商陆属2种植物花器官发生过程观察

摘要

该研究采用扫描电镜观察红蕊商陆(Phytolacca esculenta)和浙江商陆(Phytolacca zhejiangensis)的花器官发生过程,以明确商陆属植物花的基数,以及雄蕊和雌蕊是否具有叶性器官发生的特点,阐明商陆属植物花发生的模式.观察结果显示:(1)红蕊商陆和浙江商陆在花原基发生后,小苞片以2/5圆周相继发生,花被片的发生紧接小苞片的发生进行,花被与小苞片的发生均有顺时针和逆时针方向,且二者的发生方向始终一致.(2)花被发生结束后,雄蕊在花顶端分生组织的环状分生组织上发生,没有明显的发生顺序,近似同时发生;2轮雄蕊时内轮雄蕊先发生;外轮雄蕊有少数有时偶然与花被互生,但因外轮雄蕊数多于花被数,雄蕊与花被常不互生,也没有规律性.(3)红蕊商陆和浙江商陆的心皮都在雄蕊发生后,紧接着开始发生,且雌蕊与雄蕊(或内轮雄蕊)互生发生;心皮没有发生的先后次序,且每个心皮在基部连成一个整体形成雌蕊基部并发育成为子房.(4)红蕊商陆和浙江商陆的花基数为5,雄蕊和雌蕊的发生及数目不符合5基数的特点.研究认为,红蕊商陆和浙江商陆为5基数花,该研究结果不支持商陆属植物为3基数花的发生模式.%This paper used SEM to observe the flower organ ontogeny process,in order to know the flower base number of Phytolacca and whether or not its stamen and pistil derived from leave,than to clarify the model of Phytolacca flower ontogeny.The results show that:(1) after flower primordia initiated,two bractlets of two species initiated one by one.Than the perianths initiated one by one,the bractlets and perianths initiated can be clockwise or counterclockwise,and they are with the same direction.They all initiated by 2/5 circumference spiral.(2) When the perianths had initiated over,the stamens initiated on ring meristem of flower top meristem,and the stamens ontogeny almost at same time,and there is no any order;and while the flower has two rounds of stamen,the inner round first initiate,in some time,the out stamen alternate with perianths,out round stamens also did not opposite to perianths.(3) Carpels of two species initiate alternate with stamen (or inner stamen),and carpel initiates almost at same time,no order.Phytolacca flower is 5 base number flower,but the stamen and carpel were not fit with 5 base number,because they all initiated on ring meristem.(4) The flower of Phytolacca ontogeny is no any relation with 3 base number flower.When stamens are multi-round,the out round initiate lately.At the end,the flower of Phytolacca is 5 base number,and the results did not support the flower of Phytolacca is 3 base number ontogeny model.