Utilisation of organic nitrogen and phosphorus sources by mycorrhizal endophytes of Woollsia pungens (Cav.) F. Muell. (Epacridaceae)

Abstract

The ability of four ericoid mycorrhizal endophytes isolated from roots of Woollsia pungens (Cav.) F. Muell. (Epacridaceae) to utilise organic forms of nitrogen and phosphorus during growth in axenic culture was assessed. All isolates were able to utilise glutamine, arginine and bovine serum albumin (BSA), along with NH4 + or NO3 –, in most cases yielding at least as much biomass as the ericoid mycorrhizal endophyte Hymenoscyphus ericae (Read) Korf & Kernan. All isolated endophytes were able to utilise BSA, arginine and glutamine as sole sources of N and C. With the exception of a single isolate (C40), which showed little growth on glutamine, biomass yields on glutamine as the sole N and C source was significantly greater for all isolates than on either of the other two organic N sources. Two isolates from W. pungens (C40 and A43) utilised DNA and sodium inositol hexaphosphate as sole P sources, in each case yielding significantly more biomass than H. ericae. The results suggest that mycorrhizal endophytes from epacrid plant hosts and those from ericaceous hosts have similar abilities to utilise organic forms of N and P.