Two Resistant Responses in Cowpea Induced by Different Strains of Xanthomonas campestris pv. vignicola. R. D. Gitaitis, Department of Plant Pathology, University of Georgia, Coastal Plain Experiment Station, Tifton 31793. Plant Dis. 67:1025-1028. Accepted for publication 30 March 1983. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-1025.

Twenty-eight cowpea cultivars and plant introductions were identified as resistant to bacterial blight and canker. Two types of resistant responses were observed and characterized. The first response was a rapid confluent necrosis, typical of a normal hypersensitive response, and was expressed against incompatible fluorescent pseudomonads and most strains of Xanthomonas campestris pv. vignicola. The second response was represented by a brown-red discoloration without complete collapse of the tissue. The brown-red reaction was expressed against two strains of X. campestris pv. vignicola as well as all other pathovars of X. campestris that had been isolated from a variety of hosts other than cowpea.

Keyword(s): Vigna unguiculata.