Preformed adventitious root initiation in brittle willows grown in a controlled environment

Abstract

Nodal preformed adventitious root primordia of brittle willow develop from initial cells which appear first and only in the fourth node below the terminal leaf cluster of plants grown under the described environmental conditions. The onset of root initial formation is related to the cessation of rapid aerial development which occurs at node 4, and also with the start of secondary thickening which occurs in this node. Brittle willow is an ideal subject with which to study the cellular physiology of root initials since nodes showing the earliest stages of root initial formation and development can be selected. In addition, the root initials are readily located in histological preparations.