Assessment of β-tubulin gene as a complementary molecular marker for desert truffle identification: a study case on Tunisian samples

Abstract

Tunisian desert truffles have been identified on the basis of the internal transcribed spacer (ITS) locus as Tirmania nivea, Terfezia bouderii and T. arenaria. ITS and, for the first time, β-tubulin gene were employed in the phylogenetic analyses of these species to assess whether β-tubulin gene could be a complementary molecular tool for resolution of phylogenetic species. From their comparison, both markers showed to be suitable to distinguish Tirmania nivea from Terfezia bouderii and T. arenaria and, focusing on the T. boudieri complex, to assign the phylogenetic types previously described. In addition to give a first glimpse into the distribution of desert truffles from north to south of Tunisia, we then suggest to use the β-tubulin gene as a complementary marker to ITS. This indication can be useful above all for the phylogenetic reconstruction of the T. boudieri complex.

Keywords:

• Desert truffles
• ITS
• β-tubulin gene
• phylogenetic analysis
• molecular markers

Acknowledgements

We thank Carla Ferraris for her help in the material preparation for molecular analysis, Fabiano Sillo for the map preparation and Alfredo Vizzini for microscopic examination and advice for interpretation of phylogenetic trees.