Abstract: A comparison of the caryopsis development, rice quality characteristics and the size, pattern, structure of the endosperm amyloplasts (starch granules) in the two indica rice varieties was made.The quality traits in Yangdao 6 were better than those in Xiangzaoxian 33. In the primary period after flowering, the dry matter in Yangdao 6 was accumulated more slowly than that in Xiangzaoxian 33 but faster in the later period, and the starch was filled strongly in the later period after flowering.There were two kinds of amyloplasts: single and compound amyloplasts, 4.7 μm and 9.7μm in diameter on average with the range of 2.4-8.0 μm and 5.7-19.5 μm, respectively. In the case of the endosperm of Xiangzaoxian 33, most of the single amyloplasts were elliptic or round with loose arrangement and great difference in size, and the coefficient of variation was high;While in the endosperm of Yangdao 6, most of the amyloplasts were single, well developed, polyhedral, crystalline and compact-arranged, and the coefficient of variation was low. The amyloplasts in dorsal part of endosperm were developed better than those in abdomen and center. The chalkiness in the endosperm resulted from badly-developed and loose-arranged starch, which was closely relevant to the transport of filling materials.

Key words: indica rice, development, quality traits, amyloplast, chalkiness

摘要： 比较了两个籼稻品种颖果的发育,籽粒的主要品质性状以及胚乳淀粉体的大小、形状、结构等特性。结果表明： 扬稻6号的主要品质性状优于湘早籼33；在开花后前期扬稻6号干物质积累速率较慢，但在后期较快，淀粉充实度较高； 淀粉胚乳细胞内存在两种淀粉体，即单粒淀粉体，直径2.4~8.0 μm，平均4.7 μm；复合淀粉体，即由多个单粒淀粉体结合而成，直径5.7~19.5 μm，平均9.7 μm。湘早籼33单粒淀粉体多数为椭圆形或圆球形，大小差异较大，排列疏松，变异系数较大；扬稻6号胚乳单粒淀粉体基本为晶体多面形，发育良好，大小较为一致，排列紧密，变异系数较小。胚乳背部淀粉体的发育和排列结构优于腹部和中部。胚乳垩白的出现是由于淀粉体发育不良、排列疏松所致，而淀粉体的充实又与灌浆物质的输入途径紧密相关。

关键词: 籼稻, 发育, 品质性状, 淀粉形成体, 垩白