云南植物研究
雲南植物研究
운남식물연구
ACTA BOTANICA YUNNANICA
2001年
1期
72-78
,共7页
王印政%李军%梁汉兴%吴征镒
王印政%李軍%樑漢興%吳徵鎰
왕인정%리군%량한흥%오정일
小孢子%胚囊%双大孢子母细胞%胚%胚乳%河口异叶苣苔%苦苣苔科
小孢子%胚囊%雙大孢子母細胞%胚%胚乳%河口異葉苣苔%苦苣苔科
소포자%배낭%쌍대포자모세포%배%배유%하구이협거태%고거태과
对河口异叶苣苔的胚胎学观察旨在为该属的系统学研究提供参考。该种的花药药壁由表皮、药室内壁、中层和绒毡层4层细胞组成。2~3-核细胞在绒毡层频繁出现。胚珠属倒生,单珠被和薄珠心型。胚囊发育属蓼型。该种胚囊发育中的双大孢子母细胞现象,分别为并列和前后排列型。前者发育至双并列四分体,后者发育到呈棱形的4个大孢子。胚乳的发育属细胞型,并在合点端和珠孔端分别具有吸器。珠孔吸器发育早期为单核、2-细胞,后期为两核、2-细胞或单核、4-细胞,有时为多细胞,并在发育过程中向外伸长形成外珠孔。合点吸器为两核。由于合点吸器和珠孔吸器的活动,位于珠被最外层细胞和珠被绒毡层之间的2~3层细胞逐渐解体和被吸收。胚的发生和发育属柳叶菜型。在胚的发育过程中,胚乳几乎被吸收耗尽,仅剩下一层胚乳细胞紧贴内种皮。成熟种子的种皮由珠被最外层细胞和珠被绒毡层发育而来。本文对河口异叶苣苔的胚胎发育过程同苦苣苔科其它类群进行了广泛的比较和讨论。
對河口異葉苣苔的胚胎學觀察旨在為該屬的繫統學研究提供參攷。該種的花藥藥壁由錶皮、藥室內壁、中層和絨氈層4層細胞組成。2~3-覈細胞在絨氈層頻繁齣現。胚珠屬倒生,單珠被和薄珠心型。胚囊髮育屬蓼型。該種胚囊髮育中的雙大孢子母細胞現象,分彆為併列和前後排列型。前者髮育至雙併列四分體,後者髮育到呈稜形的4箇大孢子。胚乳的髮育屬細胞型,併在閤點耑和珠孔耑分彆具有吸器。珠孔吸器髮育早期為單覈、2-細胞,後期為兩覈、2-細胞或單覈、4-細胞,有時為多細胞,併在髮育過程中嚮外伸長形成外珠孔。閤點吸器為兩覈。由于閤點吸器和珠孔吸器的活動,位于珠被最外層細胞和珠被絨氈層之間的2~3層細胞逐漸解體和被吸收。胚的髮生和髮育屬柳葉菜型。在胚的髮育過程中,胚乳幾乎被吸收耗儘,僅剩下一層胚乳細胞緊貼內種皮。成熟種子的種皮由珠被最外層細胞和珠被絨氈層髮育而來。本文對河口異葉苣苔的胚胎髮育過程同苦苣苔科其它類群進行瞭廣汎的比較和討論。
대하구이협거태적배태학관찰지재위해속적계통학연구제공삼고。해충적화약약벽유표피、약실내벽、중층화융전층4층세포조성。2~3-핵세포재융전층빈번출현。배주속도생,단주피화박주심형。배낭발육속료형。해충배낭발육중적쌍대포자모세포현상,분별위병렬화전후배렬형。전자발육지쌍병렬사분체,후자발육도정릉형적4개대포자。배유적발육속세포형,병재합점단화주공단분별구유흡기。주공흡기발육조기위단핵、2-세포,후기위량핵、2-세포혹단핵、4-세포,유시위다세포,병재발육과정중향외신장형성외주공。합점흡기위량핵。유우합점흡기화주공흡기적활동,위우주피최외층세포화주피융전층지간적2~3층세포축점해체화피흡수。배적발생화발육속류협채형。재배적발육과정중,배유궤호피흡수모진,부잉하일층배유세포긴첩내충피。성숙충자적충피유주피최외층세포화주피융전층발육이래。본문대하구이협거태적배태발육과정동고거태과기타류군진행료엄범적비교화토론。
The embryology of Whytockia hekouensis Y. Z. Wang, as arepresentative of the genus Whytockia, was investigated in order to provide information on the systematics of the genus. The anther wall comprises four layers—epidermis, endothecium, middle layer and tapetum. 2—3-nucleate cells are frequently observed in the tapetum. The anatropous, unitegminal and tenuinucellar ovules, and the embryo sac of the Polygonum type conform to those of the most members of the Gesneriaceae. Twin megaspore mother cells occasionally occur during megasporogenesis. The development of the endosperm is of cellular type. The micropylar haustorium of Whytockia is 2-celled uninucleate in the early development and 2-celled binucleate or 4-celled uninucleate, and sometimes multi-celled in the late development, while the chalazal haustorium is binucleate. The extra-micropylar structure has been observed during the development of the micropylar haustorium. The development of the onagrad type embryo consumes up the endosperm except one layer that remains in the mature seed. The coat of a mature seed consists of two layers which develop respectively from the outer epidermal cells and the endothelial cells of the integument. The embryology of W. hekouensis is compared and discussed with that of others in the Gesneriaceae.