Unveiling new sequestrate Cortinarius species from northern Patagonian Nothofagaceae forests based on molecular and morphological data

PASTOR, N ; MUJIC, A ; KUHAR, F ; NOUHRA, E; CHIAPELLA, J ; CRESPO, E

MYCOLOGIA.

ALLEN PRESS INC

Lugar: New York; Año: 2019 vol. 2019 p. 103 - 117

0027-5514

Because of systematic sampling campaigns in the northern Patagonian Nothofagaceae forests ofArgentina, several specimens of sequestrate fungi were collected. Some of those collections showedphylogenetic affinities and morphological similarities to members of the formerly recognizedsequestrate genus Thaxterogaster, currently a synonym of Cortinarius on the basis of moleculardata. Comparisons of macro- and micromorphological features and sequences of nuc rDNA internaltranscribed spacer (ITS) regions have revealed that these collections belong to formerly undescribedspecies. The sequences of the four new taxa presented here, Cortinarius flavopurpureus,C. translucidus, C. nahuelhuapensis, and C. infrequens, were combined into a data set includingadditional sequences generated from herbarium collections and retrieved from public gene databases and analyzed by maximum likelihood and Bayesian inference methods. The four new specieswere resolved as distinct clades with strong support; at the same time, they showed uniquemorphological characteristics (hypogeous to subhypogeous habit, complete gasteromycetation,and spore shape and ornamentation) that separate them from previously described Cortinariusspecies. In addition, several undescribed and/or not previously sequenced species from these forestswere detected through phylogenetic analysis of ectomycorrhizal root tip sequences. A key ofcharacters to identify the sequestrate Cortinarius from Patagonia is provided.