Translocation in Grasses

Abstract

Summary Bermuda grass (Cynodon dactylon (L.) Pers.) plants raised in a glasshouse were transferred to growth rooms at 24°c and 70% relative humidity under a light intensity of 1,200 foot-candles. A single spot of 14C-labelled urea, amitrole, or maleic hydrazide was placed at the base of a mature lamina. The translocation of 14C after periods of 3 to 48 hours was determined by gross autoradiography. Assimilate movement in the phloem, as shown by tracer migration, was strongly polarised toward the tip of a large 14C-treated stolon and slightly less polarised toward the tip of a small stolon. Tracer movement to the parent stolon from a treated tiller appeared to be as great as or greater than movement to the tip of that tiller. Assimilate movement from one stolon to another occurred only rarely in intact plants in full light. Darkening or partial defoliation of a stolon could induce the movement of assimilate from another treated stolon on the same plant, but the effect occurred regularly only with prolonged...