Category Archives: Volume 60(1-2) 2022

Venturioscypha nigropila (Hyphodiscaceae, Helotiales) – a new genus and species from xeric Pinus bark

Authors: Baral, Hans-Otto & Kosonen, Timo & Polhorský, Adam & Stöckli, Elisabeth & Huhtinen, Seppo & Hansen, Karen
Journal: Karstenia, Volume 60 (2022), Issue 1-2, pages 28–48.
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Key words: apothecial proliferation, desiccation tolerant, Hyphodiscus, multi-gene phylogeny, pigmented excipulum, Venturiocistella

Abstract: A new genus and species, Venturioscypha nigropila, is proposed for a minute inoperculate discomycete with long, cylindrical, partly flexuous, dark blackish-brown, smooth, finally thick-walled hairs. It has been collected repeatedly in Europe on dead, corticated branches of Pinus spp. attached to living or recently dead trees. At first glance the species resembles members of Pirottaea (Pyrenopezizaceae), but the relationship is shown by molecular phylogenetics to be close to Hyphodiscus, Hyphopeziza, Fuscolachnum, and Venturiocistella (Hyphodiscaceae). These genera differ in having hairs with more or less conspicuous warts, in Hyphopeziza also with glassy solidifications, and Venturiocistella in having in addition long, stiff, thick-walled, apically acute, dark brown hairs, which are warted in their lower part. The hair wall of Venturioscypha appears superficially smooth, but the surface is inconspicuously pitted as viewed under light microscopy. Venturioscypha is unique in Hyphodiscaceae by its peculiar hairs, inamyloid asci with a thin apical wall that ruptures irregularly by a terminal split at spore discharge, spores with a delicate sheath, and apothecial proliferation.

Results of myxomycete experiments could be affected by temperature in standard laboratory conditions

Authors: Rojas, Carlos & Valverde, Randall
Journal: Karstenia, Volume 60 (2022), Issue 1-2, pages 18-27.
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Key words: data, normalization, microcosm, protocol, slime molds

Abstract: Moist chamber cultures are valuable for myxomycete research and can be used for the analysis of ecological patterns with implications in ecosystem conservation programs. However, to make comparisons between datasets valid, the method should be redesigned considering potential biases affecting the generation of results. In the present study, both the effect of the general climate of the laboratory and two microclimatic variables within the moist chamber were studied in relation with the obtained data. Of all the recorded variables, temperature was observed to affect the results, both at the level of the general laboratory climate and in relation with the microclimate of the moist chamber. Increments in laboratory and moist chamber temperature increased the probability, three or fourfold, associated with a higher number of records or species within a group of equivalent samples. Such probabilistic differences are significant enough to suggest that using the moist chamber technique in “standard” laboratory conditions is not enough for cross-dataset comparisons that increase the potential of myxomycete data for applications outside of the biological sciences.

Observations of the impact of bushfire on a community of myxomycetes

Authors: Stephenson, Steven L. & Elliott, Todd F.
Journal: Karstenia, Volume 60 (2022), Issue 1-2, pages 10-17.
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Key words: microbial ecology, moist chamber cultures, Amoebozoans, fire ecology, bushfires, slime molds

Abstract: In this study, we examined the impacts of a bushfire on a community of myxomycetes (also known as plasmodial slime moulds or myxogastrids) in northeastern New South Wales, Australia. Using the moist chamber culture technique, we prepared 40 moist chamber cultures from four different substrates. We collected the same four types of substrates on either side of a fire line approximately six months post-fire in order to assess what impact fire had on the myxomycete communities. Sixty percent of moist chamber cultures yielded evidence (plasmodia or fruiting bodies) of myxomycetes representing eleven species in eight genera. But only 40% of samples from the burned site were positive for myxomycetes, and only one species produced fruiting bodies. In contrast, 80% of samples from the unburned site were positive, and all eleven species were recorded. These data suggest that fire reduced the abundance and diversity of the myxomycete community at our site.

Amanita indogrisea, a new species of Amanita subg. Amanitina sect. Roanokenses from India

Authors: Kumar, Anil & Sharma, Roshi & Verma, Komal & Mehmood, Tahir & Sharma, Yash Pal
Journal: Karstenia, Volume 60 (2022), Issue 1-2, pages 1-9.
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Key words: Amanita, Jammu & Kashmir, new taxon, nrLSU, taxonomy

Abstract: Amanita indogrisea is described here as a new species from coniferous forests in the Union Territory of Jammu and Kashmir, India based on morpho-anatomy and molecular data. This species is characterized by its small to medium-sized basidiomata, ash grey to lilac-grey pileal surface with ash grey to greyish brown pulverulent-floccose to felted veil remnants, ash grey to greyish-white stipes with ovoid to ellipsoid basal bulb, ellipsoid to elongated basidiospores (10.5–15.0 × 7.0–10.0 μm) and the absence of clamps in all tissues. Molecular phylogenetic analysis based on nuclear ribosomal large subunit (nrLSU) sequences confirmed its identity as a new species nested within A. subgen. Amanitina sect. Roanokenses. Description of the new species is provided in this study.