小麦胚乳淀粉精细结构与理化特性的关系机制及其调节研究

Starch is the predominant component of wheat (one of the most important cereal crops in China) and its fine structures were closely related to physicochemical properties, which decided its application in food and non-food industries. However, there was little knowledge about the development regularity and regulatory pathway of starch fine structures in wheat endosperm during grain filling as yet, as well as the relationships of starch fine structure characteristics and physicochemical properties. All the above seriously restricted the development and utilization of wheat starch. Therefore, in this study we selected different genotype wheat cultivars, designed various environmental and cultivated experiments, and reconstituted distinct starches, at the same time, tested the physicochemical properties of purified starch samples, to further study the formation process of starch fine structures in wheat endosperm, to comprehensively analyze the relationships between the characteristics of starch fine structure and physicochemical properties, and to broadly research the regulating effect of external factors on wheat starch quality. Results would be favorable to deepen the understanding on fine structure forming and functional properties of wheat starch, so as to provide the technical approach and theoretical basis of improving wheat starch quality by genetic engineering and cultivated regulation, and of developing wheat starch application in food and non-food industries.

小麦是我国重要的粮食作物。淀粉是小麦籽粒的主要组成部分。淀粉精细结构决定其在食品和非食品工业的用途和产品的品质，与理化特性密切相关。然而，迄今关于小麦胚乳淀粉精细结构的发育规律、与理化特性的关系机制以及调节途径认识浅薄，严重限制了小麦淀粉的开发和利用。本研究选用不同基因型小麦品种，设计氮肥、密度、光照、水分等调控措施，组配不同结构混合淀粉，测定提纯淀粉的膨胀、糊化、粘度、热力学、晶体和回生等特性，深入研究小麦胚乳淀粉精细结构的形成过程，全面分析淀粉结构与理化特性的关系，广泛探讨环境栽培因子对小麦胚乳淀粉品质的调控效应。研究结果将进一步加深对小麦淀粉结构形成和功能特性的认识，为通过基因工程和栽培措施提高小麦淀粉品质，并拓宽其在食品和非食品工业中的用途提供技术途径和理论依据。

小麦淀粉结构决定其用途和产品品质。然而，关于小麦淀粉结构的发育规律、影响因素，以及与理化特性的关系知之甚少。本研究选用直链淀粉含量存在差异的小麦品种，设计了氮肥、水分、密度、弱光等试验处理，测定了小麦籽粒灌浆过程中淀粉分子的含量和结构的变化，同时测定了提纯淀粉的粒度分布、膨胀特性、糊化特性、晶体特性和热力学等特性。. 结果表明，小麦籽粒中淀粉的精细结构因灌浆时期和基因型的不同而存在明显差异,并且受环境条件和栽培措施的影响。小麦籽粒灌浆过程中存在3个淀粉粒形成高峰期，花后20-25天检测到最大淀粉粒的存在。与强筋小麦相比，糯小麦籽粒中小淀粉粒的比例较高，而弱筋小麦籽粒中大淀粉粒的比例较高。花后遮光显著影响小麦籽粒中淀粉粒的生长发育，淀粉粒的生成高峰期推迟或减少。小麦籽粒灌浆过程中光合产物供应降低的情况下，有限的光合产物优先供给现有淀粉粒，其次用于生成更多的淀粉粒。灌水、施氮和密度等栽培措施影响小麦淀粉积累，改变淀粉结构，进而调节淀粉特性。相关分析表明，小麦淀粉的组成结构与其理化特性相关。. 通过本研究，加深了对小麦淀粉组成结构与其理化特性关系机制的认识，进一步明确了环境条件和栽培措施对小麦淀粉结构的调控效应，为提高小麦籽粒淀粉品质和拓宽淀粉的用途提供了一定的理论依据和技术途径。