大麦胚和胚乳发育的相关性及贮藏营养物质的积累

大麦(Hordeum vulgare L.)开花后1d,见合子及退化助细胞,游离核胚乳尚未形成;开花后2～3d,胚为5及10个细胞,胚乳为游离核期;开花后4及5、6d,胚为梨形及长梨形,胚乳达细胞化期;开花后8d,胚为胚芽鞘期,糊粉层原始细胞产生;开花后10d,胚具1叶,糊粉层1～2层;开花后13d胚为2叶胚,亚糊粉层发生;开花后17d,3叶胚形成,糊粉层多为3层并停止分裂,菱柱形及不规则胚乳细胞分化;开花后21～29d,胚为4叶胚,胚乳进一步分化;开花后33d,胚为5叶成熟胚,胚乳亦成熟。淀粉、蛋白质在胚中积累始于开花后13d。在盾片中由基向顶发生,在胚芽鞘及叶原基中,首先在顶端出现。成熟盾片顶端的淀粉消失。开花后6d,胚乳开始积累淀粉;开花后10d,糊粉层及胚乳细胞积累蛋白质。开花17d后胚乳的蛋白质体多聚集,29d后蛋白质体显著减少。开花后17d,在盾片及糊粉层细胞中检测到油脂。果长或果长与稃片长之比和盾片长可作为不同发育期胚和胚乳的形态指标。

RELATIONSHIP BETWEEN EMBRYO AND ENDOSPERM DEVELOPMENT AND ACCUMULATION OF STORAGE RESERVES IN BARLEY

In barley (Hordeum vulgare L. cv. Aente 13) the zygote with one or two degenerated synergids was seen on day 1 after anthesis but the free nuclear endosperm had not yet appeared. On day 2 and 3 after anthesis the embryo was 5- and 10-celled when the endosperm was at the free nuclear phase. When the embryo was pear- and long pear-shaped by day 4, 5 and 6 after anthesis, the endosperm reached the cellularization stage. The embryo was at the coleoptilar stage and the aleu-rone initial cells appeared by day 8 after anthesis. When the embryo produced its first leaf on day 10 after anthesis,the aleurone cells formed 1 to 2 layers. On day 13 after anthesis the embryo became 2-leafed as the subaleurone layer occurred. The 3-leafed embryo was visible by day 17 after anthesis, at which time the aleurone cells were mostly 3-layered and mitotic divisions ceased and the prismatic and irregular cells of endosperm were differentiated. On day 21 to 29 after anthesis, the embryo was 4-leafed as the endosperm differentiation continued. The embryo was 5-leafed and matured about the time (33 days after anthesis) when the endosperm also became mature. Starch and protein firstly accumulated in the 2-leafed embryo and deposition proceeded acropetally in the scutellum, but appeared firstly in the apex cells in the coleoptile and leaf primordia. Starch disappeared in the upper part of the mature scutellum. Starch was firstly found in endosperm cells by day 6 after anthesis and on day 10 after anthesis protein deposition began in the aleurone layer and endosperm cells. Aleurone grains formation began on day 21 after anthesis and ended by day 29 after anthesis. From day 17 after anthesis onwards, protein bodies in the endosperm cells were mostly clustered together and markedly decreased afterwards. Lapid accumulation was detected in both scutellum cells and aleurone cells by day 17 after anthesis. Caryopsis length, especially the ratio of caryopsis length to lamma length and scutellum length could be used as the morphological indicators to identify the stages of embryo development and endosperm development as well.