Translocation of 32P between wood resources recently colonised by mycelial cord systems of Phanerochaete velutina
The basidiomycete fungus Phanerochaete velutina was inoculated centrally into trays of compressed, non-sterile woodland soil on precolonised 1 cm3 beech wood blocks. Mycelial systems developed from this and colonised two ‘baits’ (wood blocks or inert plastic controls), one on either side of the inoculum block. 32P-orthophosphate was supplied to a bait and its appearance in the other bait was monitored non-destructively with time, and destructively by liquid scintillation counting 60 or 70 days after addition of the radioisotope. Phosphorus was taken up by the first bait, translocated back to the inoculum block and onwards to the second bait. When the second bait was added 10 days after the first, translocation to the former was much more rapid indicating a large demand for phosphorus during early stages of colonisation. The size of the bait to which the 32P was added appeared to determine the amount taken up by the whole system, and the size of the second bait determined how much 32P was translocated to it. Decayed and/or small baits had less demand for phosphorous. The ecological relevance of these findings is discussed.