Effects of Abscisic Acid on the Sprouting of Aerial Tubers of Begonia evansiana and Dioscorea batatas

Abstract

D-Abscisic acid (ABA) inhibited the sprouting of aerial tubers of B. evansiana, which had been vernalized, at concentrations from 3×10^-6 to 10^-5M. In some experiments it caused promotion of sprouting at 10^-6M. Though weaker, similar effects were observed with cut aerial tubers of D. batatas. Intact tubers of this species did not respond to ABA. The low responsiveness of D. batatas to added ABA may not originate from its inactivation or decomposition, since the ABA added was recovered without any change. ABA was ineffective in inducing the formation of aerial tubers on B. evansiana plants under long-day conditions.