西南獐牙菜的胚胎学及其系统学意义

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，孔子房为3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党性一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。

Embryology of Swertia cincta (Gentianaceae) and Its Systematic Value

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 development 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