【作者】 李春燕；

【导师】 封超年；

【作者基本信息】 扬州大学 ， 作物栽培学与耕作学， 2006， 博士

【摘要】 本研究选用大面积生产上推广应用的非糯性小麦品种和糯性小麦品系为材料，研究分析不同类型(糯性与非糯性)小麦籽粒淀粉粒形成和淀粉及其组分积累动态的差异，支链淀粉的链长分配差异及其对淀粉理化特性的影响；探讨籽粒中淀粉合成的生理机制，分析酶和内源激素与淀粉合成的关系；研究阐明不同小麦品种Waxy蛋白亚基组成及其与直链淀粉含量和淀粉膨胀势的关系；通过氮肥试验，以求进一步明确氮肥对弱筋小麦扬麦13号上述指标的调控机理，其结果可以进一步丰富淀粉形成的机理，为小麦优质栽培调控提供理论依据。本文的主要研究结果如下： 1、明确糯性与非糯性小麦籽粒淀粉积累动态、淀粉粒形成过程及品种间的差异。结果表明：不同类型小麦籽粒中总淀粉、直链淀粉、支链淀粉含量和积累量随灌浆进程推移不断上升，呈“慢-快-慢”的变化趋势，糯小麦扬0369的直链淀粉含量和积累量显著低于非糯品种；直链淀粉积累速率在花后25-30天达到峰值，支链淀粉及总淀粉积累速率峰值期在花后20-25天，花后15-30天糯小麦扬0369的直、支链淀粉及总淀粉积累速率均显著低于非糯品种，因而其粒重最低。同时还对籽粒中淀粉粒形成过程进行了电镜观察，结果显示：小麦籽粒灌浆前期是以Ⅰ型淀粉粒为主，花后10天Ⅰ型淀粉粒出现了小的乳头状突起，形成体积比Ⅰ型淀粉粒明显小的Ⅱ型淀粉粒，灌浆中后期以分化Ⅱ型淀粉粒为主，之后Ⅰ、Ⅱ型淀粉粒充实直至成熟。同一籽粒腹部Ⅱ型淀粉粒多于背部，扬麦13号、扬0369Ⅱ型淀粉粒数目多于中优9507，但前两者差异不显著。采用X-射线能谱仪测定小麦籽粒糊粉层富更多还原

【Abstract】 Based on the field experiments on non-waxy wheat cultivars applied in production and waxy wheat varieties, the differences of starch granule development in grain endosperm cells, grain starch accumulation dynamics and amylopectin chain length distribution among different genotypes and their relationship to wheat flour characteristics were examined. The physiological basis of starch synthesis was also studied. Composition of waxy protein sub-unit and its relations to amylose content and swelling power in different wheat varieties were analyzed. Effects of nitrogen fertilizer on physicochemical characteristics of starch formation and relevant mechanism were also studied, which could provide more knowledge about starch synthesis mechanism and supply theoretical reference for producing wheat with good grain quality. The main results were as follows.1 Dynamics and differences of grain starch accumulation, starch granule structure in different wheat varieties were studied. The results showed that amylose, amylopectin and starch contents in grains rose gradually after anthesis. The maximum accumulating rate of amylose appeared on the 25-30^th day after anthesis （DAA）, while that of amylopectin appeared on the 20-25^th DAA. Amylose, amylopectin and starch accumulating rates of waxy wheat Yang 0369 were lower than those of the others from 15^th to 30^th DAA, therefore its grain weight was the lowest. Starch granule structure in grain endosperm cells of wheat varieties Yangmai 13, Yang0369 and Zhongyou9507 was observed by use of scanning electronic microscopy during the grain filling period. Only did a few starch granules appear in endosperm cells on the 5^th DAA. The number of type I starch granules increased mainly at early grain filling stage （5-10DAA）. Then mastoid protuberance started to appear on the surface of type I starch granules and developed into type II starch granules. The number of type II starch granules rose mainly at the middle and late grain filling stages. Type I and II starch granules kept更多还原