| 摘要: |
| 首次报道了南方山荷叶大、小孢子发生和雌、雄配子体形成。主要结果如下:花药4室,花药壁发育为基本型,由7层细胞组成,由外到内依次为表皮、药室内壁、3层中层和2层绒毡层; 药室内壁有带状加厚现象,绒毡层细胞多具双核,为腺质型绒毡层; 多孢原,发生于表皮下; 小孢子母细胞减数分裂为同时型,小孢子四分体多为四面体型,少数为十字交叉形、直线形、左右对称形或“T”形; 成熟花粉粒为2-细胞型,偶见3-细胞型; 成熟花粉粒呈圆形,具单萌发孔。雌蕊1枚,子房单心皮,纵切面呈瓶状; 1室,边缘胎座,具4～5枚发育不同步的横生胚珠。胚珠具双珠被,厚珠心; 珠孔由两层珠被共同形成,在一直线上或呈“之”字形。多孢原,位于珠心表皮下。直线形四分体,合点端的1个大孢子发育为功能大孢子,胚囊发育为蓼型。成熟胚囊中,3个反足细胞大而明显,但宿存时间短,较早退化。 |
| 关键词: 山荷叶 小孢子 雄配子体 大孢子 雌配子体 |
| DOI： |
| 分类号:Q944.4 |
| Fund project: |
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| Genesis of microspore, megaspore and the development of male gametophyte, female gametophyte in Diphylleia sinensis |
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HUANG Heng-Yu, LONG Hua, LI Li*
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Key Laboratory of Plant Resources Conservation and Utilization(Jishou
University), College of Hunan Province, Jishou 416000, China
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| Abstract: |
| The microsporogenesis & megasporogensis and the formation of male gametophyte and female gametophyte in Diphylleia sinensiswere first reported. The main results can be concluded as follows:anthers are tetrasporangiate and its wall development conforms to the basic type and comprises of epidermis,endothelium,three middle layers and two tapetums at the mature stage from outer to inner. The endothelium develops fibrous thickening and the tapetum was of two cell nuclei mostly,belongs to glandular type. Cytokinesis in the microsporocyte meiosis is of the simultaneous type and the microspore tetrads are mostly tetrahedral and there were still a few other types,such as dilateral,linear,isobilateral and“T”shape. Circular pollen grains are mainly 2-celled type when shed,occasionally 3-celled type,and had one aperture. Solitary pistil is consisted of only one carpel. Ovary is unilocular. Ovules are amphitropous arrangement on marginal placenta and their development is asynchtonous and crassinucellate with double integument. Micropyle is composing of inner and outer integument. Multi-archesporial comes of the first cell layer under nucellar epidermis. The tetrad of megaspores is linear shaped,with the first cell from the chalazal end being functional. The development of embryo sac belongs to the polygonum type. Three antipodal cells are big and obvious in mature embryo sac,but they are ephemeral. |
| Key words: Diphylleia sinensis microspore male gametophyte megaspore female gametophyte |
