Symplasmic unloadlng of photoassimilate occurs through bulk flow and diffusion,but apoplasmic unloading is clarified into two types according whether sucrose is hydrolysable or not.

he transport of photoassimilate in higher plants was mainly affected by the development of vascular bundle, sometime limiting crop production,and the distribution of assimilate among sink organs was mainly determined by the characteristics of sink itself.

Using the methods of physiological,biochemical mensuration and the stable isotope analysis technique,we studied the regulative effects of the exogenous GA_3 on the growth,photoassimilate and sucrose-metabolizing enzymes.

Adjustment of photoassimilate partitioning of Malus pumila M. by flower thinning and its physiological performance;