Characterization of powdery mildew (Leveillula taurica) in globe artichoke (Cynara scolymus)

Abstract

Globe artichoke (Cynara scolymus L.) is an economically important plant that is mostly grown in Mediterranean Basin in the world. In 2016 and 2017, chlorotic spots on adaxial surface but white fungal patches abaxial surface of leaves of globe artichoke were observed in the Western Mediterranean Region of Turkey. To determine causal agent of these symptoms, leaf samples were taken sporadically in 2016, 2017 and 2020. Based on morphological and ITS sequence data, the causal agent was determined to be powdery mildew fungus Leveillula taurica (Lév.) G. Arnaud. Pathogenicity test was conducted using seedlings of globe artichoke in a greenhouse. Additionally, infections caused by the fungus were examined in a two-year field study. Several surveys were carried out according to simple random sampling method and a total of 79 farmer fields (570 da) were screened in the region. Disease incidence and prevalence of the powdery mildew in 2016 were 14.2 and 36.1%, while they were 30.1 and 53.4% in 2017, respectively. Mean disease incidence and prevalence in the both years were 22.1 and 45.5%, respectively. The disease was previously reported on globe artichoke in Italy, U.S.A., Spain and Egypt. To our knowledge, this is the first record of L. taurica causing powdery mildew on globe artichoke in Turkey and globe artichoke is a new host for L. taurica in Turkey.