Abstract:
Cowpea is one of the most important protein rich legumes worldwide. This study used the Random Amplified Polymorphic DNA (RAPD) assays to reveal the positive and negative DNA markers in seven cultivars of cowpea,which could use for cultivars identification and discrimination, for future breeding programs and derivation of novel genotypes. Also, to evaluate the proportion of genetic relationship among the cultivars by detecting the genetic polymorphism at molecular level and correlate the obtained results with some morphological traits and source of cultivars. RAPD Results showed that a total number of 56 DNA fragments were amplified, ranged in size between 1637 bp and 163 bp, while the total polymorphic bands number was 45 and the percentage of polymorphism was 80.3 %. Five cultivars (Cream-12, Chinese red, Blackeye crowder, Brown crowder, and Cream-7) appeared to have whether positive or negative markers with different molecular weight, while Azmerly and Dokki-331 cultivars did not produce any specific bands. The dendrogram of RAPD data showed that the 7 cultivars of cowpea were grouped in 6 clusters based on genetic similarities; the highest value of similarity was 86.6 % between Azmerly and Dokki-331, while the lowest was between Cream-12 and Blackeye crowder with a value of 54.2 %. The obtained results suggest that RAPD markers were better linked to the source of the cultivar and to the extent of seed crowding in pod trait, while the seed colour and the growth habit traits might or might not show correlation with the molecular data.