Development of edible desert truffles as new crops in Israel: characterization of morphology, molecular markers, volatile profiles, and agrotechnologies

The desert truffles of the Negev desert in Israel are mycorrhizal fungi forming symbiosis with plants of the Cistaceae family. Truffles are providing important sustenance to populations in arid areas and descriptions of their consumption on clay tablets date back to the Amorites kingdom. To develop new crops for arid zones, we screened the natural habitat and identified three species based on PCR-RFLP and morphological characters. These include Picoa lefebvrei (Pat.), Tirmania nivea (AU) and Terfezia boudieri (Chatain), all associated with Helianthemum sessiliflorum. The most promising species for cultivation is the ectendomycorrhizal truffle T. boudieri. In summer, the fungus lived as ectomycorrhiza but also as endomycorrhiza with intracellular coiled hyphae inhabiting the cortical cells surrounded by necrotic tissue and no mantle. In winter and during the fruiting season, the ectomycorrhizal lifestyle was the dominant one. We developed methods for host inoculation and planting which probably affected morphology and yields of fruit bodies. The growth rate of fruit bodies and their aroma volatiles composition under these conditions were determined. The main volatiles of T. boudieri and T. nivea were 1-octen-3-ol and hexanal, however the latter species emitted branched chain amino acid derivatives such as 2-methylbutanal and 3-methylbutanal, phenylalanine derivatives such as benzaldehyde and benzenacetaldehyde, and methionine derivatives such as methional and dimethyldisulfide. The least aromatic truffle, Picoa lefebvrei, contained low levels of 1-octen-3-ol as the main volatile. This work highlights differences in the volatile profiles for future selecting of superior genotypes and ways to increase yields.