INFLUENCE OF ETHYLENE ON APEX DEVELOPMENT AND MOBILIZATION OF SOLUBLESACCHARIDES IN THE CORM OF LIATRIS

We studied the influence of ethephon (2-chloroethylphosphonic acid) on the first stages of development of the main apex of Liatris spicata c v. Callilepis and its relation to the mobilization of soluble sacchari des in the corm. Ethephon enhanced cell expansion during the first wee ks of cultivation but did not affect the timing of newer initiation. S oluble saccharide concentration in the corm reached a maximum after sp routing, probably due to rapid growth of the shoot. There was no chang e in the concentrations of soluble saccharides immediately prior to ne wer initiation, which suggested that quantitative changes in these sac charides were not responsible for activating flower initiation. When c orms were treated with ethephon there was a greater degree of soluble saccharide mobilization during the first weeks of cultivation than in untreated corms. However, this did not seem to be the direct result of the addition of this phytohormone and was more probably the consequen ce of cell growth being encouraged.