Bacterial blight of Crambe abyssinica in Missouri caused by Xanthomonas campestris

Crambe abyssinica is being evaluated as an oilseed crop for Missouri. During 1990-1992, a blight affecting leaves and stems was observed on virtually all plants growing in three experimental fields in central Missouri. A yellow-pigmented, gram-negative bacterium was consistently recovered from symptomatic tissue. A combination of physiological tests and gas chromatographic analysis of cellular fatty acids identified the bacterium as Xanthomonas campestris. The pathogen was closely related to X. c. armoraciae and X. c. campestris. The bacterium was found to be seedborne, contaminating 50-67% of tested seed of cv. Meyer. The bacterium was detected predominantly on the silicle and the surface of the seed coat and was possibly systemic within the seed (.)