摘要： 以O₂基因为遗传背景的高级氨酸玉米（简称O₂玉米）比普通玉米同型种一般产量低7-15%，这是粉质胚乳导致子粒容重降低的结果。育种上解决的途径是利用硬胚乳修饰基因选育子粒容重较高的硬胚乳或半硬胚乳O₂自交系。不同类型玉米携带的硬胚乳修饰基因贫富悬殊很大，只有筛选利用较丰富的亲本材料，通过自交或自交与姊妹交相结合的二环系选育方法，以早代子粒出现“角帽”和“角圈’为选择目标，才能有效地育成硬胚乳或半硬胚乳O₂玉米交系。

关键词: 硬胚乳, O2玉米, 育种

Abstract: O₂(Opaque No.2)corn generally yields 7-15% less than common corn of the same type,due to reduced kernel volume weight caused by starch endosperm.The way to solve this problem in breeding is to use the hard endosperm modifier(gene)and to select hard or semi-hard O₂ inbred lines with higher kernel volume weight.Since different types of corn carry different amount of hard endosperm modifiers,only by screen-ing and utilizing parent materials rich in hard endosperm modifiers,through the breeding method of self-cross or a combination of selfing and sib-mating with the selection objective of showing"corny cap"and"corny ring",can hard endosperm or semi-hard endosperm O₂ corn inbred lines be effectively bred.

Key words: Hard endosperm, O₂ corn, Breeding