Molecular Biology and Innovative Bacterial Application to Understanding Truffle Ecosystem Dynamics

Truffles are edible ectomycorrhizal fungi of the Tuber genus with considerable economic value. Studying valuable Tuber species is essential not only for their commercial potential but also to understand the little-known aspects of their biology. Today, climate changes and anthropogenic activities strongly affect forest natural production. Consequently, most truffles harvested worldwide are now produced in orchards, where seedlings are inoculated under controlled nursery conditions. Truffles play a central role in the agro-economy of the Marche region. This region boasts diverse natural habitats that provide ideal growing conditions for various truffle species, including the prized white truffle (Tuber magnatum) and the black truffle (Tuber melanosporum). In addition, truffle cultivation represents a significant economic activity in the Marche region, particularly in marginal areas with limited agricultural opportunities. The “Angellozzi Tartuficoltura” is a family company that has refined the knowledge and improved techniques for truffle cultivation, significantly contributing to the richness and uniqueness of the truffle industry in the region. “Angellozzi Tartuficoltura” partnered in this research thesis, which was funded by the Marche Region under the “Progetto di Dottorato Innovativo a caratterizzazione industriale” (POR Marche- FSE 2014/2020). The thesis aims to understand the truffle ecosystem, involving microbiology, botany, ecological-forestry, and molecular biology. The research leads to finding new strategies to improve and increase the production of natural truffle ground or truffle orchards. The strategy proposed consists in the use of bacteria, that take part in the symbiotic relationship between truffles and plants. Numerous studies have revealed their potential roles in affecting the aroma and fitness of the plant, promoting plant and mycelium growth, protecting against pathogens, fixing nitrogen, and modulating spore germination and hyphal growth. The research was conducted in the nursery and the field. We analyzed the effects of Pseudomonas spp. and Bradyrhizobium spp. on stimulating the mycorrhization process and the quality of Quercus ilex seedlings mycorrhized with T. melanosporum. Additionally, we evaluated the influence of Bradyrhizobium japonicum on the quantity of T. magnatum mycelia in the soil of a natural truffle ground in Sant’Angelo in Vado (PU). These findings could provide useful insights for developing innovative cultivation strategies using bacterial inoculation in greenhouses and fields, thereby supporting the regional economy by improving truffle production.