绿豆大小孢子发生与雌雄配子体发育

1)小孢子多孢原起源,小孢子母细胞减数分裂为同时型,四分体为四面体型。2)花粉壁由三层结构组成:最外为表皮,其次为药室內壁和中层,绒毡层为腺质型。3)单柱小孢子分裂为营养柱和生殖核后,再不进行分裂,成熟的花粉粒为2—细胞型。4)大孢子孢原进行平周分裂,产生一个周缘细胞和一个造孢细胞。造孢细胞直接起大孢子母细胞的功能。珠心属厚珠心类型。5)外珠被分化迟于內珠被,但发育较内珠被快,尤其是位于胚珠凸出一边的外珠被发育更快。胚珠类型属弯生胚珠型。6)四个大孢子其孔端三个退化,合点端一个大孢子有功能,胚囊类型属蓼型。反足细胞在极核融合时消失,所以成熟胚囊似待霄草型。7)同一朵小花中,从产生孢原细胞到形成大小孢子母细胞,雄蕊发育均早于雌蕊,减数分裂不同步现象更为明显。

Mung Bean Micro-mega Spore Production and Male-female Gametophyte Development

(1) A microspore is full of archesporium origin, the meiosis of microspore mother cell is simultaneous type, its four-quarter section is a tetrad is a tetrahedron type. (2) A pollen wall consists of three layers of structure; the first layer is epidermis, the next is endothecium and middle layer, tapetum is glandular type. (3)After a single nucleus microspore splits into vegatative and reproductive cell, doesn't split any layer, the ripe pollen grain is 2-cell type. (4) The megaspore archesporium splits circumference, it circumferential edge cell and a sporogenous cell. The sporogenous cell plays a role of the megaspore's mother cell straightly. The nucellus belongs to thick nucellus type. (5) The outer integument splits up later than the inner integument. but it grows faster than the inner integument especially the outer integument in the convex side of ovule grows much more faster, the ovule type belongs to campylotro pous ovule type. (6) At the end of the micropyle three of the four megaspores degenerate. and at the end of chalaza anly one megaspore functions. The type of embryo sac belongs to polygonium type, the antipodal cell disappears when polar nucleus mixes together, so the ripe embryo sac is like oenothera type. (7) In the same small flower, from producing archesporium cell to forming micro-mega spore's mother cell, stamen grows earlier than pistil, the phenomenon of meiosis unassimilation is more obvious.