早生黄金梨雌雄性细胞发育及其对应关系

Development and its corresponding relation of male and female cells of Josengwhangkeum pear

以早生黄金梨为试材,运用石蜡切片法对雌雄性细胞的发育进行细胞学观察,探讨了它们的发育规律及其与外部形态的相关性。结果表明,1)早生黄金梨的花药为4室;药壁发育属双子叶型;腺质绒毡层;小孢子母细胞减数分裂为同时型;开花前7～9d花粉成熟,成熟花粉为2-细胞型。2)大孢子母细胞减数分裂形成的4个大孢子呈直线排列,其中合点端的大孢子具功能,经过3次分裂后,于开花当天形成成熟八核胚囊;胚囊发育属蓼型。3)在发育过程中,不仅雌雄性细胞的形成之间有比较稳定的对应关系,而且它们与花芽或花的外部形态特征之间也有着相对稳定的关系。根据它们的时序性对应关系,可以通过花芽或花的外部形态特征来对其内部的性细胞发育进程进行即时判别。

Cytological observation on the development of female and male cells of Josengwhangkeum pear was carried out by the method of paraffin sectioning, and the developmental pattern and its correlation with configuration of female and male cells were explored. Results showed： （ 1 ） its anther had 4 chambers ; anther wall development was of Gemini-cotyledon type with secretory tapetum ; the meiosis of microspore mother cell was simultaneous type. Pollen matured 7 to 9 d ahead of bloom and mature pollen was 2-cellular type. （2） 4 megaspores formed from meiosis of female megaspore disposed in beeline; among which functional megaspore was at the top of chalaza and developed to 8-nuclear embryo sac after splitting 3 times on the same blooming day; its embryo sac belonged to polygonum type. （3） during the processing of development, not only the formation of androecium and gynoecium had stable corresponding relations, but they all corresponded with exterior configurations of bloom bud and flowers as well. According to this sequence corresponding relations, the development process of interior sexual cell could be identified simultaneously by exterior configuration characters.