密肥调控对中、弱筋小麦生育后期旗叶生理特性的影响

以弱筋小麦扬麦9号、中筋小麦扬麦11号为试材,研究了密肥（基本苗、氮肥）调控对中、弱筋小麦生育后期旗叶生理特性的影响。结果表明：在小麦后期生长过程中,旗叶SOD活性、POD活性、叶绿素含量总体呈现下降趋势,膜脂过氧化产物丙二醛（MDA）总体呈现上升趋势。本试验条件下,中筋小麦扬麦11号在120万/hm2基本苗的基础上,以240 kg/hm2施氮量、氮肥运筹5∶1∶4处理最能延缓植株的衰老,延长籽粒的灌浆时间,增强旗叶光合能力,提高籽粒蛋白质含量,从而取得优质高产;弱筋小麦扬麦9号在240万/hm2基本苗基础上,以180 kg/hm2施氮量、氮肥运筹5∶1∶4处理可以保证其品质达标的同时,增强植株后期旗叶中的SOD、POD活性,降低MDA含量,适当延缓植株的早衰,从而较好协调弱筋小麦高产与优质的矛盾。

Effects of Plant Density and Nitrogen Fertilizer on Physiological Characteristics of Flag Leaf of Weak-and Medium-gluten Wheat at Late Growth Stage

The experiment was conducted to study the effects of plant density and nitrogen fertilizer on the physiological characteristics of flag leaf in weak gluten wheat Yangmai 9 and medium gluten wheat Yangmai 11 at late growth stage.The results indicated that the SOD and POD activities and chlorophyll content showed a trend of decreasing,while the MDA content showed a trend of increasing at late growth stage.Under the experimental condition,240 kg/hm2 N with the ratio of basic∶tillering∶elongation and booting fertilizer as 5∶1∶4 could postpone the plant senescence,prolong the grain-filling time,increase the photosynthetic ability of flag leaf and protein content in grains of Yangmai 11 with 120×104 basic seedlings per hectare,so good quality and high yield could be obtained.But for Yangmai 9 with 240×104 basic seedlings per hectare,180 kg/hm2 N with the ratio of basic∶tillering∶elongation and booting fertilizer as 5∶1∶4 was the best for coordinating the contradiction between high yield and good quality,which could guarantee the quality reach the standard and increase the SOD and POD activities,chlorophyll content and the photosynthetic ability of flag leaf,but decrease MDA content and delay the plant senescence.