TRANSLOCATION OF P-32 BETWEEN WOOD RESOURCES RECENTLY COLONIZED BY MYCELIAL CORD SYSTEMS OF PHANEROCHAETE VELUTINA

The basidiomycete fungus Phanerochaete velutina was inoculated central ly into trays of compressed, non-sterile woodland soil on precolonised 1 cm(3) beech wood blocks. Mycelial systems developed from this and c olonised two 'baits' (wood blocks or inert plastic controls), one on e ither side of the inoculum block. P-32-orthophosphate was supplied to a bait and its appearance in the other bait was monitored non-destruct ively with time, and destructively by liquid scintillation counting 60 or 70 days after addition of the radioisotope. Phosphorus was taken u p by the first bait, translocated back to the inoculum block and onwar ds to the second bait. When the second bait was added 10 days after th e first, translocation to the former was much more rapid indicating a large demand for phosphorus during early stages of colonisation. The s ize of the bait to which the P-32 was added appeared to determine the amount taken up by the whole system, and the size of the second bait d etermined how much P-32 was translocated to it. Decayed and/or small b aits had less demand for phosphorous. The ecological relevance of thes e findings is discussed.