Heterogeneity of the white truffle Tuber magnatum in a limited geographic area of Central-Southern Italy

Molise region (Central-Southern Italy) is one of theItalian richest areas of truffles and contributes significantlyto the national production of the preciousTuber magnatum. Nevertheless, Molise truffle hasreceived little scientific attention. Accordingly, in thepresent study, two T. magnatum populations collectedin two different sites of Molise region werecharacterised from a morphological, genetic andmicrobiological point of view. A considerable variabilitybetween and within the two analysed groupsemerged, suggesting an interesting heterogeneity ofMolise white truffle populations. Ascocarps of thetwo groups significantly differed in size and maturationdegree, although no linear correlation betweenweight and maturity was found. Genetic investigationsfocused on the Sequence-Characterised AmplifiedRegion SCAR A21-inf. Three haplotypes,randomly distributed within the two truffle groupsregardless of their collection sites, were detected.The 16S rRNA gene amplicon high-throughputsequencing provided an overview of the compositionof the ascocarp-associated bacterial communities. Apredominance of ?-Proteobacteria was observed,with Bradyrhizobium among the main genera. However,some truffles showed unusual microbial profiles,with Pedobacter, Polaromonas and otherbacterial genera as dominant taxa.