Laboratory Exercise Demonstrating the Importance of Leaves in the Rooting of Herbaceous Stem Cuttings

Abstract

A teaching exercise that rapidly and inexpensively demonstrates the effects of leaf reduction on the rooting of stem cuttings is described. Coleus stem cuttings with whole leaves, half leaves, or no leaves are placed in sand on either misted or nonmisted greenhouse benches. Rooting response is recorded by ranking root systems by comparison to a diagram. A demonstration is also described that uses leafless cuttings cultured in vitro on solidified media containing a carbohydrate and/or auxin source. This demonstration gives students information that will help them speculate on the physiological reasons for the poor rooting response of leafless herbaceous cuttings.