High diversity and morphological convergence among melanised fungi from rock formations in the Central Mountain System of Spain

Abstract

Melanised fungi were isolated from rock surfaces in the Central Mountain System of Spain. Two hundred sixty six isolates were recovered from four geologically and topographically distinct sites. Microsatellite-primed PCR techniques were used to group isolates into genotypes assumed to represent species. One hundred and sixty three genotypes were characterised from the four sites. Only five genotypes were common to two or more sites. Morphological and molecular data were used to characterise and identify representative strains, but morphology rarely provided a definitive identification due to the scarce differentiation of the fungal structures or the apparent novelty of the isolates. Vegetative states of fungi prevailed in culture and in many cases could not be reliably distinguished without sequence data. Morphological characters that were widespread among the isolates included scarce micronematous conidial states, endoconidia, mycelia with dark olive-green or black hyphae, and mycelia with torulose, isodiametric or moniliform hyphae whose cells develop one or more transverse and/or oblique septa. In many of the strains, mature hyphae disarticulated, suggesting asexual reproduction by a thallic micronematous conidiogenesis or by simple fragmentation. Sequencing of the internal transcribed spacers (ITS1, ITS2) and 5.8S rDNA gene were employed to investigate the phylogenetic affinities of the isolates. According to ITS sequence alignments, the majority of the isolates could be grouped among four main orders of Pezizomycotina: Pleosporales, Dothideales, Capnodiales, and Chaetothyriales. Ubiquitous known soil and epiphytic fungi species were generally absent from the rock surfaces. In part, the mycota of the rock surfaces shared similar elements with melanised fungi from plant surfaces and fungi described from rock formations in Europe and Antarctica. The possibility that some of the fungi were lichen mycobionts or lichen parasites could not be ruled out.

Cambios en la composición de la comunidad fúngica de biopelículas sobre roca calcárea a través de una cronosecuencia en Campeche, México

“…The isolation technique used in this study may promote the growth of rare and uncommon species; these results do concur with those found by other authors who used both taxonomic and molecular identification techniques (Collado et al, 2007;Ruibal et al, 2008;Gómez-Cornelio et al, 2012). Additionally, the abundance of dominant species of the three analyzed biofilms was variable and may be determined by time of exposure, similar to the variations observed in Lan et al (2010) in the microorganism community of old and fresh biofilms.…”

“…The fungal composition was dominated by species of the Ascomycota class, which are common in rock substrates; these Hyphomicetous asexual species are able to colonize rocks during the first year of exposure (Ruibal et al, 2008;Gleeson et al, 2010;Hallman et al, 2011;Gómez-Cornelio et al, 2012). In contrast, Coelomycetous species are known to colonize limestone in Mediter- ranean regions (Wollenzien et al, 1995).…”

A New View of Sooty Blotch and Flyspeck

“…Did SBFS species therefore evolve from plant-parasitic ancestors? Alternatively, many characteristics of SBFS fungi closely resemble those of fungi that grow on rocks (52,53) and as lichen symbionts (54). Like these fungi, SBFS species are extremophiles, colonizing environments with wide variations in light levels and water availability, and they must function as oligotrophs since their substrate is likely to be nutrient-poor most of the time.…”

Data report: cultivation of microorganisms from basaltic rock and sediment cores from the North Pond on the western flank of the Mid-Atlantic Ridge, IODP Expedition 336

“…F1). It has been reported that many fungal isolates from terrestrial rocks are grouped into the order Chaetothyriales (Sterflinger et al, 1997;Ruibal et al, 2008).…”

“…Solid dots = spp. which are reported to be isolated from terrestrial rocks (Ruibal et al, 2008 Table T1. Cultivation media used in this study.…”