Seed Storage Proteins Arl2 and Its Variants from the Apa Locus of Wild Tepary Bean G40199 Confers Resistance to Acanthoscellides Obtectus When Expressed in Common Beans

Wild tepary beans (Phaseolus acutifolius) contain arcelins and arcelin-like (ARL2) proteins that are co-expressed with other proteins of the arcelin, -amylase inhibitors and phytohemagglutinins (APA) locus. Arcelin and ARL2 protein from a wild tepary bean accession G40199 were transferred into common bean cultivars ICA Pijao and Rojo. Inbred backcross lines were developed and selected for segregation of the proteins at BC 2 F 2:3 generations. Seeds from homozygous, segregating lines expressing the arcelin and ARL2, plus those without the proteins, were used for screening against resistance to A. obtectus. Significant delay of 63 days for 50% adult emergence and reduced number of emerged F 1 of A. obtectus adults were observed in backcross lines with homozygous expression of arcelin and ARL2 tepary bean proteins. Furthermore, a reduction in size and weight of emerged adult insects to almost half was observed. This work demonstrates the superior resistance common bean backcross lines to A. obtectus conferred by the presence of the APA proteins introgressed from tepary bean.