PhysicoChemical Bases And Grain Filling Cytochemical Characteristics Of Rice Quality Differences Development

Harmony of "sink, source and stream" during grain filling, which were carbon, nitrogen and lipids metabolisms virtually, were mostly related to rice quality differences development. In C metabolism, the assimilates transported from the leaves and stems are used for starch synthesis and deposited in the amyloplast of the starchy endosperm through carbon metabolism. The most nitrogen taken up from soil and stored in the shoots before flowering are assimilated, and accumulated in the form of protein. The bulk of proteins are deposited in protein bodies of the starchy endosperm. Lipid, the production of lipid metabolism, deposited in lipid bodies. Chalkiness is the untranslucent part of rice grain, and was supposed tobe the result of uncompleted accumulateion of starch during grain development. Therefore, it was be helpful to clarify the rules and intrinsic factor of rice quality differences development by studying starch (containing chalkiness), protein, lipid and the corresponding "sink, source and stream" in rice.Effect of protein and lipid in rice on starch physicochemical characteristics, difference between the region of non-chalkiness and chalkiness of rice, dynamic variation of cell structure and CaM distribution on rice spike were expounded in this study. It was found that protein and lipid in rice had important effect on starch gelatinization, there were distinct differences between the region of non-chalkiness and chalkiness of rice, vascular bundle system in rice spike was changed during grain filling, difference quality of different position of rice spike was more distinct in dense spike rice for more powerful vascular bundle system, the development of rice seeds was corresponded to pericarp development, difference quality of different position of rice spike was also related to transport function of rachilla besides activity of "source", and calmodulin relative activity was closely related to grain filling velocity and enginery properties.Effect of protein and lipid in rice on cooking and tasting quality, molecular weight range of the different protein components beween the region of non-chalkiness and chalkiness of rice, variation of vascular bundle in rice spike, effect of vascular bundle on position quality of rice spike, variation of cell structure and CaM distribution on rice spike was proved up elementarily. And the mechanism of these effects and variation was also elementarily analysed. The results must be helpful in rice quality improving work.