运用扫描电镜与半薄切片技术 ,观察了玉米 (ZeamaysL .)的胚发育过程 ,得到以下认识 :第一、关于原胚。玉米合子细胞分裂形成的原胚分为胚柄、胚基与胚体三部分。胚柄短小 ,寿命短暂。胚基具有生长带 ,纵向伸长长度大 ,胚基的上部参与形成胚根鞘 ,其余部分干缩后附在胚根鞘末端。第二、玉米胚的背腹极性及二型子叶。原胚初期胚体出现背腹极性 ,腹面的细胞小 ,细胞质稠密 ,液泡较少 ;背面的细胞较大 ,细胞质稠密度略低 ,液泡较多。原胚后期胚体分化为腹部与背部 ,腹部从腹面的中央突起 ,背部在腹部的周围 (从左至右侧 )及整个胚体背面。进入幼胚时期 ,腹部分化为胚芽鞘、生长锥、胚轴、胚根和胚根鞘 (大部分 )。期间 ,胚芽鞘原基和根原始细胞的分化都从胚体的中轴部位开始 ,然后向两侧和四周扩展 ,表现出胚体腹面形态的两侧对称性。原胚的背部形成盾片原基 ,盾片原基经历向左、右、上、下的迅速扩展和加厚的生长 ,将整个腹部所分化形成的构件藏于盾片的纵沟之中 ,最后盾片从纵沟的边缘长出的左、右侧鳞均向胚体的中轴线生长 ,完整显示出玉米胚腹面的两侧对称。玉米胚由腹部顶端形成胚芽鞘和生长锥的情况与水稻胚的胚芽鞘 (顶生子叶 )和生长锥的形成相同 ,玉米的胚芽鞘也是顶生子叶 ,盾片则是侧生子叶。玉 The embryo development of Zea mays (Zea mays L.) was observed by scanning electron microscopy and semi-thin sectioning techniques, and the following findings were obtained: First, the proembryo. Maize zygotic cell progenitor cells formed into embryogenic stem, embryo and embryo body three parts. Short embryo handle, short life expectancy. Embryoid with growth zone, the longitudinal elongation of the length of the embryo-based upper part of the formation of radicle sheath, the rest of the shrinkage attached to the radicle sheath end. Second, the polarity of the dorsum of the maize embryo and type II cotyledons. The embryo body of primordial embryos showed the dorsoventral polarity, the ventral cells were small, the cytoplasm was dense and vacuoles were less; the cells on the back were larger, the cytoplasm was slightly lower in density, and vacuoles were more. The proembryo embryoid body differentiates into the abdomen and the back, the abdomen protrudes from the center of the ventral surface, the back is around the abdomen (from left to right), and the entire back of the embryo body. During the immature embryo, the abdomen differentiates into coleoptile, growth cone, hypocotyl, radicle and radicle sheath (mostly). During the differentiation of coleoptile primordium and root primordial cells from the central part of the embryo body, and then to both sides and around the expansion, showing the morphology of the embryo on both sides of the symmetry of the ventral shape. The original embryo formed scutellum on the back of the original base, the scutellum primo underwent to the left, right, up and down the rapid expansion and thickened growth, the entire belly of the formation of the components hidden in the longitudinal groove of the scutellum, The last scutellum grows from the edge of the longitudinal groove on the left and right scales all grow towards the central axis of the embryo body, which completely shows that both sides of the corn embryo ventral face are symmetrical. The formation of coleoptiles and growth cones from the top of the abdomen in maize embryos is the same as the formation of coleoptiles (top cotyledons) and growth cones in rice embryos. The coleoptile maize is also the terminal cotyledon, while the scutellum is the cotyledon. jade