primary endosperm nucleus

…The ovule of angiosperms undergoes double fertilization to become a seed. In other words, the two sperm nuclei that enter the embryo sac fertilize the egg nucleus and become an embryo, and the other fertilizes the two polar nuclei to become a triploid ( 3n ) primary endosperm nucleus, which undergoes cell division (or just nuclear division) to increase in volume and cell number, storing starch, protein, oils, etc. to become endosperm. The nucleus of the ovule usually disappears or becomes a thin membrane, but in some cases, such as Swiss chard and pepper, nutrients are stored in the nucleus, which is called the perisperm (also called the exosperm or exosperm). …

*Some of the terminology that mentions "primary endosperm nucleus" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…被子植物の胚珠は重複受精し，種子となる。すなわち，胚囊に入った二つの精核は卵核と受精し胚になり，他の一つは二つの極核と受精し，三倍体(3n)の初生胚乳核primary endosperm nucleusとなり，細胞分裂(または核分裂のみ)をして細胞数とともに体積を増し，デンプン，タンパク質，油脂などをたくわえ胚乳となる。胚珠の珠心は，普通，消失するか，薄い膜状となるが，フダンソウ，コショウのようにこの珠心に養分がたくわえられることがあり，これを周乳perisperm(外胚乳，外乳ともいう)と呼ぶ。…

※「primary endosperm nucleus」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報