冰草种子发育的解剖学研究

Anatomical Observation on the Seed Development of Agropyron Desertorum

对诺丹冰草种子发育过程的切片进行观察和研究。合子的第一次分裂为横分裂,形成顶细胞和基细胞。接着顶细胞纵分裂,基细胞横分裂,胚胎发生属紫宛型。胚发育经过椭圆形至棒形,并出现凹陷,开始初分化直至成熟胚。部分种子出现有斜向原胚及胚囊中缺少胚的现象。胚乳为核型胚乳,胚乳细胞化始于多细胞原胚期,成熟胚乳最外层发育糊粉层。其它胚乳细胞充满淀粉粒。珠心与珠被在胚发育过程中细胞质作为营养物质被吸收、解体,细胞壁则被挤压成为一厚壁层,构成乳熟期的种皮。子房壁细胞中的大量淀粉粒在胚、胚乳的发育过程中作为营养物质被吸收。

The growth process of the seed of Agropyron desertorum cv.Nordan were observed by microscope.The zygocyte was transversely divided into a terminal cell and a basal cell,then the terminal cell took a vertical division and the basal cell took a transversely division,forming four-cell proembryo.The proembryo continued cell division in very directions forming globular proembryo and then pear-shaped proembryo.After that the embryo organs began to occur and the embryo differentiated into matured embryo.The phenomena of lacking of embryo were observed in the embryo sac that developed within about a week after anthesis.The endosperm development was nuclear type,and the endosperm cell formation began when the globular proembryo was formed.The out side layer of endosperm cells formed aleurone layer,and the other cells contained plentiful starch.The nucellar tissue,integument and ovary wall were largely absorbed and crushed,and their cellulose walls became a part of seed coat.The inner epidermis of the ovary wall was live until seed matured.