Morphological and phylogenetic analyses of Nia vibrissa, a marine Basidiomycota collected in Portuguese waters

This study presents morphological and phylogenetic characterizations of Nia vibrissa specimens detected on Fagus sylvatica baits, after six months of incubation in moist chambers at the laboratory. The baits had been submerged at Cascais marina, Portugal, during a survey carried out in 2006-2008. Morphological observations evidenced differences in basidiocarp color and in the morphology of the peridial hairs, varying from straight to curved and with bifurcate to non-bifurcate ends. Morphological variability has often been reported, associated to the suggestion that N. vibrissa is a species complex. We addressed this subject through the evaluation of pairwise distances and phylogenetic analyses applying Bayesian and Maximum Likelihood methods, to multi-sequence alignments involving the large subunit (LSU) of the nuclear ribosomal DNA. Even though the six N. vibrissa isolates under analysis consistently clustered together with high support values and most of their pairwise distances ranged between 0 and 3%, one of them presents a higher distance value (4%) relative to other two isolates. These results recommend the need of further genetic evaluations, involving more isolates and gene regions, to answer the question addressed in this study: is N. vibrissa a species complex?