Leaf Surface Wax Research Articles

Ecotypic variation in Eucalyptus viminalis Labill. I. Leaf surface waxes, a temperature × origin interaction

Electron microscopic evidence is presented to show that leaf surface waxes from three ecotypes of Eucalyptus viminalis Labill. react differently to temperature. Density of wax rodlet coverage on juvenile leaves declined markedly over the temperature range 18-33°C for two of the ecotypes while the third showed only a gradual decline. A differential response to temperature was also noted with regard to wax rodlet morphology. Possible explanations for ecotypic differences are discussed.

Leaf Surface of Beta vulgaris-Electron Microscope Study

The waxy surface of the epidermis of table-beet leaves has been examined with the light and electron microscopes. On very young leaf surfaces, wax occurs in the form of stubby rodlets. As cells enlarge during leaf growth, extrusion of the rodlets continues and they coalesce to form plaques. In young-mature, non-stomatal cells, a central wax plaque is surrounded by peripheral rodlets. By full maturity the entire cell surface is covered. As the extrusion rate slows in aging leaves, the waxy surface becomes flatter and smoother. The surface wax dissolves in chloroform or other wax solvents. After exposure of plants to polluted air containing solar-irradiated auto exhaust (smog), morphological changes occur in the leaf surface wax. These changes may be related to differences in the rate of wax rodlet extrusion. The wounding caused by feeding aphids results in a different surface pattern.