胚珠的

Egg apparatus The three haploid nuclei that are situated at the micropylar end of the embryo sac in most flowering plants. The central nucleus is the female gamete and those to either side of it are called the synergids.

卵器：在大多数显花植物的胚囊中，位于珠孔端的三个单倍体核，其中卵细胞位于中央，两个助细胞分别位于两边。

Seeds 2 or 1 by abortion, ovoid or ellipsoid, on carunclelike strongly tapered funicle; testa crustaceous, endosperm absent; cotyledons thick, plano-convex.

种子2或1 败育，卵球形的或椭圆形的，生于种阜状强烈渐减的珠柄；壳质的种皮，缺席的胚乳；子叶厚，平凸。

The megaspore mother cell is located at the 3rd or 4th layer of cells in the nucellus top end. It divides transversally to form a linear megaspore tetrad, and the megaspore at the chalazal end develops into the embryo sac mother cell.

大孢子母细胞位在珠心顶表皮下第三或四层细胞处，经横分裂后产生一直线形的大孢子四分体，其中位居合点端的大孢子发育成胚囊母细胞。

Food materials may be stored in a special tissue derived from the nucellus, called the perisperm.

营养物质可以贮藏于由珠心产生的一种特殊组织，叫外胚乳。

In conventional sexual hybridization of citrus, nucellar polyembryony, pollen/ovule sterility, genetic heterozygosity, wild sexual incompatibility of most citrus cultivars make it very time-consuming and low efficiency to improve fruit characters.

但是，由于柑橘类植物中存在的珠心胚现象、一些品种中的雌雄性败育、童期过长、远缘有性杂交不亲和等特点使通过传统的有性杂交方式进行品种改良进程缓慢，效率不高。

Synergid cells Two haploid cells located near the egg cell at the micropylar end of the embryo sac in flowering plants.

助细胞：存在于开花植物胚囊内，是位于珠孔端的卵细胞两侧的两个单倍体细胞。

It takes about 0.5 h for a pollen tube from germination to arrive at the micropyle. About 0.5 h after pollination, the pollen tube releases two sperms into one synergid. At 0.5-2.5 h after pollination, the egg cell fuses with one sperm to form a zygote. About 10.0 h after pollination, the division of the zygote begins. The duration of the zygote lasts about 2.5-10.0 h. However, one sperm nucleus fuses with two polar nuclei at 1.0-3.0 h after pollination, and 5.0 h after pollination the primary endosperm nucleus begins to divide.

水稻受精过程经历的时间表如下：授粉后，花粉在柱头萌发；花粉萌发至花粉管进入珠孔大约需要0.5小时；授粉后0.5小时左右，花粉管进入一个助细胞，释放精子；授粉后0.5-2.5小时，精卵融合形成合子；授粉后约10.0小时，合子第1次分裂，合子期为授粉后2.5-10.0小时；授粉后1.0-3.0小时，精核与两极核融合；授粉后约5.0小时，初生胚乳核分裂。

Lots of starch grains in nucellar cells and integumentary cells surrounding endosperm haustoria decreased and disappeared with the development of endosperm haustoria.

随着胚乳吸器的发育，吸器附近的珠心细胞和珠被细胞中贮存的大量淀粉粒逐渐减少和消失。

Using DNA extracted by CTAB silicon-based method from leaves and endosperm of Torreya grandis, a silver staining-based AFLP system was established for leaves and endosperm respectively.

以香榧的叶片和胚乳为材料，利用改进的CTAB-硅珠吸附法提取DNA，分别就叶片与胚乳建立了香榧的AFLP银染反应体系。

Megaspore mother cells undergo meiosis, which results in the formation of 4 megaspores in a row. The chalazal-most cell develops into an 8-nuclei embryo sac after 3 rounds of mitosis. A mature embryo sac is produced after cellularization and nuclear migration.

结果表明：1大孢子母细胞经过减数分裂形成直线排列的4个大孢子，其中珠孔端的3个大孢子退化，合点端的大孢子进行3次有丝分裂，形成八核胚囊， 8个核迅速细胞化，最终发育为成熟胚囊。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。