不同氮素水平对小麦旗叶生理特性和产量的影响

为了明确氮素营养对小麦生育后期一些生理特性的影响,提高氮素利用率,本试验以豫麦49-198为材料,在河南科技大学试验农场,通过设置120,180,240和300 kg/hm²四个氮素水平,系统研究了小麦抽穗后旗叶光合速率,丙二醛(MDA)、可溶性糖、脯氨酸、可溶性蛋白质含量和超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性等生理性状的变化。结果表明,在一定范围内随施氮水平的增加可以显著提高可溶性糖、脯氨酸和可溶性蛋白质的含量,增加SOD、POD、CAT活性,降低MDA含量,但施氮水平超过一定水平后,各指标增幅(降幅)不明显或呈下降趋势。研究表明,在本试验条件下,施氮水平在240 kg/hm²时,光合速率和可溶性糖含量等生理指标达到最大值,因此,在4个氮素处理水平中,240 kg/hm²氮素处理最有利于小麦的生长发育和产量提高。

Effect of different levels of nitrogen on physiological characteristics of flag leaves and grain yield of wheat

The effects of different levels of nitrogen on wheat (Triticum aestivum) growth and development, on nitrogen use efficiency, on reducing the effects of excessive application of fertilizer on environmental pollution, and to increase crop yields were assessed using Yumai 49-198. The experiment was carried out at the experimental farm of Henan University of Science and Technology using nitrogen treatments of 120 kg/ha, 180 kg/ha, 240 kg/ha and 300 kg/ha. Plant response was measured in terms of photosynthetic rate, malondiadehyde (MDA) content, soluble sugar content, proline content, soluble protein content and superoxide dismutase (SOD), catalase (CAT) and peroxide enzyme (POD) activities in wheat leaves after heading. Increasing nitrogen within a certain range significantly increased photosynthetic rate, soluble sugar content, proline content, soluble protein content and SOD, CAT and POD activities, but MDA content decreased. When nitrogen exceeded a certain level, there was no obvious change in any of the indexes. With a nitrogen level of 240 kg/ha, the photosynthetic rate, soluble sugar content and other physiological indexes reached a maximum, so this was the optimum of the four nitrogen levels, for growth and yield increase of wheat.