First Report of Xanthomonas euvesicatoria Causing Bacterial Spot Disease in Pepper in Northwestern Nigeria

Bacterial spot (BS) has been reported as an important disease on pepper in Nigeria (4). Xanthomonas campestris pv. vesicatoria was identified as the causal agent using phenotypic and pathogenicity tests; however, X. campestris pv. vesicatoria is a synonym for two genetically distinct groups that have been elevated to the species X. euvesicatoria and X. vesicatoria (2). Furthermore, the latter two species and X. gardneri cause similar diseases on pepper (2). In order to determine the species associated with BS on pepper, leaves with irregular, dark brown lesions were collected from pepper plants in fields from northwestern Nigeria, and isolations were made on nutrient agar (NA). Yellow, mucoid colonies typical of Xanthomonas were isolated. Six strains isolated from pepper were determined to be non-amylolytic. For race determinations, bacterial suspensions of the pepper strains, derived from 24-h cultures grown on NA at 28°C, were adjusted to 108 CFU/ml and infiltrated into leaves of tomato and pepper diffe...