中文摘要：

以内单314为材料,研究了施氮量对超高产春玉米花粒期不同层位叶片衰老过程及产量的影响。结果表明,在0 kg.hm-2-439.8kg.hm-2施氮量范围内,随着施氮量的增加,花粒期玉米各层位叶片保护酶（POD、CAT、SOD）活性明显提高,相对电导率和MDA含量显著降低,较高的群体叶面积指数和叶干重得到维持。施氮量超过439.8kg.hm-2时,各层位叶片的上述参数出现相反趋势,且叶位越低越显著。当施氮量为439.8kg.hm-2时,超高产春玉米花粒期不同层位叶片衰老得到延缓,利于其花粒期干物质积累和产量形成,是实现超高产的重要基础。

英文摘要：

ND314 test were used to study the effect of nitrogen application rates on yield and senescence process of leaves from different positions of spring maize with super-high yield during anthesis stage.The results indicated that：when nitrogen application rates were between 0kg·hm-2-439.8kg·hm-2,as the N application rates grew higher,protective enzymes（POD,CAT,SOD）activity of leaves from different positions during anthesis stage increased obviously,relative conductivity and MDA content droped significantly,higher leaf area index and dry leaves weight of groups can be maintained.when the rates were over 439.8kg·hm-2,parameters mentioned above of leaves from different positions showed the opposite trend,the lower positions got more change.When 439.8kg·hm-2 N application amounts was used,senescence of leaves of super-high yield sping maize during anthesis stage could be alleviated,which was helpful for dry matter accumulation and grain yield formation.It was an important foundation for achieving high yield.