Abstract:

The ovule of Doritis pulcherrima Lindl. is anatropous, tenuinucellate and bitegmic. The mature megagametophyte is composed of seven cells with eight nuclei and its formation belongs to Allium type. Its embryo sac matures about 45 d after pollination. The megasporogenesis in vitro by ovule culture can be induced on all media whether with exogenous hormones or not 3 d after inoculation, but the later megagametogenesis will stop on the medium without hormone or only with auxin or cytokinin. Mature embryo sac can form from megaspore mother cell on the modified VW medium supplemented with 0.5 mg/L BA and 0.1 mg/L NAA.

    五唇兰(Doritis pulcherrima Lindl.)的胚珠属于倒生型，具薄珠心，两层珠被。胚囊发育类型为双孢子葱型，授粉后约45 d形成七细胞八核的成熟胚囊。五唇兰未受精胚珠在离体培养初期对外源激素的依赖性很小，在没有外源激素的培养基上，大孢子母细胞也能经过减数分裂发育为二核胚囊。在培养后期，外源激素对胚囊发育的影响很大。在培养基无外源激素或仅含生长素或细胞分裂素时，雌配子体的发生过程不能顺利完成；在改良VW培养基上添加0.5 mg/L BA和0.1 mg/L NAA时，形成成熟胚囊。

Key words: Doritis pulcherrima , ovule, embryo sac, in vitro , embryology