A Special Type of Tracheary Element Associated with "Xylem Discontinuity" in the Floral Axis of Wheat

Abstract

In wheat, the continuity of xylem between the pericarp of the caryopsis and the rachilla is interrupted by a core of thick-walled cells which have been characterized as a special type of tracheary element. We have provided evidence to show that the xylem discontinuity restricts the flow of material from the xylem in the rachilla to that in the pericarp.