【作者】 张书玲； 张成合； 申书兴； 王梅； 刘世雄；

【Author】 Zhang Shuling, Zhang Chenghe, Shen shuxing, Wangmei, Liu shixiong (Department of hourticultur, Hehei agri, univ, Baoding 071001)

【机构】 河北农业大学园艺系；

【摘要】 本文对二倍体和四倍体菜心的胚胎发育过程进行了观察比较。结果表明,二倍体和四倍体的胚胎发育过程基本相似。授粉后24h已有花粉管进入胚囊并释放其中的内含物;授粉后 3d,合子已完成第一次分裂,形成由顶细胞和基细胞构成的二细胞原胚;授粉后14-15d,由多细胞原胚分化为心形胚;授粉后20d,成熟胚已基本形成。与二倍体比较,四倍体菜心的胚乳核开始细胞化的时期较早,一般在球形胚期,而二倍体在心形胚期。此外,四倍体菜心的胚珠受精率及膨大胚珠率较低,个别胚胎在发育中途政育,因而结籽率降低。更多还原

【Abstract】 The process of embryo development in diploid and autotetraploid false pakchoi (Brassica campestris L. ssp chinensis var until is Tsen et Lee) was observed in present work. The results are summarized as follows: (l)About 24 hours after anthesis, the pollen tube has already reached the micropyle in some ovu-les, and in some cases, it has even entered further into the embryosac and discharged its contents;(2)The first mitotic division of the zygote has finished and the 2-celled proembryo formed three days after anthesis;(3)About 14-15 days after anthesis. the proembryo with many cells has developed into the heart-liked embryo which further developed into mature embryo in 6-7days; (4)Compared with the diploid. the stage of endosperm nucleus turning into the endosperm cell is much earlier, generally at globe shaped embryo stage in the tetroploid, and at heart-liked embryo stage in the diploid. Besides, the rate of fertilized embryosacs and inflated ovules is much lower and some ovules degenerated at the early stage of embryo development in the tetraploid.更多还原