Changes in the Distribution of Magnesium, Potassium, Calcium and Phosphorus during Growth ofCucurbitaSeedlings

Abstract

Ockenden, I. and Lott, J. N. A. 1988. Changes in the distribution of magnesium, potassium, calcium and phosphorus during growth of Cucurbita seedlings—J. exp. Bot. 39: 973–980. Etiolated seedlings of Cucurbita maxima cv. Warted Hubbard and Cucurbita andreana, grown in distilled water, showed considerable growth. However, only a small percentage of the minerals stored in the large cotyledons was mobilized to the root-shoot axis of the etiolated seedlings. The proportion of minerals removed from the cotyledons to the root-shoot axis was about two-times higher in C. andreana than in C. maxima. When the seedlings were grown in distilled water in the presence of light, the percentage of cotyledon mineral content that was mobilized was lower than the amount mobilized during growth in the dark. Cotyledons of light-grown seedlings that were given adequate nutrients, took up minerals from the medium. These fully-expanded and photosynthetic cotyledons had slightly more P and Mg than did the cotyledons of the dry embryos but had increased their K content 5-fold and their Ca content 50-fold.