冬小麦碳氮积累、转运和籽粒产量对小花发育期追氮的响应

为给冬小麦高产优质栽培过程中氮肥的合理调控提供参考依据，通过河南郑州和兰考两点大田试验，分别在总施氮量240和180 kg·hm^-2下，以全部基施为对照，进行基施和追施各50%施氮处理［追肥时期分别在返青期(二棱末期)、返青后10 d(护颖原基分化期)、20 d(雌雄蕊原基分化期)和30 d(雌蕊凹期)］，探讨了小花发育期施氮对两种穗型冬小麦碳、氮积累和转运及产量构成的影响。结果表明，在小花发育期追施氮肥均有利于花前碳、氮的贮藏积累和转运，且兰考矮早8品种贮藏碳、氮转运对籽粒的贡献率分别高于对照处理4.49和3.98个百分点，而豫麦49198品种分别高于对照处理1.68和0.47个百分点；两个品种花前贮藏氮素转运对籽粒的贡献率分别高于碳素42.97和38.47个百分点。在本试验条件下，在小花雌雄蕊原基分化期追施氮肥增加了兰考矮早8的千粒重和豫麦49198的穗粒数，且追肥处理的穗粒数、千粒重和籽粒产量显著高于其他处理，氮素积累和转运的增加也显著提高了籽粒蛋白质含量和产量。根据本研究结果，在总施氮量180~240 kg·hm^-2下，采取基施和小花雌雄蕊原基分化期追施氮肥各50%，提高了籽粒产量和蛋白质产量。

The Response of Carbon and Nitrogen Accumulation and Translocation and Grain Yield to Nitrogen Fertilizer Dressing in Winter Wheat at Floret Development Period

Under field conditions, the effects of nitrogen fertilizer on dry matter accumulation, photosynthetic characteristics after anthesis and grain yield of winter wheat were studied by using two types of cultivars (Lankao aizao8 and Yumai 49 198) as experimental materials under total pure N 240 kg·hm^-2 in Zhengzhou and 180 kg·hm^-2 in Lankao. With total basal N fertilization as the control, and treatment with 50% base fertilization and 50%dressing the topdressing were applied at returnning green stage and 10 d, 20 d and 30 d post returnning green stage, respectively. The results indicated that postponing N fertilizer application can increase the accumulate and translocation of carbon and nitrogen in floret development, and the contribution of pre anthesis stored carbon and nitrogen to grain yield were increased by 4.49% and 3.98% for Lankao aizao8, and 1.68% and 0.47% for Yumai 49 198 with delaying N application, respectively. And the contribution rate of nitrogen stored to grain was higher by 42.97% (Lankao aizao8) and 38.47% (Yumai 49 198) than that of carbon stored to grain. 1000 grain weight of Lankao aiao8 and spike grain number of Yumai 49 198 were increased. Grain number per spike, 1000 grain weight and grain yield of the treatment with topdressing N fertilizer at 20d after regreening were significantly higher than those of other treatments. The increase of nitrogen accumulate and translocation also significantly improve the grain protein content and the protein yield. According to this research, under the total pure N180~240 kg/ha, 50% basal N fertilization and 50% topdressing at the female and stamen primordiun differentiation stage could improve the grain yield and grain protein yield of wheat.