海南山薯雌花发育及胚胎发育的研究

通过研究山薯的雌花及胚胎发育,为山薯的胚胎学研究以及杂交育种奠定基础。结果表明:山薯大部分为雌雄异株,海南岛的山薯雌花花期约3个月,为9月初至11月末。子房3室,每室有2个倒生胚珠;胚珠具厚珠心,双珠被。珠孔一端表皮下的孢原细胞逐渐发育为大孢子母细胞。大孢子母细胞减数分裂形成4个呈线形排列的大孢子,其中只有1个可以发育为功能大孢子。成熟的胚囊为7胞8核胚囊,其胚囊发育类型为蓼型。卵细胞的受精属于有丝分裂前型。其胚的发育类型为柳叶菜型,经过二细胞原胚、倒T型原胚、棒状胚、球形胚和梨形胚这5个发育阶段。胚乳的发育为核型。

Studies on Female Flower Development and Embryonic Development of Dioscorea fordii Prain et Burk. in Hainan

This paper studied the development of female flowers and embryo in Dioscorea fordii Prain et Burk., and laid the foundation for it on the study of embryology and hybridization breeding. The results showed that: most of D. fordii Prain et Burk. was dioecious, and female flowering period was about 3 months in Hainan, from early September to the end of November. There were three rooms in its ovary, and two anatropous ovules in each room; The ovule was crassinucellate and bitegminous. The archesporial cell under the micropyle epidermis gradually developed into megasporocyte mother cell. Then the megaspore mother cell underwent meiosis and formed 4 megaspore in line, and only one of megaspore developed into functional megaspore. The mature embryo sac was Polygonum type with 7 cells and 8 nuclei. The fertilization of egg cell was premitotic type. The development of embryo was onagrad type, and went through 5 development stages, including two cell proembryo, inverted T type proembryo, globular embryo clavate embryo and pear shaped embryo. The development of endosperm was karyotype.