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Université de Cordoba (2019)

Estudio de la competencia entre especies patogénicas de Colletotrichum spp.

SUCU Halil

Titre : Estudio de la competencia entre especies patogénicas de Colletotrichum spp.

Auteur : SUCU Halil

Université de soutenance : Université de Cordoba

Le programme du Master est organisé conjointement par Universidad de Córdoba (UCO), Consejería de Agricultura, Pesca y Medio Ambiente de la Junta de Andalucía (CAP), Instituto Andaluz de Investigación y Formación Agraria, Pesquera, Alimentaria y de la Producción Ecológica (IFAPA), Centre International de Hautes Etudes Agronomiques Méditerranéennes (CIHEAM) à travers l’Institut Agronomique Méditerranéen de Zaragoza (IAMZ), Consejo Superior de Investigaciones Científicas (CSIC) et Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)

Grade : Master Universitaire en Oliviculture et Oléotechnie 2019

Résumé en Espagnol – Anglais
Olive Anthracnose, caused by Colletotrichum spp., is the most critical fruit disease of olives and impacts highly in oil quality. Overall, in each olive growing region, a dominant species of Colletotrichum, and some secondary species of this genus, have been identified as causal agents of Anthracnose. For example, C. godetiae, dominates in Spain, while C. nymphaeae predominates in Portugal. This situation may be due to differences in the original population of the pathogen between each olive-growing area, or it could be associated with pathogenic specialization on the majority cultivar, adaptation to climatic conditions, or the possession of higher competitive ability. The main goal of this research work was to characterize the competitive capacity of C. godetiae and C. nymphaeae in culture media and olive fruits and leaves. The competition between both species was studied in the PDA (Potato Dextrose Agar) and diluted-PDA at 20 °C by periodically quantifying the number of colonies of each isolate, which were cultured at different spore proportions. Subsequently, Colletotrichum spores were extracted from colonies in medium and re-cultured successive times. Besides, the severity of symptoms generated by each species on ‘Galega vulgar’ and ‘Hojiblanca’ fruits incubated at 15, 20, and 25 oC was evaluated. Finally, we studied the capacity of both species to survive in inoculated leaves. The species C. godetiae displaced C. nymphaeae in both culture media (PDA and diluded-PDA) even at a low initial inoculum rate (5:95%, respectively). The cv. Hojiblanca was significantly more susceptible to both species than ‘Galega vulgar’. The species C. godetiae and C. nymphaeae showed a similar virulence in the olive fruits of both cultivars, and no important interaction pathogen species-olive cultivar was observed. When olive fruits were coinoculated with both species, C. godetiae showed higher competition capacity than C. nymphaeae. Finally, it was found that both species show similar survival capacity in olive leaves.

Source : Master of Oliviculture et Oleotechnie

Page publiée le 26 février 2021