Vascular Transfer Cells in the Wheat Spikelet

Abstract

Xylem and phloem transfer cells are present at the nodal regions where the sterile glumes, lemma, palea, and caryopsis are attached to the rachis and rachilla. The course and distribution of the vascular tissues and the structure of the transfer cells are described. Experiments with colloidal lanthanum tracer fed via the trans-piration stream have indicated that the walls of the transfer cells are relatively porous. The possibility that the transfer cells play an important role in the regula-tion of solute transfer to the developing grain is discussed.