Bacterial leaf spot of lettuce caused by Xanthomonas hortorum pv. vitians in the Aegean Region of Turkey

Samples of diseased plants were collected from 12 lettuce fields in Aydin province of the Aegean Region of Turkey. A total of 8 bacterial isolates were identified by morphological characterization, sequence analysis of 16S rDNA and gyrB genes, and pathogenicity. The survey included twelve lettuce fields of three different cultivars [Yedikule (romaine type), Robinson and Chianti (iceberg type)]. The incidence of the disease ranged from 48 to 95%. Plants of cv. Chianti were the most severely infected cultivars. To our knowledge, this is the first report of the presence of Xanthomonas hortorum pv. vitians in lettuce plants in Turkey.