福建九龙江口桐花树叶片的盐腺系统

STUDY ON LEAF SALT-GLANDS OF AEGICERAS CORNICULATUM IN JIULONG ESTUARY,FUJIAN

本文选用九龙江口沿岸红树林中桐花树的成熟叶片作材料,以徒手切片、石蜡切片和透射电镜进行观察,结果表明:盐腺系统包括5个部分,从叶肉向叶表排列是:收集细胞;基细胞;分泌细胞;收集室;盐腺盖。盐腺分泌细胞的结构特征:从叶片纵切面看,分泌细胞是一层长柱形细胞;从其平周切面看,则是个椭圆形的细胞群;在其短轴上,呈二列细胞,而其长轴则为一列由几个至20余个甚至达42个细胞并排而成的两列环,这现象属首次发现。宽向与狭向细胞排列可能与叶小脉输送从维管束来的盐分方向有关。单位面积盐腺系统数目和盐腺系统中分泌细胞数目均随土壤盐度的增加而增加,气孔数目则相反。

The leaves of adult Aegiceas corniculatum,which is from some mangrove stands on the coast at Jiulong Estuary near Xiamen,were observed with general bare-handed section,paraffin section and transmission eletron microscope.The results are as follows:A salt-gland system consists of five parts.Their arrangement from mesophyll to leaf surface is in the following order:1.collecting cell;2.basal cell;3.secreting cell;4.collective chamber;5.cuticle sheath of the salt gland.The structural features of secreting cells of the salt gland of Aegiceras corniculatum are such as below;1.The secreting cell is a layer of long cylindrical cells in the cross section of a leaf.2.In the paradermal secteion of leaf,the secreting cells is a long elliptical celluar group;On the short axis,it consists of two rows of cells,and on the long axis,it is an elliptical annulation which consists of several to twenty cells,even to fortytwo cells,in two lines.This phenomenon was first discovered.Arrangement of cell on both long and short axises of a salt gland relates possibly to direction of transports of salt solution by a voinlet from vein.When the soil salinity rises,the numbers of salt gland at a unit area at the leaf surface and of secreting cell in a salt gland increase;In contrast,the amount of stomata at a unit area of loaf surface decreases.