长喙毛茛泽泻的花器官发生  

Floral Organogenesis of Ranalisma rostratum (Alismataceae)*

作　　者：王玉国[1,2,3] 王青锋 陈家宽[1,2,3] 袁秀平 

机构地区：[1]武汉大学生命科学学院植物科学系 [2]复旦大学生物多样性研究所,遗传研究所 [3]中国科学院水生生物研究所

出　　处：《云南植物研究》1998年第3期303-308,共6页Acta Botanica Yunnanica

摘　　要：用扫描电镜对长喙毛茛泽泻（ＲａｎａｌｉｓｍａｒｏｓｔｒａｔｕｍＳｔａｐｆ．）的花器官发生进行了观察。该种的花器官发生在泽泻科中既典型又比较特殊。其特殊之处在于从花原基的发生直至最外轮６枚雄蕊原基的发生过程都存在单向发育：３个萼片原基和３个花瓣原基的发生存在次序性，萼片原基和花瓣原基均为顺时针发生，邻近花序侧生分支复合芽的萼片原基和花瓣原基倾向于优先发生；最外轮６枚雄蕊的发生是成对的按对萼的形式发生。这是以往对该属花器官发生研究没有注意到的。由雄蕊原基向心皮原基的转变发生在与最外轮６枚雄蕊相交替的６个位点，其中一些位点仍可能被雄蕊原基所占据，最初心皮的发生或多或少地与前一轮雄蕊交替，而以后的心皮的发生顺序看上去是螺旋状排列的。鉴于花器官发生过程出现的具体情况，长喙毛茛泽泻花的单向发育可能真正代表着原始螺旋策略的相继发生在花部的保留和花序的两侧对称向花器官的扩展；最外轮６枚雄蕊原基的对萼排列，不支持花瓣－雄蕊复合原基的存在；本文还通过花部结构分化的差异对毛茛泽泻属与黄花蔺科的联系进行了讨论。The floral development of Ranalisma rostratum Stapf. has been observed under scanning electron microscope (SEM). Floral organogenesis of R. rostratum is generally typical in Alismataceae, but it is unique in having unidirectional development up to the stage of initiation of the first six stamen primordia. The initiation of the three sepal primordia and the three petal primordia is in proper order. The former is clockwise and the latter too. The sepal primordia and the petal primordia initiate first towards the side of the flower adjacent to the lateral branch complex of the inflorescence. The transition from stamen to carpel initiation occurs at six sites alternating with the first six stamens, some of them may be occupied by stamen primordia. Initiation of first carpel primordia alternate more or less with previous stamen primordia, but the initiation of later carpel primordia appear to be spiral. In view of specific condition occurring on the process of floral organogenesis, floral unidirectional development in R. rostratum may really represent reservation of successive initiation of original spiral tactics and continuation of bilateral symmetry tactics of the inflorescence. Antisepalous characteristic of the first six stamens , has even not been paid attention to, provides the evidence that the existence of petal-stamen complex primordia is impossible in Ranalisma. Basing on the difference of differentiation floral constructure, the relationship between Ranalisma and Limnocharitaceae is still discussed.

关 键 词：泽泻科 长喙毛茛泽泻 花器官发生 

分 类 号：Q944.58[生物学—植物学] Q949.712.5