籽粒的品质也是许多国家水稻育种的主要目标(Hargrone,1978)。在发展半矮性水稻品种后,水稻产量虽然成倍增长,但它们的品质很差。继此之后,水稻品质育种有了相当大的进展(Paule,1981)。稻米的品质包括籽粒外观以及碾磨、蒸煮和食味的质量。淀粉即多聚葡萄糖是米的主要成份。直链淀粉和支链淀粉为两个主要组分。米饭质地反映了直链淀粉和支链淀粉的比例,决定着蒸 Grain quality is also a major goal of rice breeding in many countries (Hargrone, 1978). After the development of semi-dwarf rice varieties, although the rice yield doubled, but their quality is poor. Since then, there has been considerable progress in rice quality breeding (Paule, 1981). The quality of rice includes the appearance of the grain and the quality of milling, cooking and eating. Starch is polyglucose is the main ingredient of rice. Amylose and amylopectin are two major components. Rice texture reflects the ratio of amylose and amylopectin, determines the steamed