GIBBERELLINS A(19) AND A(24) FROM YAMS, DIOSCOREA-BULBIFERA, D-PENTAPHYLLA AND D-OPPOSITIFOLIA

Gibberellin A(19) (GA(19)) and GA(24) were identified by gas chromatog raphy-mass spectrometry from growing shoots of four strains of three s pecies of Dioscorea, D. bulbifera var. vera, D. pentaphylla and D. opp ositifolia (yams), which are distributed in the subtropical and tropic al regions of Asia. An earlier report indicated the presence of severa l GAs including GA(19) and GA(24) in a cultivated temperate species of East Asia, D. opposita; these findings suggest possible coexistence o f two GA biosynthetic pathways, early 13-hydroxylation and non-13-hydr oxylation pathways commonly in Asian species of Dioscorea.