Effect of soil properties and vegetation characteristics in determining the frequency of Burgundy truffle fruiting bodies in Southern Poland

Virtual Truffle Hunting—A New Method of Burgundy Truffle (Tuber aestivum Vittad.) Site Typing

The aim of this study was to enable searches for truffles (Tuber spp.), particularly the Burgundy truffle (T. aestivum Vittad.), to be carried out in forests based on a method that has been constantly developed since 2007 by the Forest Research Institute. The method is termed “Virtual Truffle Hunting” and it takes 12 parameters into account: bedrock, soil pH, Ca+ and CaCO3 content in soil, C/N ratio, soil structure, altitude of terrain, type of forest site, forest structure, the Burgundy truffle host trees, and the presence of particular species including orchids and insects. A simple “Virtual Truffle Hunting” software has also been developed, which makes the use of the method easy, fast, and effective. This method is to ascertain the truffle potential for all areas in which digital maps are not available. In 2015, the method was tested in 20 sites, representing forests in 5 Polish macroregions. Hunting for hypogeous fungi was conducted from June to October with the help of trained dogs. Thanks to this method, 14 new truffle sites were found. The knowledge of environmental conditions conducive to the Burgundy truffle growth enabled us to form an effective tool in order to identify new sites of truffle presence.

Frequency of the two mating types in the soil under productive and non-productive trees in five French orchards of the Périgord black truffle (Tuber melanosporum Vittad.)

The Périgord black truffle (Tuber melanosporum Vittad.) is an ectomycorrhizal fungus forming edible fructifications. The production of T. melanosporum relies mainly on man-made plantations. T. melanosporum is a heterothallic species requiring the meeting of two partners of opposite mating types to fruit. It is common to have productive and non-productive trees in the same orchard. The aim of our study was to assess the distribution of T. melanosporum mating types in soil under productive and non-productive trees to test whether the presence or absence of one or two mating types could be an indicator of productivity. To achieve this aim, five orchards were selected in various French regions. Soils were harvested under productive and non-productive Quercus pubescens; soil characteristics and the distribution of the mating types in the soil were investigated. No significant differences between productive and non-productive soils according to soil parameters were detected. The total content of T. melanosporum DNA in the soil was significantly higher under productive trees compared with non-productive trees, and it was positively correlated only with soil available phosphorous. Under productive trees, it was more frequent to find both mating types than under non-productive trees. Soils with only one mating type were more frequent under non-productive trees than under productive ones. Moreover, no mating type was detected in the soil of 22% of the non-productive trees. These results suggest that the detection of T. melanosporum mating types in soil could be a tool to optimise the management of truffle orchards (e.g. by spore inoculation).