桂花受精作用的研究  

Studies on Double Fertilization in Osmanthhus fragrans

作　　者：杨琴军[1] 黄燕文[2] 李和平[2] 

机构地区：[1]华中农业大学林学系,武汉430070 [2]华中农业大学理学系,武汉430070

出　　处：《华中农业大学学报》2001年第4期382-390,共9页Journal of Huazhong Agricultural University

摘　　要：对桂花开花前后雌雄蕊的发育状态与受精作用进行了研究 ,结果表明 :在金桂中存在 2种性别的植株 ,两性株 (雌、雄均可育 )和雄株 (雄性可育 ,雌性不育 )。两性株开花时 ,多数胚囊处于 2核至 4核期 ,花后约 4d开始出现成熟胚囊。成熟胚囊由 1个卵细胞、2个助细胞和 2个相互靠近的极核组成 ,3个反足细胞已退化。成熟花粉粒为二细胞型 ,在桂花中存在一定比例的二型花粉。FDA染色法显示 ,桂花花粉的生活力较低。开花后5～ 7d ,胚囊开始受精。花粉管进入胚囊 ,穿过 1个助细胞 ,释放出 2个精子。精卵融合速度慢于精子与极核的融合。受精前两极核不一定融合成次生核。受精作用持续时间约为 6～ 2 0d。Studies were carried out on the development of gynoecium and androecium fore and after anthesis and fertilization in Dsmanthus fragrans . Results showed that there were two kinds of plants in Jingui:hermaphroditic plants and male plants. Most embryo sacs were in the period of two nucleus or four nucleus when blooming and didn't mature until the fourth day after anthesis. The mature embryo sac was made up of one egg, two synergids and two close polar nuclei. Three antipodal cells degenerated. Mature pollen grains were 2 celled.Obvious pollen dimorphism was observed. Fluorescein diacetate tests showed that pollen viability was somewhat generally low. Fertilization began in the embryo sac after 5 to 7 days after anthesis. The pollen tube entered the embryo sac, cut across a synergid, then released two sperms. The fusion between the male nucleus and the egg cell was slower than the fusion between the male nucleus and the polar nucleus. It was uncertain that the two nuclei fused into the secondary nucleus before fertilization. It took 6～20 days to finish the double fertilization. The double fertilization is the type of premitotic syngamy.Reasons of Gui fruit setting failure, deviation of megagametophyte development, additional sperms entering embryo sac and pollen dimorphism are also discussed.

关 键 词：桂花 成熟胚囊 雌雄蕊 受精作用 生殖生物学 

分 类 号：S685.13[农业科学—观赏园艺]