【摘要】 调查了18个水稻品种(系)的垩白度、垩白粒率和垩白大小,并对米粒胚乳横断面上的胚乳细胞和淀粉粒进行了电镜扫描.结果表明,供试品种(系)的垩白粒率和垩白度存在显著差异,但垩白大小差异不显著,不同品种(系)在稻米胚乳细胞的形态结构和排列方式上有所不同,其横断面上淀粉粒的分布情况也有明显差异.不同品种(系)的垩白米之间,品种内垩白米与非垩白米之间,以及垩白米不同部位之间的淀粉粒形态具有差异.米粒横断面背腹径方向上长方柱状细胞群(细胞长度为宽度的两倍以上)与垩白发生有一定相关性,但不是垩白发生的决定性因素.淀粉粒在米粒横断面上分布情况与垩白发生有着更为密切的关系,淀粉粒分布越均匀越不易发生垩白,而如果淀粉粒分布不均匀,则使得其排列疏松并最终产生垩白.本文还对垩白发生的机理进行了探讨.更多还原

【Abstract】 Chalkiness characters such as percentage of grains with chalkiness(PGWC)、degree of endosperm chalkiness(DEC) and square of chalky endosperm(SCE) have be investigated.Endosperm cells and starch granules in cross section of eighteen rice varieties(lines) have be observed with scanning electron microscope.The results showed that there were remarkable difference of PGWC and DEC,and were not significant difference in SCE in these rice varieties(lines).There were difference of morphological characters of the starch granule among the rice varieties(lines)、chalky grain and non-chalky grain and the different part of chalky grains.It was found that the vertical arrangement of rectangular cell groups in cross section are correlated with chalkiness formation,but it is not the deciding factor.For the first time,It was found that the distribution of starch granules in cross section had very close correlation with the chalkiness formation.If the starch granules distributed uniformly,chalkiness is not easy to occur in the rice kernel.The mechanism of chalkiness formation also have be discussed.更多还原