东北地区白桦雌配子体的形成与胚胎发育研究  

Megagametophyte and Embryo Development of Betula platyphylla in Northeastern China

作　　者：刘雪梅[1] 杨传平[2] 

机构地区：[1]东北林业大学生命科学学院,哈尔滨150040 [2]东北林业大学林学院,哈尔滨150040

出　　处：《植物学通报》2005年第2期147-152,共6页Chinese Bulletin of Botany

基　　金：国家自然科学基金项目(39970627);国家科学技术部重大项目(2002BA515B05)资助

摘　　要：以20年生白桦(Betula platyphylla)的雌花序为材料,研究了白桦的大孢子发生、雌配子体形成和胚胎发育过程。结果表明:1)大孢子母细胞经过减数分裂形成直线排列的4个大孢子,其中珠孔端的3个大孢子退化,合点端的大孢子进行3次有丝分裂,形成八核胚囊,8个核迅速细胞化,最终发育为成熟胚囊。胚囊发育类型为单孢子蓼型胚囊;2)胚的发育经过原胚、球形胚、心形胚和鱼雷胚等阶段发育为成熟胚;胚柄在球形胚时期最发达,但胚柄短小,只由3个扁平细胞组成,之后逐渐退化。本文同时对雌花的结构和发育特点在桦木科各属中的异同、白桦胚胎发生类型及胚胎发育进程的同步性进行了讨论。This paper describes megasporogenesis, megagametogenesis, and the process of embryonic development of the female inflorescence in 20-year-old Betula platyphylla. Megaspore mother cells undergo meiosis, which results in the formation of 4 megaspores in a row. The chalazal-most cell develops into an 8-nuclei embryo sac after 3 rounds of mitosis. A mature embryo sac is produced after cellularization and nuclear migration. The other cells of the tetrad undergo degeneration. The mature embryo sac consists of an egg apparatus, a central cell, and 3 antipodal cells. The embryo sac is a monosporic Polygonum type. The zygote develops into a mature embryo going through proembryo, globular, heart, and torpedo stages. The suspensor is developed fully at the stage of globular embryo and consists of 3 cells, which are degenerated later. The organization and development of the female flower and the type and synchrony of embryogenesis in Betulaceae are also discussed.

关 键 词：白桦 发育研究 雌配子体 东北地区 胚胎发育过程 大孢子母细胞 大孢子发生 直线排列 减数分裂 有丝分裂 成熟胚囊 发育类型 发育经过 阶段发育 细胞组成 发育特点 发育进程 发生类型 球形胚 雌花序 细胞化 单孢子 桦木科 

分 类 号：S792.153[农业科学—林木遗传育种] S885.135[农业科学—林学]