大孢子母细胞

大孢子和雌配子体发生：孢原为一个细胞，它直接起大孢子母细胞功能。

Megasporogenesis and Female Gametogenesis : Archesporium is of one cell , it directly functions as macrospore mother cell .

高水平的ZT/IAA有利于大孢子母细胞和花粉粒的形成，而大孢子四分体的形成则需要高的GA3/ZT比值。

It appears however that the formation of megaspore tetrad associated with the high GA3 / ZT ratio .

大孢子母细胞、大孢子四分体及功能大孢子中含较少不溶性多糖，但却含丰富的RNA和蛋白质。

The insoluble polysaccharides are at very low level in the MMC , tetrads and functional megaspore stages while RNA and protein are at higher level in all of them .

大孢子母细胞及二、四核胚囊的核质显示Feulgen正反应。

The nuclear plasm of megaspore and 2 and 4 nucleate embryosac shows a positive Feulgen reaction .

金针菜的孢原细胞在花蕾长0.5cm左右时形成，孢原细胞直接发育为大孢子母细胞。

The archesporial cell is formed when the alabastrum length reaches 0 . 5 cm or so and the macrosporocyte develops from the archesporial cell directly .

蓼型（Polygonum-type）胚囊大孢子母细胞减数分裂时，其珠孔端细胞壁出现胼胝质荧光，并逐渐扩展到整个细胞壁。

Polygonum-type & During the process of megasporocyte meiosis , callose occurs first in the wall of megasporocyte from micropylar end , then gradually envelops the whole cell .

低温（12-18℃）处理的蝴蝶兰，授粉50d开始分化胚珠原基、60d胚囊处于大孢子母细胞时期，比常温（20-25℃）下的推迟10-15d；

The differentiation of ovule primordium of a hybrid of Phalaenopsis initiated at low temperature ( 12-18 ℃) 50 days after pollination , and megasporogenesis appeared 60 days after pollination . The megasporogenesis at normal temperature ( 20-25 ℃) was delayed for 10-15 days .

大孢子母细胞经过两次减数分裂形成四个大孢子，沿胚珠长轴排成一列，即线形四分体。

The megaspore mother cell undergoes meiosis to form four megaspore in line .

初生造孢细胞直接形成大孢子母细胞。

Primary sporogenous cell forms directly megaspore mother cell .

珠心表皮下的雌性孢原直接发育为大孢子母细胞。

The archesporial cell below nucellus epiderm functions directly as the megaspore mother cell .

凤眼莲大孢子母细胞减数分裂的观察

Observation on meiotic division of the megasporocyte of Eichhornia crassipes ( mart . ) solms

大孢子母细胞时期细胞壁内缺少胼胝质。

The wall of the generative cell contains callose . Callose was absent at megasporocyte stage .

该配子体是由大孢子母细胞进行减数分裂而来。

The gametophyte is derived from the product of a reduction division in the megaspore mother cell .

大孢子母细胞减数分裂产生T形四分体和少数线形四分体。

The megaspore mother cell undergoing meiotic divisions produces a T-shaped , or , rarely , linear tetrad .

在异型孢子体种类中，可区分为大孢子母细胞和小孢子母细胞。

In theterosporous species , a distinction is usually made between megaspore mother cells and microspore mother cells .

孢原细胞直接发育成大孢子母细胞，然后大孢子母细胞减数分裂形成大孢子。

The archesporium in its pistils directly developed into megaspore mother cells , which later divided into macrospores through meiosis .

造孢细胞，大孢子母细胞和四分体时期，周缘细胞仅1层。

There is only one layer of parietal cells at the stage of sporogenous cell , megaspore mother cell and tetrad .

大孢子母细胞期间，其珠孔端沉积胼胝质，但并不完全包围之；

During meiosis , callose deposit on the micropylar end wall of the megasporocyte , but the cell was not enclosed by callose .

孢原细胞平周分裂形成一个周缘细胞和一个造孢细胞，造孢细胞直接发育成大孢子母细胞，四分体大孢子呈线形排列，它们均可成为功能大孢子；

The sporogenous cell functioned directly as megaspore mother cell . The tetrad of megaspores was linear in arrangement , and every megaspore might be functional .

3月下旬大孢子母细胞形成，4月初进行减数分裂形成四分体，功能大孢子位于近合点端。

The megasporocyte forms in late March and undergoes meiosis to form the megaspore tetrad in early April , The functional megaspore lies nearby the chalaza end .

子房具胚珠20&23枚，胚珠横生，珠被二层，薄珠心，孢原细胞直接起大孢子母细胞作用。

The ovary contains 20-23 ovules . The ovules are hemitropous , with 2 integuments , tenuinucellate and the archesporial cell functions directly as the mega-spore mother cell .

孢原细胞为表皮下3～4层细胞处的一个细胞，孢原细胞不经分裂直接发育成大孢子母细胞。

The archesporial cell is a cell of 3 ￣ 4 layer cells under the nucellar epidermis , the archesporial does not undergo meiosis and becomes the megaspore mother cell .

例如在蒲公英中，在第一次减数分裂后，大孢子母细胞的染色体仍在一个细胞中，形成一个再组核。

In dandelion ( Taraxacum ), for example , the chromosomes of the megaspore mother cell remain in one cell after the first meiotic division , forming a restitution nucleus .

雌雄蕊发育的对比关系：其雄蕊先熟，散粉时，雌配子体还未发育成熟，处于大孢子母细胞减数分裂阶段。

The corresponding relationship of the development of stamen and pistil . Flowers are protandrous . When pollen grains shed , female gametophyte is not mature yet , which is in the meiosis of megasporocyte .

大孢子母细胞继续生长，先在珠孔端出现一个较大的液泡，液泡随后移向合点端，细胞核移至珠孔端，此时环状内质网消失；

With the megasporocyte developing , a bigger vacuole appears in the micropyle end , then it migrating toward the chalazal end with the nucleus in the micropyle end , ringed ER disappears in this phase .

造孢细胞直接发育成大孢子母细胞，它进行减数分裂形成四个呈T&形排列的大孢子，只有合点端的一个大孢子发育成胚囊。

The megaspore mather cell is derived from the sporogenous cell , and divided into four megaspores by the meiotic division , megaspores present the rank of T & type , among which only one near chalaza can be developed to the embryo sac .

雌配子体在大孢子母细胞发育阶段发现不能形成大孢子和大孢子形成后退化或发育不良等多种发育异常的雌配子体败育类型，而且败育频率高达36.7%。

At the stage of megaspore mother cell development female gametophytes were observed to form no megaspores or to form such aborted female types as megaspores which formed and then degenerated soon or developed poorly and their abortion rate was as high as 36.7 % .

雌配子体发育的特点是：倒生胚珠、基底胎座、厚珠心、双珠被、孢原细胞直接长大成大孢子母细胞、反足细胞退化早，胚珠发育为蓼型。

The character of macrospore in development were as followed : anatropal ovule , basal placenta , thick nucellar , two integument , megaspore mother cell coming directly from archesporial cell , early degenerating antipodal cell , thedevelopment of the embryo sac being conformed as the polygonum type .

其大孢子发生和雌配子体发育过程正常，大孢子母细胞减数分裂形成线形或T形四分体，合点端大孢子为功能大孢子，胚囊发育属蓼型。

In female flowers , megasporogenesis and development of female gametophytes were normal : the tetrad of megaspores was linear or T shaped ; the chalazal megaspore was usually functional ; the development of embryo sac was of the Polygonum type .

大孢子孢原细胞2~3个，其中1个发育为大孢子母细胞，大孢子母细胞减数分裂形成直线四分体，合点端的大孢子为功能大孢子，珠孔端3个大孢子退化。

Hypodermal archesporium is 2 or 3 cells ; a single cell well developed into megaspore mother cell . Undergoes meiotic divisions , produces a linear tetrad .