Abstract
Gibberellin (GA) relationships were examined in a spontaneous dwarf mutant and its original normal variety of sweet potato. The dwarf strain had shorter internodes than the normal strain although its leaf petiole remained unchanged. Grafting of dwarf scion onto normal stock did not induce normal growth of the dwarf scion, and normal scion grafted onto dwarf stock did not alter the normal growth. The amount and kind of endogenous GAs did not seem to differ between the normal and dwarf strains. Applied GA3 markedly stimulated the growth of normal strain but did not stimulate the growth of dwarf strain markedly. Application of CCC, an inhibitor of GA biosynthesis, greatly reduced the amount of GAs and the growth of leaf petioles and stems in both strains. It was suggested that dwarf strain had a partial block to the utilization of GAs in the stem but not in the leaf petiole.
