摘要
为进一步研究商陆科的系统位置提供花器官发生和发育的证据 ,在扫描电子显微镜下观察了商陆Phytolaccaacinosa、多雄蕊商陆P .polyandra和垂序商陆P .americana的花器官发生。结果表明 :商陆属植物花被的发生均为 2 5型螺旋发生。在同一个种不同的花蕾中 ,花被的发生有两种顺序 :逆时针方向和顺时针方向。远轴侧非正中位的 1枚先发生。雄蕊发生于环状分生组织。在单轮雄蕊的种中 8-1 0枚雄蕊为近同时发生 ;两轮雄蕊的种 8枚内轮雄蕊先发生 ,6- 8枚外轮雄蕊随后发生 ,内轮雄蕊为同时发生 ,外轮雄蕊发生次序不规则。心皮原基也发生于环状分生组织 ,8- 1 0枚心皮原基为同时发生。在后来的发育过程中 ,商陆的心皮发育成近离生心皮雌蕊 ;其他 2种心皮侧壁联合发育成合生心皮雌蕊。对商陆属植物花器官发生的类型及发育形态学做了分析 。
To provide data of floral development for the genus Phytolacca and to have a further insight into the systematic relationships of the family Phytolaccaceae, floral organogenesis of three species in this genus, viz., P. acinosa, P. polyandra and P. americana, was examined under scanning electron microscope (SEM). The first tepal primordium is initiated in non-median abaxial position and the second one in median adaxial position. Five tepal primordia arise in a 2/5 sequence on the periphery of the floral apex. Their initiations have anticlockwise or clockwise directions in different floral buds of the same species. The stamen and carpel primordia all arise on a ring meristem. In the species with monocyclic stamens 8 - 10 stamen primordia arise nearly simultaneously after the initiation of tepal primordia. In the species with dicyclic stamens 8 stamen pnimordia in the inner whorl first arise simultaneously and then 6 - 8 in the outer whorl irregularly initiate. Eight to ten carpel primordia arise simultaneously in alternate position with the stamen primordia. In the following developmental process the carpels in P. acinosa develop nearly into apocarpous gynoecium and in P. polyandra and P. americana into syncarpous gynoecium. Patterns of floral organogenesis and the flower development morphology in Phytolacca were analysed. Evidence from floral organogenesis supports the primitive position of Phytolaccaceae in the Caryophyllales.
出处
《植物分类学报》
CSCD
北大核心
2004年第4期352-364,共13页
Acta Phytotaxonomica Sinica
基金
国家自然科学基金资助项目 ( 3 0 1 3 0 0 3 0 )~~
