Occurrence of Verticillium dahliae defoliating pathotypes on olive trees in Tunisia

Olive trees (cv. Chemlali) showing typical symptoms of wilt and dieback were collected from several areas in Tunisia. Visual diagnostic, isolation and microscopic observations identified the causal pathogen as Verticillium dahliae. The pathotype was determined using specific primers pairs for D (defoliating) and ND (non-defolitating) . Artificial inoculation of olive plants resulted in typical wilting with defoliation, proving that the isolate tested was pathogenic on olive, and this isolate belongs to the D pathotype. This is the first report of the defoliating pathotype causing wilting disease on olive in Tunisia.