Dormancy inDioscorea: Generality of gibberellin-induced dormancy in asexual dormant organs

摘要

Effects of GA3and CCC application on the sprouting of bulbils or subterranean dormant organs of 10 species in the genusDioscoreawere observed. Although the efficiency of both chemicals differed by species, in general GA3inhibited and CCC promoted the sprouting of the above dormant organs. In some species, however, diluted GA3(0.003–0.3μM) has a promotive and diluted CCC (3–30μM) has an inhibitive effect on sprouting.Effects of GA3application on shoot elongation were tested on sprouted bulbils. GA3promoted elongation when applied directly to the shoots and inhibited it when applied to the bulbous parts.These results suggest that GA activates two opposing reactions—sprouting-promoting and sprouting-inhibiting—in these organs. The complicated relation between GA3or CCC concentrations and sprouting were explainable by assuming that the two counteractive reactions were activated by GA in differen