Dismantling a complex of anther smuts (Microbotryum) on carnivorous plants in the genus Pinguicula

ABSTRACTThe anther smuts of the genus Microbotryumare known from host plant species belonging to the Caryophyllaceae, Dipsacaceae, Lamiaceae, Lentibulariaceae, Montiaceae, and Primulaceae. Of these, the anther smuts on Caryophyllaceae, in particular on Silenespp., are best known because they include model organisms studied in many disciplines of fungal biology. For Microbotryumspecies parasitic on Caryophyllaceae, a high degree of host specificity was revealed and several cryptic species were described. In contrast, the host specificity within Microbotryum pinguiculaeoccurring in anthers of different Pinguiculaspecies (Lentibulariaceae) has not been investigated in detail until now. The anther smuts on Pinguicula alpina, P. villosa, and P. vulgaris, on which M. pinguiculaewas described, were analyzed using nuc rDNA ITS1-5.8S-ITS2 and nuc rDNA 28S D1–D2 sequences and morphology to determine if they belong to one polyphagous species or rather represent three host-specific species. The results of the morphological investigations revealed no decisive differences between the anther smuts on different Pinguiculaspecies. However, genetic divergence and molecular phylogenetic analyses, which split the specimens according to host plant species, supported host specificity of the anther smuts on different Pinguiculaspecies. Accordingly, in addition to Microbotryum pinguiculaes. str. on Pinguicula vulgaris, M. alpinumsp. nov. on P. alpinafrom Europe and M. liroisp. nov. on P. villosafrom Asia are described and illustrated.