Stimulation of Flowering in Certain Short-day Plants by Abscisin

Abstract

ALTHOUGH day-length is known to control flowering in some plant species, and a variety of vegetative responses, including dormancy, runnering and tuberization, in other species the relationship between these different types of photoperiodic effect is obscure. Evidence has been presented that the induction of dormancy in woody plants in response to short days involves the newly discovered growth-regulator, abscisin II (‘dormin’)¹, and it has been possible to induce the formation of resting buds by application of endogenous inhibitor in birch². Evans has recently reported the inhibition of flowering in the long-day plant, Lolium temulentum, by abscisin³. Thus it is pertinent to investigate whether abscisin II will stimulate flowering in short-day species. The availability of synthetic abscisin⁴ has made it possible to carry out a, range of experiments on this problem.