Common bacterial blight (CBB) is an economically important disease of dry bean worldwide caused by Xanthomonas axonopodis pv. phaseoli, (Xap). The objectives of this research were to determine the frequency of CBB resistance in NDSU breeding materials and to evaluate the effectiveness of two SCAR markers, SAP6 and SU91, linked with major QTL for CBB resistance, across this host population. A total of 593 advanced and preliminary lines were phenotyped in the greenhouse and genotyped using SAP6 and SU91. Phenotyping revealed CBB resistance in 310 lines, with a higher frequency of resistant lines in the pinto, great northern and small red market classes. A total of 188 lines were phenotyped under field condition and only 23 lines were found resistant. The presence of the SU91 marker, and both markers in combination, more effectively identified CBB resistance than did the SAP6 marker alone. Identification of resistant lines should accelerate breeding efforts.Northarvest Bean Growers AssociationNorth Dakota Dry Edible Bean Seed Growers Associatio
