Inheritance of Stem Fasciation and Its Effect on Some Agronomic Traits of Cowpea

Abstract

ABSTRACTCowpea [Vigna unguiculata (L.) Walp] is a major source of dietary protein for many people in the tropics. It is affected by pests and diseases throughout its life cycle and during storage, with yield losses up to 100% in Africa. Stem fasciation in this study was genetic in origin and had an important influence on agronomic traits. A fasciated stem mutant was crossed to three normal stem lines. Six generations comprising parents, F1, F2, and BC were produced and planted on the field at the Teaching and Research Farm of the University of Ibadan, Nigeria. Data were collected on phenotypic traits and the following quantitative traits: days to flowering and ripe pod and seed traits. Data on the experiments were analyzed using χ 2, mean, standard error, and correlation analysis. The fasciated stem mutant segregated in the ratio 3normal stem: 1fasciated stem, thus indicating that the traits were controlled by monogenic recessive genes. The gene symbol fas‐2 was assigned to its recessive condition. Number of days to fasciation was negatively correlated with pod length in two crosses (−0.34, −0.23; mean significant at < 0.01 probability level). The fasciated plant in this study displayed delayed maturity, increased plant height, and greatly decreased seed yields.