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文摘
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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 microsporrocyte meiosis is simultaneous type and the microscpore 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 ovules. The ovule is unitegmic, tenuinucellar and ana-campylotropous, The embryo sac orignates from the single-archesporial cell. The one chalazal megaspore in lienar tetrad become the functional megasore. 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 Plathnema is better treated as distinct section and is more advanced than section Ophelia according to the evolutionary trends of embryological characters. |
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其他语种文摘
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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。 |
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来源
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云南植物研究
,2002,24(1):75-81 【核心库】
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关键词
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sweria cincta
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gentianaceae
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embryology
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systematic relationships
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地址
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1.
Kunming Institute of Botany, Chinese Academy of Science, Kunming, 650204
2.
Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xining, 810001
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语种
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英文 |
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文献类型
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研究性论文 |
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ISSN
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0253-2700 |
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学科
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植物学 |
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基金
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中国科学院生物分类区系学科发展特别支持费项目
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文献收藏号
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CSCD:1078339
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