Evidence of in situ competition between fungi in freshwater

Abstract

Five species of fungi, isolated from submerged wood collected from a Brunei peat swamp forest, were tested for their competitive ability. Annulatascus velatisporus, Beverwykella pulmonaria, Dactylella sp., Monodictys pelagica and Pleurophragmium sp. were paired in all possible combinations on wood and agar in the laboratory. In addition, autoclaved wood blocks were inoculated with these isolates and placed back into water in the peat swamp forest. On agar, there was a competitive hierarchy of Dactylella sp. > Pleurophragmium sp. > A. velatisporus > B. pulmonaria > M. pelagica. In the inoculated blocks exposed in the peat swamp forest however, M. pelagica, A. velatisporus and B. pulmonaria were the only species to significantly reduce the colonisation of other fungi, showing a strong disparity between field and laboratory results. Laboratory studies on wood revealed that A. velatisporus reduced the reproductive capability of other fungi. This study demonstrates the influence of interspecific competition in fungal colonisation of submerged wood.