Fine‐scale spatial genetic structure of the black truffle (<i>Tuber melanosporum</i>) investigated with neutral microsatellites and functional mating type genes

<jats:title>Summary</jats:title><jats:p> <jats:list list-type="bullet"> <jats:list-item><jats:p>The genetic structure of ectomycorrhizal (<jats:styled-content style="fixed-case">ECM</jats:styled-content>) fungal populations results from both vegetative and sexual propagation. In this study, we have analysed the spatial genetic structure of <jats:italic>Tuber melanosporum</jats:italic> populations, a heterothallic ascomycete that produces edible fruit bodies.</jats:p></jats:list-item> <jats:list-item><jats:p>Ectomycorrhizas from oaks and hazels from two orchards were mapped and genotyped using simple sequence repeat markers and the mating type locus. The distribution of the two <jats:italic>T. melanosporum</jats:italic> mating types was also monitored in the soil. In one orchard, the genetic profiles of the ascocarps were compared with those of the underlying mycorrhizas.</jats:p></jats:list-item> <jats:list-item><jats:p>A pronounced spatial genetic structure was found. The maximum genet sizes were 2.35 and 4.70 m in the two orchards, with most manifesting a size < 1 m. Few genets persisted throughout two seasons. A nonrandom distribution pattern of the <jats:italic>T. melanosporum</jats:italic> was observed, resulting in field patches colonized by genets that shared the same mating types.</jats:p></jats:list-item> <jats:list-item><jats:p>Our findings suggest that competition occurs between genets and provide basic information on <jats:italic>T. melanosporum</jats:italic> propagation patterns that are relevant for the management of productive truffle orchards.</jats:p></jats:list-item> </jats:list> </jats:p>