薏苡胚乳发育及营养物质积累的研究

薏苡 ( Coix lacryma- jobi)授粉后 2 d,游离核胚乳已转变为细胞胚乳。授粉后 3d,中央细胞被胚乳细胞充满。起初 ,全部胚乳细胞均进行分裂 ,一定时期后 ,细胞分裂主要发生在胚乳周边区。授粉后 1 0 d,表皮停止平周分裂变为糊粉层 ,内方的数层形成层状细胞行平周分裂直到颖果接近成熟。胚乳内部生长则依赖于细胞体积扩大。胚乳基部 (颖果基部的胚乳 )形成了数层传递细胞。授粉后 9d,淀粉积累。授粉后 1 0 d,糊粉层及其内方数层细胞产生了脂体 ,后者的脂体以后又消失。授粉后 1 3、1 5 d,糊粉层细胞的液泡积累蛋白质。授粉后 2 0 d,液泡变为糊粉粒。授粉后 1 5 d淀粉胚乳细胞产生蛋白质体 ,营养物质积累持续到颖果成熟。还观察了胚和胚乳发育的对应关系。

STUDIES ON ENDOSPERM DEVELOPMENT AND DEPOSI TION OF STORAGE RESERVES IN COIX LACRYMA JOBI

The transition from free nuclear to cellular endosperm of Coix lacryma jobi was completed 2 days after pollination. By 3 days after pollination the central cell was filled with endosperm cells.At first all cells of endosperm underwent division, later cell division was li mited mainly in the peripheral region. 10 days after pollination the epidermal layer ceased its periclinal division and became the aleurone layer.Cell division persisted in the subepidermal cambium like layers until the caryopsis nearly matured. Cells of the inner region of endosperm became enlarged. Several layers of transfer cells were formed at the basal part of the endosperm.Starch grains appeared in endosperm cells on the 9th day after pollination. 10 days after pollination, lipid bodies occurred in the aleurone layer and the underlying layers. 13 and 15 days after pollination, the small vacuoles of aleurone cells contained protein and 20 days after pollenation they became aleurone grains.By 15 days after pollination protein bodies were formed in starch endosperm.Storage reserve deposition continued until the grain ripened. A correlation between endosperm and emoryo development was also observed.