云南植物研究
雲南植物研究
운남식물연구
ACTA BOTANICA YUNNANICA
2002年
1期
75-81
,共7页
西南獐牙菜%龙胆科%胚胎学%系统关系
西南獐牙菜%龍膽科%胚胎學%繫統關繫
서남장아채%룡담과%배태학%계통관계
Sweria cincta%Gentianaceae%Embryology%Systematic relationships
报道了西南獐牙菜的大、小孢子发生及雌、雄配子体发育过程,并以此讨论了獐牙菜属宽丝组和多枝组的分类等级和系统演化关系.西南獐牙菜花药四室;药壁发育为双子叶型;绒毡层二型起源,腺质型;中层细胞2层;药室内壁纤维状加厚,药壁表皮宿存.小孢子母细胞减数分裂为同时型;小孢子四分体的排列为四面体形;成熟花粉为3-细胞型.子房为2心皮,1室,胚珠12列,故为超侧膜胎座.薄珠心,单珠被,倒弯生胚珠.大孢子母细胞减数分裂形成4个大孢子呈直线形排列,合点端的大孢子具功能.胚囊发育为蓼型.两极核在受精前融合为次生核.3个反足细胞次生增殖为5~8个,宿存.比较宽丝组和多枝组的胚胎学性状表明宽丝组从多枝组中分出是合理的,在系统位置上宽丝组较多枝组进化.
報道瞭西南獐牙菜的大、小孢子髮生及雌、雄配子體髮育過程,併以此討論瞭獐牙菜屬寬絲組和多枝組的分類等級和繫統縯化關繫.西南獐牙菜花藥四室;藥壁髮育為雙子葉型;絨氈層二型起源,腺質型;中層細胞2層;藥室內壁纖維狀加厚,藥壁錶皮宿存.小孢子母細胞減數分裂為同時型;小孢子四分體的排列為四麵體形;成熟花粉為3-細胞型.子房為2心皮,1室,胚珠12列,故為超側膜胎座.薄珠心,單珠被,倒彎生胚珠.大孢子母細胞減數分裂形成4箇大孢子呈直線形排列,閤點耑的大孢子具功能.胚囊髮育為蓼型.兩極覈在受精前融閤為次生覈.3箇反足細胞次生增殖為5~8箇,宿存.比較寬絲組和多枝組的胚胎學性狀錶明寬絲組從多枝組中分齣是閤理的,在繫統位置上寬絲組較多枝組進化.
보도료서남장아채적대、소포자발생급자、웅배자체발육과정,병이차토론료장아채속관사조화다지조적분류등급화계통연화관계.서남장아채화약사실;약벽발육위쌍자협형;융전층이형기원,선질형;중층세포2층;약실내벽섬유상가후,약벽표피숙존.소포자모세포감수분렬위동시형;소포자사분체적배렬위사면체형;성숙화분위3-세포형.자방위2심피,1실,배주12렬,고위초측막태좌.박주심,단주피,도만생배주.대포자모세포감수분렬형성4개대포자정직선형배렬,합점단적대포자구공능.배낭발육위료형.량겁핵재수정전융합위차생핵.3개반족세포차생증식위5~8개,숙존.비교관사조화다지조적배태학성상표명관사조종다지조중분출시합리적,재계통위치상관사조교다지조진화.
This paper reports the mega-, micro-sporogenesis and female-, male-gametogenesis of Swertia cincta for the first time, with the aim of discussing the systematic position of section Platynema and section Ophelia of Swertia. Anthers are tetrasporangiate. The developmem of anther walls conforms to the dicotyledonous type. The tapetum cells have dual origin and are similar to the glandular type. There are two middle layers. The endothecium and epidermis persist. Cytokinesis in the microsporocyte meiosis is simultaneous type and the microspore teads are tetrahedral. Pollen grains are 3-celled. The ovary is bicarpellum and unilocular. The placentation is of suparietal placentation with 12 series of ovules. The ovule is unitegmic, tenuinucellar and ana-campylotropous. The embryo sac originates from the single-archesporial cell. The one chalazal megaspore in linear tetrad becomes the functional megaspore. The development of embryo sac is of the Polygonum type. Before fertilization, two polar nuclei fuse into one secondary nucleus. Three antipodal cells persisted and divided into 5 - 8 cells. A comparison between two sections indicates that section Platynema is better treated as distinct section and is more advanced than section Ophelia according to the evolutionary trends of embryological characters.