ENDOGENOUS GROWTH FACTORS AND FLOWER FORMATION IN WEDGWOOD IRIS BULBS

Abstract

1 The changes in growth substance composition of buds and scales of Wedgwood iris bulbs during flower formation were determined. 2 The scales contain several thermostable flower forming substances which, in the course of a low temperature treatment, are transported to the bud. 3 The flower forming substances have physiological and chemical properties of gibberellins. 4 Compounds with RF 0.3, 0.45-0.50 and 0.75 in 80% isopropanol successively accumulate in the bud and attain maximum concentrations at successive stages of differentiation of the floral primordium. 5 The significance and possible mode of action of the gibberellins in flower formation is discussed.