沙枣(Elaeagnus angustifolia L.)体内、外胚胎发育的比较研究

本文应用经典制片法和离体培养法。对沙枣体内、外胚胎发育的各阶段做比较研究。主要区别于原胚期:1)、形态发生:体内只有一种方式,即两极分化方式。而离体的有二种方式,即器官发生和胚状体发生途径。2)、胚性细胞起源:体内只一种起源(即起源于受精卵),离体的胚性细胞的起源有三种方式:a由紧邻表皮细胞的单个薄壁细胞产生;b由表皮细胞横分裂产生和c由表皮及其下的薄璧细胞共同参与产生。3)胚性细胞的细胞学特征:体内发生的合子具明显的极性分化,细胞质、淀粉粒和细胞核集中在合点端。它第一次分裂后,顶、基细胞在细胞学特征上具明显区别。而离体条件下的胚性细胞第一次分裂后无典型的顶、基细胞之分。故也缺乏典型的胚柄细胞。胚分化和成熟期、二者在形态学特征上基本相同

Comparative Studies of Embryogenesis in Elaeagnus angustifolia L. in Vitro and in Vivo

This is a comparative studies of embryogenesis in vitro and vivo on Elaeagnus angustifolia L.by the classical paraffin method. The main differences are at proembryo stage:1)Morphogenesis in vivo is only one type: the type of two polar differentiation. But there ate two types in Vitro:the way of organogenesis and the way from embryoid. 2)Origin of em- bryonic cells: There is only one type of origin in vivo (origin from fertilized egg) and there are three types of origin from embryonic ceils in vitro: a)Single parenchymatous cell adjacent to epidermis of callus originates; b)A transverse division of epidermal cells; c)Both epidermis and parenchymatous cells below from embryoid. 3)The cytological features of embryonic cells: Zygote in vivo appears polarity in differentiation evidently, namely, the cytoplasm, starch grains and nucleus concentrated on chalazal end. The cytological features of apical and basal cells are different clearly after the first division of zygote. There is no typical differentiation of apical and basal cell after first division of embryonic cells in vitro and hence no typical suspensor structure. The morphological features of differential embryo and mature embryo stages are mainly similar.