珍稀濒危植物巴东木莲胚胎学研究(英文)  

Megasporogenesis,Microsporogenesis and Development of Gametophytes in the Rare Endangered Plant Manglietia patungensis Hu

作　　者：陈发菊[1,2] 李凤兰[2] 梁宏伟[1] 姚露[2] 何正权[1] 

机构地区：[1]三峡大学生物技术研究中心,宜昌443002 [2]北京林业大学生物科学与技术学院,北京100083

出　　处：《植物研究》2008年第6期657-662,共6页Bulletin of Botanical Research

基　　金：National nature Science Foundation of China (No:30670202)

摘　　要：对巴东木莲(Manglietia patungensis Hu)的花发育以及胚胎发育过程进行了系统研究。巴东木莲花顶生,花器官头年年底开始分化到第二年3月分化出花被、雌雄蕊群直至6月发育成熟。雌蕊成熟时胚珠倒生,双珠被,厚珠心,大孢子四分体线形排列,合点端发育成功能大孢子,珠孔端的3个退化,大孢子为单孢子发生型,胚囊发育方式属蓼型;雄蕊花药外侧壁玫瑰红色,内侧有4个白色花粉囊,绒毡层有1层多核细胞,小孢子四分体排列方式多为左右对称形和交叉形,四面体形,偶为T字形和线形,成熟花粉粒为二细胞型。在巴东木莲花发育和大、小孢子发生以及雌、雄配子体形成过程中未见异常现象,因此笔者认为该物种的花器官发育以及雌、雄配子体发育并不构成导致该物种濒危的因素。A detailed morphological description of megasporogenesis, microsporogenesis, and development of the male and female gametophytes in the rare endangered plant Manglietia patungensis Hu is presented for the first time after three-year＇ s continuous investigation. The ovule is anatropous, bitegmic, erassinueellate and with a obturator. No irregularities have been found in the process from the differentiation of archesporial cells to the formation of megaspores. The megaspore mother cells undergo mi- osis and develop into a linear tetrad. The large one at ehalazal end is functional megaspore and developed into a polygonum type of embryo sac after the third mitotic division. Each anther of M. patungensis Hu with four sacs, a mature anther wall successively comprises an epidermis, endothecium, two-layered middle layer and one or two-layered glandular tapetum. The meioses of mierospore mother cell is normal and eytokinesis is modified simultaneous type, and tetrads are tetrahedral, deeussate and isoblateral,occassionally linear. The pollen grains are monocolpate and two-celled at shedding and the pollen grains germination rate is more than 90%. These results indicate that the key factors for the low seeding rate do not involved the development process of male and female gametophytes.

关 键 词：巴东木莲 大孢子发生 小孢子发生 雌雄配子体发育 

分 类 号：Q949.747.1[生物学—植物学] S759.94[农业科学—森林经理学]