乌桕乳汁管的产生及乳汁的分泌与植物体地上部分生长的关系

乌桕的乳汁管是由顶端分生组织产生并且是无节的,在茎内的乳汁管是不分枝的,而在叶片中的可以形成分枝。 乌桕乳汁管仅产生于当年生的幼枝近上端和叶片以及花序轴和幼果柄内。随着叶面积的增加,乳汁量也相应加多,以后随着叶片的逐渐老化,其乳汁量也相应减少,最后停止分泌乳汁。当花序轴分化形成花的过程中,乳汁则在轴中形成,这时在茎中乳汁减少。雌蕊受精后果柄生长,乳汁则出现在果柄中。如果有的当年生枝顶端不产生花序,那么乳汁可一直保持在枝的上端产生,直到叶枯黄为止。

The relationship between development of laticifer,production of latex and growth of above-ground part of Sapium sebiferum (Linn.) Roxb.

The laticifers of Sapium sebiferum (Linn.) Roxb. are non-articulated ones, which are differentiated from apical meristem. Both simple and branched laticifers existed, with fomer in the stem and latter in the leaf. The latex of S. sebiferum is only produced in the near apex of annual young shoots, leaves, floral axes and fruit stalks. The amount of latex in leaves will increase as the leaf area enlarges, then slowly reduce with the leaves aging. But the place latex produced will still be in the apex of young shoots. With the differentiation and growth of floral axis, latex will also be produced in the axis, but the amount in shoots will reduce at the same time. After pistil is fertilized and fruit stalk developes, latex will apear in the stalk. But if no infloressence is formed in the apex of annual shoots, the latex will keed on producing in the apex until the leaves wither.