摘要
对金柑胚珠与胚囊的发育进行了观察.当花蕾长0.25～0.3 cm 时,在胎座上形成胚珠原基.花蕾为0.55～0.6 cm 时,胚珠原基已发育成为倒生胚珠.胚珠为厚珠心,具2层珠被,胚囊母细胞经减数分裂以后形成四分体.四分体线形排列,近合点端的1个发育成胚囊,其余3个细胞退化.开花前先天发育成单核胚囊,开花后第1 d 进行第1次有丝分裂,开花5～6 d 多数胚囊发育成熟.开花后7～8 d 普遍出现幼胚.在开花后第2 d 即二核胚囊时,珠心内有多个大型活跃细胞,以后发育成无性胚.
The development process of ovule and embryo sac in kumquat wasinvestigated.The ovule primordium is formed when the flower bud is 0.25～0.3 cm,anddevelops into anatropous ovule when it is 0.55～0.6 cm.The ovule is crassinucellate withtwo layers of integument,The embryo sac mother cell forms the tetrad through meiosis.Thetetrad is in linear arangement.The one near the chalaza develops into uninuclear embryo sacthe day before anthesis.The other three degenerate.The uninuclear embryo sac undergoesthe first mitotic divison on the first day after anthesis.Most of the embryo sacs are matured5～6 days later after their ant heses,and young embryos could be seen on the 7th or the 8thday after their antheses.Several large active cells could be seen in nucellus the second dayafter anthesis(i.e.the uninuclear embryo sac stage),which develops day into asexualembryo.
关键词
柑
胚珠
胚囊
发育
金柑
citrus reticulata
ovules
embryo sac
development(biology)/kumquat
