| Cold-type wheat is a kind of germplasm whose canopy temperature sustained low during the whole grouting, while the Warm-type wheat is the kind of germplasm whose canopy temperature sustained high during the filling stage. By means of leaf-cutting and spikelet-removing ,the research studied the effect of source-sink change on the proliferation of endosperm cell and dynamics of grain volume, dry weight,water content ,soluble sugar content, starch content and total protein content of Shan229 and NR9405 . The results showed that:1. During the first and third days after leaf-cutting and 50% spikelet-removing, the endosperm experienced a free nuclear stage, at this stage cell division was slow; during 4th~12th days the number of endosperm cells grew rapidly, and the volume also increased rapidly, at the same time , starch began to be accumulated in the endosperm cells; after 12th days, the endosperm cells division were in a slow growth period, and the endosperm cells were gradually filled. The endosperm cells and starch accumulation increased significantly by 50% spikelet-removing , while after cutting the flag leaf for 6 days the grain endosperm cells and starch accumulation of cold-type and warm-type wheat were decreased compared to the control.2. The dry weight, volume, soluble sugar, starch content and total protein content increased by spikelet-removing and Cold-type wheat varieties are much superior to warm-type ones;the dry weight, volume, soluble sugar, starch content and the total protein content of NR9405 grain reduced by leaf-cutting,but the total protein content of Shan229 grain influenced slightly by leaf-cutting.3. Grain dry weight showed very significantly correlated with the starch content and volume, while there was a significant negative correlation between the grain dry weight and the soluble sugar content, and soluble sugar content had highly significant negative correlation with starch grain content. |
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