Methods to Observe Leaf Epicuticular Wax Layer of Trees

Leaf surface of almost all plants is covered by epicuticular wax layer. This layer protects the interior parts of leaves against environmental conditions. Destruction of this layer due to environmental factors or atmospheric pollutants will change the amount of wettability of plant leaves. Therefore, this research investigates methods for observing epicuticular wax layer of plant’s leaves via scanning electron microscopy (SEM), measurement of leaf wettability, and measurement of epicuticular wax amount. Three species (Sambucus nigra L., Acer Pseudoplatanus L. and Quercus robur L.) were selected for this purpose. The results showed that observing epicuticular wax layer via SEM is precise but is very expensive, time-consuming and is practically difficult to do in large scale. The presence of epicuticular wax layer can be estimated by measuring the epicuticular wax amount, but this method is not able to estimate the changes of wax on leaf surface. While, by measuring the leaf wettability via measuring drop contact angle it is possible to estimate the changes on the leaf surface. Moreover, this research has shown that leaves with similar epicuticular wax structure have similar wettability. As a result of this research, among mentioned methods, measuring leaf wettability via drop contact angle is introduced as an easy, reliable, fast, and inexpensive method for observing epicuticular wax layer.