氮肥运筹对彩色小麦花青苷积累和籽粒品质的调控研究

Color wheat is kind of high nutritional wheat crops that possess high tolerance to drought and cold, and rich in natural anthocyanin, amino acids and microelements. It is conducive to the sustainable development of color wheat to improve its grain quality and yield. Nitrogen influences the key enzyme′s activity of anthocyanin synthesis, affecting crop yield and quality. Currently, there are much reports on the nutritional value and health functions of black wheat, but fewer study on the regulation mechanism and the effects of nitrogen on color wheat′s color formation and quality. In this experiment, we are setting different N-fertilizer rate and ratio of base and topdressing in field, using cultivars planted in large area as material and common white wheat as control. Clarifying the effect and regulation mechanism of nitrogen application on anthocyanin content and grain quality in color wheat is not only perfect its anthocyanin theory , but also provide theoretical basis and technical support for the good quality cultivation of color wheat. In this study, in order to reveal the enzymatic regulation mechanism of nitrogen on anthocyanin synthesis, we plan to monitoring the dynamic variation of anthocyanin content and activity of synthetic enzyme in grains that lies in different position under different nitrogen management modes,as well the content of assoluble sugars. By means of plant physiological and biochemical methods, through determine the accumulation and transportation of photosynthetic products and nitrogen, starch content and its components ,protein content and its composition, amino acid content, flour quality, dough rheological properties and baking quality, we are going to analyze the influence of nitrogen application on grain quality and relationship between anthocyanin accumulation and sucrose metabolism. Through a comprehensive analysis to clarify the effect and mechanism of nitrogen application on anthocyanin accumulation and grain quality regulation in color wheat, initially proved the internal relations between grain color and quality of color wheat, and clear nitrogen application program for good quality cultivation of color wheat.

彩色小麦是富含天然花青素等物质的高营养型麦类作物，改善其籽粒品质，提高其产量，利于彩色小麦生产的发展。氮素调控花青苷代谢，影响作物产量与品质形成，阐明施氮量及其基追比例对彩色小麦花青苷积累和籽粒品质的调控效应与机制，不仅可完善彩色小麦花青苷代谢理论，还可为彩色小麦优质栽培提供理论依据与技术支持。本研究通过对不同氮肥运筹模式下不同粒位籽粒中花青素含量、关键酶活性、多种可溶性糖含量的动态监测，揭示氮素对花青苷形成的调控效应与作用机制；采用植物生理生化方法测定光合产物和氮素的积累与转运、淀粉含量及组分、蛋白质含量及组分、氨基酸含量、面粉品质、面团流变学特性和烘培品质，比较分析氮肥运筹对彩色小麦籽粒品质的影响，揭示籽粒品质形成与花青苷代谢的关系。通过综合分析，阐明氮肥运筹对彩色小麦花青苷积累和籽粒品质的影响及其生理基础，初步探明彩色小麦籽粒颜色与品质的关系，明确实现彩色小麦优质栽培的氮肥运筹方案。

彩色小麦籽粒中含有大量天然色素，营养价值和开发潜力均较高。氮素作为作物生长发育必需的大量营养元素之一，合理运筹氮肥影响小麦碳氮代谢及产量与品质；但大量的氮肥投入不仅降低资源利用率，亦导致农田生态环境恶化。本项目通过布置大田和盆栽试验，以紫麦、绿麦、白麦为研究对象，重点监测了不同施氮量、底追比例及水氮互作模式下，不同粒色小麦籽粒花青素积累、营养品质与加工品质等特征。结果表明，紫麦LZ1和绿麦ND3688的第一限制性氨基酸赖氨酸、必需氨基酸和氨基酸总量均高于普通白麦JM20，具有较高的营养价值；与JM20相比，LZ1和ND3688的面团粉质仪参数对底追比例的敏感性较弱，面团品质较为稳定。施氮量由240kg·hm-2降为180 kg·hm-2不会显著降低紫麦LZ1和绿麦ND3688的籽粒花青素含量及其灌浆前、中期的花青素积累速率，对籽粒氨基酸总量及必需氨基酸所占比例亦无显著影响，并且有利于提高出粉率；底追比例3:7较5:5有利于降低LZ1和ND3688的灌浆后期的花青素含量下降速率，并改善烘焙品质。水分胁迫条件下，施氮量过高或者过低均不利于LZ1籽粒各蛋白质组分含量的提高；水分极度亏缺时，施氮量的增加对LZ1灌浆过程并无促进作用；在花后缺水的条件下，增施氮肥能够提高LZ1的灌浆速率。