Lasiodiplodia, Dothiorella, Spencermartinsia, and Sphaeropsis genera (Gramaje et al 2018))-Neofusicoccum parvum (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips (Laveau et al 2009;Úrbez-Torres et al 2006;Urbez-Torres 2011) and Diplodia seriata De Not (Rolshausen et al 2010) stand out as the most usual choices for pathogenicity studies, given that the former one is particularly virulent and both are fast in terms of wood-colonization (Wallis 2021).…”

“…In particular, the use of resistant/tolerant cultivars poses an attractive and sustainable solution to limit the impact of these diseases, aligned with the criteria of the European legislation currently in force (Article 14 in the European Directive 2009/128/EC). There is consensus that this strategy would be the cheapest, easiest, safest, most environmentally friendly, and most effective way to control these fungi (Martinez-Diz et al 2019;Chacon et al 2020;Chacon-Vozmediano et al 2021;David Gramaje et al 2018).…”

“…Moreover, cultivars grafted on SO4 present a higher incidence of symptoms associated with the mentioned esca than those grafted on 1103 P (Maldonado-González et al 2018). In addition, 'Merlot', 'Malbec', 'Petit Verdot', 'Pinot Noir', 'Chardonnay', and 'Riesling' would also show some degree of tolerance against various GTDs (Ramirez et al 2018;Chacon-Vozmediano et al 2021;Sosnowski et al 2022).…”