不同生境下榕树叶片形态观察

Leaf Morphology of Ficus microcarpa in Different Environments

关键词:  榕树  叶片  形态  解剖结构  环境污染

Key words:  Ficus microcarpa  leaf  morphology  dissecting structure  environmental pollution

摘要:

为了探讨环境污染对植物叶片的影响,于2000年11月19日15:30,同时在广州市区内的水泥厂、硫酸化工厂、麓湖、白云山、环市路,采集榕树南向树冠的外展枝条上成熟的叶片10片,观察叶片的主要形态和解剖结构。结果显示:水泥厂、硫酸化工厂种植的榕树的叶片较薄,短且窄,叶片的二级脉间距较窄;而白云山、麓湖生长的榕树的叶片厚、长且宽,各级叶脉较粗,二级脉间距宽。5个点的叶片均有3层细胞组成的上表皮,但水泥厂、硫酸化工厂采集的叶片表皮层占叶片的总厚度增加,细胞壁增厚,栅栏薄壁组织细胞的纵向直径与横向直径的比值增加,栅栏薄壁组织占叶片总厚度的百分比上升,在海绵薄壁组织中出现非胞间隙的圆形穿孔。玻璃幕墙形成的强光反射长时间对榕树照射也造成叶片的机械组织发达、而海绵组织不甚发达。较强的二次光源对植物产生影响。

Abstract:

To probe into the effect of environmental pollution on leaf morphology of plants, ten matured leaves on the abducent twigs in the southward of crown of Ficus microcarpa were collected on each one of five spots in Guangzhou city,south China at the same time on Nov. 11th 2000. The five spots are a cement mill,a viltiol plant, Luhu(lake),Baiyunshan(mountain),city bypass. The leaves are found thin,short,narrow and having small space between the secondary veins in the cement mill and vitriol plant,and inverse in Baiyunshan and Luhu. All leaves from five spots have an upper epidermis composed of three layers of cells. Compared to other three spots,the leaves from the cement mill and vitriol plant are thicker in epidermis and cell wall,and have higher aspect ratio of palisade parenchymam cells, and higher proportion of palisade parenchyma to leaf thickness;some round holes which are not cell intervals are found in spongy parenchyma Long time lighting of strong light reflecting from glass wall of buildings could lead to upgrowth of mechanical parenchyma,and downgrowth of spongy parenchyma. The strong secondary source lighting also affects growth of plants.