氮肥运筹对寒地水稻籽粒植酸、蛋白质和矿质元素的影响

Effects of Nitrogen Fertilizer Management on Phytic Acid, Protein and Mineral Elements in Rice Grain in Cold Region

为探究寒地水稻优质栽培的氮肥施用方式,以粳稻品种垦粳7号和垦粳8号为试验材料,通过2年(2017-2018年)田间试验,设置4种氮肥运筹方式:习惯施肥(T1,施氮量150 kg·hm-2,基肥∶蘖肥∶穗肥=6∶3∶1)、氮肥后移1(T2,施氮量150 kg·hm-2,基肥∶蘖肥∶穗肥=4∶3∶3)、基于T2的减氮施肥(T3,施氮量135 kg·hm-2,基肥∶蘖肥∶穗肥=4∶3∶3)和氮肥后移2(T4,施氮量150 kg·hm-2,基肥∶蘖肥∶穗肥=5∶3∶2),其中以T1为对照,研究氮肥运筹对寒地水稻籽粒植酸、总蛋白质及组分、矿质元素含量的影响及其互作效应。结果表明,氮肥、品种对水稻籽粒中植酸含量的影响均达显著或极显著水平。与T1相比,T2、T3和T4水稻籽粒中植酸含量平均分别显著降低了31.92%、48.94%和21.28%;T2、T3和T4水稻籽粒中清蛋白、球蛋白、谷蛋白以及总蛋白质含量均增加,且T2作用效果更明显,分别较T1显著提高了0.14、0.10、0.45和0.60个百分点(2017年两品种均值);T2和T3的醇溶蛋白含量略有降低,T4则略有增加,但与T1差异均不显著;T2和T3水稻籽粒中Cu、Mn、Fe、Ca、K、Zn含量均增加,且T2增加更明显,T4水稻籽粒中各矿质元素含量变化则无明显规律。通过分析氮肥运筹下水稻籽粒植酸含量与蛋白质、8种矿质元素含量的相关性可知,植酸含量与总蛋白质、清蛋白、球蛋白、谷蛋白以及Cu、Mn、Fe、Zn、Ca、Mg、K含量均呈负相关,其中与球蛋白含量和2018年Zn和Ca含量呈显著负相关。综上所述,氮肥平衡分配能降低水稻籽粒中植酸含量,增加总蛋白质和矿质元素含量,有效改善蛋白质组分,从而提高稻米营养品质。本研究结果为寒地稻米的优质栽培的氮肥运筹方式提供了理论依据。

In order to explore the application mode of nitrogen fertilizer for high-quality cultivation of rice in cold regions, japonica rice cultivars Kenjing 7 and Kenjing 8 were used as experimental materials. Through two years of field experiments(year 2017-2018), four methods of nitrogen fertilizer application were set up: conventional fertilization(T1, 150 kg·hm-2 N, base fertilizer∶tiller fertilizer∶spike fertilizer=6∶3∶1), nitrogen fertilizer postpone 1(T2, 150 kg·hm-2 N, base fertilizer∶tiller fertilizer∶spike fertilizer=4∶3∶3), nitrogen reduction based on T2(T3, 135 kg·hm-2 N, base fertilizer∶tiller fertilizer∶spike fertilizer=4∶3∶3) and nitrogen fertilizer postpone 2(T4, 150 kg·hm-2 N, base fertilizer∶tiller fertilizer∶spike fertilizer=5∶3∶2). T1 was used as the control to study the effects of nitrogen application on phytic acid, protein and mineral elements of rice grains in cold regions. The results showed that the effect of nitrogen fertilizer and variety on phytic acid content of rice grain was significant or extremely significant.Compared with T1, the content of phytic acid in T2, T3 and T4 decreased by 31.92%, 48.94% and 21.28%, respectively. T2, T3 and T4 increased the contents of albumin, globulin, glutenin and protein in grains, especially T2 treatment, with an average increase by 0.14, 0.01, 0.45 and 0.60 percent, respectively. The content of gliadin decreased in T2 and T3 treatment, and increased slightly in T4 treatment, but there was no significant difference with T1. T2 and T3 increased the contents of Cu, Mn, Fe, Ca, K, Zn in rice, especially T2;Under T4 treatment, the content of each mineral element has no obvious regularity. By analyzing the correlation between phytic acid content and protein, eight mineral elements content in rice under nitrogen fertilizer management, it was found that phytic acid content was negatively correlated with protein, albumin, globulin, glutenin and Cu, Mn, Fe, Zn, Ca, Mg and K, especially, it has a significant negative correlation with globulin, Zn and Ca content. In conclusion, the balanced distribution of nitrogen fertilizer can reduce the content of phytic acid in rice, increase the content of protein and mineral elements, and effectively improve the protein components, so as to improve the nutritional quality of rice. The results of this study provide a theoretical basis for the nitrogen management of high quality rice cultivation in cold regions.