PCR primers specific for the genus Tuber reveal the presence of several truffle species in a truffle-ground

摘要

Truffles are hypogeous Ascomycete fungi belonging to the genus Tuber and forming fruiting bodies highly prized for their taste and aroma. The identification of the genus Tuber and its species is important to investigate their ecology and avoid fraud in the food market. As genus-specific primers are not available, the aims of this work were (1) to assess the usefulness of the beta-tubulin gene as a DNA barcoding region for designing Tuber genus-specific primers, (2) to test the primers on a range of fruiting bodies, representing a large part of truffle biodiversity and (3) to check their ecological usefulness, applying them to truffle-ground soil. The new primers designed on the b-tubulin gene were specific to the Tuber genus in nested PCR. When applied to DNA from soils, they gave a positive signal for 23 of 32 soils. Phylogenetic analysis confirmed that the bands corresponded to Tuber and that at least five Tuber species were present in the truffle-ground. b-tubulin was found to be a good barcoding region for designing Tuber genus-specific primers, detecting a high Tuber diversity in a natural environment. These primers will be useful for understanding truffle ecology and for practical needs in plantation management.