Response Of Improved Cowpea Genotypes To Alectra Vogelii Strains From Selected Areas Of Tanzania

EXTENDED 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.