Browsing by Subject "Basidiomycetes"

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  • Karsten, P. A. (Helsingfors, 1899)
    Floristiska handböcker för begynnare / Societas pro fauna et flora Fennica ; 1
  • Spirin, Viacheslav; Volobuev, Sergey; Malysheva, Vera; Miettinen, Otto; Kotiranta, Heikki; Larsson, Karl-Henrik (2021)
    Background and aims - To date, Megalocystidium leucoxanthum, a corticioid fungus originally described from the Italian Alps, was considered as a widely distributed species inhabiting numerous angiosperm hosts in the northern hemisphere. Its specimens collected in different geographic areas and from various host species revealed a high morphological variability and thus obfuscated differences from the closely related M. luridum. The objective of this study was to re-establish M. leucoxanthum based on newly collected and sequenced specimens and clarify the identity of morphologically deviating collections previously ascribed to this species. Material and methods - In total, 87 specimens of Megalocystidium spp. (including two historical types) were studied by morphological methods. Their phylogenetic relations were investigated based on DNA sequences (nrITS, nrLSU, and tef1) of 29 specimens. Key results - Based on morphological, ecological and DNA data, we showed M. leucoxanthum sensu typi is a rare species restricted to Alnus alnobetula in subalpine and subarctic zones. Consequently, records from other hosts (mostly representatives of Salicaceae) belong to three other species, M. olens, M. perticatum, and M. salicis, described as new to science. The fourth newly introduced species, M. pellitum, occurs on the same host tree as M. leucoxanthum but it can be separated from the latter due to distinctive morphological traits and DNA sequences. Additionally, Aleurodiscus diffissus is combined in Megalocystidium and the identity of M. luridum is clarified.
  • Norros, Veera Maria; Karhu, Elina; Nordén, Jenni; Vähätalo, Anssi Vesa; Ovaskainen, Otso Tapio (2015)
    Assessment of the costs and benefits of dispersal is central to understanding species' life-history strategies as well as explaining and predicting spatial population dynamics in the changing world. While mortality during active movement has received much attention, few have studied the costs of passive movement such as the airborne transport of fungal spores. Here, we examine the potential of extreme environmental conditions to cause dispersal mortality in wood-decay fungi. These fungi play a key role as decomposers and habitat creators in forest ecosystems and the populations of many species have declined due to habitat loss and fragmentation. We measured the effect of simulated solar radiation (including ultraviolet A and B) and freezing at -25 degrees C on the spore germinability of 17 species. Both treatments but especially sunlight markedly reduced spore germinability in most species, and species with thin-walled spores were particularly light sensitive. Extrapolating the species' laboratory responses to natural irradiance conditions, we predict that sunlight is a relevant source of dispersal mortality at least at larger spatial scales. In addition, we found a positive effect of spore size on spore germinability, suggesting a trade-off between dispersal distance and establishment. We conclude that freezing and particularly sunlight can be important sources of dispersal mortality in wood-decay fungi which can make it difficult for some species to colonize isolated habitat patches and habitat edges.