RT Journal Article SR Electronic T1 Investigation of the sexual reproduction strategy of the Périgord black truffle (Tuber melanosporum Vittad.) revealed trioecy JF bioRxiv FD Cold Spring Harbor Laboratory SP 073650 DO 10.1101/073650 A1 Herminia De la Varga A1 François Le Tacon A1 Mélanie Lagoguet A1 Flora Todesco A1 Torda Varga A1 Igor Miquel A1 Dominique Barry-Etienne A1 Christophe Robin A1 Fabien Halkett A1 Francis Martin A1 Claude Murat YR 2016 UL http://biorxiv.org/content/early/2016/09/06/073650.abstract AB Fungi display a rich variety of sexual reproduction systems and are therefore good models to investigate sex evolution. Moreover, understanding the investment in sexual reproduction of edible fungi is a critical challenge for improving their cultivation. The Périgord black truffle (Tuber melanosporum Vittad.) is a heterothallic ascomycete associated with trees through ectomycorrhizas and forming highly prized ascocarps. The aim of this study was to unravel the sexual reproduction strategy (hermaphroditic versus male/female specialization) of T. melanosporum in a truffle orchard by disentangling the contribution of female and male genotypes to the formation of ascocarps in a five-year investigation. Few genotypes were hermaphrodites, co-occurring with numerous genotypes behaving only as female or male, revealing trioecy. The genetic diversity of the male genotypes was higher than female diversity, suggesting for male elements a higher recruitment from ascospores. Most of the female and male genotypes were transitory (present only one year), whereas some genotypes persisted for several years: female-fertile genotypes as mycorrhizas, and male-fertile genotypes as soil free-living mycelium. Contrary to other ascomycetes, a high number of female-fertile only genotypes was found. We hypothesized that the mycorrhizal life style favours female-fertile strains and therefore that the life strategy influences fungal sexual strategy.