Phylogenetic study on Cucurbita species by means of esterase zymogram

For the purpose of biochemical approach towards taxonomic and phylogenetic inquiries in the genus Cucurbita, esterase compositions in the seedlings of various forms of Cucurbita moschata, C. maxima and C. pepo were analyzed by the zymogram, and following results were obtained. 1) The distinct differences among C. moschata, C. pepo and C. maxima were observed in the electrophoretic mobilities of their esterases. From the result of previous experiment on Brassica species (Eguchi and Matsui, 1969), it could be estimated that there are inter-genomic differences among those 3 species. 2) The differentiations within C. pepo were more significant in extent than those within C. moschata or C. maxima. 3) The forms of C. pepo could be divided into 3 groups, such as the Table Queen, Vegetable Marrow, and Pumpkin groups, 4) Pumpkin group seems in its esterase patterns to be intermediate between the Table Queen and Vegetable Marrow groups. That is, an array of esterase bands in the Pumpkin group was found to bc composed of both of the bands present in two other groups. This fact suggest that the Pumpkin group might have been arisen through hybridization between the Vegetable Marrow and Table Queen groups.