DETERMINATION OF GENETIC VARIATION OF EGYPTIAN COWPEA (VIGNA UNGUICULATA (L.) WALP.) USING RAPD-PCR PATTERNS

Cowpea (Vigna unguiculata (L.) Walp.) is the most important grain legume crop grown in tropical and subtropical regions. Seeds of cowpea have a high nutritional value containing high amount of protein (23–29%). Seeds of 19 landraces of cowpea (Vigna unguiculata) were obtained from gene bank of Cairo University (11 landraces) and from Agricultural Research Station Kafr El-Sheikh (Sakha) (8 varieties). The seeds planted till maturity. Random amplified polymorphic DNA (RAPD) was assayed to determine the genetic variation of 19 varieties of cowpea cultivated in different regions of Egypt. A total of five random primers were used in the study. Amplification of genomic DNA of Egyptian cowpea landraces with these RAPD primers yielded 54 fragments that could be scored, of which 45 were polymorphic. Number of amplified fragments with random primers ranged from 4 (OP 856) to 14 (OP 880). Percentage polymorphism ranged from 75% (OP 856) to a maximum of 100% (OP 889, OP 868, Op 808 and OP 880), with an average of 95%. A dendrogram produced by the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) based on Jaccard‟s similarity coefficient revealed that the cowpea varieties divided into two groups which showed variability that may be exploited for crop improvement. The overall range of genetic similarities ranged from 0.48 to 0.93 in 19 landraces of cowpea which indicates there was high variability among the varieties. Based on genetic distance in RAPD analysis the landraces no. 9 and 12 appeared as most divergent and could be used in breeding programme of cowpea. It could be concluded that RAPD markers are important tools for genetic analysis for cowpea(Vigna unguiculata (L.) Walp.).