title: Morphological and molecular characterization of Fusarium spp. associated with olive trees dieback in Tunisia.
abstract: Dieback and wilting symptoms caused by complex soilborne fungi are nowadays the most serious threatening disease affecting olive trees (Olea europaea) in Tunisia and presumably in many Mediterranean basin countries. Fusarium is one of the important phytopathogenic genera associated with dieback symptoms of olive trees. The objective of the present study was to confirm the pathogenicity of Fusarium spp. isolated from several olive-growing areas in Tunisia. According to the pathogenic test done on young olive trees (cv. Chemlali), 23 out of 104 isolates of Fusarium spp. were found to be pathogenic and the others were weakly or not pathogenic. The pathogenic Fusarium spp. isolates were characterized using molecular methods based on ITS PCR. Isolation results revealed the predominance of Fusarium solani (56.5%) and F. oxysporum species (21.7%) compared to F. chalmydosporum (8.7%), F. brachygibbosum (8.7%) and F. acuminatum (4.34%). Based on pathogenicity test, disease severity was highly variable among the 23 pathogenic isolates tested (P < 0.05) where F. solani was the most aggressive dieback agent. To the best of our knowledge, this is the first work that shows that Fusarium spp. might be a major agent causing dieback disease of olive trees in Tunisia.
authors.affiliation: Laboratoire d'Amélioration et Protection des Ressources Génétique de l'Olivier, Institut de l'Olivier, Université de Sfax, BP1078, Sfax, Tunisia.|Laboratoire de Recherche Toxicologie-Microbiologie Environnementale et Santé (LR17ES06), Faculté des Sciences de Sfax, Université de Sfax, Sfax, Tunisia.
authors.forename: Rahma
authors.initials: R
authors.lastname: Trabelsi
authors.affiliation: Laboratoire de Recherche Toxicologie-Microbiologie Environnementale et Santé (LR17ES06), Faculté des Sciences de Sfax, Université de Sfax, Sfax, Tunisia.
authors.forename: Hanen
authors.initials: H
authors.lastname: Sellami
authors.affiliation: Laboratoire d'Amélioration et Protection des Ressources Génétique de l'Olivier, Institut de l'Olivier, Université de Sfax, BP1078, Sfax, Tunisia.|Laboratoire de Recherche Toxicologie-Microbiologie Environnementale et Santé (LR17ES06), Faculté des Sciences de Sfax, Université de Sfax, Sfax, Tunisia.
authors.forename: Yâakoub
authors.initials: Y
authors.lastname: Gharbi
authors.affiliation: Laboratoire d'Amélioration et Protection des Ressources Génétique de l'Olivier, Institut de l'Olivier, Université de Sfax, BP1078, Sfax, Tunisia.
authors.forename: Samira
authors.initials: S
authors.lastname: Krid
authors.affiliation: Laboratoire d'Amélioration et Protection des Ressources Génétique de l'Olivier, Institut de l'Olivier, Université de Sfax, BP1078, Sfax, Tunisia.
authors.forename: Manel
authors.initials: M
authors.lastname: Cheffi
authors.affiliation: Laboratoire d'Amélioration et Protection des Ressources Génétique de l'Olivier, Institut de l'Olivier, Université de Sfax, BP1078, Sfax, Tunisia.
authors.forename: Sonia
authors.initials: S
authors.lastname: Kammoun
authors.affiliation: Laboratoire d'Amélioration et Protection des Ressources Génétique de l'Olivier, Institut de l'Olivier, Université de Sfax, BP1078, Sfax, Tunisia.
authors.forename: Mariem
authors.initials: M
authors.lastname: Dammak
authors.affiliation: Laboratoire d'Amélioration et Protection des Ressources Génétique de l'Olivier, Institut de l'Olivier, Université de Sfax, BP1078, Sfax, Tunisia.
authors.forename: Aymen
authors.initials: A
authors.lastname: Mseddi
authors.affiliation: Laboratoire de Recherche Toxicologie-Microbiologie Environnementale et Santé (LR17ES06), Faculté des Sciences de Sfax, Université de Sfax, Sfax, Tunisia. gdoura.radhouane@gmail.com.
authors.forename: Radhouane
authors.initials: R
authors.lastname: Gdoura
authors.affiliation: Laboratoire d'Amélioration et Protection des Ressources Génétique de l'Olivier, Institut de l'Olivier, Université de Sfax, BP1078, Sfax, Tunisia.
authors.forename: Mohamed Ali
authors.initials: MA
authors.lastname: Triki
keywords: Disease symptoms; Fusarium spp.; Molecular identification; Olive tree (Olea europaea); Pathogenicity