The endosperm and cotyledon tissues of Ricinus communis seeds and young seedlings were examined for changes in the mineral nutrient composition of globoids during early seedling growth. The effect on globoid composition of providing mineral nutrients to the developing seedling was also investigated. Globoids in endosperm and cotyledon tissues of castor bean seeds contained P, Mg and K, as well as trace amounts of Ca, Fe and Zn. Irrespective of the addition of mineral nutrients, K content in globoids of endosperm and cotyledon tissues declined significantly during initial seedling growth. During early seedling growth, amounts of Fe, Zn and Ca increased in cotyledon globoids. Ca contents of globoids of endosperm tissues also increased. The changes in Fe, Zn and Ca globoid contents were not influenced by providing mineral nutrients to growing castor bean seedlings.
