Diversity of fungi on wild fruits in Hong Kong

Abstract

Eighteen species of wild fruits were examined for fruit-decaying fungi in nature. Surface-sterilized and non-sterilized fruits were incubated for 1-4 weeks and the fruiting bodies were identified. A total of 540 samples and 495 microfungi from 102 taxa were identified. Colletotrichum and Phomopsis were the most frequently recorded fungal genera. Ilex cinerea had the most diverse fungal species, while Wikstroemia nutans had the lowest diversity. Fifty-eight percent of fungal genera found in this survey have not been recorded on cultivated fruits. The fungal community that developed on non-sterilized fruits after incubation was generally more diverse than on surface-sterilized fruits, but both were colonized mostly by non-specific fungi. Related fruit species did not, in general, have more similar fungal communities than unrelated species. The ability of detached fruits to resist fungal infection under incubation varied greatly, with 77% of fruits of Wikstroemia nutans still not infected after 4 weeks. Fungi were classified into three types: pathogens, latent opportunists and fast-colonizing opportunists. Fast-colonizing opportunists, such as Cladosporium, Fusarium and Penicillium, were the most important taxa on wild fruits.