Suchergebnisse

[EN] 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 Alejandria', 'Sauvignon Blanc', and 'Airen' 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%). ; This research was founded by FEDER funding through a State Program of I+D+i oriented to the Challenges of Society (RTA2015-00015-C02-00), supported by The National Institute for Agricultural and Food Research and Technology (INIA). D.G. and J.M. were supported by the Ramon y Cajal program, Spanish Government (RyC-2017-23098 and RyC-028404). ; Chacón-Vozmediano, JL.; Gramaje, D.; León Santana, M.; Armengol Fortí, J.; Moral, J.; Izquierdo-Cañas, PM.; Martínez-Gascueña, J. (2021). Cultivar Susceptibility to Natural Infections Caused by Fungal Grapevine Trunk Pathogens in La Mancha Designation of Origin ...

[EN] A field survey conducted on asymptomatic grapevine propagation material from nurseries and symptomatic young grapevines throughout different regions of Algeria yielded a collection of 70 Phaeoacremonium-like isolates and three Cadophora-like isolates. Based on morphology and DNA sequence data of I3-tubulin (tub2) and actin, five Phaeoacremonium species were identified including Phaeoacremonium minimum (22 isolates), Phaeoacremonium venezuelense (19 isolates), Phaeoacremonium parasiticum (17 isolates), Phaeoacremonium australiense (8 isolates), and Phaeoacremon bun ira nianu m (4 isolates). The latter two species (P. australiense and P. iranianum) were reported for the first time in Algeria. Multilocus phylogenetic analyses (internal transcribed spacer, tub2, and translation elongation factor 1-alpha) and morphological features, allowed the description of the three isolates belonging to the genus Cadophora (WAMC34, WAMC117, and WAMC118) as a novel species, named Cadophora sabaouae sp. nov. Pathogenicity tests were conducted on grapevine cuttings cultivar Cardinal. All the identified species were pathogenic on grapevine cuttings. ; This work was supported by the Ministerstvo Skolstvi, Mladeze a Telovychovy, Czech Republic under grant no. CZ-02-1-01/0-0/0-0/16-025/0007314, the Technologicka Agentura Ceske Republiky under grant no. TJ02000096, and the Spanish Government, Ramon y Cajal program under grant no. RYC-2017-23098 (to D. Gramaje). ; Aigoun-Mouhous, W.; Mahamedi, AE.; León Santana, M.; Chaouia, C.; Zitouni, A.; Barankova, K.; Eichmeier, A. (2021). Cadophora sabaouae sp. nov. and Phaeoacremonium Species Associated with Petri Disease on Grapevine Propagation Material and Young Grapevines in Algeria. Plant Disease. 105(11):3657-3668. https://doi.org/10.1094/PDIS-11-20-2380-RE ; S ; 3657 ; 3668 ; 105 ; 11

[EN] Two hundred and twenty-fiveDiaportheisolates were collected from 2005 to 2019 in almond orchards showing twig cankers and shoot blight symptoms in five different regions across Spain. Multilocus DNA sequence analysis with five loci (ITS,tub,tef-1 alpha,calandhis), allowed the identification of four knownDiaporthespecies, namely:D. amygdali,D. eres,D. foeniculinaandD. phaseolorum. Moreover, a novel phylogenetic species,D. mediterranea, was described.Diaportheamygdaliwas the most prevalent species, due to the largest number of isolates (85.3%) obtained from all sampled regions. The second most frequent species wasD. foeniculina(10.2%), followed byD. mediterranea(3.6%),D.eresandD. phaseolorum, each with only one isolate. Pathogenicity tests were performed using one-year-old almond twigs cv. Vayro and representative isolates of the different species. Except forD. foeniculinaandD. phaseolorum, allDiaporthespecies were able to cause lesions significantly different from those developed on the uninoculated controls.Diaporthe mediterraneacaused the most severe symptoms. These results confirmD. amygdalias a key pathogen of almonds in Spain. Moreover, the new species,D. mediterranea, should also be considered as a potential important causal agent of twig cankers and shoot blight on this crop. ; Research funded by the Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA), grants RTA2017-00009-C04-01, -02, -03 and -04 and with matching funds from the European Regional Development Fund (ERDF). G. Elena and C. Agusti-Brisach were supported by the Spanish post-doctoral grants "Juan de la Cierva-Formacion" and "Juan de la Cierva-Incorporacion", respectively. J. Luque and X. Miarnau were partially supported by the CERCA program, Generalitat de Catalunya. D. Gramaje was supported by the Ramon y Cajal program, Spanish Government (RYC-2017-23098). ; León Santana, M.; Berbegal Martinez, M.; Rodríguez-Reina, JM.; Elena, G.; Abad Campos, P.; Ramón-Albalat, A.; Olmo, D. (2020). Identification and ...