Journal of Nuclear Agricultural Sciences ›› 2015, Vol. 29 ›› Issue (4): 724-733.DOI: 10.11869/j.issn.100-8551.2015.04.0724

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Starch Granule Structure and Diameter Distribution in Relation to Starch Physicochemical Properties for Rice Sugary Endosperm Mutant (Sug-11)

ZHAO Hua1,2, ZHANG Qifang2, ZHAO Qian2, WANG Junmin3, MEI Shufang1, LIU Xianglei1, CHENG Fangmin2   

  1. 1. Jinhua Polytechnic, Jinhua, Zhejiang 321017;
    2. College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang 310058;
    3. Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang 310031
  • Received:2014-09-10 Revised:2014-12-21 Online:2015-04-13 Published:2015-04-16

水稻胚乳糖质突变体Sug-11的淀粉粒结构和粒径分布及相关理化特性

赵华1,2, 张其芳2, 赵倩2, 王俊敏3, 梅淑芳1, 刘向蕾1, 程方民2   

  1. 1. 金华职业技术学院, 浙江 金华 321017;
    2. 浙江大学农业与生物技术学院, 浙江 杭州 310058;
    3. 浙江农业科学院作物与核技术研究所, 浙江 杭州 310031
  • 通讯作者: 程方民, 男, 教授, 主要从事作物品质形成与分子调控研究.E-mail:chengfm@zju.edu.cn
  • 作者简介:赵华, 男, 副教授, 主要从事作物种质创新、评价与利用研究.E-mail:zhh5188@163.com
  • 基金资助:

    国家自然科学基金(31271655),浙江省公益性技术应用研究项目(2012C22035)

Abstract:

The endosperm sugary mutant (Sug-11) and its wild-type (‘Zhonghua11’) were applied to comparative analysis their rice starch granule morphological structure, distribution, crystal structure, enzymolysis resistance and the thermodynamics parameters in the process of their starch gelatinization by using scanning electron microscope, laser scattering particle diameter analyzer, differential scanning calorimetry (DSC) and the X-ray diffraction pattern for purpose of figuring out the physicochemical characteristic of endosperm sugary rice starch and further to provide theoretical basis for improving rice grain quality and developing functional rice product. The results indicate that the starch granule diameter of Sug-11 present unimodal Gaussian distribution and its average diameter (6.48 μm) significantly decreased comparing with‘Zhonghua11’, that the proportion of large starch granule (diameter greater than 8 μm) significantly lowered (21.63%) while the small and middle one notably increased, that the starch granule structure of Sug-11 is more close to when grain-filling process has not been fully enrich observing under scanning electron microscopy; that the enzymolysis resistance of Sug-11 starch granule dropped significantly compared with its wild-type and its content of resistant starch decreased about 50%; that Sug-11 has relatively lower starch gelatinization temperature and its thermal enthalpy (ΔH) in the process of starch gelatinization was also significantly reduced. In addition, Sug-11 has the same starch crystal type (type A) with its wild-type but its starch granule relative crystallinity (35.3%) is slightly lower than its CK, and the main differences between them is their relative crystallinity and the performance of all peak's relative intensity ratio where Sug-11 is higher than its wild-type at 20° 2θ/18° 2θ. Finally, sugary mutant significantly effect chemical composition, swelling power and solubility to rice starch in which both the content of apparent amylose and the starch swelling power of mutant Sug-11 are significantly lower but the starch solubility is obviously higher than its wild-type.

Key words: rice, sugary mutant, starch granule, size distribution, crystallinity structure

摘要:

本试验以水稻胚乳糖质突变体Sug-11与其野生型对照中花11为材料, 利用扫描电镜、激光散射粒度分析仪、差示扫描量热分析仪和X-射线衍射图谱等方法, 对两者稻米淀粉粒的形态结构、粒径分布、晶体结构和酶解抗性及其糊化过程中的热力学参数变化进行比较分析, 揭示胚乳糖质稻米淀粉的理化特征, 为稻米品质改良和功能稻米的开发提供理论依据.结果表明, 胚乳糖质突变体Sug-11的稻米淀粉粒径分布呈单峰状正态分布, 与野生型对照相比其稻米淀粉平均粒径值(6.48μm)显著降低, 大型淀粉粒(粒径大于8μm)比例(21.63%)显著减少, 而小型和中型淀粉粒比例则明显增多, 扫描电镜下Sug-11的淀粉粒结构更接近于籽粒灌浆过程胚乳尚未完全充实时的淀粉粒形态结构特点;突变体Sug-11的淀粉粒酶解抗性与野生对照相比显著下降, 其抗性淀粉含量的下降幅度接近50%, 同时, Sug-11除具有相对较低的淀粉糊化温度外, 其淀粉粒糊化过程的热焓值(ΔH)也显著降低.Sug-11糖质突变体的淀粉晶体类型与野生对照相同(A型淀粉晶体), 其淀粉粒的相对结晶度(35.3%)略低于对照, 两者间的差异主要表现在诸尖峰的相对强度比值和相对结晶度上, 而20°2θ/18°2θ的尖峰相对强度比值则高于其野生对照;糖质突变对稻米淀粉的化学组分(成)、膨胀势和溶解度也产生了十分显著的影响, 突变体Sug-11的淀粉溶解度显著高于野生对照, 而淀粉膨胀势和表观直链淀粉含量则显著低于野生对照材料.

关键词: 水稻, 糖质突变, 淀粉, 粒径分布, 晶体结构