Effects of Leaf Morphological and Chemical Properties on the Population Sizes of Epiphytes

To explore the main factors affecting the distribution of microbes on leaf surfaces, the relationship between population sizes of epiphytes and the morphological structure and main physical and chemical properties of leaves from stylo (Stylosanthes guianensis), alfalfa (Medicago sativa), maize (Zea mays), and cocksfoot (Dactylis glomerata) were investigated. The research results showed that the contents of soluble sugar and total phenolics on the leaf surfaces were positively correlated with those in the leaf tissues (P < 0.001). The leaves with high wax content had better moisture retention capacity. The content of soluble sugar on the leaf surfaces was positively correlated with population sizes of lactic acid bacteria (LAB), aerobic bacteria, yeasts, and molds (P < 0.001). Likewise, a positive correlation was found between the content of inorganic phosphorus on the leaf surfaces and population sizes of LAB and aerobic bacteria. The total amount of wax on leaf surfaces was negatively related to population sizes of microbes, especially aerobic bacteria (P < 0.01) and molds (P < 0.001). On the contrary, the presence of trichomes provides a shelter for epiphytes and was positively correlated with population sizes of epiphytes at different degrees of significance. In conclusion, population sizes of epiphytes on the leaf surfaces were not only affected by chemical properties, but also by morphological traits of leaves.