我国稻米品质的改良

 本文论述我国稻米的品质改进，内容包括：⑴稻米品质的评价；⑵品质性状的遗传；⑶品质性状的育种改良；⑷影响稻米品质的非遗传因素。稻米品质性状的遗传表达，可能受母株基因型或胚乳基因型控制，或兼而有之。现已明确，米的一些形态性状，如粒长、粒宽、粒重等，主要受母株基因型控制；这些性状在F#-2米粒间无明显分离。而糊化温度、直链淀粉含量等理化性状，则主要由胚乳基因型控制，它们在F#-2米粒间均发生分离。杂种稻米的理化性状是很难一致的。当前优质米育种应特别注意：⑴改进米的外观品质；⑵根据用途改进米的蒸煮和食用品质；⑶选育含胚米；⑷改进特种米（黑米、香米和糯米）的丰产性和抗逆性。

QUALITY IMPROVEMENT OF RICE GRAIN IN CHINA

Rice qualities are discussed in this paper, which includes (1) Quality evaluation of rice grain; (2) Inheritance of quality characters; (3) Genetical improvement for qualities; and (4) Non-heritable factors affecting qualities. Genetic expression of rice grain qualities may be subject to the genotype of a maternal plant, or the genotype of an endosperm, or both. It has been found that some morphological characters of rice, such as grain length, grain width, grain weight etc., are mainly controlled by the genotype of a maternal plant, and no significant segregation would be observed among F_2's grains On the other hand, some physicochemical characters, such as amylose content, gelatinization temperature and protein content, are generally determined by the genotype of an endosperm, and segregation is presented among F_2's grains. Therefore, physicochemical characters of hybrid rice are rarely to be uniform. For breeding of quality rice, special attentions should be laid on:(1) Improvement of rice appearance quality; (2) Improvement of cooking and eating quality according to applications;(3)Breeding for milled rice with embryo; and(4)Improvement of yielding and stress resistance for special rice (black rice, scented rice and glutinous rice).