UC Riverside

Cowpea (Vigna unguiculata [L.] Walp.) is a crop with a rising profile. Today, cowpea is mostly grown as a subsistence crop by smallholder farmers in marginal conditions. Over 90% of cowpea production occurs in a sub-Saharan Africa, where it serves as an important source of calories, protein, and micronutrients. Despite its importance in developing countries, few resources have been invested in researching the genetic control of consumer- and agronomic-related traits in cowpea. Long considered an orphan crop, as new genetic and genomic resources are developed, new opportunities arise for research into genetic control of traits. Research into the genetics of cowpea dates to the early twentieth century when researchers made crosses to identify factors controlling various traits. New resources made available in recent years facilitate examination of the mechanisms of control over these traits. In this dissertation, I present findings demonstrating mapping of black seed coat and purple pod color, seed coat pattern, and leaf aspect ratio. The mapping of these traits identifies the physical locations of genetic factors identified over the past century, including the Black Color (Bl), Color Factor (C), Holstein (H), Watson (W), and various leaf shape loci. Further, genetic markers have been developed for use in marker assisted selection for these traits. Adding insight into how the seed coat develops, I present a system following seed coat development which explains some of the observed variation in seed coat patterns. Finally, to assist breeders in determining what traits should be focused on for breeding purposes, I present a consumer-preference analysis performed in Ghana during August and September 2018. In combination, the findings presented in this thesis will facilitate breeders’ efforts to develop new varieties for changing conditions.