Endophytic fungi in evergreen shrubs in western Oregon: A preliminary study

Abstract

Endophytic fungi were isolated from five species of broad-leaved evergreen shrubs from 16 sites in western Oregon. Rates of infection were 76% for Mahonia nervosa, 44% for Arctostaphylos uva-ursi, 37% for Gaultheria shallon, 29% for Mahonia aquifolium, and 25% for Umbellularia californica. Incidence of leaf infections by more than one fungal taxon was 20–56%, 72–90% of which had only two infections. Rates of overall infection were higher in samples taken from densely wooded sites than in samples taken from more open sites. A pattern of species dominance is seen where the most common endophyte of a given host is isolated less frequently from other hosts; less commonly isolated endophytes appear to be less host specific. The most commonly isolated endophytes include Phyllosticta pyrolae on A. uva-ursi and G. shallon, Leptothyrium berberidis on M. nervosa, Septogloeum sp. on M. nervosa and U. californica, and Phomopsis sp., predominantly on M. aquifolium, but present on all hosts. Some of the fungi isolated from evergreen shrubs in this study were previously isolated from conifer needles; however, most represent new records.