INHERITANCE OF PHENOTYPIC TRAITS AMONG PARENT AND F2 COWPEA [VIGNA UNGUICULATA (L.) WALP] HYBRIDS

ABSTRACT Cowpea (Vigna unguiculata L. Walp) is a vital legume crop for food security in tropical and subtropical regions, but its productivity is limited by a lack of genetic understanding of key traits. This study assessed the inheritance of phenotypic traits and heterosis in parental lines (SAMPEA-20T, TVu-17327, and TVu-172324) and their F₂ hybrids to support cowpea breeding efforts. A completely randomized block design was used, and data were collected on both quantitative traits (such as plant height, pod length, seed yield) and qualitative traits (such as flower colour, leaf colour, and seed coat colour). Results showed significant genetic variation, with high heritability (>90%) and genetic gain for traits related to yield, indicating strong additive gene effects. Heterosis was notable in hybrids SAMPEA-20T × TVu-17327 and TVu-172324 × TVu-17327, which outperformed in emergence (up to 77.20% heterosis), seed yield (55.64%), and pod number per plant. Correlation analysis revealed strong links between yield and traits like pod length and seed weight, suggesting potential for indirect selection. Qualitative traits showed complex inheritance patterns, with flower colour and seed coat pattern fitting digenic (9:7, 15:1) and epistatic (9:6:1) ratios. The results highlight the potential of heterosis breeding and trait-based selection to improve cowpea productivity. Recommendations include advancing high-performing hybrids for multi-environment trials and incorporating molecular markers to better understand gene interactions for targeted improvement. This research provides a basis for developing high-yielding, stress-tolerant cowpea varieties to help address global food security challenges.