Mineral storage in Cucurbita embryos. I. Calcium storage in relation to embryo size

Abstract

Cucurbita maxima cv. Warted Hubbard has large fruits up to 10 kg in weight and its seeds have an average weight of about 0.25 g. Cucurbita andreana has fruits < 1 kg in weight and its seeds have an average weight of about 0.02 g. Within each species fruit weight was highly variable, while seed weight was quite stable. The overall range of variation in seed weight within both species was about 2.5-fold. Embryos of the species with the small seeds (C. andreana) contained less Ca on a per embryo basis than did those of C. maxima, but on a per gram basis these small embryos contained three times more Ca than the larger C. maxima embryos. Within C. maxima embryos, Ca varied as much as fivefold, with heavy and long embryos tending to have less Ca per gram tissue than smaller C. maxima embryos. Calcium concentrations within C. andreana were not correlated with embryo size.