Lamprospora sylvatica Egertová & Eckstein, 2018

Egertová, Zuzana, Eckstein, Jan, Sochor, Michal & Vega, Marcel, 2018, Lamprospora sylvatica (Pyronemataceae), a new bryophilous ascomycete on Dicranum montanum, Phytotaxa 357 (1), pp. 17-29 : 18-22

Lamprospora sylvatica Egertová & Eckstein , sp. nov. ( Figs 1–5 )

Mycobank MB 824682

Diagnosis: — Differs from other species of the genus Lamprospora by the following combination of characters: pinkish, orange to reddish-orange apothecia with a fimbriate margin, globose ascospores with more or less regular areolate ornamentation, infection of Dicranum montanum , and infectious structures consisting of an appressorium surrounded by many thick-walled cells, located on strong rhizoids of the host, and a haustorium within the rhizoids.

Etymology:—The specific epithet reflects the occurrence in forests.

Holotype:— UKRAINE. Zakarpattia Oblast , 3.3 km NW from Nimetska Mokra, 48°23’42”N, 23°48’27”E, 740 m asl., on Dicranum montanum covering a rotten stem of a conifer, 8 July 2017, Z. Egertová and M. Sochor ( PRM 946415 ).

Description:— Apothecia (0.3–)0.5–1(–1.3) mm broad, first closed, later hemispherical to discoid, thick, sessile, with a narrow, fimbriate margin, hymenium pinkish, orange or reddish orange, rarely whitish, outer surface concolorous. Asci 240–370(420) × 20–27(29) μm, cylindrical, 8-spored, operculate, inamyloid, arising from croziers. Ascospores globose, (15.5–)16–18(–19) μm in diameter, hyaline, with a large spherical drop of 9–11.5 μm, uniseriate. Ornamentation areolate, consisting of ridges 0.4–1.6 μm wide and 0.8–1.4 μm high, forming a complete, ± regular reticulum of 5–7 meshes/diameter, meshes 1.5–4.5(8) μm broad. Paraphyses filiform, straight, mostly simple, rarely forked, pluriseptate, containing orange pigment, 2.5–4 μm broad, terminal cell 33–103 μm × 4–6.5 μm. Subhymenium consisting of thin-walled, variously shaped, hyaline cells 2.5–6 μm broad, merged with the medullary excipulum. Medullary excipulum about 150–220 μm thick (in the thickest part), made up of thin-walled, variously shaped cells - cylindric, pyriform, broadly ellipsoid, subglobose or indefinite. Ectal excipulum about 70–120 μm thick, consisting of thick-walled, globose, subglobose to subangular cells (textura subglobulosa) of 6–35 × 7–26 μm, the outermost cells often flattened, cell wall up to 5 μm thick. Margo of parallel hyphae of size 13–47 × 6–24 μm (textura prismatica - porrecta). Infections located on strong rhizoids of Dicranum montanum . Infectious structures consisting of spherical to irregular clusters of cells firmly attached to and often completely surrounding the rhizoid. Cells within the clusters more or less isodiametric, 10–20 μm wide with walls 2–5 μm thick. Appressoria situated at the centre of these clusters sitting directly on the rhizoid wall, very thick-walled, ± isodiametric or often slightly higher than wide, with 20–28 × 17–25 μm in diameter only slightly larger than surrounding cells. Infectious clusters up to 110 μm wide. Infection peg 4–5 μm wide, surrounded by a tube of rhizoid cell-wall material, forming intracellular haustoria.

Habitat and distribution: —In all cases the fungi grew in forests on strongly decayed logs covered by Dicranum montanum . Other accompanying bryophytes included Buxbaumia viridis ( De Candolle 1815: 227) Mougeot & Nestler 1823: 724 , Cephaloziella spec. ( Spruce 1882: 62–63) Schiffner 1893: 98), Herzogiella seligeri ( Bridel 1801a: 47–48) Iwatsuki (1970: 374) and Hypnum cupressiforme Hedwig (1801: 291) . The species is so far known from locations in Ukraine, Slovakia, Germany and Norway.

Additional specimens examined: GERMANY. Thuringia, Hainich National Park, 51°04’06”N, 10°26’26”E, 420 m asl., on Dicranum montanum on strongly rotten conifer wood, 26 October 2015, J. Eckstein ( B Eckstein-43421). NORWAY. Østfold, Aremark Bøen saeter, Tjøstøltjern, 150 m asl., on Dicranum montanum on wood in mixed forest, mostly Picea , 15 November 1997, R. Kristiansen (97.65). SLOVAKIA. Malá Fatra National Park, 110 m N of the Kopa Peak, 49°10’58”N, 18°55’46”E, 1093 m asl., on Dicranum montanum on a strongly rotten Picea stem, 17 November 2014, Z. Egertová and M. Sochor ( PRM 946416); ibid. 1 November 2015 ( PRM 946417); ibid. 4 November 2017 ( PRM 946418); Malá Fatra National Park, 550 m SSW of the Kopa Peak, 49°10’37.3”N, 18°55’39.8”E, 895 m asl., on Dicranum montanum on a rotten conifer stem, 4 November 2017, Z. Egertová and M. Sochor ( PRM 946419).

Phylogenetic analyses: Lamprospora sylvatica was represented by five collections in the analysis. Of these, the Norwegian one was the oldest, and its DNA was very fragmented. As a result, an ITS sequence from this accession could not be obtained. However, the LSU region was identical in all five specimens, and ITS exhibited a singlenucleotide deletion in a poly-C microsatellite in the Slovak collections. The BLAST search resulted in one entry 100% identical to L. sylvatica in the LSU sequence— Lamprospora sp. , accession number EU 940123. Unfortunately, this sequence contains reading gaps precisely in the most variable regions, and therefore cannot be assigned to the new species with certainty. Furthermore, the specimen has been destroyed ( S. Huhtinen pers. comm.) and is not available for study anymore.

Based on both markers (particularly LSU), it is clear that L. sylvatica is related to L. feurichiana ( Kirschstein (1935: 205) Benkert (1976: 639) and L. kristiansenii Benkert (1990: 635) , but differs significantly (similarity around 71 % in ITS and 96 % in LSU) from both species. Nevertheless, both BI and MP for LSU indicated its closer relationship with L. campylopodis W.D. Buckley (1923: 44 ; Fig. 6 ; similarity 59 % in ITS and 95 % in LSU), although with very low bootstrap support in MP (33 %; Supplementary File 2). ITS was hypervariable in the group, and its alignment was very ambiguous among distant species; phylogeny inference was therefore highly dependent on the model/method used and resulted mostly in low statistical support of many splits ( Fig. 6 and Supplementary File 2). Nonetheless, ITS proved useful as a species-specific marker.

Figures

FIGURE 1. Lamprospora sylvatica (a. PRM 946419, b. B Eckstein-43421, c. holotype, PRM 946415, d. PRM 946418). a. typical habitat—a moss covered rotten conifer log, b, c, d. apothecia between shoots of Dicranum montanum. Scale bar: b = 1 mm. Photos M. Sochor (a), J. Eckstein (b), Z. Egertová (c, d).

FIGURE 2. Lamprospora sylvatica (a–b, e–i. holotype, PRM 946415, c–d. PRM 946419) a–c. ascospores stained with cotton blue, d. ascospores in water, e. young asci, f. upper part of paraphyses, g. cross section of an apothecium showing hymenium, subhymenium, medullary and ectal excipulum, h. cross section showing subhymenium, medullary and ectal excipulum, i. marginal hyphae of an apothecium. Scale bars: a–f, i = 20 μm; g = 100 μm; h = 50 μm. Photos Z. Egertová.

FIGURE 3. Lamprospora sylvatica (a–b. B Eckstein-43421, c, d. PRM 946416) SEM of ascospores. Scale bars: a–d = 10 μm. Photos J. Eckstein.

FIGURE 4. Lamprospora sylvatica (a–b. PRM 946416) a. shoot of Dicranum montanum with infections on rhizoids indicated by arrows, b. microscopic image of an infection, note the cluster of thick-walled cells, the brown short-celled hyphae at bottom (arrows) do not belong to L. sylvatica. Scale bars: a = 1 mm; b = 50 μm. Photos J. Eckstein.

FIGURE 5. Lamprospora sylvatica (PRM 946416) drawings of two infectious structures in optical section. Scale bar = 50 μm. Illustrated by J. Eckstein.

FIGURE 6. Bayesian inference phylogeny trees based on LSU and ITS loci; posterior probabilities shown above branches. Note that basal splits in the ITS tree may be influenced by its hypervariability in the group and ambiguous alignment. Collection numbers are given after underscores.