无距虾脊兰胚珠发育及种子形成研究  

Ovule Development and Seed Formation of Calanthe tsoongiana T.Tang et F.T.Wang

作　　者：连静静[1] 钱鑫[1] 王彩霞[1] 刘芬[1] 田敏[1] 

机构地区：[1]中国林业科学研究院亚热带林业研究所,浙江富阳311400

出　　处：《西北植物学报》2013年第3期494-500,共7页Acta Botanica Boreali-Occidentalia Sinica

基　　金：浙江省省院合作项目(2012SY02-3)

摘　　要：采用石蜡切片、半薄切片、扫描电镜技术对无距虾脊兰不同时期的子房(蒴果)进行研究。结果表明:(1)无距虾脊兰授粉后19d,胎座上分化出上万个胚珠原基,这些胚珠原基由1列细胞外包1层表皮细胞构成,其中胚珠原基内部顶端的细胞分化为孢原细胞,授粉后45d,孢原细胞发育分化为大孢子母细胞。(2)无距虾脊兰成熟胚珠为倒生胚珠,双珠被,薄珠心,胚囊发育为蓼型,且胚珠的发育即便在同一个果实内也是不同步的。(3)受精后合子经过一次不均衡横裂形成基细胞和顶细胞;基细胞不参与胚体构成,分化为单细胞的胚柄,最后退化消失;顶细胞经多次分裂形成原球胚,胚胎发育类型为石竹型。(4)成熟种子呈纺锤形,由球形胚和内外双层种皮构成,双层种皮分别由内外珠被发育而来。The fruits at different developmental stages of Calanthe tsoongiana were sectioned and observedthrough conventional paraffin section, semithin section and scanning electron microscope. The results showed that：（1）The ovule primordia began to differentiate from placenta 19 days after pollination. The o-vule primordia was a layer of epidermal cells encircled a list of cells. The top cell differentiated into arches- porial cell. Then archesporial cell differentiated directly into megaspore mother eell,45 days after pollina-tion. （2）The mature ovule was anatropous,bidntegument and tenuinucellar. Development of embryo sac was polygonum type. Ovule development was not syncbronized even in the same fruit. （3）The first zygotedivision was unequal,producing a basal ceil and a terminal cell. The basal cell gave rise to the suspensor and it did not participate in the formation of embryo proper. The suspensor degenerated at the late stage of theembryo development. Terminal cell gave rise to embryo proper. Development of embryo was Caryophyllad type. （4）The shape of mature seed liked spindle. It consisted of globular embryo,endoplenra and episperm. Endopleura and episperm developed from inner tegument and outer integument respectively.

关 键 词：大孢子 雌配子体 胚珠 胚胎 胚柄 

分 类 号：Q944.58[生物学—植物学] Q248