两种木莲属植物的花器官发生与发育

Floral Organogenesis of Manglietia fordiana Oliv.and Manglietia chingii Dandy

用扫描电镜观察桂南木莲(Manglietia chingii Dandy)和木莲(Manglietia fordiana Oliv.)两种木莲属植物的花器官发生及发育过程。结果显示,两种植物的花被片皆为向心发生,木莲的花被片3基数3轮,而桂南木莲的花被片4轮,前3轮3基数,第4轮普遍存在退化现象。雄蕊与心皮皆多枚,螺旋状向心发生。两种植物花发育的特殊之处在于花被片为轮状不同时发生,即从发生位置上看为3基数轮生,但同一轮花被片之间在发生时间上存在差异。这种花被片的轮状不同时发生可能是螺旋状发生向轮状发生演化的一个过渡阶段,这对探讨被子植物花器官发生与发育的演化具有重要意义。

The floral organogenesis of Manglietia chingii Dandy and Manglietia fordiana Oliv. were observed under scanning electron microscope （SEM）. Tepals of Manglietia chingii and Manglietia fordiana initiate asynchronously in whorls, Tepals of Manglietia fordiana are arranged in 3 whorls with the number of 3. Tepals of Manglietia chingii are arranged in 4 whorls, and degenerative tepals in the fourth whorl can be observed frequently. Stamens and carpels of Manglietiafordiana and Manglietia chingii all arise spirally and in acropetal succession.