干旱胁迫对小麦不同品种胚乳淀粉结构和理化特性的影响

摘要

[目的]全面了解干旱胁迫对小麦不同品种胚乳淀粉组成、 粒度分布、 糊化特性以及晶体特性的影响,揭示小麦淀粉结构与理化特性的内在关系.[方法]2013-2015年度以小麦品种京冬8(JD8)河农825(HN825)、 冀麦585(JM585)、 农大211(ND211)为试验材料,设节水灌溉(W)和旱作(D)2种处理,研究干旱胁迫对小麦胚乳淀粉结构及其理化特性的影响.[结果]干旱胁迫显著抑制了小麦胚乳淀粉的积累,但对小麦淀粉直/支比的影响不显著.小麦胚乳淀粉粒体积表面积和数目分布均呈双峰曲线变化,干旱胁迫对淀粉粒粒度分布的影响因基因型和粒径大小的不同而存在差异,其中对粒径15μm的淀粉粒与终结黏度和回生值均呈显著正相关、 小麦淀粉粒体积分布与结晶度的相关性不显著.小麦淀粉糊化峰值黏度和稀懈值与结晶度分别呈极显著和显著负相关,而糊化温度与结晶度呈显著正相关.[结论]干旱胁迫改变了小麦胚乳淀粉组分、 粒度分布、 结晶度及其主要糊化参数.小麦胚乳淀粉结构与晶体特性和糊化特性之间均存在明显的相关性,表明干旱对小麦淀粉结构的影响,间接影响了其理化特性,因此,可以通过调节水分条件来生产一定品质的小麦.%[Objective] The objective of this experiment is to study the effects of drought stress on the composition, granule size distribution, pasting properties and crystal properties of wheat endosperm of different varieties, and reveal the intrinsic relationship between the structure and physicochemical properties of wheat starch.[Method] The wheat cultivars Jingdong8(JD8), Henong825(HN825), Jimai585(JM585) and Nongda211(ND211) were used as the test materials, and irrigated and rainfed treatments were designed in research of the effects of drought stress on wheat endosperm starch structure and physicochemical roperties.[Result]Drought stress significantly inhibited the accumulation of starch in wheat endosperm, but it had no significant effect on the Am/Ap ratio of wheat starch. The granule volume, surface area and number distribution of wheat endosperm showed a bimodal curve. The effect of drought stress on starch grain size distribution of wheat endosperm was different due to the difference of genotype and grain size, in which it had a great influence on the surface area and the number distribution of starch granule size15μm was positively correlated with final viscosity and setback. The correlation between granule volume distribution and crystallinity of wheat was not significant. Wheat starch peak viscosity and breakdown, respectively, showed an extremely significant and significant negative correlation with crystallinity, but there was a significant positive correlation between the pasting temperature and crystallinity.[Conclusion] Drought stress changed the wheat endosperm starch composition, granule size distribution, crystallinity and pasting parameters. There were significant correlations between wheat endosperm starch structure and physicochemical properties, indicating that the effects of drought stress on the structure of wheat starch, indirectly affected the physicochemical properties, therefore, the cultivation conditions could be adjusted to achieve the purpose of quality wheat production.