Apparent difference of CND among all Ntreatments showed before early grain filling stages in Jingdong8, but post-anthesis in Zhongyou9507.There appeared apparent vertical gradients of both leaf N concentration and CND in canopy.

• 叶片含氮量与籽粒品质指标的相关程度高于茎鞘含氮量，京冬8开花期叶片含氮量与蛋白质含量的相关性最高，9507则灌浆盛期最高。