Auxin Effects on Vascular Differentiation in Ostrich Fern

Abstract

Surgical experiments have confirmed the capacity of a fern shoot apex to give rise to a mature vascular system in the absence of leaves. When the shoot apex of Matteuccia struthiopteris Tod. was isolated by vertical incisions and incipient leaf primordia were suppressed systematically for more than 5 weeks, a mature siphonostele with reduced diameter and uninterrupted by leaf gaps replaced the normal dictyostele. If one or two leaf primordia were allowed to develop, a transitional stele with one or two gaps was formed