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Poster: Biology & Disease Mgmt: Biological Control


Fungal antagonism of bacteria isolated from Cultivated and Wild Cranberry Bogs
S. SOBY (1), G. Ebadzad (1), E. Batory (1) (1) Midwestern University, U.S.A.

Natural environments are characterized by a relative equilibrium that can be brought into disequilibrium by the introduction of agricultural plants. Both natural and agronomic systems should thus contain microbes that contribute to system equilibria by suppressing parasitic organisms. However, few biological niches have been systematically explored for biological control agents. Cranberry bogs in southeastern Massachusetts are a good model system for these studies because of the genetic similarity between wild and domesticated cranberry plants, and their location in the same geographic region. Soil and plant samples were collected from wild and cultivated bogs over several growing seasons to determine the microbial composition of cranberry bogs. 68 bacterial isolates were assessed for in vitro inhibition of the pathogenic fungi, Phomopsis sp., Colletotrichum sp., and Coleophoma sp. isolated from cranberry, as well as Trichoderma sp. Individual isolates varied in antifungal ability within and between fungi. Bacillus spp. were most antagonistic to these fungi, but several other bacterial genera were active against one or more of the fungi as well. In a preliminary assessment, 82% of the chosen bacterial isolates had activity against Phomopsis, 44% against Colletotrichum, 63% against Coleophoma, and 19% against Trichoderma. These results suggest that bog soils and plants harbor a large number of candidates for development as biological control agents in agriculture.