Genetic diversity of egyptian cowpea (vigna unguiculata (L.) walp.) landraces and their genetic relationships based on seed storage protein and isozymes

Abstract

THE CURRENT research was performed to study the genetic diversity of 19 cowpea landraces (Vigna unguiculata (L.) Walp.) from 7 localities in Egypt using seed storage protein and three isozymes (α-esterase, β-esterase, and peroxidase) gel electrophoresis. The results of the seed protein pattern of the studied landraces revealed a total number of 29 bands with molecular weights ranged from 7 to 265kD (one unique, 26 polymorphic, and 2 monomorphic bands) were detected. The unique band with a molecular weight of 205kD was detected in only one landrace. The number of bands in different 19 landraces ranged from 9-14 bands per landrace. The highest number of bands (14 bands) was detected in one landrace only (Sohag number 2) and the lowest number of bands (9 bands) was detected in 3 landraces (numbers 4,7 and 8 from Sohag, Luxor, and Dakahlia, respectively). Banding patterns of three isozymes (α- esterase, β-esterase and peroxidase) in Egyptian cowpea landraces showed that seven loci were present in all studied landraces of cowpea, one locus of α-esterase, five loci of β-esterase and one locus peroxidase. The number of loci varied in different landraces and ranged from 2-6 loci for α-esterase isozyme, 5-7 loci of β -esterase isozyme and 1-5 loci for peroxidase. The α-esterase and peroxidase banding patterns showed higher polymorphism in cowpea landraces compared with β-esterase. By using the combined protein and isozyme data, high variability among landraces was obtained and analyzed by the NTSYS-pc software program.