以京科968为材料，2013年在甘肃分析授粉后35～62 d的不同成熟度种子的5个物理特性（长度、宽度、灰度、百粒重和容重）和8个生理生化特性（糖、蛋白、淀粉、油脂和MDA含量以及含水量、电导率和SOD酶活性）。结果表明，随着收获期的推迟，京科968品种5个物理特性和蛋白、淀粉、油脂、SOD酶活性逐渐增加，然后达到平台期；糖、MDA、含水量和电导率则随之下降。采用标准发芽率、人工老化发芽率、冷冻发芽率和冷浸发芽率分析不同成熟度种子的活力。结果表明，随收获期推迟种子活力不断提高，在授粉后59 d，4种评价方法的活力指标均处于最高点，该时期为该品种的最佳收获期。相关性分析发现，种子活力指标与种子物理特性和生理化学特性之间均存在显著相关性。

Seed of hybrid maize Jinke968 was harvested from 35 days after pollination(DAP) to 62 DAP. Five seed physical traits and eight chemical traits were investigated. With the harvest stage postponing, four chemical traits of protein content, starch content, oil content and SOD activity, and all five physical traits of seed length, width, color, volume weight and hundred seed weight increased firstly and then reached a plateau; while other four chemical traits(sugar content, moisture content, electricity conductivity and MDA content) showed decrease tendency. Vigor of seed from different maturity were also evaluated by standard germination(SG), artificial aging test(AG), cold test germination(CT) and submergence cold test(ST). All these four seed vigor parameters increased from 35 DAP to 59 DAP, and then showed a little decrease at 62 DAP, suggesting that the best harvest time for hybrid line Jingke968 was 59 DAP. Correlation analysis revealed significant correlations between each tow of the investigated seed traits.

农业部公益类行业（农业）科研专项（201303002）、国家玉米产业技术体系重点研发任务（CARS-08）