人工控温条件下稻米垩白形成变化及胚乳扫描结构观察

 利用人工气候箱设高温（33℃）和适温（23℃）2个不同的温度处理，对2个不同垩白类型品种西农8116和广二矮104抽穗后稻米垩白的变化动态进行了研究，并通过对不同温度下稻米胚乳内部淀粉体形态、大小、发育程度、排列结构的扫描电镜观察，分析了稻米垩白形成变化与胚乳内部淀粉体结构特征的关系，结果表明，水稻灌浆结实期稻米垩白形成的变化过程主要是在抽穗5 d到15~20 d的这一时期，其余时段垩白度的变化幅度不大；高温（33℃）与适温（23℃）处理相比，以抽穗后10~20 d间的变化差别最为明显；胚乳淀粉体表现为“裸露型”还是“非裸露型”，主要与胚乳细胞内部淀粉粒发育程度有关，而与品种本身的垩白类型特征无必然联系

Dynamic Change of Chalkiness and Observation of Grain Endosperm Structure with Scanning Electron Microscope under Controlled Temperature Condition

Based on the experiment with two chalkiness types of indica rice variety (Xinong8116 and Guang’er’ai 104) and two different temperature treatment (the daily average temperature was 33℃ and 23℃, respectively) in climatic chamber, chalkiness change of rice grain during grain filling stage and its relationship with the endosperm starch structure characteristics such as starch shape, size, developing degree and arrange pattern which was observed by scanning electron microscope were analysed.The result showed that the key stage of the chalkiness change of rice grain during the filling stage was from 5 days to 15-20 days after heading, but at the other stage the chalkiness change was not clear; the difference of chalkiness change between 33℃ high temperature treatment and 23℃ proper temperature treatment was mainly at the stage of 10 days to 20 days after heading; through the observation of grain endosperm structure with scanning electron microscope, it was found that the distinguish between “uncovered endosperm starch” and “ covered endosperm starch” had close relationship with starch developing degree in endosperm cell, no inevitable relative to the chalkiness type of rice variety.