不同水氮处理对豫麦49-198籽粒抗氧化物含量的影响

2012-2013年度, 在温县和郑州大田条件下, 研究不同水氮处理对冬小麦品种豫麦49-198籽粒总酚、类黄酮、类胡萝卜素含量及抗氧化活性的影响。结果表明, 在施纯氮0~300 kg hm^–2范围内, 所有观测指标均随施氮量的增加而增加, 以施氮300 kg hm^–2处理最高。随灌水次数(0~2次)的增加, 总酚、类黄酮含量和抗氧化活性呈先增加后降低趋势, 以灌拔节水处理最高；类胡萝卜素含量在不同试点间表现不一致。水氮耦合, 以灌拔节水+施氮240~300 kg hm^–2处理的抗氧化物含量及抗氧化活性较高, 而总酚、类黄酮及类胡萝卜素的积累量则以灌拔节和开花水+施氮240~300 kg hm^–2处理较高。相关分析表明, 籽粒总酚、类黄酮含量与抗氧化活性均呈显著正相关, 表明总酚、类黄酮含量增加可以提高小麦籽粒抗氧化活性；不同深度土层土壤水分含量及硝态氮含量与籽粒抗氧化物质含量的相关性存在差异, 总体而言, 氮含量有助于总酚及类胡萝卜素含量的积累, 而水分含量可能有助于类黄酮含量的提高。

Effects of Irrigation and Nitrogen on Antioxidant Contents in Yumai 49-198 Grains

Two field experiments were carried out in Wenxian and Zhengzhou of Henan Province in 2012–2013 wheat season to study the effects of nitrogen (N) application rate and irrigation on total phenol, flavonoids, and carotenoid contents and antioxidant activity in winter wheat cultivar Yumai 49-198. In the N application range of 0–300 kg ha^-1, all indices tested increased with increasing N rate and reached peak values under 300 kg ha^-1. With the increase of irrigation frequency (0–2 irrigations), total phenol and flavonoids contents and antioxidant activity had the maximum values under one irrigation condition at jointing, whereas the carotenoid content varied across locations. The interaction between N application rate and irrigation had a significant effect on antioxidants in wheat grain. Treatments of irrigation at jointing stage plus N application of 240–300 kg ha^–1 resulted in the high antioxidant content and antioxidant activity, whereas twice irrigation at jointing and anthesis stages plus N application of 240–300 kg ha^–1 resulted in antioxidant accumulation. Total phenol and flavonoids contents were positively correlated with antioxidant activity, indicating that high contents of total phenol and flavonoids were favorable for high antioxidation. The correlations of grain antioxidant content with soil moisture and NO₃^--N content varied in different soil layers. Generally, N fertilizer had the effect on increasing total phenol and carotenoid contents and soil water had the effect on accumulating flavonoids.