First record of Cladosporium species causing leaf spots on globe artichoke (Cynara scolymus)

In 2016 and 2017, circular and irregular leaf spots on globe artichoke (Cynara scolymus) were observed in seven locations of the Mediterranean region of Turkiye. In a preliminary microscopic examination, fungal spores in the leaf spots were similar to the genus Cladosporium. However, three different methods (direct transferring, agar-plate, and blotter) were used for isolation of possible causal agent(s) of those leaf spots. Based on morphological and molecular data (ITS and Actin), fungal colonies isolated from those leaf spots belonged to Cladosporium cladosporioides and Cladosporium pseudocladosporioides. Pathogenicity tests were fulfilled using globe artichoke seedlings of cv. Bayrampasa in a greenhouse. In addition, to detect prevalence of the leaf spots on globe artichoke, surveys were conducted in 79 commercial fields in two consecutive years. As a result, mean disease incidence was 17.4% in 2016, while it was 24.4% in 2017. The results of the present study suggest that Cladosporium cladosporioides and Cladosporium pseudocladosporioides are associated with the leaf spots on globe artichoke. Cladosporium was previously reported to be associated with leaf spots on sycamore fig, papaya, pecan, wheat, eggplant, tomato and ladies palm. To the best of our knowledge, this is the first record of Cladosporium species causing leaf spots on globe artichoke in the world.