Effects of Gibberellic Acid on Juvenility in Marsilea and certain other Plants

Abstract

IN addition to the more familiar effects of gibberellic acid, it has recently been found, by several authors, that this substance can affect the duration of the juvenile stages of certain plants. Thus, Robbins¹, discovered that when an arborescent form if ivy (Hedera canariensis variegata var. arborescens) was supplied with gibbereliic acid, branches with completely juvenile characteristics were produced by some of the treated plants. Robbins believed that gibbereliic acid is probably comparable with the ‘Jugendsubstanz’ postulated by Frank and Renner² in explanation of their own observations, and earlier work by Doorenbos³ on the rejuvenation of adult ivy shoots. Scurfield and Moore⁴, however, found that seedlings of Eucalyptus species, when treated with gibbereliic acid, developed the adult leaf type earlier than the control plants, although Njoku⁵, using seedlings of Ipomoea caerulea, obtained a prolongation of the juvenile phase.