Isozyme and storage protein polymorphisms in seventeen accessions of groundnuts (Arachis hypogaea L.)

Abstract

Knowledge of the genetic relationships among the genetic resources of crop plants is important for facilitating the transfer of useful genes and maximising the use of germplasm. The aim of this study was to characterise 17 accessions of groundnuts. The methods employed were starch gel and sodium dodecyl sulphate polyacrylamide gel electrophoresis for isozymes and storage proteins, respectively. Starch gel electrophoresis of crude protein extracted from the root-tip of two-week old plants followed by staining in appropriate stain solutions for three enzymes, acid phosphatase, esterase and peroxidase exposed variations among the accessions. Peroxidase revealed the most variation, while acid phosphatase showed the least variation. When the results of the three isozymes were combined, 13 accessions could unambiguously be distinguished. The remaining four accessions fell into two groups of two each. Similarity indices were estimated to determine relatedness among the accessions based on the isozyme data. There was very little variation in storage protein patterns. Only three phenotypes were observed. Combining both isozyme and storage protein data allowed distinction of the accessions. These results suggest that an integrated approach utilising both morphological and molecular markers can allow a proper characterisation of the genetic resources of the crop.