狭叶锦鸡儿(Caragana stenophylla Pojark)的胚胎发育

本文对狭叶锦鸡儿的胚胎发育过程进行了研究,主要结论如下:胚囊发育属蓼型.在卵与次生核周围的原生质中聚集多糖.卵细胞、助细胞具明显极性,幼期的卵细胞、助细胞和中央细胞具完整的细胞壁.受精时,次生核与卵器相贴近,卵与助细胞在合点端的细胞璧消失.受精后,合子在合点端重新产生不连续的细胞壁,胚胎发育属柳叶菜型.基细胞纵横分裂产生多细胞胚柄.球胚早期,胚柄呈泡沫状团块结构,珠孔端胚囊璧以及胚柄基部,与胚囊璧毗邻处都具明显的传递型细胞壁,胚柄细胞中积累网球状颗较,从球孔端至合点端其分布密度具一定梯度,珠孔端珠被细胞中富含多糖类物质,同时,与胚囊相邻的珠被细胞质膜与壁之间具壁旁体,显示珠被组织对早期胚胎发育的营养关系,胚乳细胞化完成后,胚柄即行退化.

Development of Embryo in Caragana stenophylla pojark

In this paper,the development of embryo in Caragana stenophylla pojark is studied.The main results are as follows:The development of embryo sac is of the p(?)lygonum type.There is polysaccaride in the cyto- plasm of the egg cell and around the secondary nucleus.The polarity of the egg and synergid cells is obvi- ous.In the early stage of the eight-nuclear embryo sac,each cell of the egg apparatus and the central cell are seperated by complete walls.Just before fertilization,the wall bordering the egg cell and synergids in cha- lazal end disappears.After fertilization,a discontinuous new wall regenerated at the chalazal end of the zy- gote.The development of the embryo confirms to the onagrad type.The ventical and transversal divisions of the basal cell result in a multicellular suspensor.The basical suspensor cell wall adjacent to embryo sac wall and the embryo sac wall at the micropyle end all appear obviously ingrowth.The globular bodies are accumu- lated in the cytoplasm of the suspensor cell,and the density at the micropyle end is different from the cha- lazed end.There is abundant polysacearide in the integument cells at the micropyle end.After cellularization of the free nuclear endosperm,the suspensor is degenerated.