不同水氮组合对滴灌冬小麦叶片保护性酶活性及产量的影响

Effects of Different Water and Nitrogen Combinations on Protective Enzyme Activities and Yield of Winter Wheat under Drip Irrigation

【目的】分析水氮组合对滴灌冬小麦叶片保护性酶活性及产量的影响,研究水氮调控的生理机理,为新疆冬小麦水氮运筹提供理论依据。【方法】选用新冬20号为材料,采用水氮两因素裂区试验设计,测定不同水氮条件下四种保护性酶活性的变化及产量构成。【结果】(1)适宜的水氮条件能增加小麦叶片SOD、POD、CAT的活性。低水低氮、高水高氮组合MDA含量较高。(2)水氮对MDA含量及保护性酶活性具有较强的耦合调控效应,在干旱条件下,适当增施氮肥,或在氮素亏缺条件下,保证灌溉,可有效降低叶片MDA含量、提高叶片保护性酶的活性,促进叶片细胞的生理活性。(3)随施氮量和灌水量增加,小穗数、穗粒数和千粒质量呈现先增后降的趋势,N3W2、N2W3和N2W2的产量显著高于其他处理。水氮对产量构成及产量的调控效应大小为供水效应>供氮效应>耦合效应。【结论】适宜的水氮供应为滴水量4 050～5 400 m^3/hm^2和滴氮量207～276 kg/hm^2,此时小麦叶片的膜脂过氧化程度较小,产量表现最佳。

【Objective】This project aims to study the effects of water and nitrogen combinations on the protective enzyme activities and the yield of winter wheat leaves under drip irrigation in the hope of revealing the physiological mechanism of water and nitrogen regulation and providing theoretical basis for water and nitrogen management of winter wheat in Xinjiang.【Method】Xindong 20 was selected as the experimental material,and the experimental design of water and nitrogen split zone was used to determine the changes of the four protective enzymes activities and the yield components under different water and nitrogen conditions.【Result】(1)Suitable water and nitrogen conditions could increase the activities of SOD,POD and CAT in wheat leaves.The combination of low water,low nitrogen and high water and high nitrogen produced higher MDA content.(2)Water and nitrogen had a strong coupling regulation effect on the MDA content and the protective enzyme activity.Under drought conditions,proper application of nitrogen fertilizer or irrigation under nitrogen deficiency conditions could effectively reduce the MDA content,increase the protective enzyme activity and promote the physiological activity of leaf cells.(3)With the increase of nitrogen application and irrigation,spikelet number,grain number per spike and 1,000-grain weight increased first and then decreased.The yields of N3W2,N2W3 and N2W2 were significantly higher than those of other treatments.The order of regulation effect of water and nitrogen on yield components and yield was water supply effect >nitrogen supply effect >coupling effect.【Conclusion】The suitable water and nitrogen supply ranges in this region are 4,050-5,400 m^3/hm^2 and 207-276 kg/hm^2,respectively.At this time,the degree of membrane lipid peroxidation in wheat leaves is small and the yield performance is the best.