Pattern of 14C-assimilates distribution in relation to their supply and demand in sunflower. Part II

Reduction of photosynthetic activity by 6 or 7 days of preshading increased to some extent migration of 14C-assimilates to the stem and decreased that to the roots. Restriction of roots demand for assimilates by feeding them with sucrose decreased the share of roots in 14C-export from the blades and increased 14C-transport to the other acceptors: stem and apical part, mainly in plants with roots actively accumulating radioactive substances in control plants, in which competition for assimilates was strong. A very small or even no effect of sucrose was observed in seedlings with relatively lower activity of roots as well as in the plants translocating labelled assimilates in darkness