Synthesis and establishment of Tuber melanosporum Vitt. ectomycorrhizae on two Nothofagus species in Chile

Axenically germinated seedlings of two species of Southern beech (Nothofagus obliqua, N. glauca) from Chile were inoculated with spores of the Périgord black truffle (Tuber melanosporum). Ectomycorrhizal development was monitored for 6 months in the greenhouse and compared to the performance of the natural host species Quercus ilex and Quercus robur. Seedling survival and mycorrhization showed major differences in both Nothofagus species: T. melanosporum readily formed ectomycorrhizae with seedlings of N. obliqua, although at a lower rate than with Q. ilex but at a proportion very similar to Q. robur; survival and colonization rates were high, and seedling growth was not visibly affected by the high soil pH required by T. melanosporum. In contrast, more than 50% of N. glauca seedlings died after inoculation, and mycorrhiza formation was very sparse. In both species, no colonization by adventive ectomycorrhizal fungi could be observed, whereas both species of Quercus showed minor colonization by another fungus, probably Inocybe or Hebeloma. Our results show that it is possible to infect N. obliqua with the Périgord black truffle under greenhouse conditions, which opens up the possibility of cultivating this truffle as a secondary crop during reforestation with N. obliqua in Chile.