论文部分内容阅读
利用切片技术对台湾翅果菊Pterocypsela formosana胚胎发育过程进行了显微观察。研究结果表明,花药4室,药壁发育为双子叶型,由表皮、药室内壁、中层和绒毡层4层细胞组成,腺质绒毡层;小孢子母细胞减数分裂为同时型,四分体主要为四面体型,成熟花粉为2-细胞型。子房下位,2心皮,1室,单胚珠,基生胎座;单珠被,倒弯生胚珠,具发达的珠被绒毡层;大孢子孢原细胞直接发育为大孢子母细胞,属薄珠心类型;大孢子细胞减数分裂形成直线形4分体,仅合点端1个发育为功能大孢子,功能大孢子经3次连续的有丝分裂形成7细胞8核的成熟雌配子体,雌配子体发育方式为蓼型。2个极核在受精前融合为次生核,合点端反足细胞短命,形成后不久即退化消失。珠孔受精,属有丝分裂前类型;初生胚乳核早于合子分裂,胚乳发育为核型,具胚乳吸器;胚胎发育为紫菀型菊苣变型,早期发达的胚柄对胚的发育具重要意义。
The development of embryos in Pterocypsese formosana from Taiwan pteridophytes was observed using the microtome technique. The results showed that the anther 4 chamber and the wall of the anther developed into a dicotyledonous type and consisted of 4 layers of epidermis, inner wall of the drug chamber, middle layer and tapetum, and the tapetal tapetum. The meiosis of microspore mother cells was simultaneous, Tetrahedron mainly tetrahedral, mature pollen for the 2-cell type. Ovary inferior, 2 carpels, 1 compartment, single ovule, basal placentation; single beaded, abaxially born ovules, with developed tapestry tapetum; megasporidial cells directly develop into megaspore mother cells, Megaspore cells are melanocytes type; megaspore meiosis to form a linear 4 points, only the junction of the end of the development of a functional megaspore, functional megaspore by 3 consecutive mitosis to form 7-cell 8-core mature female gametophyte, female Gametophyte development for Polygonum type. The two polar nuclei fuse into secondary nuclei before fertilization, and the antiapoptotic cells at the junction point are short-lived, and disappear soon after they are formed. Beads are fertilized, which belongs to the pre-mitotic type. The primary endosperm nucleus is earlier than the zygotic division, the endosperm develops into a karyotype with endosperm aspirator, and the embryo develops into a purple type chicory variant. The early developed embryo stem is of great significance for embryo development.