海韭菜的花器官发生

Floral Organogenesis of Triglochin maritimum Linn. (Juncaginaceae)

运用扫描电镜(SEM)观察了海韭菜(Triglochin maritimum)的花器官发生发育过程。结果表明:海韭菜花发育是典型的单子叶植物发生模式,即两轮花被片、两轮雄蕊和两轮心皮以三基数轮状交替发生,花器官是以向心向顶的方式发生的,未发现"花被片—雄蕊复合原基"。发育后期雄蕊和与之对生的花被片之间的共同基部可能是相继向上居间生长的结果。花被片轮和雄蕊轮二者之间在发育位置、时间和速率上存在差异,内轮花被片原基和外轮雄蕊原基的不同发育时间和发育速度使得在成熟花中内轮花被片位于外轮雄蕊的内方。观察结果不支持水麦冬属植物的花是退化(或压缩)的花序侧分枝等假花的观点。

The floral organogenesis of Triglochin maritimum Linn. was observed under scannning electron microscope （SEM）. Floral development of T. maritimum consists of the sequential initiation of alternating, trimerous whorls of floral appendages in centripetal and aeropetal succession ： two whorls of tepals, two of stamens, and two of carpels in the typical monocotyledonous pattern. Our observation did not find an association of the tepal and stamen primordia （ the ＂CA complex＂ ）. The common base of the stamen and its opposing tepal in later stage maybe a result of subsequent intercarary upgrowth, which is secondary result. There are differences in position, timing and rates of development between whorl of tepals and stamens. Differential timing and rates of growth of the inner tepals and outer stamens result in the former appearing to be located internal to the latter in the mature flower. In the late stage of floral development, we observed the decreasing ease of the number of carpel. It seems that the present observation of T. maritimum does not support the interpretation of the flower of Triglochin as a reduced lateral branch of the inflorescence, though a more detailed study would be requried to confirm this.