Patterns of assimilate distribution in soybeans at maturity. II.* The time course of changes in 14C distribution in pods and stem sections

Abstract

Leaves at two levels in the canopy of determinate soybeans were allowed to assimilate 14CO2 at one of several stages of development from late pre-flowering until pod maturity, and the distribution of 14CO activity in above-ground parts of the plants was followed up to maturity. Between pre-flowering and early pod development, assimilate was stored in stems and transferred to pods during later development; at later stages, current assimilate went directly from leaves to pods. Carbon fixed subsequent to flowering went to pods in the axils of treated leaves, and to pods at the second nodes above and below fed leaves but not to adjacent nodes. The source of substrate for filling pods in the apical raceme was not apparent from this study. __________________ *Part I, Aust. J. Aguic. Res., 28: 203 (1977).