Genetic Resources and Crop Evolution 39: 7-88, 992 © 992 Kluwer Academic Publishers Printed in the Netherlands Genetic relationships within Vigna unguiculata (L) Walp based on isozyme analyses

Isozyme analyses of genetic diversity in Vigna unguiculata were performed to determine genetic relationships and level of genetic diversity between wild and cultivated cowpea Thirty-four cultivated accessions of V unguiculata, 56 wild accessions of V unguiculata, and six accessions representing five related wild Vigna species were analyzed Ten enzyme systems were polymorphic within Vigna unguiculata: AAT, ACO, G6PDH, DIAP, LAP, MUE, ME MDH, PRX, and SOD Fourteen of 24 putative loci (58%) were polymorphic within wild V unguiculata, but only one locus (4%) was polymorphic within cultivated cowpea; when five related Vigna species were examined, 2 of the 24 bands of activity showed polymorphisms (88%) adding 33 alleles to the 48 identified within V unguiculata In one F 2 population of 68 plants (UCDVg 36 x UCDVg 2) a loose linkage was indicated between Diap-2 and G6pd- (X ' = 5 39; p = 4) with an estimated distance of 36 cM ± 5 2 (recombination (r) = 3) Also in another F2 population of 38 plants (CB 88 x UCDVg 2) a loose linkage was indicated between Lap- and Prx (X ' = 962; p = 47) with an estimated distance of 39 8 cM ± 7 (r = 33) Total genetic diversity (HT) was 85 over all of the accessions including the one classified as V nervosa Within accession diversity (HS) approached zero and between accession diversity (D ST) was responsible for all of the genetic diversity present Therefore the coefficient of gene differentiation (Gs, = DSTHT) approached Absolute gen