摘要
本文用扫描电镜观察了泽苔草的花器官发生过程,观察结果表明:花萼以螺旋状方式向心发生,花瓣以接近轮状方式近同时发生,不存在花瓣雄蕊复合原基。雄蕊和心皮均以轮状向心方式发生,6枚雄蕊分两轮分别在对萼和对瓣的位置先后发生,至发育的后期排成一轮,但仍分别处于对萼和对瓣的位置;随后发生的第一轮3个心皮原基与3枚萼片相对,第二、三轮心皮原基分别为1～3个,与前一轮心皮相间排列向心发生。本文首次揭示了泽苔草花被的外轮3个萼片螺旋状发生方式,这种螺旋状方式很可能是泽泻科植物的花部结构在进化过程中适应环境而保留下来的一种较原始的叶性特征。
The floral organogenesis of Caldesia parnassifolia (Bassi ex L.) Parl. was observed under scanning electron microscope (SEM). The primordia of the floral appendage initiated in trimerous pattern and acropetal succession. Three sepal primordia first initiated on radii spirally, and a whorl of three alternisepalous petal primordia formed nearly simultaneously after the inception of sepal primordia. The petal and stamen primordia initiated separately, and no petal-stamen complex was observed. The three anti-sepalous outer stamens arised after the initiation of petals, the other three inner (anti-petalous) stamens arised subsequently, and the six stamens were arranged in one whorl at subsequent stages of development, but still anti-sepalous and anti-petalous separately. The first whorl of 3 pistil (carpel) primordia originated opposite the sepal primordia, while subsequent pistil primordia formed rapidly in alternation with the preceeding ones, each whorl with 1~3 pistils. The significance of the spiral, acropetal development of corolla is discussed.
出处
《植物分类学报》
CSCD
1997年第4期289-292,共4页
Acta Phytotaxonomica Sinica
基金
国家自然科学基金
关键词
泽泻科
泽苔草
花器官发生
Caldesia parnassifolia
Floral organogenesis
