Influence of pH on in vitro mycelial growth in three Japanese truffle species: Tuber japonicum, T. himalayense, and T. longispinosum

Truffle species indigenous to Japan include a white-colored truffle Tuber japonicum and two black-colored truffles, T. himalayense and T. longispinosum. As the fruiting bodies of these Tuber species are promising edible, studies on the artificial cultivation for these truffles are currently underway in Japan. In the present study, we investigated the influence of pH on in vitro mycelial growth in these Tuber species to determine the optimal pH conditions for the cultivation of these truffles. Mycelia of five strains from each species were cultured in modified Melin–Norkrans liquid medium at different pH values. Tuber japonicum grew well at pH 5.0 and 6.0, whereas T. himalayense and T. longispinosum grew well at pH 7.0. This results suggest that the optimal pH for mycelial growth varies among Tuber species. The growth data collected in this study can be used to design optimal pH conditions for artificial cultivation of these Japanese truffles.