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A hybrid swarm involving O. sativa, O. glaberrima and O. longistaminata occuring in Jebba, Nigeria was studied to investigate the processes involved in the population dynamics. Reproductive parameters such as pollen stainability, pollen size, anther structure, seed set were investigated. The chromosomes of the hybrid population were also studied. The study reveals post-zygotic mechanism involving segregational as well as developmental hybrid sterility to be the major isolating mechanism involved the reproductive isolation existing among the parent populations in the swarm. Hybridization and introgression have played significant roles in creating this hybrid swarm which holds a lot of promise for speciation in the genus.

Cowpea coat color is a consumer-related trait that determines consumer preference and acceptability of the commodity in the market. Understanding the mode of inheritance of seed coat color will assist in choosing appropriate breeding technique in developing desirable cowpea varieties. This study was conducted to confirm the specific mode of inheritance of seed coat color in cowpea. Three bi-parental crosses using five different varieties of cowpea with contrasting seed coat colors were carried out to obtain F1 seeds at the Greenhouse, Faculty of Agriculture, Obafemi Awolowo University, Ile – Ife, Nigeria. The F1s were advanced to obtain F2 segregating populations which were evaluated by visual observation and the seeds were categorized into different distinct groups. The observed seeds of the F2 population of all the three crosses deviated extremely from Mendelian monogenic inheritance ratio in different degrees. TVu4669 × TVu43 segregated into two color groups resulting in brown mottled (15.4 %) and black mottled (84.6 %). Ife Brown  × TVnu699 segregated transgressively into five distinct groups of colors giving rise to brown (51.4%), black (23.7%), grey (14.8%), red (5.3%) and speckled (4.8% ); while Ife Brown × TVu2723 segregated into three color groups involving mottled black (4.3%), black (85.1%) and speckle (10.6%) coat colors. It could be inferred that more than one gene controls the inheritance of the seed coat color in cowpea, which implies that the trait is polygenic. It is recommended that molecular genetics’ techniques be explored in order to have better understanding of the mode of inheritance of seed coat color in cowpea.

The shortcomings of genotype x environment interaction  necessitated the use of molecular methods in characterizing many plant species and in determining their phylogenetic relationships. In this study, some selected cowpea lines (27 varieties) from Obafemi Awolowo University, Ile – Ife, the Institute of Agricultural Research (IAR), Samaru, Kaduna and Genetic Resource Centre, IITA, Ibadan were characterized using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) profiling. The protein banding profiles of the 27 cowpea varieties were scored and subjected to cluster analysis using Ward's minimum-variance method (WMVM) for dendrogram grouping. The dendrogram generated from the SDS-PAGE profiles grouped the varieties into seven clusters at 52% similarity coefficient. Hence, the biochemical characterization revealed more precise discrimination among the 27 cowpea varieties studied. Keywords: Cowpea, electrophoretic banding profiles, dendrogram grouping, total proteins

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