Different Phenotypes Associated with Incompatible Races and Resistance Genes in Bacterial Spot Disease of Pepper. A. M. Hibberd, Former Graduate Assistant, Vegetable Crops Department, University of Florida, Gainesville 32611. R. E. Stall, and M. J. Bassett. Professor, Plant Pathology Department, and Professor, Vegetable Crops Department, University of Florida, Gainesville 32611. Plant Dis. 71:1075-1078. Accepted for publication 7 July 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-1075.

Three distinct resistance systems to Xanthomonas campestris pv. vesicatoria are distributed among plants of PI 271322 of Capsicum annuum. One plant was selected from a population of PI 271322 that was homozygous for all three resistances, and progeny of the plant were designated line 271-4. Multiplication of a strain of each incompatible race in leaves of this line ceased at different population levels. The time to host cell collapse (phenotype) after inoculation with 5 × 10⁸ cfu/ml was different for each resistance and incompatible race. The phenotypes and multiplication of incompatible strains in heterozygotes differed from that in homozygotes. These resistances may be incompletely dominant.