COMPARATIVE-STUDY ON SEED PROTEINS OF IPOMOEA

Species homology and genetic relationship among nine wild, two horticu ltural and one semicultivated species of Ipomoea were studied. Compara tive studies of total seed protein, its globulin and albumin fractions were carried out by SDS-PAGE. Vicilin (7-8S) and Legumin (11-12S) app ear to be ubiquitous throughout different dicotyledonous families and were found to be major seed storage proteins contained in twelve speci es of Ipomoea studied. Pairing affinities among the species were calcu lated from SDS-PAGE profile and a dendrogram showing hierarchical clus tering was constructed for total seed protein, globulin and albumin fr actions separately. The highest pairing affinity value (94.5%) for tot al protein and globulin was shown by species pair I. hispida and I, qu amoclit and for albumin (92.6%) by I. pes-tigridis and I. triloba. The least pairing affinity value (61.8%) for total protein was recorded i n species pair I. fistulosa and I triloba, for globulin (60.3%) by I. aquatica and I. triloba and for albumin (55%) by I. pes-caprae and I. chryseides. The dendrograms for total protein, globulin and albumin fr action revealed three major groups of species. The dendrograms of tota l seed protein and globulin were very similar but that of albumin was somewhat different.