Development of a Molecular Marker to Track APA G40199 Introgression in Common Bean for Bruchid Resistance

Abstract

In common bean (Phaseolus vulgaris), the main seed storage pests are the bruchid beetles. Damage done to the seed by the larvae has a large impact on seed quality and yield. Arcelin (ARC), phytohaemagglutinin (PHA), and α-amylase inhibitor (α-AI) are linked seed storage proteins that form the APA locus on chromosome Pv04 and are associated with resistance. A major breeding objective is to introduce bruchid resistance into common bean from a resistant tepary genotype, G40199, by introgressing the resistant APA locus into susceptible common bean backgrounds. Here we developed a molecular marker that tracks the introgression. A set of PCR primers to the α-amylase inhibitor locus amplified a DNA fragment that showed a 45 base pair insertion in the middle of a lectin Leg_b domain. This enhanced locus characterization and insertion/deletion marker may preclude the need for bruchid resistance screening early in the breeding.