Abstract:
Copwpea, (Vigna unguiculata L. Walp), belonging to the family Fabaceae, is one of the
most important food legumes in semi-arid areas. It is a multipurpose crop with immense
nutritional value and has significant potential to address malnutrition. However, the
parasitic weed Alectra vogelii poses major threat to cowpea productivity throughout
tropical and sub-tropical Africa. A. vogelii has developed strains specific to cowpea.
Effective control of damage caused by A. vogelli in cowpea fields can be done through
incorporation of resistance in cowpea varieties. The current study focused on determining
existing genetic variability amongst strains of A. vogelli and response of improved
cowpea genotypes. A total of 23 simple sequence repeats (SSR) markers were used to
assess the genetic variability. The polymorphic information content (PIC) value computed
was 0.929 with a gene diversity of 0.7913. Cluster analysis revealed existence of four
distinct clusters amongst assessed populations of A. vogelli collected from different
locations. This highlights the importance of developing and testing cowpea genotypes
resistant to A. vogelii in multiple locations. The ability of improved cowpea varieties to
thrive alongside A. vogelli was evaluated in pots in a screenhouse arranged in a split plot
manner with treatments in randomized complete block design (RCBD). The results
revealed that A. vogelii had negative significant effect on cowpea genotypes. Cowpea
genotype B 301 had the highest yield compared to the rest of the improved varieties
followed by vuli-1. Results from this study also indicated existence of high diversity of A.
vogelli.
