Pezizales in Israel: Molecular Phylogenetic and δ13Cδ15N Stable Isotope Data Reveal New Records and Potential Discrepancies in Their Trophic Ecology

The order Pezizales (Ascomycota) consists of cup and truffle fungi growing in a wide range of habitats and geographical zones worldwide, exhibiting diverse nutritional behaviors. In Israel, morphological studies have designated most Pezizales as saprotrophs. We re-screened Pezizales mushrooms collected in northern Israel between 2020-2022 using molecular tools based on DNA sequences of partial large subunit rRNA (28S), internal transcribed spacer (ITS), and partial heat shock protein (<i>Hsp90</i>) regions, along with macro images of each freshly collected samples. Trophic mode was determined through available literature and δ¹³C and δ¹⁵N stable isotope analysis along with a quadratic discriminator analysis (QDA) model to predict trophic modes: 112 collections were positively identified with identification of 23 genera; 23 taxa were resolved to the species level, 11 to approximate species, and 15 to the genus level. <i>Helvella</i> was the most species-rich genus; 25 species and species approximations were newly reported for Israel. Further molecular phylogenetic studies are needed to resolve species identity of the Israeli Pezizales. Most Pezizales collections were determined by trophic mode studies to be ectomycorrhizal, with a few saprotrophs. The QDA model yielded several samples with undefined nutritional behavior or a different trophic mode than previously inferred, suggesting that more in-depth study is needed to understand their trophic ecology. This study improves knowledge regarding species diversity, ecology, and evolution of Israeli Pezizales.