Re-examination of the Southern Hemisphere edible genus Cyttaria (Ascomycota, Helotiales) and characterization of two new species from Patagonia

Abstract

Two new species of Cyttaria (Ascomycota, Helotiales), obligate biotrophic associates of Nothofagaceae, are described fromthe Patagonian Andean forests in Argentina (Chubut and Tierra del Fuego provinces). Cyttaria gamundiae and C. pumilioniswere found parasitizing branches of Nothofagus pumilio and morphologically resemble C. hookeri and C. hariotii, respectively.Morphological traits were documented through microscopy, while genetic identification was performed using threemolecular markers: double-stranded partial nucSSU, nucLSU, and TEF1. Phylogenetic analyses were carried out to determinespecies relationships and variability. Results revealed morphological differences, though subtle, among the analyzed Cyttariaspecimens, supporting the presence of distinct species within the studied region. Molecular data corroborated these findings,showing genetic divergence that aligns with previously described species boundaries. The existence of pseudocrypticspecies in the genus is highlighted and challenges pathogen/host relationships concepts. A key for species identification isprovided. These findings contribute to a better understanding of Cyttaria diversity and evolution in Patagonian ecosystems.The integration of morphological and molecular approaches provides a robust framework for species identification, essentialfor future ecological research and conservation efforts.