糯玉米opaque2基因近等基因系的创制

opaque2基因能够提高糯玉米赖氨酸、色氨酸等必需氨基酸的含量。用2种优质蛋白玉米(QPM)CA339和鲁2548自交系作为opaque2基因供体,25个品质较好的糯玉米自交系作为受体,利用回交技术和SSR分子标记辅助选择育种,创制糯玉米opaque2近等基因系。分子标记结果表明,不同受体以及两种供体间都存在多态性。5套创制成功的opaque2近等基因系的赖氨酸含量比其轮回亲本分别提高了59.0%、52.7%、48.5%、46.3%和61.9%,分别由0.308%、0.313%、0.309%、0.341%、0.323%提高到0.489%、0.478%、0.458%、0.498%、0.522%。本研究表明,可以利用此方法通过向不同遗传背景的多种受体导入opaque2,选取赖氨酸含量提高较大、透明表型的近等基因系,提高糯玉米的营养价值和经济价值。

Construction of Waxy Maize opaque2 Near-isogenic Lines

In waxy maize, the opaque2 gene can increase the content of essential amino acids, such as lysine and tryptophan. Two high quality protein maize (QPM) inbred lines, CA339 and Lu 2548, were used as opaque2 gene donors. Twenty-five waxy maize with advantageous traits were used as receptors. Application of backcrossing and SSR marker-assisted selection in breeding can create waxy maize opaque2 near-isogenic lines. The results of molecular marker indicated that there were polymorphisms in different receptors and between the two donors. Lysine content of five sets of successfully created opaque2 near-isogenic lines was tested, showing that the content of lysine in o2w-NILs was 59.0%, 52.7%, 48.5%, 46.3%, and 61.9% higher than that in their recurrent parents, which was increased from 0.308%, 0.313%, 0.309%, 0.341%, 0.323% to 0.489%, 0.478%, 0.458%, 0.498%, and 0.522%, respectively. Using this method, opaque2 could be introgressed into multiple receptors with different genetic backgrounds to select near-isogenic lines with high lysine content and transparent phenotype, so as to improve nutritional and economic values of waxy maize.