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Istituto Agronomico Mediterraneo di Bari (IAMB) 2008

Occurrence of the olive knot disease in Egypt

Ahmad, Add elmonim Ali

Titre : Occurrence of the olive knot disease in Egypt

Auteur : Ahmad, Add elmonim Ali

Etablissement de soutenance : Istituto Agronomico Mediterraneo di Bari (IAMB) - Centre international de hautes études agronomiques méditerranéennes (CIHEAM)

Diplôme : Master of science : Integrated pest management of Mediterranean fruit crops (2008)

Résumé
Field surveys were carried out in the main Egyptian olive growing regions to verify whether olive knot disease, caused by Pseudomonas savastanoi pv. savastanoi, was present and to determine its geographic distribution and incidence/severity. The presence of typical disease symptom i.e. knots on olive branches and trunk was observed in EI-fayoum region, with low disease incidence and severity. The isolation of the pathogen from the olive knots was difficult to perform due to the massive and constant presence of a bacterium overgrowing in vitro, which we identify as Brevundimonas diminuta on the basis of its 165 rDNA sequence. However, 4 bacterial isolates whose colonies resembling those of the pathogen were isolated from olive knots. Morphological, biochemical, physiological, pathogenicity and molecular tests, showed that Egyptian isolates belong to P. savastanoi pv. savastanoi. Molecular characterization of these isolates performed with rep-PCR demonstrated 97-100% of similarity with the pathovar reference strain LMG 2209T of P. savastanoi pv. savastanoi. This is the first report of olive knot disease in Egypt.

Mots-clés : OLIVES PSEUDOMONAS SAVASTANOI PCR SURVEYS EGYPT

Présentation (IAMB Library)

Page publiée le 22 juin 2014, mise à jour le 4 décembre 2017