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Research Article
The genus Parasola in Pakistan with the description of two new species
expand article infoShah Hussain§, Habib Ahmad|, Sadiq Ullah§, Najam-Ul-Sehar Afshan, Donald H. Pfister#, Hassan Sher, Haidar Ali, Abdul N. Khalid
‡ University of Swat, Swat, Pakistan
§ Hazara University, Mansehra, Pakistan
| Islamia College, Peshawar, Pakistan
¶ University of the Punjab, Lahore, Pakistan
# Harvard University, Cambridge, United States of America
Open Access

Abstract

Parasola is a genus of small, veil-less coprinoid mushrooms in the family Psathyrellaceae (Agaricales). The genus is not well documented in Asia, specifically in Pakistan. In this study we describe two new species Parasola glabra and P. pseudolactea from Pakistan, based on morphological and molecular data. Phylogeny based on three DNA regions: nuc rDNA region encompassing the internal transcribed spacers 1 and 2 along with the 5.8S rDNA (ITS), nuc 28S rDNA D1-D2 domains (28S) and translation elongation factor 1α gene (TEF1α) show that the new taxa are clustered in a clade formed by the members of section Parasola of genus Parasola. Parasola glabra with grayish pileus, slightly depressed pileal disc, lamellae separated from the stipe by pseudocollarium, basidiospores 14.5–16.5 × 9.5–11.5 × 8.0–10.5 µm, in front view broadly ovoid to oblong, some with rhomboidal outline, in side view ellipsoid, with eccentric germ-pore of 1.5 µm diameter. Parasola pseudolactea with yellowish brown to dull brown pileus, disc indistinctly umbonate, lamellae free, pseudocollarium absent, basidiospores 13.5–14.5 × 10.5–12.0 × 9.5–10.5 µm, in face view rounded triangular to heart shaped, rarely ovoid to subglobose, in side view ellipsoid to oblong, with eccentric germ-pore of 1.5 µm diam. In addition to these new species, P. auricoma and P. lilatincta were also studied. Morphological descriptions for the new species and comparison with known Parasola species are provided. Our observations highlight the diversity of Parasola in northern Pakistan and further document the need for additional systematic focus on the region’s fungi.

Keywords

Basidiomycota, diversity, Parasola, phylogeny, taxonomy

Introduction

Parasola Redhead, Vilgalys & Hopple is a genus of small, veil-less coprinoid mushrooms belonging to family Psathyrellaceae Vilgalys, Moncalvo & Redhead (Redhead et al. 2001, Nagy et al. 2009, Schafer 2010). These fungi are saprotrophs of decayed organic matter in bare soil, grassland, on woody debris including wood chips and on herbivore dung (Schafer 2014). The genus Parasola typified by Parasola plicatilis (Curtis) Redhead, Vilgalys & Hopple (Redhead et al. 2001), currently comprises 18 established species, distributed world-wide. The genus is well documented in Europe (Orton and Watling 1979, Uljé and Bas 1988, Uljé and Bender 1997, Schafer 2014, Szarkándi et al. in press). Some species are reported from North America, Africa, Lesser Antilles (Pegler 1966, 1983, Dennis 1970), and Asia (Ahmad 1980, Pegler 1986, Hongo 1987, Hussain et al. 2016, 2017) and Australia (Grgurinovic 1997).

Species of Parasola are divided into section Auricomi (Singer) D.J. Schaf. and section Parasola Redhead, Vilgalys & Hopple (previous references to Parasola section Glabri (Lange) D.J. Schaf. – see Schafer (2010) – should be replaced by Parasola section Parasola to conform with the International Code of Nomenclature for Algae, Fungi and Plants (Schafer, D.J., personal communication). The sections are distinguished on the basis of presence or absence of hair-like, golden- to dark brown, thick walled sclerocystidia in the pileipellis (Schafer 2010). In mature fruitbodies during basidiospore discharge, the gill cystidia of Parasola lose turgor and collapse, a characteristic feature of the genus (Nagy et al. 2009).

Basidiospore shape and size are the main descriptive features for species identification in Parasola (Nagy et al. 2009, 2010, Schafer 2014, Hussain et al. 2017).

Previously, five species of this genus (Parasola auricoma (Pat.) Redhead, Vilgalys & Hopple, P. lilatincta (Bender & Uljé) Redhead, Vilgalys & Hopple, P. malakandensis S. Hussain, N. Afshan & H. Ahmad, P. plicatilis and P. setulosa (Berk. & Broome) Redhead, Vilgalys & Hopple) have been reported from Pakistan (Ahmad 1980, Hussain et al. 2016, 2017). In this study, we describe two new species P. glabra and P. pseudolactea, based on morphological characters and phylogenetic analyses of nuc rDNA region encompassing the internal transcribed spacers 1 and 2, along with the 5.8S rDNA (ITS), nuc 28S rDNA D1-D2 domains (28S) and translation elongation factor 1α gene (TEF1α). In addition to these new species we also studied P. auricoma and P. lilatincta.

Materials and methods

Sampling and morphological characterization

Specimens were collected from Malakand, Shangla and Swat districts of Khyber Pakhtunkhwa, Pakistan in summer seasons, 2013–2017. Basidiomata were photographed, tagged and field notes were made. Munsell (1975) was used for determination of color. The specimens were air-dried and kept in zip-lock bags. Specimens examined in this study are deposited in the Herbaria of Hazara University Mansehra, Pakistan (HUP), University of the Punjab, Lahore, Pakistan (LAH) and University of Swat, Pakistan (SWAT).

For anatomical studies slides were prepared in 5% aqueous KOH (w/v). Microscopic features such as size and shape of basidiospores, basidia, cheilocystidia, pleurocystidia and pileipellis were studied under a light microscope (MX4300H, Meiji Techo Co., Ltd., Japan) with at least 20 structures measured in each instance. Cheilocystidia and pleurocystidia were observed and measured by cutting the gill edge from the rest of gill to avoid confusion between the two types of cystidia. In the case of basidiospores, 50 spores were measured in face view and/or side view through 1000× magnification with a calibrated optical micrometer and measurements were rounded to the nearest 0.5 µm. Basidiospores measurements are presented as follows: length range × breadth range × width range. Q values were calculated as: Q1 = length divided by breadth; Q2 = length divided by width (Nagy et al. 2010).

DNA extraction, PCR and sequencing

We extracted genomic DNA using the DNeasy Plant Mini Kit (Qiagen, Redwood City, California, USA.). We amplified nuc rDNA internal transcribed spacer (ITS) and 28S loci and translation elongation factor 1α gene (TEF1α) using the primer combinations ITS1F/ITS4; LR0R/LR5 and EF1-983F/EF1-1567R, respectively (White et al. 1990, Gardes and Bruns 1993, Rehner and Buckley 2005). For PCR amplification, we followed Hussain et al. (2017). PCR products were purified using the QIAquick PCR Purification kit (Qiagen). Sequencing was performed with the same PCR primers using the Big Dye Sequencing Kit v.3.1 on an ABI-3730-XL DNA Analyzer (Applied Biosystems, Foster City, California, USA). Sequences produced for this study have been deposited in GenBank (Table 1).

Voucher numbers, geographic origins and GenBank Accession numbers for the specimens included, in boldface are sequences produced in this study.

Species Geographic origin Voucher number GenBank Accessions
ITS 28S TEF1α
Parasola auricoma Pakistan LAH-SHP-P6 KX212106 KY461729 MG587083
Pakistan LAH-SHP-P7 KY461721 KY461730 MG587084
Pakistan LAH-SHP-P11 KY621802 KY461728
Hungary NL0268 FM163186 FM160723
Hungary NL0087 FM163185 FM160724 FM897236
P. conopilus Hungary NL0465 FM160686 FM163223
Hungary NL0286 FM160685 FM163224
Hungary NL0285 FM160684 FM163225 KJ732832
P. glabra Pakistan LAH-SHP-5 (Holotype) KY461717 KY621806 KY461735
Pakistan HUP-SHP-23 KY461718 KY621805
P. hercules Netherlands Uljé 1269 (L) FM163190 FM160719
Netherlands L146 holotype HQ847027 HQ847112
P. kuehneri Netherlands Uljé 904 (L) FM163191 FM160718
P. lactea Hungary NL0466 FM163192 FM160717 FM897241
Sweden NL0095 FM163188 FM160721
Germany NL0283 FM163194 FM160715 FM897239
Sweden NL0288 FM163193 FM160716
Hungary NL6601 FM163187 FM160722
USA MICH232885 KM403384
Latvia KuP6.2.2.1 KP698198
P. pseudolactea Pakistan HUP-SU-412 (Holotype) KY461719 KY621799 KY461733
Pakistan HUP-SU-413 KY461720 KY621800 KY461734
P. lilatincta Pakistan LAH-SHP-8 KY461722 KY461725 KY461731
Pakistan LAH-SHP-31 KY461723 KY461726 KY461732
Pakistan LAH-SHP-12 KY461724 KY461727
Hungary NL0683 FM163203 FM160706 FM897231
Hungary NL0660 FM163195 FM160714 FM897230
Hungary NL0472 FM163199 FM160709
Hungary NL0667 FM163198 JQ045886
Pakistan SH4 KP886462
Pakistan SHP2 KP886463
Pakistan SHP9 KP886464
P. aff. lilatincta Hungary NL0086 FM163204 FM160705
Sweden NL0096 FM163205 FM160704
P. megasperma Denmark C 19683 FM163206 FM160703
Sweden NL1924 FM163208 FM160701 FM897232
P. malakandensis Pakistan LAH-SHP-17 KU599827 KU599830 KU599832
Pakistan HUP 17501 KP738713 KU599829 KU599831
P. misera Hungary NL0677 FM160698 FM163211 FM897240
Hungary NL0280 FM160699 FM163210
Hungary NL0490 FM163209 FM160700
P. plicatilis Sweden NL0477 FM163212 FM160697 FM897235
Hungary NL0295 FM163216 FM160693 FM897242
P. plicatilis Sweden NL0097 FM163215 FM160694
Hungary NL0075 FM163214 FM160695
Hungary NL0284 FM163189 FM160720
P. schroeteri Netherlands LBrier:1051999 FM163219 FM160690
P. setulosa Hungary L32 HQ847030 HQ847115
Parasola sp. Norway NL3167 JN943136 JQ045865
Parasola sp. Norway NL3621 JN943134 JQ045875
Parasola sp. Hungary NL4175 HQ847025 HQ847110
Parasola sp. Hungary NL0287 FM163218 FM160691
Parasola sp. Hungary NL2952 HQ847028
Psathyrella candolleana Hungary NL2937 FN396114 FN396165 FN396220

Alignments and phylogenetic inference

ITS, 28S and TEF1α sequences were aligned using BIOEDIT v 7.2.5 (Hall 1999) and CLUSTAL X 2.1 (Larkin et al. 2007). The ITS, 28S and TEF1α alignments were concatenated into a supermatrix. Psathyrella candolleana (Fr.) Maire was selected as outgroup. Alignments are submitted to TreeBase (Treebase ID 21639). Phylogenetic inference was conducted using Bayesian and Maximum Likelihood (ML) methods. For Bayesian inference, we used BEAST 1.6.2 (Drummond and Rambaut 2007) with a Markov chain Monte Carlo (MCMC) coalescent approach. A Yule tree prior (Gernhard 2008) was used in all simulations, and the starting tree was randomly generated. Four independent runs were undertaken. Chain length was 10 million generations, with a sampling frequency of 1000. TRACER 1.6 (Rambaut et al. 2014) was used to check the effective sample size (ESS), and burn in values were adjusted to achieve an overall ESS (Effective Sample Size) of ≥ 200. Maximum clade credibility tree (20% burn-in) was generated using TREEANNOTATOR 1.6.2 (Drummond and Rambaut 2007). Maximum Likelihood analyses were run in RAXML-VI-HPC (Stamatakis 2006). Rapid bootstrap analysis/search for best-scoring ML tree (-f a) was configured. For the bootstrapping phase, the GTRCAT model was selected. One thousand rapid bootstrap replicates were run. Nodes were considered strongly supported when maximum likelihood bootstrap (MLB) were ≥ 70% and Bayesian posterior probability (BPP) were ≥ 0.95.

Results

Phylogenetic analyses

Sequence length varied from 631 bp (SHP-8) to 644 bp (SHP-11) for our 10 new ITS (ITS1-5.8S-ITS2) sequences and 1042 bp (SHP-12) to 1144 bp (SHP-8) for 10 28S sequences. The 7 TEF1a sequences generated for this study varied from 402 bp (SHP-5) to 502 bp (SU-412). The ITS dataset contained 52 taxa and 631 characters long after being trimmed (Trimming was done manually in BIOEDIT v 7.2.5). The combined ITS-28S dataset represented 47 taxa and 1892 characters long after being trimmed. Similarly, the combined ITS-28S-TEF1a dataset comprised 20 species and with 2890 nucleotides, after being trimmed.

The results of phylogenetic analyses of ITS, ITS-28S and combined ITS-28S-TEF1a datasets are summarized in Figures 1, 2 and 3, respectively. Each tree represents ML phylogeny produced by RAXML analysis. Maximum likelihood bootstrap (MLB) percentages > 70% are given above or below the branch node, followed by Bayesian posterior probabilities (BPP) > 0.95. The novel sequences in this study are represented in boldface (Figures 1, 2 and 3), their Genbank accessions are provided in Table 1.

Figure 1. 

Phylogeny of Parasola species based on 52 ITS sequences. Our sequences are indicated in boldface. Other sequences are from Nagy et al. (2009). Numbers above or below branches indicate maximum likelihood bootstrap percentages followed by Bayesian posterior probabilities. Species in section Parasola are gray highlighted where the new species are shown as light-blue highlighted, while the HOLOTYPE collection for P. glabra (LAH-SHP-5) and P. pseudolactea (HUP-SU-412) are represented by stars (*).

Figure 2. 

Phylogeny of Parasola species based on 47 sequences of combined ITS-28S dataset. Our sequences are indicated in boldface. Other sequences are from Nagy et al. (2009). Numbers above or below branches indicate maximum likelihood bootstrap percentages followed by Bayesian posterior probabilities. Species in section Parasola are gray highlighted where the new species are shown as light-blue, while the HOLOTYPE collection for P. glabra (LAH-SHP-5) and P. pseudolactea (HUP-SU-412) are represented by stars (*).

Using Bayesian and ML methods, P. auricoma, P. conopilus, P. setulosa and P. malakandensis were recovered as basal groups with strong support, collectively forming section Auricomi, whereas species of section Parasola fall in a single clade represented as gray highlighted, called ‘the crown Parasola’ clade (Nagy et al. 2009). Statistical support for the specimens that represent P. pseudolactea was strong in ITS dataset (MLB 98% and BPP 1), and excellent in combined ITS-28S and ITS-28S-TEF1a datasets, respectively (MLB 100% and BPP 1). Similarly, statistical support for P. glabra in both ITS and combined ITS-28S datasets was maximal (MLB 100% and BPP 1). In combined ITS-28S-TEF1a dataset P. glabra was represented by a single specimen and poorly recovered (Figure 3).

Figure 3. 

Phylogeny of Parasola species based on 20 sequences of combined ITS-28S-TEF1α dataset. Our sequences are indicated in boldface. Other sequences are from Nagy et al. (2009, 2011). Numbers above or below branches indicate maximum likelihood bootstrap percentages followed by Bayesian posterior probabilities. Species in section Parasola are light-brown highlighted where the new species are shown as light-blue, while the HOLOTYPE collection for P. glabra (LAH-SHP-5) and P. pseudolactea (HUP-SU-412) are represented by stars (*).

Taxonomy

Parasola glabra Hussain, Afshan, Ahmad & Khalid, sp. nov.

MycoBank No: MB819601
Figures 4, 5

Diagnosis

The diagnostic features of Parasola glabra are grayish pileus, deeply plicate towards margin; disc slightly depressed, strong reddish orange; lamellae free, separated from the stipe by pseudocollarium; basidiospores 14.5–16.5 × 9.5–11.5 × 8.0–10.5 µm, in front view broadly ovoid to oblong, some with rhomboidal outline, in side view ellipsoid, with eccentric germ-pore of 1.5 µm diam.

Type

PAKISTAN. Khyber Pakhtunkhwa Province, Malakand, Qaldara, scattered under herbaceous plants, 480 m alt., 15 August 2014, S. Hussain SHP5 (holotype: LAH SH-P5; GenBank accessions: ITS = KY461717; 28S = KY621806; TEF1α = KY461735).

Description

Pileus 20–30 mm diam, initially subglobose, later convex to hemispheric; at first smooth, without veil, the center glabrous at maturity, becoming deeply plicate towards the margin; light gray (2.5R 6/2) to moderate gray (7.5R 6/2); disc slightly depressed, strong reddish orange (7.5R 5/12). Lamellae free, fairly crowded, separated from the stipe by pseudocollarium, 0–2 lamellulae, regular, initially whitish, then dark brown becoming black at maturity, finally losing turgor and collapsing. Stipe 30–60 × 2–3 mm, central, equal, smooth, slightly sub-bulbous at the base, hollow, white, fragile, without annulus.

Figure 4. 

Basidiomata of Parasola glabra sp. nov. A, B Collection SHP-5 (HOLOTYPE LAH-SHP-5). Scale bars: 20 mm.

Figure 5. 

Anatomical features of Parasola glabra sp. nov. (LAH-SHP-5). A Basidiospres B Basidia C Pleurocystidia D Pileipellis E Cheilocystidia. Scale bars: 12 µm (A), 20 µm (B–E).

Basidiospores (13)14.5–16.5(18) × (7.5)9.5–11.5(15) × (9)8.0–10.5(11.5) µm, on average 15.8 × 10.9 × 10.1 µm, Q1 = 1.3–1.5, Q2 = 1.4–1.6, avQ = 1.4; in face view broadly ovoid to oblong, some with rhomboidal outline, in side view ellipsoid, germ-pore eccentric and upto 1.5 µm diam; wall upto 1.5 µm thick, dark brown to blackish in KOH. Basidia 28–41 × 10–13 µm, clavate to cylindrical, 4-spored, hyaline in KOH. Cheilocystidia 50–63 × 17–23 µm, oblong, ellipsoid, narrowly to broadly utriform, hyaline. Pleurocystidia 60–75 × 22–38 µm, clavate to broadly lageniform, hyaline. Pileipellis hymeniform, consisting of clavate cells 47–60 × 13–16 µm, bright yellow at the base in KOH. Clamp connections present mostly in the pileipellis and at the base of basidia. Sclerocystidia absent.

Habitat and distribution

Saprotrophic, scattered under herbaceous plants on grass land. So far only known from the lowland of northern Pakistan. This species is, however, common in lowland northwest Pakistan.

Etymology

Specific epithet ‘glabra’ refers to the glabrous cap found in species of section Parasola of the genus Parasola, where this species belongs.

Additional specimen examined

PAKISTAN, Khyber Pakhtunkhwa Province, Malakand, Qaldara, 480 m alt., 28 May 2015, S. Hussain SHP23 (HUP SHP-23).

Comments

The distinguishing features of the new species P. glabra are: basidiospores broadly ovoid to oblong, some with rhomboidal outline in face view, ellipsoid in side view, on range 14.5–16.5 × 9.5–11.5 × 8.0–10.5 µm, pileus light gray to moderate gray but reddish orange at the disk, without sclerocystidia. Lacking sclerocystidia, P. glabra belongs in section Parasola. On basidiospore dimensions, it could be thought close to P. plicatilis and P. megasperma (P.D. Orton) Redhead, Vilgalys & Hopple but these are distinguishable on the basis of spores shape, length and breadth together and on the color of the cap disk. Using maximum likelihood phylogeny, these two species are clearly distinct from P. glabra and, based on ITS and 28S loci, the more closely related species are: P. hercules (Uljé & Bas) Redhead, Vilgalys & Hopple; P. kuehneri (Uljé & Bas) Redhead, Vilgalys & Hopple; P. lilatincta and P. schroeteri (P. Karst.) Redhead, Vilgalys & Hopple. The new species can be distinguished from these species on account of basidiospore morphology: among these species, P. hercules has the largest spore breadth (11.3–16.9 µm), followed by P. schroeteri (9–13 µm), P. glabra (9.5–11.5 µm), P. lilatincta (9–11.2 µm) and smallest spore breadth (5.5–8.4 µm) in P. kuehneri. On the basis of basidiospore length/breadth ratio (Q1), the new taxon P. glabra (Q1 = 1.3–1.5), can be easily distinguished from these species: in P. hercules (Q1 = 1.04–1.28), P. schroeteri (Q1 = 1.16–1.27), P. lilatincta (Q1 = 1.14–1.33) and P. kuehneri (Q1 = 1.12–1.28), respectively (Nagy et al. 2010, Schafer 2014). Comparison of morphological characters of P. glabra with regards to these and other species of section Parasola genus Parasola are set out further in Table 2.

Characteristics distinguishing Parasola glabra and P. pseudolactea from the remaining species in section Parasola.

Taxa Pileus diam; and pileus color Stipe size Basidiospores size, length/breadth (Q1), length/width (Q2) ratios Basidiopores shape and germ-pore position References
P. glabra 20–30 mm diam, light-gray to moderate-gray 30–60 × 2–3 mm 15.8 × 10.9 × 10.1 µm; Q1 = 1.3–1.5, Q2 = 1.4–1.6, avQ = 1.4 In face view broadly ovoid to oblong, some with rhomboidal outline, in side view ellipsoid; germ-pore eccentric, upto 1.5 µm diam. Observed during this study.
P. hercules 15–20 mm diam, orange-brown to red-brown 75 × 1.5 mm 15.83 × 15.42 × 10.63 µm;Q1 = 1–1.15, Q2 = 1.4–1.5 In face view rounded triangular to quadrangular, rarely subglobose to ovoid, in side view ellipsoid to amygdaliform; germ-pore eccentric, upto 2.7µm diam. Nagy et al. 2010, Schafer 2014.
P. kuehneri 35 mm diam, dark light grayish-brown 100 × 3 mm 9.36 × 7.85 × 5.9 µm;Q1 = 1.1–1.2, Q2 = 1.4–1.6 In face view ovoid to rounded triangular, rhomboid to mitriform, in side view amygdaliform; germ- pore eccentric, 1.5 µm diam. Nagy et al. 2010, Schafer 2014.
P. lactea 15–23 mm diam, yellow-brown to dull red-brown 140 × 3 mm 10.73 × 8.81 × 6.73 μm; Q1 = 1.02–1.25, Q2 = 1.66–2.10 In face view mostly broadly ovoid to subglobose, rarely angular to rounded triangular, in side view broadly ellipsoid to ellipsoid; germ-pore eccentric, upto 1.8 μm diam. Nagy et al. 2010, Schafer 2014.
P. pseudolactea 15–25 mm diam, initially yellow-brown to dull-brown, moderate gray at maturity 30–50 × 1 mm 14.0 × 11.3 × 9.7 µm; Q1 = 1.3–1.5, Q2 = 1.4–1.5, avQ = 1.4 In face view mostly rounded triangular to heart shape, rarely ovoid to subglobose, in side view ellipsoid to oblong, germ-pore eccentric, upto 1.5 µm diam. Observed during this study
P. lilatincta 30–50 mm diam, dark reddish brown, not plicate 70–100 ×2–4 mm 14.4 × 10.8 × 9.2 µm; Q1 = 1.3–1.4, Q2 = 1.3–1.5 In face view rounded triangular to quadrangular, in side view ellipsoid to amygdaliform; germ-pore eccentric, upto 2.5 µm diam. Uljé and Bender 1997, Nagy et al. 2010, Schafer 2014, Hussain et al. 2016.
P. megasperma 35 mm diam, chestnut-brown to red-brown or ochre-tawny 50–100 × 1.5–3 mm 16.5 × 10.66 × 8.5 μm; Q1 = 1.40–1.78, Q2 = 1.83–1.95 In face view ellipsoid to broadly ellipsoid, rarely ovoid, in side view ellipsoid to subamygdaliform; germ-pore slightly eccentric, upto 2.3 µm diam. Nagy et al. 2010, Schafer 2014.
P. misera 2–5 × 1–3 mm, tawny-orange to cinnamon-brown 50 × 0.5 mm 7.0–10.6 × 6.5–10.0 × 5.9–6.6 μm In face view heart-shape to rounded triangular, irregularly globose, in side view ellipsoid; sometimes broader than long; germ-pore eccentric. Schafer 2014.
P. plicatilis 35 mm diam, yellow-brown to dull pinkish-brown 30–70 × 0.5–3 mm 12.41 × 8.21 × 7.14 μm; Q1 = 1.34–1.67, Q2 = 1.61–1.86 In face view mostly leminiform-subhexagonal, rarely ovoid, in side view ellipsoid to subamygdaliform; germ-pore eccentric, 2.3 µm diam. Nagy et al. 2010, Schafer 2014.
P. schroeteri 20–30 mm diam, yellow-brown to grayish red-brown 40–60 × 1 mm 14.44 × 11.83 × 9.72 μm, Q1 = 1.16–1.27, Q2 = 1.46–1.68 In the face view rounded triangular to subglobose, in side view ovoid to amygdaliform; germ-pore eccentric, upto 2.5 μm diam. Uljé and Bender 1997, Nagy et al. 2010, Schafer 2014.

Parasola pseudolactea Sadiqullah, Hussain & Khalid, sp. nov.

MycoBank No: MB819600
Figures 6, 7

Diagnosis

Pileus yellowish brown to dull brown, deeply plicate towards margin; disc subumbilicate, deep orange yellow; lamellae free, pseudocollarium absent; basidiospores 13.5–14.5 × 10.5–12.0 × 9.5–10.5 µm, in face view rounded triangular to heart shape, rarely ovoid to subglobose, in side view ellipsoid to oblong, with eccentric germ-pore of 1.5 µm diam; sclerocystidia absent.

Type

PAKISTAN, Khyber Pakhtunkhwa Province, Shangla, solitary to scattered under Quercus incana, 1480 m alt., 9 July 2014, Sadiq Ullah SU412 (holotype: HUP SU-412; GenBank accessions: ITS = KY461719; 28S = KY621799; TEF1α = KY461733).

Description

Pileus 15–25 mm diam, initially obtusely conical, later becoming applanate and deeply plicate towards margin; yellowish brown to dull brown (10YR 6/4) when young, moderate gray (7.5R 6/2) on maturity; disk subumbilicate, deep orange-yellow (7.5YR 6/12). Lamellae free, 0–2 lamellulae, distant, pseudocollarium absent, initially dark gray, becoming blackish at maturity and finally losing turgor and collapsing. Stipe 30–50 × 1 mm, equal, smooth, grayish-brown, translucent, hollow, without annulus.

Figure 6. 

Basidiomata of Parasola pseudolactea sp. nov. P. auricoma and P. lilatincta. A Parasola pseudolactea sp. nov. collection SU-412 (HOLOTYPE HUP SU-412) B Parasola lilatincta collection SHP-8 (HUP-SHP-8) C Parasola auricoma collection SHP7 (LAH-SHP-7). Scale bars: 20 mm.

Figure 7. 

Anatomical features of Parasola pseudolactea sp. nov (HUP-SU-412). A Basidiospores B Basidia C Pileipellis D Pleurocystidia E Cheilocystidia. Scale bars: 12 µm (A), 20 µm (B–E).

Basidiospores (12.0)13.5–15.0(16.0) × (9.5)10.5–12.0(13.0) × (7.5)9.5–10.5(12.0) µm, on average 14.0 × 11.3 × 9.7 µm, Q1 = 1.3–1.5, Q2 = 1.4–1.5, avQ = 1.4; in face view mostly rounded triangular to heart shaped, rarely ovoid to subglobose, in side view ellipsoid to oblong, with eccentric germ pore of 1–1.5 µm diam, dark to blackish in KOH. Basidia 24–31 × 8–12 µm, clavate to cylindrical, 4-spored. Cheilocystidia 55–70 × 22–29 µm, clavate, broadly clavate to broadly cylindrical. Pleurocystidia 44–67 × 19–23 µm, utriform to lageniform. Pileipellis hymeniform, consisting of clavate cells, 33–38 × 17–22 µm. Clamp connections present. Sclerocystidia absent.

Habitat and distribution

Solitary to scattered on humus rich loamy soil, under Quercus incana. So far only known from northwest Pakistan.

Etymology

The prefix “pseudo” means similar and “lactea” refers to the epithet of the species (Parasola lactea) that this species closely resembles. This species is known so far from low to moderate altitude mountains of northwest Pakistan.

Additional specimens examined

PAKISTAN, Khyber Pakhtunkhwa Province, Shangla, 1480 m alt., 9 July 2014, Sadiq Ullah SU413 (HUP SU-413).

Comments

The new species belongs to Parasola section Parasola due to the absence of sclerocystida in the pileipellis. This species resembles Parasola lactea and is close to that species in the molecular phylograms. However, its spores are substantially larger, closer to P. schroeteri or P. hercules in size. The spores of P. pseudolactea are mostly rounded triangular, rarely ovoid to subglobose in face view and larger (14.0 × 11.3 × 9.7 µm), whereas those of P. lactea are mostly broadly ovoid to subglobose, rarely rounded triangular in face view, and comparatively smaller (10.73 × 8.81 × 6.73 μm). Other species similar to the new taxon are P. megasperma and P. plicatilis. Both these species share pileus color with P. pseudolactea. Lamellae of P. megasperma and P. plicatilis are separated from the stipe by a pseudocollarium, whereas in P. pseudolactea, a pseudocollarium is generally absent. Basidiospores are more ellipsoid rarely ovoid in face view and on average 16.5 × 10.66 × 8.5 μm in P. megasperma. Basidiospore shape is quite variable in P. plicatilis, in face view mostly limoniform-subhexagonal, rarely ovoid, in side view broadly ellipsoid, on average 12.41 × 8.21 × 7.14 μm (Nagy et al. 2010). Comparison of morpho-anatomical features of P. pseudolactea with regards to other species of the genus Parasola are set out in Table 2, where the new species can be differentiated by careful comparison of the morphology of its basidiospores.

Parasola auricoma (Pat.) Redhead, Vilgalys & Hopple, Taxon 50: 235. 2001.

Figures 6, 8

Synonymy

Coprinus auricomus Pat., Tab. analyt. Fung. 5: 200, 1886.

Description

Pileus 15–30 mm diam, convex to broadly convex, deeply plicate towards the margin, light grayish-brown (2.5YR 5/2) to grayish reddish-brown (2.5YR 3/2); disc indistinctly umbonate to umbilicate, dark reddish orange (7.5R 4/8) to grayish reddish orange (2.5YR 5/6). Lamellae free and remote, pseudocollarium absent, closed, initially concolorous with pileus, later on dark black, finally losing turgor and collapsing. Stipe 40–65 × 2–5 mm, equal, smooth, central, hollow, without annulus.

Figure 8. 

Anatomical features of Parasola auricoma (LAH-SHP-7). A Basidiospores B Basidia C Cheilocystidia D Pileipellis. Scale bars: A = 10 µm, B–D = 20 µm.

Basidiospores (10.5)12.5–13.5(15.0) × (8.0)8.5–9.5(10.0) × (7.0)8.0–9.0(10.0) μm, on average 12.9 × 9.0 × 8.5 μm, Q1 = 1.5–1.6, Q2 = 1.3–1.4, avQ = 1.5; in face view subcylindrical to ellipsoid or ovoid, in side view ellipsoidal to elliptical; with central germ-pore, 2–2.5 μm diam, wall 1.5 µm thick, strong reddish-brown to blackish in KOH. Basidia 30–38 × 7–11 μm, clavate to subcylindrical, 2- or 4-spored. Cheliocystidia 33–45 × 12–25 μm, subclavate to subglobose, abundant. Pleurocystidia 30–40 × 11–15 μm, cylindrical to clavate, pale brown at the base, rare. Sclerocystidia 90–170 × 4–7 μm, dark brown, with acute apex and bulbous base, wall 1.5–2 μm thick. Clamp connection present.

Specimens examined

Pakistan, Khyber Pakhtunkhwa Province, Malakand, Kharkai, alt. 460 m, scattered in grassland under herbaceous plants, 10 August 2014, S. Hussain SHP6 (LAH-SHP-6), 10 August 2014, S. Hussain SHP7 (LAH-SHP-7), Malakand, Qaldara 10 August 2014, S. Hussain SHP11 (LAH-SHP-11); Khyber Pukhtunkhwa Province, Swat, Kanju Township, alt. 1023 m, 27 July 2017, S. Hussain SHP34 (SWAT SHP-34).

Parasola lilatincta (Bender & Uljé) Redhead, Vilgalys & Hopple, Taxon 50: 236. 2001.

Figures 6, 9

Synonymy

Coprinus lilatinctus Bender & Uljé, Persoonia 16: 373, 1997.

Description

Pileus 20–30 mm diam, hemispheric to pulvinate, smooth, deeply plicate towards margin, yellow brown (2.5R 9/2–5R 9/2) to grayish red brown (2.5R 7/2–5R 7/2); disc slightly depressed, brilliant orange (2.5YR 8/12 – 5YR 8/12) to strong orange (2.5YR 6/12–5YR 6/12). Lamellae free, separated from the stipe by pseudocollarium, distant, lamellae edge blackish while faces initially concolorous with the pileus but later on black and finally losing turgor and collapsing. Stipe 40–60 × 1 mm, equal, smooth, white, fragile, without annulus with slightly sub-bulbous base.

Figure 9. 

Anatomical features of Parasola lilatincta (LAH-SHP-8). A Basidiospores BBasidia C Pleurocystidia D Cheilocystidia E Pileipellis. Scale bars: A = 10 µm, B–E = 20 µm.

Basidiospores (12)13–14.5(15.5) × (11.5)12–12.5(13.5) × (6.0)8.5–11(13.5) μm, on average 14.5 × 12.5 × 9.9 μm, Q1 = 1.1–1.2, Q2 = 1.2–1.5, avQ = 1.3; in the face view rounded triangular to subglobose, in side view ovoid to amygdaliform, with eccentric germ-pore of 2–2.5 μm diam; wall upto 2 µm thick, dark brown in KOH. Basidia 17–22 × 6–9 μm, 4-spored, cylindrical to clavate, hyaline in KOH. Cheilocystidia 25–29 × 23–26 μm, rounded to globose, rare. Pleurocystidia 34–40 × 11–14 μm, cylindrical to subclavate. Pileipellis of clavate cells, 33–37 × 9–12 μm, with rounded apex, bright yellow at the base. Clamp connections present in most of the tissues. Sclerocystidia absent.

Specimens examined

PAKISTAN, Khyber Pakhtunkhwa Province, Malakand, Qaldara, alt. 430 m, scattered under herbaceous plants, 11 August 2014, S. Hussain SHP-8, SHP-31, SHP-12 (LAH SHP-8; LAH SHP-31; LAH SHP-12); Khyber Pakhtunkhwa Province, Swat, Kanju Township, alt. 1023 m, on road trails, 27 July 2017, S. Hussain SHP35 (SWAT SHP-35).

Discussion

The incorporation of molecular phylogenetics has significantly benefited the systematic and taxonomic studies of coprinoid mushrooms. These mushrooms are deliquescent or, at least, have morphological characters like gill cystidia, coloration and surface features that are quickly changed during basidioma maturation. So morphology based taxonomy of coprinoid mushrooms is always a difficult task for mushroom biologists. In the present study two new species of mushroom genus Parasola are described from Pakistan, based on morphological and molecular data.

On account of absence of sclerocystidia in the pileipellis, both the new species P. glabra and P. pseudolactea belong to section Parasola of genus Parasola. Parasola glabra with light gray to moderate gray pileus was collected in Malakand region of Pakistan. This region is rich in diversity of Parasola species (Hussain et al. 2016, 2017). The new species P. glabra with broadly ovoid to oblong, some with rhomboidal basdiospore is closely related to P. hercules. Morphological features of P. glabra are discussed with other species of section Parasola genus Parasola, set out in Table 2. Phylogenetic inference of P. glabra based on ITS and combined ITS-28S datasets was strongly supported (MLB 100% and BPP 1). While in combined ITS-28S-TEF1a dataset, P. glabra was represented by single specimen and was poorly recovered.

Similarly, the second new species P. pseudolactea in this study was collected in Shangla district, Khyber Pakhtunkhwa province of Pakistan. This species with yellow brown to dull brown pileus, basidiospores mostly rounded triangular to heart shape, was found in a Quercus forest. The species most closely related to P. pseudolactea on the basis of basidiospore morphology is P. lactea. Basidiospores are mostly rounded triangular to heart shape, rarely ovoid to subglobose in face view in P. pseudolactea; while spores are ovoid to subglobose, rarely rounded triangular in face view in P. lactea. A poorly described species P. subprona (Cleland) J.A. Simpson & Grgur. with elliptical basidiospores (15 × 8 µm) can be differentiated from both the new species on account of central germ-pore (Grgurinovic 1997). Phylogenetic analyses recovered P. pseudolactea well supported in ITS, combined ITS-28S and combined ITS-28S-TEF1a datasets (Figures 1, 2 and 3), respectively. Along with these new species, collections of P. auricoma and P. lilatincta from Pakistan were also documented in this study. The phylogenetic separation of P. auricoma collected in Pakistan from European collections (albeit into adjacent clades) suggests that the taxon from Pakistan may be a distinct, previously undescribed species. However, morphological features do not yet provide a basis for distinguishing separate species.

Conclusion

It is concluded form this study that low altitude mountains of northern Khyber Pakhtunkhwa Province of Pakistan are rich in the diversity of Parasola and other coprinoid mushrooms.

Acknowledgments

We greatly acknowledge Derek J. Schafer (UK) and Laszlo G. Nagy (Synthetic and Systems Biology Unit, Institute of Biochemistry, BRC, Szeged, Hungary) for the critical review of the manuscript. Financial support for this study was provided by the Higher Education Commission of Pakistan under International Research Support Initiative Program (IRSIP). Molecular work was carried out in Molecular Lab, Department of Organismic and Evolutionary Biology, Harvard University.

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