Morpho-phenological Variability of Flowers Traits and Hybridization of Five Inbred Lines of Cowpea [Vigna unguiculata (L.) Walp.] in Côte d'Ivoire

Abstract

Knowledge of the morphology and floral phenology and the mastery of a manual pollination technique in a plant species are essential for its genetic improvement. The objective of this work will be to determine the morpho-phenological characteristics of the flowers of five self-fertilization lines of cowpea and to identify an indicated manual pollination technique. The study was carried out in the Botanical Garden of University Peleforo GON COULIBALY, Côte d’Ivoire where 10 morpho-phenological characters of the flower were evaluated on five lines of cowpea self-fertilization. Thus, three manual pollination techniques (A, B and C) were tested by evaluating traits such as knotting rates, filling rates and maternal and paternal effects on fruit yields. The results revealed four stages of flower development in cowpea. These are successively stage of “floral button initiation”, “dark green floral button”, “pale green or pale-yellow floral button” and “blooming flower”. Of the three manual pollination techniques tested, technique C resulted in higher rates of knotting (45.38%) and pod filling (58.03%). Results also showed significant maternal and xenia effects on fruit yields in the cowpea. On the basis of the results generated on the floral biology of the cowpea, it appears that a hybridization program can now be conducted at the UPGC Botanical Garden for the creation of high-performance varieties adapted to climate change for the benefit of producers in Côte d’Ivoire.