Abstract
Many methods have been used to study phylloplane fungi, most of which have constraints and may result in biased results. This study used light microscopy and scanning electron microscopy (SEM) to investigate fungal abundance on the leaves of the most common mangrove trees in Hong Kong, Kandelia candel and Aegiceras corniculatum. Species richness was investigated using light microscopy and a leaf washing method. Methods to study phylloplane fungi are discussed and the performances of these three investigation methods are evaluated. Seven mitosporic fungal taxa were found by light microscopy, while 30 sporulating taxa and 18 Mycelia sterilia were isolated using the leaf washing method. Fungal abundance in terms of percentage cover investigated with light microscopy was similar using the SEM method, and was significantly higher on Aegiceras corniculatum than on Kandelia candel. Fungal abundance peaked in the summer and was lowest in the winter. This study indicates that light microscopy reveals the most typical phylloplane fungi and is more efficient than SEM, while the leaf washing method reveals many casual species and is not quantitative.
Dr. Gray A. Williams of the Department of Ecology & Biodiversity, The University of Hong Kong, is thanked for comment on the experimental design and the manuscript. Ms Helen Leung (DEB) and Mr. W. S. Lee of Electron Microscope Unit, HKU, are thanked for technical support. O. H. K. Lee acknowledges The University of Hong Kong for the award of a Postgraduate Studentship.