Changes of Soluble Sugar Contents in Leaf, Stem and Grain in Winter Wheat and Its Relationship with Grain Starch Accumulation

Sugar contents in the flag leaf, penult stem and grain, as well as grain starch accumulating rate of two winter wheat ( Triticum aestivum L.) cultivar, Lumai 22 and Lumai 14 were investigated in the experiment of pool culture. Peaks of total soluble sugar and sucrose contents in the flag leaf occurred at 15~20 days after anthesis. Contents of total soluble sugars, sucrose and fructosans in the penult stem presented single-peak curves, and their highest contents also occurred at 15~20 days after anthesis. Contents of total soluble sugars and sucrose in grain decreased during grain filling stage. Sugar contents in leaf, stem and grain were closely related with grain starch accumulation from 20 days after anthesis to maturity.