Polyacrylamide gel electrophoresis was employed in an investigation of peroxidase isozymes extracted from the mature fruits of seventeen individuals belonging to the genusThe purpose of this study was to develop procedures which could supplement existing information contributing to the biosystematics of this genus.Samples were detected on 5%-20% linear gradient gels in a sodium borate - boric acid buffer (pH, 9.0). Following electrophoresis, incubation was carried out in a solution containing benzidine dihydrochioride and hydrogen peroxide in an acetate buffer (pH, 4.5).Resulting zymograms were analyzed and eight different isozyme bands identified, based on width, staining characteristics and relationship to a horseradish peroxidase standard zymogram. Composite zymograms were drawn for each Species, based on frequency of occurrence of individual bands. Within each species, some isozymes were observed in 100% of the individuals, while other bands appeared in 20% to 92% of the gels examined. Three of the seven species investigated exhibited unique zymograms. Similarities were noted in isozyme patterns among species. Three groups of species were established based on the presence or absence of certain variable bands. Two of these groups had some correspondence to series groupings based on observable morphological characteristics. A third group consisted of species not related in traditional classification.