Understanding the Genetic Basis of Resistance to Cowpea Scab: Insights into Parental Combining Ability and Gene Action in Breeding Strategies

Abstract

Cowpea (Vigna unguiculata) is an essential leguminous crop with significant importance in global agriculture and food security. However, it is susceptible to various diseases, with Cowpea Scab (a fungal disease caused by Sphaceloma sp.) being a major constraint to its production. Breeding for resistance to Cowpea Scab is a crucial strategy to enhance cowpea productivity and reduce yield losses. This review paper examines the role of parental combining ability and gene action in breeding for resistance to Cowpea Scab. Parental combining ability of scab resistance has been evaluated on different cowpea germplasm and has shown that General Combining Ability (GCA) is more important than Specific Combining Ability (SCA) in the inheritance of scab resistance. The higher narrow sense heritability also signifies the contribution of additive genetic variability in scab resistance inheritance.