Inheritance of hairiness and pod shattering, heritability and correlation studies in crosses between cultivated cowpea (Vigna unguiculata (L.) Walp.) and its wild (var. pubescens) relative

Abstract

Crosses were made between five cultivated cowpea varieties and a wild relative var. pubescens (as pollen parent) to study the inheritance of hairiness, pod shattering, as well as heritability and correlations among yield and yield related traits. F₁ plants exhibited dominance for both hairiness and pod shattering traits. Segregation in F₂ populations approximated 3:1 and 13:3 for hairy and non-hairy stem and 13:3 for hairy and non-hairy pod. The ratio of 13:3 and 15:1 ratios were observed among the F₂ populations for shattering and non-shattering pods. Broadsense heritability estimates showed that days to pod maturity averaged 77.93%, 100 seed weight 68.45%, seeds pod⁻¹ 69.76% and number of branches plant⁻¹ had 62.54% (all high). Days to first flowering and pod length were moderate (57.31 and 54.29%, respectively). Number of pods plant⁻¹ had low heritability estimates with an average of 39.0%. Correlations among number of pods plant⁻¹, seeds pod⁻¹, seeds plant⁻¹ and seed yield plant⁻¹ (0.485–0.568) were significantly positive. Correlations between seed pod⁻¹ and seed plant⁻¹ with number of pods plant⁻¹ were 0.909 and 0.996, respectively. High broadsense heritability averaged 77.93% for days to pod maturity, 68.45% for 100 seed weight, 69.76% for seeds pod⁻¹ and 62.54% for number of branches plant⁻¹. Days to flowering and pod length plant⁻¹ had moderate estimates of 57.31 and 54.29%, respectively, while pods plant⁻¹ was low (39.90%). Potential utilization of the hairiness trait and the implication of pod shattering in cowpea improvement were discussed. Positive correlations among these yield components, as well as high to moderate broadsense heritability estimates of the yield related traits can be utilized for direct and indirect selection to improve grain yield in cowpea.