Determination of the peridium thickness of Tuber magnatum ascomata from Molise region

Several studies focused on Tuber magnatum, the most valuable truffle species, with a limited geographical distribution. However, no comprehensive information on the thickness of its peridium (the external surface of fruiting bodies) is available. Accordingly, to fill this lack of information and in order to provide a more in-depth morphological characterisation of white truffle populations from Molise region (one of the Italian richest areas of truffles), the peridium thickness of twenty-one T. magnatum ascomata collected from two different study sites was measured by light microscope observations. A considerable variability within the analysed populations emerged, with values ranging from 271.25 μm (minimum) to 1231.25 μm (maximum), and an average peridium thickness of 622.33 μm. Interestingly, significant differences were observed between the two groups, with truffles harvested in an inner area of the region showing a peridium significantly thinner than those collected on the border with Abruzzo region. No linear correlation between peridium thickness and other morphological parameters (ascoma weight and maturity) emerged. It is likely that the differences observed between the two T. magnatum populations could be related to factors such as soil characteristics, site-specific features, genetic traits, as well as truffle collection period, which should be properly investigated.