Surveying Mosses for Fungicidal Activity

Abstract

The emergence of resistance to current fungicides is of serious concern because of the widespread diseases caused by fungi. One way to combat this problem is to discover new compounds that have antifungal properties. Plants are extensively attacked by fungi and many have evolved defenses, including fungicides and other compounds, such as a waxy cuticle, that make attack difficult. The mosses (Bryophyta) lack a cuticle. This makes them a likely group to survey for fungicidal activity because they may have additional chemical defenses. In this study, we made aqueous and ethanolic extracts from crushed mosses and tested their effect on the growth of the yeast Saccharomyces cerevisiae. These mosses were collected across a broad geographical range (locally, from Arkansas, and from Alaska) to test the hypothesis that resistance to fungal attack may correlate with the general suitability for fungal growth of the environment. Results include the demonstration of fungicidal activity in some, but not most, of the mosses. There was no correlation with geographical origin. Both solvents seem able to extract compounds that will suppress yeast growth. In addition, re-tests of some samples suggest that fungicidal properties may be lost during drying. Several of the mosses show strong enough antifungal activity that further investigation seems warranted.