Didymium xerophilum, a new myxomycete from the tropical Andes

Abstract

A new species of Didymium (Myxomycetes), D. xerophilum, is described, and some details of its life cycle are provided. The new species was collected during studies of arid areas of Argentina and Peru. It can be distinguished by the persistent funnel-shaped invagination of the peridium, the top of which appears as a deep umbilicus in closed sporothecae, and the calcareous hypothallus shared among several sporocarps. This combination of characters, with a circumscissile dehiscence of the sporotheca and a cream stalk packed with rhombic lime crystals, is unknown in other described species. Morphology was examined with scanning electron microscopy and light microscopy, and micrographs of relevant details are included here. Phylogenetic analysis with 18S rDNA sequences of different species of Didymium supports the distinct identity of this new species. Some collections of this myxomycete were made at up to 4600 m, an altitude almost unknown for this group of microorganisms.

Nivicolous Trichiales from the austral Andes: unexpected diversity including two new species

“…Primer KEF_R3 published in Wrigley de Basanta et al (2017) was employed as a reverse primer. PCR conditions were those described in Wrigley de Basanta et al (2015) and Janik et al (2020). Additionally, if amplification failed, a seminested PCR was conducted using newly designed SF02 (TCATATGCTTGTCCCGAAG) and EF04 (TGGGTGT TGGACAAACTC) as forward primers for 18S and EF-1α, respectively, in a total volume of 20 µl containing: 1× AccuTaq LA Buffer (Sigma-Aldrich, St. Louis, Missouri), 0.5 mM of each dNTPs, 0.4 µM of each primer, 0.1% bovine serum albumin, 0.05 U REDAccuTaq LA DNA Polymerase (Sigma-Aldrich), and 1 µL of purified product from the first PCR adjusted with double-distilled water (ddH 2 O), with the following cycling conditions: initial denaturation for 30 s at 96 C, followed by 35 cycles of 1 min at 94 C, 45 s at 52 C, and 10 min at 68 C, and final elongation for 30 min at 72 C. Forward and reverse directions of each region were amplified and analyzed with an ABI 3730XL automated sequencer (Macrogen, Seoul, South Korea) or with an ABI 3500 sequencer (Applied Biosystems, Foster City, California) at the W. Szafer Institute of Botany, Polish Academy of Sciences.…”

Myxomycete diversity in the coastal desert of Peru with emphasis on the lomas formations

“…The sporothecae are covered with pale yellow to white lime crystals, sporocarps have short calcareous stalks, and spores 8-10 µm densely and uniformly warted. In the Neotropics previously reported from Mexico (Lado & al., 2007;Esqueda & al., 2011;Wrigley de Basanta & al., 2015), Argentina and Chile (Lado & al., 2013). These are the first records for Peru.…”

A taxonomic guide to the species of Didymium (Didymiaceae, Physarales, Myxomycetes) I. The stipitate species

“…Didymium (sporangial or plasmodiocarpic), is separated from Mucilago (aethalial) on the basis of sporocarp form. These morphological characters appear to separate valid genera, however, recent rDNA studies (Fiore-Donno et al 2008, 2012, Nandipati et al 2012, Wrigley de Basanta et al 2015 indicate that some adjustments will probably have to be made, since Mucilago crustacea and Protophysarum phloiogenum (a minute limeless species generally placed in the Physaraceae) were located in a Didymium clade, and Didymium anellus seems to be either part of a Diderma clade (Fiore-Donno et al 2008) or the Didymium clade (Wrigley de Basanta et al 2015). However, since there is not enough information to sort the large number of species of this genus into coherent phylogenic grouping within the genus, and some individual DNA determinations appear to be anomalous (possibly due to disagreements concerning the morphological identification of species), we will for this guide, use the standard morphologically determined genera and species.…”