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1 Botany Department, Field Museum, 1400 S. Lake Shore Dr, Chicago, IL 60605,
U.S.A.
2 Department of Biological Sciences, University of Illinois at Chicago, 845
W. Taylor St (MC 066), Chicago, IL 60607, U.S.A.
3 National Museums of Kenya, Botany Department, P.O. Box 45166, 00100,
Nairobi, Kenya
* Correspondence: G.K. Mugambi,
gkmugambi{at}gmail.com
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Abstract |
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 TOP Abstract INTRODUCTIONMATERIALS AND METHODSRESULTSTAXONOMYDISCUSSIONCONCLUSIONReferences |
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Taxonomic novelties: Misturatosphaeria Mugambi & Huhndorf, gen. nov., M. aurantonotata Mugambi & Huhndorf, sp. nov., M. claviformis Mugambi & Huhndorf, sp. nov., M. cruciformis Mugambi & Huhndorf, sp. nov., M. kenyensis Mugambi & Huhndorf, sp. nov., M. minima Mugambi, A.N. Mill. & Huhndorf, sp. nov., M. tennesseensis Mugambi, A.N. Mill. & Huhndorf, sp. nov., M. uniseptata Mugambi, A.N. Mill. & Huhndorf, sp. nov., M. uniseriata Mugambi, A.N. Mill. & Huhndorf, sp. nov.
Keywords Eumycota / evolution / fungi / Hypsostromataceae / phylogeny / taxonomy
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INTRODUCTION |
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TOPAbstractINTRODUCTIONMATERIALS AND METHODSRESULTSTAXONOMYDISCUSSIONCONCLUSIONReferences |
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Although the concept of Pleosporales has recently attained some consensus (e.g. Winka 2000, Lumbsch & Lindemuth 2001, Kruys et al. 2006, Schoch et al. 2006, Lumbsch & Huhndorf 2007, Kirk et al. 2008, Zhang et al. 2008), many authors have differed on the circumscription of the families therein (e.g. Chesters & Bell 1970, Holm & Holm 1988, Barr 1984, 1987, 1990a, b, Lumbsch & Huhndorf 2007, Kirk et al. 2008). In Melanommataceae, Barr (1990a) accepted five genera, Kirk et al. (2008) accepted 21 genera, while Lumbsch & Huhndorf (2007) accept 18 genera with six of questionable placement. The taxonomy of Lophiostomataceae, another family in Pleosporales, has followed a similar path with Barr (1987) recognising six genera, Holm & Holm (1988) five genera, while Kirk et al., (2008) treated 15 genera and Lumbsch & Huhndorf (2007) 12 genera in the family.
Barr's (1990a) treatment of Melanommataceae included the following genera: Ostropella, Keissleriella, Strickeria, Byssosphaeria and Melanomma united on the basis of similar erumpent to superficial ascomata with walls composed of small, thick-walled cells. Byssosphaeria was re-instated by Barr (1984) for species that are separable from Herpotrichia, where it had been in synonymy for many years. The classification of Byssosphaeria, Herpotrichia and Pseudotrichia has posed major challenges to many authors because the morphological characters used to distinguish between the genera are not necessarily obvious (Samuels & Müller 1978). This has resulted in varied taxonomic treatments of the groups (e.g. Bose 1961, Samuels 1973, Samuels & Müller 1978, Barr 1984). Detailed taxonomic revision on the genera is offered by Bose (1961) and Barr (1984). The two studies provide detailed morphological characters distinguishing the genera. Pseudotrichia differs from Herpotrichia in its rather large ascomata, often with compressed apices, while in Herpotrichia smaller ascomata are often covered with long flexuous hyphae and with subiculum that sometimes overgrows the fruiting bodies (Bose 1961, Barr 1984). Byssosphaeria on the other hand possesses superficial ascomata that are turbinate with a rounded pore and apical area that is usually light coloured (Barr, 1984). Barr (1984) initially segregated Herpotrichia into Massarinaceae but later transferred it to Lophiostomataceae (Barr 1987). Bose's (1961) study on Massarina and related genera concluded that Massarina, Herpotrichia and Keissleriella are distinct but closely related, and he placed them in the Pleosporaceae citing lack of striking characters to justify the creation of a new family. Pseudotrichia was described for ascomycete fungi with immersed-erumpent to superficial ascomata with rounded or laterally compressed apex. On the basis of the shape of the apex, Petrak (1940) placed it in Lophiostomataceae. However, Barr (1990a) accepted the genus in Platystomaceae and noted substantial variability in ascomatal apical morphology. She observed that even in a single collection it could be rounded or compressed to somewhat triangular.
The genus Ostropella was originally named as a subgenus of Ostropa for O. albocincta and was raised to generic status and redescribed by von Höhnel (1918). Müller & von Arx (1962) reduced Schizostoma, Xenolophium and Ostreionella all to synonymy under Ostropella. Barr (1990a) provided the history of Ostropella and its relationship to these other taxa. Holm & Yue (1988) presented work on Schizostoma in which they tried to clarify some misconceptions that have surrounded the genus since its establishment and to resolve the placement of some species. Chesters & Bell (1970) reduced Xenolophium into synonymy under Lophiostoma and treated it in their "L. pachythele group". Barr (1990a) pointed to the close relationship of Xenolophium to Ostropella and proposed it be accommodated under Ostropella. She also noted the differences between the low apical crest observed in Ostropella (that appears almost ornamental) from the compressed papilla in Lophiostoma and thus placed the genus in Melanommataceae. Xenolophium was established for two species of fungi from Hawaii by Sydow (in Stevens 1925). However, the genus was in synonymy for a long time until resurrected by Huhndorf (1993) who also added two new species to the group. She treated Ostropella and Xenolophium in Melanommataceae and distinguished the two genera based on their ascomatal surface structure, morphology of the ascomatal wall in longitudinal section and ascospore morphology.
Lophiostomataceae was first erected by Nitschke (1869) and in its long existence the group has greatly increased in size. The overall character that has historically been used to distinguish the family is the slit-like ostiolar opening on a laterally compressed papilla (Chesters & Bell 1970, Holm & Holm 1988). Chesters & Bell (1970) considered the family to comprise taxa with laterally compressed apices, hence they included Lophiostoma, and Platystomum in the group. However, the variability in the papillate form in the lophiostomataceous fungi had been noted for quite some time with certain species exhibiting mixed morphologies even within a single collection (Holm 1957, Eriksson 1981, Holm & Holm 1988, Barr 1990a). Holm & Holm (1988) took a broad concept of the family including taxa with laterally compressed and rounded apices in the group. They accepted five genera in the family, Lophiostoma, Lophiotrema, Massariosphaeria, Navicella and Trematosphaeria, while Barr (1987) accepted Dangeardiella, Herpotrichia, Massarina, Lophiostoma, Lophidiopsis, Trichometasphaeria, and Cilioplea. Recent molecular studies seem to support the view that the family is not exclusively composed of taxa with compressed papillae and that some taxa traditionally placed in this group belong elsewhere (e.g. Wang et al. 2007, Zhang et al. 2008).
Lophiostoma was circumscribed by Holm & Holm (1988) to include taxa that have immersed-erumpent ascomata with a distinctly flattened neck and opening by a slit-like ostiole. Asci are mostly clavate and ascospores are 1-septate, multiseptate or muriform, hyaline to dark brown. Recent phylogenetic work carried out on Lophiostoma species bearing these typical characters including the type species, L. macrostomum, indicated that the genus formed a monophyletic group (Tanaka & Hosoya 2008). Lophiotrema on the other hand was erected by Saccardo for "Hyalophragmiae" and has been used in this sense for a long time. Its circumscription is thus highly heterogeneous (Holm & Holm 1988). Chester & Bell (1970) did not recognise Lophiotrema but Holm & Holm (1988) accepted it in the strict sense for the group comprising the type species. Massariosphaeria was revised by Crivelli (1983) and Leuchtmann (1984) and its principal characteristics are the gelatinous ascospore sheath and tendency towards formation of red pigment, especially in mycelial cultures (Holm & Holm 1988). Leuchtmann (1984) transferred Lophiotrema microthecum to the group as M. grandispora. Recent molecular study of Massariosphaeria by Wang et al. (2007) indicated that the genus is highly polyphyletic with only M. grandispora among the species included in the analyses grouping in Lophiostomataceae.
Hypsostromataceae (Huhndorf 1994) was described for two tropical genera, Hypsostroma and Manglicola. In setting up the family Huhndorf (1994) noted its affinities to taxa in the Melanommatales (= Pleosporales) where she suggested it belonged but appeared unrelated to any known families. Characters that united the two genera in the family included superficial, large, elongate ascomata, soft-textured pseudoparenchymatous wall, trabeculate pseudoparaphyses, asci with an apical chamber and fluorescing ring and stipitate, basally arranged and fusiform, septate ascospores (Huhndorf 1994). Hypsostroma was erected by Huhndorf (1992) for two tropical wood-inhabiting species H. saxicola and H. caimitalensis. The two species bear close morphological resemblance, only slightly differing in their ascomatal and ascospore characters, with H. caimitalensis bearing long papillate ascomata and ascospores constricted at septum. Currently the family resides in the Dothideomycetes, family incertae sedis (Lumbsch & Huhndorf 2007).
Many of the recent molecular phylogenetic studies involving the Pleosporales seem to reject the monophyly of the families in the order (e.g. Liew et al. 2000, Lumbsch & Lindemuth 2001, Kruys et al. 2006, Schoch et al. 2006, Wang et al. 2007, Zhang et al. 2008). This polyphyly witnessed in major lineages within Pleosporales indicates that the order is in urgent need for revision. This study contributes to this endeavor and it employs two nuclear gene markers, nuclear ribosomal large subunit DNA (LSU) and translation elongation factor 1-alpha (TEF) in order to: 1) assess the generic constitution and relationships within Melanommataceae and Lophiostomataceae, 2) verify the phylogenetic placement of the genus Hypsostroma, 3) discuss phylogenetic findings with respect to morphological-based classification schemes.
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MATERIALS AND METHODS |
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TOPAbstractINTRODUCTIONMATERIALS AND METHODSRESULTSTAXONOMYDISCUSSIONCONCLUSIONReferences |
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DNA extraction, PCR amplification, sequencing and sequence alignment
Total fungal DNA was extracted from whole fruiting bodies using the DNeasy
Plant Mini Kit (Qiagen, Hilden, Germany) following the instructions of the
manufacturer. Phylogenetic analyses were conducted using partial sequences of
two genes, the Translation Elongation Factor 1-Alpha (TEF) and nuclear
ribosomal large subunit (LSU) DNA. Nuclear LSU was amplified using the primers
LR0R, LR6 and LR3 (Vilgalys & Hester
1990) and TEF was amplified using primers EF1-526F, EF1-983F,
EF1-1567R, Ef-df and EF-gr obtained from D. Hibbett's website
(www.clarku.edu/faculty/dhibbett/Protocols_Folder/Primers/Primers.htm).
Polymerase chain reaction (PCR) was carried out using the following protocol: The final volume of the PCR reaction was 25 µL and contained 2.5 µL buffer, 2.5 µL dNTP mix, 1 µL of each primer (10 µM), 5 µL of Bovine Serum Albumin (BSA), 1.5 µL Taq polymerase (Roche®, U.S.A.), 2 µL genomic DNA extract and 9.5 µL deionised water. The reaction was then allowed to run for 34 cycles. The annealing temperature was 50 °C for LSU, and initial 58 °C for TEF and then reduced by 1 °C during each of the first eight cycles and maintained at 50 °C for the remaining cycles. The fragments were sequenced using the Big Dye® Terminator Cycle Sequencing kit v. 3.1 (ABI PRISM, Applied Biosystems, Forster City, U.S.A.). Sequencing was performed using the same set of primers as the PCR. The other sequences used in the analyses were obtained from GenBank. Sequences were aligned using multiple sequence program Muscle® v. 3.6 (Edger 2004). The alignments were further manipulated manually and those regions, which could not be aligned with confidence were excluded from analyses. The final data matrices comprised of LSU data set with 140 taxa with 1179 unambiguously aligned characters, and a TEF data set with 57 taxa and 750 unambiguously aligned characters while the combined data set comprised of 49 taxa for which both genes were available with 1929 unambiguously aligned characters. Voucher specimens are deposited in the Field Museum Herbarium (F), while Kenyan specimens are deposited at the East Africa Herbarium (EA).
Phylogenetic analyses
MODELTEST v. 3.7 (Posada &
Crandall, 1998) following Akaike Information Criterion was used to
determine the best-fit model of evolution for each data set for Bayesian and
Maximum Likelihood analyses. Bayesian analyses employing Markov Chain Monte
Carlo (MCMC) were carried out using MrBayes v. 3.1
(Huelsenbeck & Ronquist,
2001). Four MCMC chains were ran simultaneously for 5–7
million generations for single-gene and combined gene analyses, the
temperature of the heated chains was set at 0.05 for LSU and at 0.2 for TEF
and combined gene analyses. Trees were sampled every 100th
generation. The TEF gene matrix was partitioned into three parts to take into
account the codon positions, while combined gene matrix had four partitions.
Independent models of evolution were applied on the partitions for Bayesian
analyses. AWTY was used to check the stationarity of the Bayesian tree
sampling procedure (Nylander et
al. 2007). All the trees obtained before the MCMC chains
attained stationarity in each analysis were discarded and posterior clade
probabilities were determined from the consensus tree generated from the rest.
The majority rule consensus tree was obtained by executing the MrBayes sumt
command. Maximum likelihood (ML) analyses were carried out for each of the
three data sets using RAxML (Stamatakis et al. 2008) employing mixed
models of evolution settings of the program and Bootstrap support obtained by
running 1000 pseudo replicates. Five independent ML tree searches were done in
RAxML (Stamatakis et al. 2008) each one starting from randomised
tree.
Test of conflict was based on single gene analyses and doing comparison based on Bootstrap and Bayesian posterior probabilities support. Clades with greater than or equal to 70 % bootstrap support (BS) and 95 % posterior probabilities (PP) were considered strongly supported. There were no major conflicts in the phylogenies obtained from single-gene analyses. The differences observed were mainly the family relationships in the Pleosporales, which nonetheless received low support. As a result the data sets were combined for Maximum Likelihood (ML) and Bayesian analyses.
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RESULTS |
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Hypsostromataceae was recovered as a well-supported clade within Pleosporales comprising two species accepted in the family (Fig. 1). Species of Ostropella, Xenolophium (except Xenolophium pachythele that groups separate in TEF tree) and other taxa assemble in a mostly unsupported clade together with a collection of Platystomum compressum, possibly representing the Platystomaceae. The taxa group together in all three trees but only obtain PP support in the combined gene tree (Fig. 3). A monophyletic clade for Delitschiaceae was recovered within Pleosporales; Hysteriaceae, Mytilinidiaceae, Gloniaceae and Tubeufiaceae were recovered as strongly supported monophyletic groups outside the Pleosporales (Figs 1, 2, 3).
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TAXONOMY |
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Etymology: Misturatus (L.) = mixed, refers to the mixed ascospore morphology in the group.
Ascomata erumpentia ad superficialia, solitaria vel aggregata, cum subiculum vel sine subicolo, apicibus rotundatis pallide coloratis vel incoloratis. Asci claviti vel cylindrici, breve stipitati, octospori, pseudoparaphysibus numerosis, hyalinis et septatis, in matrice mucosa. Ascosporae hyalinae vel brunneae, septatae, cum vagina mucosa vel sine vagina.
Typus: Misturatosphaeria aurantonotata Mugambi & Huhndorf, sp. nov.
Ascomata erumpent to superficial, occurring singly or aggregated in clusters, subiculum present or lacking, apex rounded, with raised papilla or not, ostiole area light coloured or not and ostiole opening appearing plugged by gelatinous tissue. Asci cylindrical or clavate, short stipitate, 8-spored, held in gelatinous matrix, pseudoparaphyses numerous, septate, branching and anastomosing between and above the asci. Ascospores brown or hyaline, phragmosporous or dictyosporous, external walls roughened or smooth, with or without a gelatinous sheath covering.
Misturatosphaeria aurantonotata Mugambi & Huhndorf, sp. nov. MycoBank MB516007. Fig. 25.
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Ascomata superficialia, atrobrunnea, solitaria vel dense aggregata, in subiculo sparso ex hyphis brunneis, pyriformia, 441–710 µm alta, 461–573 µm diam, apicibus rotundatis, saepe aurantiacis. Asci cylindrici-clavati, breve stipitati, octospori, 103–122 x 8–12 µm. Pseudoparaphyses numerosae, septatae, in matrice mucosa, 1–2 µm. Ascosporae fusoides, primo hyalinae, deinde atrobrunnae, 3-septatae, cum vagina mucosa, 17–22 x 5–6 µm.
Ascomata superficial, occurring singly or aggregated into large clusters, occasionally even growing on old ascomatal tissue, often sited on sparse brown subiculum, pyriform in shape, dark brown, ascomatal wall smooth, 441–710 µm high, 461–573 µm wide. Apices rounded, usually with raised papillae, ostiole area orange in colour or the colouring lacking all together. Asci are cylindrical–clavate with short stipes, 8-spored partially biseriate in arrangement, 103–122 x 8–12 µm. Pseudoparaphyses are numerous, septate, branching and anastomosing between and above the asci, held in gelatinous matrix, 1–2 µm diam. Ascospores fusiform, often slightly curved, first hyaline later becoming brown to dark brown, the outer walls are thick and roughened, 3-septate at maturity, one of the middle cells is often larger than the rest, only slightly constricted at the middle septum. Mucilaginous sheath present when the spores are young and falls off upon attaining maturity, 17–22 x 5–6 µm.
Substratum: Found on decorticated woody branches on the ground.
Anamorph: Unknown.
Distribution: Presently only known from two tropical forests in the central highlands of Kenya.
Specimens examined: Kenya, Rift Valley Province, Kajiando District, Ngong hills forest res., 1°23'934"S, 36°38'287"E, 12 July 2006, on woody branch, G.K. Mugambi, GKM1238, holotype EA, isotype F; Koibatek District, Lembus forest along Eldoret-Eldama Ravine Rd, 0°04'N, 35°35'E, 19 Jan. 2007, on branch on the ground, G.K. Mugambi, GKM1280, EA, F.
Misturatosphaeria claviformis Mugambi & Huhndorf, sp. nov. MycoBank MB516008. Fig. 26.
Etymology: Clavatus (L.) = club, refers to the club-shaped ascomata usually witnessed in the species.
Ascomata erumpentia ad superficialia, atrobrunnea, solitaria vel sparse aggregata, sine subiculo, pyriformia ad obclavata, 235–520 µm alta, 195–322 µm diam, apicibus rotundatis, ostiolata. Asci cylindrici-clavati, breve stipitati, octospori, 85–134 x 12–18 µm. Pseudoparaphyses numerosae, septatae, in matrice mucosa, 1–2 µm diam. Ascosporae ellipticae, brunneae ad atrobrunnae, muriformes, since vagina mucosa, 12–20 x 7–9 µm.
Ascomata erumpent to superficial, occurring singly or aggregated into small groups, subiculum absent, pyriform to obclavate in shape, dark brown, ascomatal wall smooth, 235–520 µm high and 195–322 µm wide. Apices rounded, usually possess raised, broad rounded papillae also with rounded openings. Asci cylindrical-clavate, with short stipes, 8-spored partially biseriate or uniseriate, oblique or sometimes irregularly arranged in an oblique fashion or irregular, 85–134 x 12–18 µm. Pseudoparaphyses numerous, septate, branching and anastomosing between and above the asci, held in gelatinous matrix, 1–2 µm diam. Ascospores elliptical, straight or inequilateral, brown to dark brown in colour, outer wall smooth, dictyosporous, with no mucilaginous sheath, 12–20 x 7–9 µm.
Substratum: Found on decorticated woody branches on the ground in forested areas.
Anamorph: Unknown.
Distribution: Currently known only from a tropical highland forest in central Kenya.
Specimen examined: Kenya, Central Province, Nyeri District, Mt Kenya forest, behind Bantu lodge, 0°6'907"S, 37°2'699"E, 30 Nov. 2006, on woody branch, G.K. Mugambi, GKM1210, holotype EA, isotype F.
Misturatosphaeria cruciformis Mugambi & Huhndorf, sp. nov. MycoBank MB516009. Fig. 27.
Etymology: Cruciatus (L.) = cross-wise, refers to the ascospore septation, transverse and longitudinal septa.
Ascomata erumpentia, atrobrunnea, solitaria vel sparse aggregata, pyriformia, globosa, 500–535 µm alta, 545–649 µm diam, apicibus rotundatis, ostiolata, since subiculo. Asci cylindrici-clavati, breve stipitati, octospori, 127–154 x 14–17 µm. Pseudoparaphyses numerosae, septatae, in matrice mucosa, 1–2 µm diam. Ascosporae oblongae ad ellipticae, brunneae ad atrobrunnae, muriformes, saepe constrictae ad septum medium, sine vagina mucosa, 19–26 x 8–13 µm.
Ascomata erumpent, usually occurring singly rarely clustered into small groups, subiculum lacking, pyriform to globose in shape, dark brown, ascomatal wall smooth, 500–535 µm high and 545–649 µm wide. Apices are rounded with papillae that are usually raised, ostiole opening rounded. Asci cylindrical-clavate in shape and bearing short stipes, 8-spored partially biseriate to sometimes overlapping uniseriate, 127–154 x 14–17 µm. Pseudoparaphyses are numerous, septate, branching and anastomosing between and above the asci, held in a gelatinous matrix, 1–2 µm diam. Ascospores oblong to elliptical, brown becoming dark brown with age, outer wall smooth, dictyosporous, usually constricted at the middle transverse septum, possess no mucilaginous sheath, 19–26 x 8–13 µm.
Substratum: Found on decorticated woody branches on the ground.
Anamorph: Unknown.
Distribution: Currently only known from a forest reserve in Illinois, U.S.A.
Specimen examined: u.s.A., Illinois, Cook Co., Swallow Cliff Woods Forest Preserve, 21 May 2004, on woody branch, G.K. Mugambi, SMH5151, holotype, F.
Misturatosphaeria kenyensis Mugambi & Huhndorf, sp. nov. MycoBank MB516010. Figs 28–29.
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Ascomata erumpentia ad superficialia, solitaria vel dense aggregata, atrobrunnea, pyriformia ad globosa, 185–305 µm alta, 245–334 µm diam, apicibus rotundatis pallide coloratis, ostiolo rotundato. Asci cylindrici-clavati, breve stipitati, octospori, 71–79 x 8–9 µm. Pseudoparaphyses, numerosae, septatae, in matrice mucosa, 1–2 µm diam. Ascosporae fusoides, hyalinae, 1–3-septatae vulgo 1–septatae, cum vagina mucosa parva, 15–24 x 4–6 µm.
Ascomata erumpent to superficial, occurring singly or aggregated into large clusters, without subiculum, pyriform to globose in shape, dark brown, ascomatal wall smooth, 185–305 µm high and 245–334 µm wide. Apices rounded, usually with raised papillae, opening rounded and the ostiole area often of lighter colour. Asci cylindrical-clavate in shape, short stipitate, 8-spored, partially biseriate in arrangement, 71–79 x 8–9 µm. Pseudoparaphyses numerous and septate, branching and anastomosing between and above the asci, held in gelatinous matrix, 1–2 µm diam. Ascospores fusiform in shape, hyaline, outer wall smooth, usually 1–3-septate but commonly 1-septate, occasionally one of the middle cells broader than others, possess small mucilaginous sheaths that extends at the tip of spores, 15–24 x 4–6 µm.
Substratum: Found on decorticated woody branches on the ground.
Anamorph: Unknown.
Distribution: Presently only known from a tropical cloud forest in Kenya.
Specimen examined: Kenya, Coast Province, Taita Taveta District, Taita hills, Ngangao forest res., 3°22'30"S, 38°20'45"E, 30 Oct. 2006, on woody branch, G.K. Mugambi, GKM1195, holotype EA, isotype F.
Misturatosphaeria minima Mugambi, A.N. Mill. & Huhndorf, sp. nov. MycoBank MB516011. Figs 30–32.
Etymology: Minus (L.) = less, refers to the relatively smaller size ascomata observed in this species.
Ascomata erumpentia ad superficialia, solitaria vel sparse aggregata, atrobrunnea, pyriformia ad globosa, 194–389 µm alta, 244–355 µm diam, since subiculo, apicibus rotundatis saepe aurantiacis, ostiolo rotundato. Asci cylindrici-clavati, breve stipitati, octospori, 72–112 x 8–11 µm. Pseudoparaphyses numerosae, septatae, in matrice mucosae, 1–2 µm diam. Ascosporae fusoides, hyalinae, 1–3-septatae, constrictae ad septum medium, cum vagina mucosa parva, 18–22 x 3–4 µm.
Ascomata erumpent through the bark or sometimes appearing superficial after the breakdown of the surrounding plant tissue, occurring singly or aggregated into small clusters usually less than five individuals, possesses no subiculum, pyriform to subglobose in shape, dark brown, ascomatal wall smooth, 194–389 µm high and 244–355 µm wide. Apices rounded, raised with rounded openings, occassionally the pore area appear orange in colour or the colouring is lacking. Asci cylindrical-clavate in shape bearing short stipes, 8-spored partially biseriate in arrangement, 72–112 x 8–11 µm. Pseudoparaphyses are numerous, septate, branching and anastomosing between and above the asci, held in a gelatinous matrix, 1–2 µm diam. Ascospores are fusiform, hyaline, the outer wall smooth, 1–3-septate and constricted at the middle septum, one of the middle cells is broader than the rest, possesses a small mucilaginous sheath that extends at the tips of the spore, 18–22 x 3–4 µm.
Substratum: Found on decorticated woody branches on the ground.
Anamorph: Unknown.
Distribution: Currently known from forested areas in Kenya, Costa Rica and U.S.A.
Specimens examined: Kenya, Coast Province, Taita Taveta District, Taita hills, Ngangao forest res., 3° 22' 30" S, 38° 20' 45" E, 1800 m elev., 13 Apr. 2005, on woody branch, G.K. Mugambi, GKM169N, holotype EA, isotype F. costa rica, San Jose, Albergue de Montagne, Savegre, Sendero la Cataracta, 9° 32' 38" N, 83° 48' 51" W, 13 May 1996, on woody branch on the ground, S.M. Huhndorf, F. Fernández, SMH2448, F. u.s.A., North Carolina, Smoky Mountains National Park, Cataloochee, Rough Fork Trail, 35° 61' N, 83° 12' W, 868 m elev., 23 May 2006, 1 cm diam woody branch on ground, A.N. Miller, A.Y. Rossman, M. Sogonov, L. Vasilyeva, G.K. Mugambi, ANM933, ILLS; Tennessee: Smoky Mountains National Park, vic. of Gatlinburg, Grotto Falls Trailhead, 35° 68' N, 83° 46' W, 944 m elev., 12 July 2004, 1 cm diam woody branch on ground, A.N. Miller, S.M. Huhndorf, G.K. Mugambi, L. Ruiz-Sanchez, ANM60, ILLS.
Misturatosphaeria tennesseensis Mugambi, A.N. Mill. & Huhndorf, sp. nov. MycoBank MB516012. Fig. 33.
Etymology: Refers to the locality where the species was collected.
Ascomata erumpentia, solitaria vel dense aggregata, atrobrunnea, pyriformia, 265–398 µm alta, 201–401 µm diam, apicibus rotundatis. Asci cylindrici-clavati, breve stipitati, octospori, 84–118 x 10–11 µm. Pseudoparaphyses numerosae, septatae, in matrice mucosa, 1–2 µm diam. Ascosporae fusoides, brunneae, 3-septatae, constrictae ad septum medium, sine vagina mucosae vagina, 14–19 x 5–6 µm.
Ascomata erumpent through the bark, usually occurring singly or aggregated into small to large clusters, subiculum lacking, pyriform in shape, dark brown, ascomatal wall smooth, 265–398 µm high and 201–401 µm wide. Apices rounded, papillae are usually raised and often slightly sulcate with rounded opening. Asci cylindrical-clavate in shape, bearing short stipes, 8-spored partially biseriate, 84–118 x 10–11 µm. Pseudoparaphyses are numerous, septate, branching and anastomosing between and above the asci, held in gelatinous matrix, 1–2 µm diam. Ascospores fusiform, sometimes slightly curved, pale brown in colour, outer wall smooth, 3-septate with the septal area often of darker colour than rest of the spore, slightly constricted at the middle septum, one half of the spore composed cells that are slightly broader, possess no mucilaginous sheath, 14–19 x 5–6 µm.
Substratum: On decorticated woody branches on the ground.
Anamorph: Unknown.
Distribution: Presently only known from a forested area in Tennessee, U.S.A.
Specimen examined: u.s.A., Tennessee, Cocke Co., Great Smoky Mountains National Park, Lower Mount Cammerer Trail, 35° 45' 256" N, 83°12' 329" W, 686 m elev., 19 May 2006, on woody branch, A.N. Miller, G.K. Mugambi, ANM911, holotype F, isotype ILLS.
Misturatosphaeria uniseptata Mugambi, A.N. Mill. & Huhndorf, sp. nov. MycoBank MB516013. Fig. 34.
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Ascomata superficialia, solitaria vel sparse ad dense aggregata, atrobrunnea, pyriformia ad globosa, 230–293 µm alta, 318–385 µm diam, sine subiculo, apicibus rotundatis pallide coloratis. Asci cylindrici-clavati, breve stipitati, octospori, 70–82 x 5–6 µm. Pseudoparaphyses numerosae, septatae, in matrice mucosa, 1–2 µm diam. Ascosporae fusoides, brunneae, 1-septatae, constrictae ad septum medium, since vagina mucosa, 12–14 x 3–4 µm.
Ascomata superficial, occurring singly or aggregated into small to large clusters, subiculum absent, pyriform to globose in shape, dark brown, ascomatal wall smooth, 230–293 µm high and 318–385 µm wide. Apices rounded, often with slightly raised papillae, ostiole area often of lighter colour, ostiole openings often quite prominent but appear plugged by centrum tissue. Asci cylindrical-clavate in shape and bearing short stipes, 8-spored partially biseriate or sometimes overlapping uniseriate in arrangement, 70–82 x 5–6 µm. Pseudoparaphyses numerous, septate, branching and anastomosing between and above asci, held in gelatinous matrix, 1–2 µm diam. Ascospores fusiform, sometimes slightly curved or straight, brown, outer wall smooth, 1-septate with the septal area of darker colour, upper cell usually shorter and broader than the basal cell, slightly constricted at septum, possess no mucilaginous sheath, 12–14 x 3–4 µm.
Substratum: Found on decorticated woody branches on the ground.
Anamorph: Unknown.
Distribution: Currently only known from a tropical forest in Ecuador.
Specimen examined: ecuador, Orellana Province, Yasuni National Park, Botanico trail, 5 Mar. 2001, on woody branch, F.A. Fernández, A.N. Miller, R. Briones, SMH4330, holotype F.
Misturatosphaeria uniseriata Mugambi, A.N. Mill. & Huhndorf, sp. nov. MycoBank MB516014. Fig. 35.
Etymology: Unicus (L.) = one, Serialis (L.) = row, refers to single-row arrangement of the ascospores in the asci.
Ascomata erumpentia, solitaria vel dense aggregata, atrobrunnea, pyriformia ad globosa, 332–343 µm alta, 309–379 µm diam, sine subiculo, apicibus rotundatis, pallide coloratis. Asci cylindrici ad cylindrici-clavati, breve stipitati, octospori, 100–130 x 8–10 µm. Pseudoparaphyses numerosae, septatae in matrice mucosa, 1–2 µm diam. Ascosporae fusoides ad ellipticae, brunneae ad atrobrunnae, 1–3-septatae, vulgo 3-septatae, constrictae ad septa omnia, since vagina mucosa, 14–19 x 4–7 µm.
Ascomata erumpent, occurring aggregated into large clusters, subiculum lacking, pyriform to subglobose in shape, dark brown, ascomatal wall smooth, 332–343 µm high and 309–379 µm wide. Apices rounded, may possess slightly raised papillae, the ostiole area usually of lighter colour, possess prominent pore opening that appears plugged by centrum tissue. Asci cylindrical to cylindrical-clavate, bearing short stipes, 8-spored, overlapping uniseriate in arrangement, 100–130 x 8–10 µm. Pseudoparaphyses are numerous and septate, branching and anastomosing between and above the asci, held in gelatinous matrix, 1–2 µm diam. Ascospores fusiform to ellptical, brown to dark brown in colour, outer wall smooth, 1–3-septate but commonly 3-septate, occasionally constricted at all three septa, with no mucilaginous sheath, 14–19 x 4–7 µm.
Substratum: Found on decorticated woody branches on the ground.
Anamorph: Unknown.
Distribution: Currently only known from forested area in the Great Smoky Mountains National Park in Tennessee, U.S.A.
Specimen examined: u.s.A., Tennessee, Cocke Co., Great Smoky Mountains National Park, Lower Mount Cammerer Trail, 35° 45' 256" N, 83° 12' 329" W, 686 m elev., 19 May 2006, on woody branch, A.N. Miller, G.K. Mugambi, ANM909, holotype F.
Notes: The nine species newly described in Misturatosphaeria (Figs 25–27, 28–33, 34–35) were collected from wide geographic localities from Africa, North, Central and South America. An additional collection was included in the analyses (Misturatosphaeria sp., Fig. 1) that probably represents another species but asci were not seen so the specimen is not described at this time (Fig. 36). Misturatosphaeria aurantonotata bears some similarity with M. tennesseensis and M. uniseriata but differs from both in its much larger superficial ascomata and quite verruculose ascospores. It also differs in its phylogenetic placement (Figs 1, 2, 3). Misturatosphaeria tennesseensis differs from M. uniseriata in the shape and loose aggregation of the ascomata, asci that are predominantly partially biseriate in arrangement and ascospores that are paler brown and strongly constricted at the mid-septum. In contrast M. uniseriata ascomata tend to occur in large clusters, asci have predominantly overlapping uniseriate ascospore arrangement, ascospores are dark brown at maturity and are only rarely slightly constricted. Molecular data also support the separation of these two species (Figs 1, 2, 3). Misturatosphaeria uniseptata differs from all the other species in the group in its pale brown, 1-septate ascospores. Misturatosphaeria minima and M. kenyensis are quite similar in their morphologies but the former differs in its ascomata that are solitary or in small groups usually less than 5 individuals. Misturatosphaeria kenyensis ascomata are aggregated in larger clusters and ascospores are slightly broader. Misturatosphaeria cruciformis shares ascospore morphology with M. claviformis, but the former differs by having much larger ascomata that are predominantly pyriform and ascospores that are often constricted at the middle septum. Misturatosphaeria claviformis has smaller pyriform to obclavate ascomata, and ascospores that are very rarely slightly constricted. Molecular data also indicate the two species are distantly related (Figs 1, 2, 3). In addition to species of Misturatosphaeria, the sixth plate of figures contains two taxa illustrated for morphological comparison: Platystomum compressum (Fig. 37), and Thyridaria macrostomoides (Fig. 38). Both species share features with members of the Lophiostomataceae but only T. macrostomoides finds placement in the family based on molecular data (Figs 1, 2, 3).
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DISCUSSION |
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TOPAbstractINTRODUCTIONMATERIALS AND METHODSRESULTSTAXONOMYDISCUSSIONCONCLUSIONReferences |
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The genus Melanomma formed the weakest structure in the clade. While the family was strongly supported, the genus did not unite in a strong clade. All five collections of Melanomma pulvis-pyrius clustered at the base of the family clade in the LSU tree, separated by very short branches (two collections appeared to be identical). The other represented species, M. rhododendri was on a long branch near M. pulvis-pyrius. Morphologically our collections fit within the genus, both species having the clustered, superficial ascomata and small 3-septate brown ascospores in a uniseriate arrangement in the asci (Figs 16–17). It appears that additional collections and other genes might be necessary to understand how the specimens and species relate to each other.
In contrast, a strongly supported, monophyletic Byssosphaeria was recovered, which in this study was represented by six species, three of them with multiple collections (Figs 1, 2, 3). Byssosphaeria was described for taxa bearing superficial ascomata, separate or usually gregarious, turbinate, globose to ovoid and with rounded or minute papilla and opening by rounded pore. The pore and surrounding cells are pallid, whitish, or grey, or bright yellow, orange or red pigmented and the pore region appearing sulcate or plicate at times. Ascomatal wall surfaces are often irregular or slightly roughened, with protruding cells and often bear hyphal hairs (described as appendages in Barr 1984). Asci are clavate to cylindric, peripherally arranged and 8-spored. Ascospores are at first hyaline becoming light reddish brown or clear brown, ellipsoid or fusoid (Barr, 1990a). Byssosphaeria schiedermayeriana, the type species of the genus, is represented by five collections that form a strongly supported clade. The collections are neither morphologically nor molecularly identical. Morphologically the main differences seen are in the ascomatal structure. The collections differ in their amount of subiculum or hyphal hairs, amount of vertical collapsing (tendency toward becoming collabent, see Fig. 11A) and in the amount of colouration around the pore area (Figs 10A, 11A, 12A, 13A, 14A, 15A). The ascospores of these collections have measurements within the size range for the species given by Barr (1984), 25–42 x 5–9 µm and a sheath is seen in some of the collections (Figs 10D, 13D). Nested within the clade is the sequence of B. diffusa from GenBank (as Herpotrichia in GenBank) and one collection representing B. salebrosa. Byssosphaeria diffusa is reported to differ from B. schiedermayeriana in having a pallid or whitish pore area and smaller ascospores (Sivanesan 1971, Barr 1984). Byssosphaeria salebrosa is distinguished by non-subiculate ascomata with a surface that is roughened by projecting masses of cells, a feature present in our collection (Fig. 14B, C). Additional collections with the characteristics of these two species should be added to see if these morphological characters are phylogenetically informative.
Byssosphaeria rhodomphala and B. jamaicana, each represented by several collections, occur in a strongly supported sister relationship (Fig. 1). The collections of Byssosphaeria jamaicana fit well within the decription of the species (Figs 4–5). The subiculate, clustered ascomata, varying in the amount of hyphal hairs, have a pale-coloured pore area, the ascospores appear to lack appendages and in at least one of our collections, the ascospores turn somewhat darker brown and become 3-septate (Fig. 4D) (as was illustrated for the species by Sivanesan 1971). Five collections represent B. rhodomphala and morphologically and molecularly they are remarkably consistent given that they are geographically distant (Figs 1, 6, 8). Among the collections, the pore region of the ascomata can show variation from red to orange to yellowish granular deposits and can macroscopically appear quite dark. The most distinct characteristic of this species and the most useful aid in identification is the oblong-ellipsoid ascospore with obtuse ends. Byssosphaeria rhodomphala differs from B. jamaicana by the colouration of the ascomatal pore region. Hyphal appendages are lacking in B. rhodomphala and the ascospores are smaller than in B. jamaicana (Barr 1984).
On a basal branch in the Byssosphaeria clade is a single collection of B. villosa. The species is distinguished by ascomata bearing a dense covering of outwardly-projecting, long villose hairs and a pale coloured apex (Samuels & Müller 1978). Its general appearance was described as being "similar to Lasiosphaeria phyllophila" (= Iodosphaeria) (Samuels & Müller 1978), an observation that aided us in correctly identifying our own collection. Our collection differs from the description by having a distinctly yellow pore area (Fig. 9). However, Samuels & Müller's (1978) description of a bright yellow colour in the colonies they obtained in pure culture allowed us to conclude that the colour of the pore area might vary among collections of the species.
Bertiella also found its placement in the Melanommataceae in contrast to the Teichosporaceae where it was previously placed (Lumbsch & Huhndorf 2007). Bertiella macrospora is represented by three collections (Costa Rica, Kenya, U.S.A.) and slightly different placements in the LSU and TEF trees. It was unfortunate that we were not able to sequence one of the same collections for both genes. The collections show the distinctive arrangement of thick-walled and highly melanised ascomatal wall cells bearing bands of less pigmented, thin-walled cells (Fig. 7) that was described by Eriksson & Yue (1986) as "resembling cephalothecioid". As reported for the type specimen (Eriksson & Yue 1986), all three recent collections have ascomata that are superficial, gregarious and non-papillate (Fig. 7) with a roughened surface and lacking appendages or subiculum. The main difference occurs in the size of the ascospores. Whereas Eriksson & Yue (1986) describe the type specimen as having ascospores in the size range of 37–43 x 8–9 µm, our collections have smaller ascospores, ranging 22–30 x 5–7 µm in size. Based on the description given by Barr (1984), another taxon that may be similar to these collections is Byssosphaeria semen. This species differs from other Byssosphaerias in having a roughened ascomatal surface that lacks hairs or subiculum and has ascospores in the same range as our collections. The main difference is that no cephalothecioid cell arrangement is reported for this species and this is quite a prominent feature of our collections.
Barr (1984) revised the genus Herpotrichia and in the process re-established several genera, including Byssosphaeria and Pseudotrichia that had been in synonymy. She suggested that Herpotrichia belonged in Massarinaceae, a family later synonymised with Lophiostomataceae (Barr 1987). Herpotrichia is characterised by immersed, erumpent or superficial ascomata, with tomentum, rounded apex opening by broad pore. The asci are clavate or cylindrical, basal and pseudoparaphyses are narrowly cellular. The ascospores are fusoid, ellipsoid or oblong, usually surrounded by a mucilaginous sheath, and are hyaline becoming light yellow to reddish brown, mostly 1-septate but developing more septa with age. Herpotrichia is represented in our analyses by H. herpotrichoides, H. juniperi and H. macrotricha, and these taxa collectively do not form a monophyletic group in the LSU analyses. Subsets of these taxa group together in the TEF and combined gene trees. Two collections are tentatively identified as H. herpotrichoides, the type species of the genus. Morphologically the collections match this species and they do not differ significantly from each other (Figs 23–24); however in the LSU tree they occur in the same clade but separate from each other. The collections are geographically distant (one from the U.S.A. and one from Kenya) so a sequenced European collection would be useful to aid in the placement of the species. Herpotrichia juniperi, represented by two strains obtained from GenBank grouped consistently separate from the other two species. They also did not appear to closely align with the other taxa in the clade but occupied a position near Melanomma (Fig. 1). Assuming these collections were correctly identified, the results presented suggested that H. juniperi may belong outside the genus and thus may bear affinities to Melanomma. However, this will only become clear with broader taxon sampling in the groups. The described morphologies of Melanomma and Herpotrichia overlap in many ways, with both sharing immersed, erumpent to superficial ascomata that are tomentose and usually sit on an ample subiculum. Asci and ascospore morphologies are also similar, although in Herpotrichia ascospores tend to initially start hyaline and 1-septate later become brown and more septate. Since the Melanomma clade did not receive strong support the true placement of H. juniperi or its relationships to the taxa in the genus remain unclear. Herpotrichia macrotricha is reported to have a wide distribution (Barr 1984) and the five collections of H. macrotricha (representatives from Costa Rica, Kenya and Puerto Rico) form a strongly supported clade (Fig. 1). The species is easily recognised by its distinctive broad cap-like ascomatal apex with a thick inner layer of hyaline pseudoparenchymatous cells (Figs 19–22). One collection stands out from the rest both in sequence data and morphology. The Costa Rican collection (SMH4913, V on Fig. 1) differs from the others in having an upper, ascomal wall with a central hyaline layer that gives the ascomata a wrinkled, collapsed appearance in the dried collections (Fig. 22). It was thought perhaps to be a separate species but other known species should be checked before making that decision.
Pseudotrichia was considered to be in the family Platystomaceae by Barr (1990b), but is correctly placed in the Melanommataceae as in the most recent outline of the Ascomycota in Myconet (Lumbsch & Huhndorf 2007). The type species, P. mutabilis, is represented by two U.S.A. collections and in our LSU tree occurs as a sister taxon to the single collection of Pleomassaria. Pseudotrichia mutabilis is distinctive and easily identified with its gregarious, yellow-green tomentose ascomata and its hyaline, fusiform, septate ascospores (Fig. 18). It is a common entity on decaying wood in temperate forests. As currently circumscribed however, the genus is not monophyletic as our other included species, P. guatopoensis, finds a placement among the taxa in the unsupported Platystomaceae clade.
Pleomassaria siparia (lectotype species of the genus) is represented by two LSU sequences in GenBank (one used here), both coming from the same CBS 279.74 culture. In our analyses the species is nested within the Melanommataceae in the clade with Pseudotrichia mutabilis. According to Barr (1982: 370) Pleomassaria siparia is characterised by immersed, depressed globose ascomata containing oblong asci with simple muriform ascospores. The ascospores are dark brown with a verruculose surface, with 5–7 transverse septa and one longitudinal septum in several cells. The characteristics this species shares with others in the clade are not obvious. Our other collection identified as belonging in the family (Pleomassariaceae; SMH5232) does not cluster with P. siparia but rather finds a placement among the taxa in the unsupported Platystomaceae clade. Additionally, our other unpublished phylogenetic analyses using sequences from putative Asteromassaria and Splanchnonema species (other taxa that are arranged in the morphologically defined Pleomassariaceae) found that these species also do not cluster with P. siparia. It will be necessary to have additional sequences from other collections of the species to confirm its placement.
In the LSU tree, Ostropella and Xenolophium occur distantly related to Melanommataceae in a clade lacking significant support that also includes Pseudotrichia guatopoensis, Platystomum compressum (Fig. 37) and an unnamed Pleomassariaceae (Fig. 1). The clade, however, received significant PP support in the combined-gene analysis (Fig. 3). Ostropella and Xenolophium share a combination of morphological characters that appears distinct from that observed in Melanommataceae s. str. They possess relatively large ascomata, bearing raised apices with slit-like ostiolar openings. The asci in these two genera are clavate with quite long stipes, which is unlike taxa that are here treated in Melanommataceae. The mostly tropical collections of Ostropella, Xenolophium, and P. guatopoensis all share the distinctive, extensive network of trabeculate pseudoparaphyses that Barr (1983, 1990a) emphasised as an important diagnostic character that separates Melanommatales from Pleosporales. Subsequent studies using DNA sequence data have established that pseudoparaphysis type is not a phylogenetically informative character at the ordinal level and hence separation of Melanommatales from Pleosporales based on this character is not supported (Liew et al. 2000, Lumbsch & Lindemuth 2001, Kruys et al. 2006, Schoch et al. 2006, Wang et al. 2007). The results of the phylogenetic analyses presented in this study corroborate these findings. Additional genera in this clade are Ulospora bilgramii and Verruculina enalia whose sequences were obtained from GenBank. Since the clade for the most part did not receive significant support, further studies involving more collections and more markers are needed to confirm the observed relationships. Furthermore, the occurrence of P. guatopoensis and P. compressum in this clade, which were previously not thought to be related to Ostropella and Xenolophium, underscores the need for more work to establish with confidence the nature of the relationships.
Lophiostomataceae
Our analyses recovered a strongly supported Lophiostomataceae
comprised of Lophiostoma and some species currently placed in
Thyridaria. Sister to the Lophiostoma clade is the strongly
supported clade of the genus Misturatosphaeria comprising nine new
species (Figs 1,
2,
3). The genus
Lophiostoma was established by Fries
(1849) to accommodate taxa
that possess mostly erumpent ascomata, bearing apices that are raised and
laterally compressed with phragmosporous hyaline or brown ascospores. Since
its inception, many more species have been added to the genus but the taxonomy
of the group remains uncertain, requiring urgent revision. Chesters & Bell
(1970) and Holm & Holm
(1988) provide comprehensive
information on the taxonomic history and morphology of the genus. Barr
(1990a) transferred several
species of Lophiostoma into Thyridaria, which she placed in
the Platystomaceae that included T. macrostomoides. We had
among our specimens, collections that bear the morphology of the species and
in analyses T. macrostomoides groups separate from taxa in
Lophiostoma (Figs 1,
2,
3). Thyridaria
macrostomoides (Fig. 38)
collections occur in an unsupported sister relationship with
Misturatosphaeria in single-gene trees but receives significant PP in
the combined-gene tree (Figs 1,
2,
3). Barr
(1990a) described
Thyridaria to include taxa with the following morphology: ascomata
that are immersed or erumpent, in valsoid groups or separate or gregarious;
ascomata globose with a well developed papilla or short beak that is rounded
or compressed; ostioles that are rounded or slit-like and periphysate or
filled with pallid or brightly pigmented hyphal ends. Asci were described as
clavate or cylindrical with trabeculate pseudoparaphyses held in gelatinous
matrix. Ascospores are brown, symmetric or asymmetric, phragmosporous, three
or more septate, smooth, verruculose or striate. The results presented here
demonstrate that at least one of the species of Thyridaria resides in
Lophiostomataceae. However, since we did not include the type species
of Thyridaria in our analyses the generic placement remains
unclear.
Misturatosphaeria differs from other genera in Lophiostomataceae by possessing ascomata that are erumpent to superficial, with rounded apices that are often raised. Ostiolar openings are rounded and plugged by gelatinous tissue and occasionally lighter coloured. Asci are cylindrical to clavate with phragmosporous or dictyosporous ascospores (Figs 25–27, 28–33, 34–36). Despite morphological differences of Misturatosphaeria from other lophiostomataceous fungi, we feel justified in placing it in Lophiostomataceae at this point due to the strong support the clade received in our analyses (Figs 1, 2, 3). The only other genus with dictyospores accepted by Barr (1990b) in this family is Cilioplea. This genus was not included in our analyses but it differs markedly from the dictyosporous members of Misturatosphaeria and others in the group in general. It possesses ascomata with thick walled brown or dark brown setae around the apex and a narrow peridium of few internal rows of compressed pallid cells, surrounded by brown hyphae into the substrate. It also differs in the ascospore shape and septation, with the ascospore longitudinal septum in this genus primarily limited to the central cells (Barr 1990b).
Hypsostromataceae
Huhndorf (1992) described
the genus Hypsostroma for two tropical species, H. saxicola
and H. caimitalensis. She did not prefer familial placement at the
time but suggested they bear affinities in the Melanommatales (=
Pleosporales). Later, Huhndorf
(1994) erected family
Hypsostromataceae for the genera Hypsostroma and
Manglicola. The two species of Hypsostroma were included in
our analyses and they grouped together in a strongly supported clade within
Pleosporales distinct from other families in the order
(Fig 1). This study is only the
second time the two specimens used for sequencing have been collected and this
expands their range outside of the Caribbean and South America.
Hypsostroma is distinctive in having asci with extremely long stipes,
similar to those found in Ostropella and Xenolophium but
much longer (Huhndorf 1992,
1994). Although the clade
shows no supported relationship with the Platystomaceae taxa, X.
guianense tentatively joins the clade in the LSU tree and the
morphological similarities of these long-stipitate taxa suggests that they may
in some way be related.
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CONCLUSION |
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TOPAbstractINTRODUCTIONMATERIALS AND METHODSRESULTSTAXONOMYDISCUSSIONCONCLUSIONReferences |
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Lophiostomataceae occurs as a strongly supported monophyletic group but its concept is here expanded to include a new genus Misturatosphaeria that bears morphology traditionally not known to occur in the family. The gregarious ascomata of Misturatosphaeria, especially M. minima, suggests a resemblance and potential relationship to Byssosphaeria species or other taxa in the Melanommataceae. The molecular data shows this not to be the case. The ascomata differ with papillate apices present in Misturatosphaeria versus plane to collapsed apices in Byssosphaeria, along with the lack of hyphal hairs or subiculum in the former. Distinctive characteristics of Misturatosphaeria are the tendencies towards lighter coloured apices (M. aurantonotata) and plugged ostioles (M. minima, M. uniseriata). Additionally the ascomata in the group are actually mostly erumpent from the substrate and not superficial as in Byssosphaeria. The mixture of didymosporous, phragmosporous to dictyosporous ascospore morphologies that gives the genus its name was problematic and for awhile we thought that more than one generic clade would resolve but the molecular data did not provide that satisfaction. Some of the phragmosporous species have ascospores that resemble those in Lophiostoma s. l.
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Acknowledgments |
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References |
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TOPAbstractINTRODUCTIONMATERIALS AND METHODSRESULTSTAXONOMYDISCUSSIONCONCLUSIONReferences |
|---|
Barr ME (1982). On the Pleomassariaceae (Pleosporales) in North America. Mycotaxon 15:349 –383.
Barr ME (1983). The ascomycete connection. Mycologia 75:1 –13.[CrossRef]
Barr ME (1984). Herpotrichia and its segregates. Mycotaxon 20:1 –38.
Barr ME (1987). Prodomus to class Loculoascomycetes. Amherst, MA. Published by the author.
Barr ME (1990a). Melanommatales (Loculoascomycetes). North American Flora, Series II, 13:1 –129.
Barr ME (1990b). Some dictyosporous genera and species of Pleosporales. Memoirs of New York Botanic Garden 62:1 –92.
Berbee ML (1996). Loculoascomycetes origins and evolution of filamentous ascomycete morpholology based on 18A rRNA gene sequence data. Molecular Biology and Evolution 13:462 –470.[Abstract]
Bose SK (1961). Studies in Massarina Sacc. and related genera. Phytopathologische Zeitschrift 41:151 –213.[CrossRef]
Chesters CGC, Bell A (1970). Studies in the Lophiostomataceae Sacc. Mycological Papers 120:1 –55.
Crivelli PG (1983). Über die heterogene Ascomycetengattung Pleospora Rabh.; Vorschlag für eine Aufteilung. Diss. ETH Zürich 7318:1 –213.
del Prado R, Schmitt I, Kautz S, Palice Z, Lücking R, Lumbsch HT (2005). Molecular data place Trypetheliaceae in Dothideomycetes. Mycological Research 110:511 –520.[CrossRef]
Edgar RC (2004). MUSCLE: multiple sequence alignment
with high accuracy and high throughput. Nucleic Acids
Research 32:1792
–1797.
Eriksson O (1981). The families of bitunicate ascomycetes. Opera Botanica 60:1 –220.
Eriksson O, Yue J-Z (1986). Bertiella (Sacc.) Sacc. & Sydow a synonym of Massarina Sacc. Mycotaxon 27:247 –253.
Fries E (1849). Summa vegetabilium Scandinaviae 2. Uppsaliae.
Höhnel F von (1918). Mycologische Fragmente. Annales Mycologici 16:35 –174.
Holm L (1957). Etudes taxonomique sur les Pléosporacées. Symbolae Botanicae Uppsaliensis 14(3):1 –188.
Holm L, Holm K (1988). Studies in the Lophiostomataceae, with emphasis on the Swedish species. Acta Universitatis Uppsaliensis, Symbolae Botanicae Uppsaliensis 28(2):1 –50.
Holm L, Yue J-Z (1988). Notes on some fungi referred to Schizostoma Ces. De Not. Ex Sacc. Acta Mycologica. Sinica Supplement 1:82 –89.
Huelsenbeck JP, Ronquist F (2001). MRBAYES: Bayesian
inference of phylogeny. Bioinformatics
17:754
–755.
Huhndorf SM (1992). Neotropical Ascomycetes 2. Hypsostroma, a new genus from the Dominican Republic and Venezuela. Mycologia 84:750 –758.[CrossRef]
Huhndorf SM (1993). Neotropical Ascomycetes 3. Reinstatement of the genus Xenolophium and two new species from French Guiana. Mycologia 85:490 –502.[CrossRef]
Huhndorf SM (1994). Neotropical Ascomycetes 5. Hypsostromataceae, a new family of Loculoascomycetes and Manglicola samuelsii, a new species from Guyana. Mycologia 86:266 –269.[CrossRef]
Huhndorf SM, Fernández FA (1998). Neotropical Ascomycetes 7. Caudatispora biapiculatis sp. nov. from Puerto Rico. Sydowia 50:200 –204.
Kirk PM, Cannon PF, David JC, Stalpers JA (2008). Dictionary of the Fungi. 10th edn. CABI International, U.K.
Kruys A, Eriksson OE, Wedin M (2006). Phylogenetic relationships of coprophilous Pleosporales (Dothideomycetes, Ascomycota), and the classification of some bitunicate taxa of unknown position. Mycological Research 110:527 –536.[CrossRef][Web of Science][Medline]
Leuchtmann A (1984). Über Phaeosphaeria Miyake und andere bitunicate Ascomyceten mit mehrfach querseptierten Ascosporen. Sydowia 37:75 –194.
Liew EC, Aptroot A, Hyde KD (2000). Phylogenetic significance of the pseudoparaphyses in loculoascomycetes taxonomy. Molecular Phylogenetics and Evolution 16:392 –402.[CrossRef][Web of Science][Medline]
Lumbsch HT, Lindemuth R (2001). Major lineages of Dothideomycetes (Ascomycota) inferred from SSU and LSU rDNA sequences. Mycological Research 105:901 –908.[CrossRef]
Lumbsch HT, Huhndorf SM (2007). Outline of Ascomycota – 2007. Myconet 13:1 –58.
Luttrell ES (1955). The ascostromatic ascomycetes. Mycologia 47:511 –532.[CrossRef][Web of Science]
Müller E, Arx JA von (1962). Die Gattungen der didymosporen Pyrenomyceten. Beiträge zur Kryptogamen-Flora der Schweiz 11:1 –922.
Nitschke T (1869). Grundzüge eines Systems der Pyrenomyceten. Verhandlungen des Naturalhistorischen Vereines der Preussischen Rheinlande und Westphalens 26(2):70 –77.
Nylander JA, Wilgenbusch JC, Warren DL, Swofford DL (2007). AWTY (are we there yet?): a system for graphical exploration of MCMC convergence in Bayesian phylogenetics. Bioinformatics 24:581 –583.[CrossRef][Web of Science][Medline]
Petrak F (1940). Mykologische Notizen. 13. Annales Mycologici 38:181 –267.
Posada D, Crandall KA (1998). ModelTest: testing the model of DNA substitution. Bioinformatics 49:817 –818.
Rodriguez F, Oliver JF, Marin A, Medina JR (1990). The general stochastic model of nucleotide substitutions. Journal of Theoretical Biology 142:485 –501.[Web of Science][Medline]
Samuels GJ (1973). The genus Macbridella with notes on Calostilbe, Herpotrichia, Phaeonectria, and Letendraea. Canadian Journal of Botany 51:1275 –1283.[CrossRef]
Samuels GJ, Müller E (1978). Life-history studied of Brazilian Ascomycetes 4. Three species of Herpotrichia and their Pyrenochaeta-like anamorphs. Sydowia 31:157 –168.
Schoch CL, Crous PW, Groenewald JZ, Boehm EWA, Burgess TI, et
al. (2009). A class-wide phylogenetic assessment of
Dothideomycetes. Studies in Mycology
64:1
–15.
Schoch CL, Shoemaker RA, Seifert KA, Hambleton S, Spatafora JW,
Crous PW (2006). A multigene phylogeny of the Dothideomycetes
using four nuclear loci. Mycologia
98:1041
–1052.
Sivanesan A (1971). The genus Herpotrichia Fuckel. Mycological Papers 127:1 –37.
Stamatakis A (2006). RAxML-VI-HPC: maximum
likelihood-based phylogenetic analyses with thousands of taxa and mixed
models. Bioinformatics
22:2688
–2690.
Stevens FL (1925). Hawaiian fungi. Bernice P. Bishop Museum Bulletin 19:97 –98.
Tanaka K, Hosoya T (2008). Lophiostoma sagittiforme sp. nov., a new ascomycete (Pleosporales, Dothideomycetes) from Island Yakushima in Japan. Sydowia 60:131 –145.
Vilgalys R, Hester M (1990). Rapid identification and
mapping of enzymatically amplified ribosomal DNA from several
Cryptococcus species. Journal of Bacteriology
172:4238
–4246.
Wang H, Aproot A, Crous PW, Hyde KD, Jeewon R (2007). The polyphyletic nature of Pleosporales: an example of Massariosphaeria based on rDNA and RPB2 gene phylogenies. Mycological Research 111:1268 –1276.[CrossRef][Medline]
Winka K (2000). Phylogenetic relationship within the Ascomycota based on 18S rDNA sequences. Ph.D. Thesis. Umeå University, Umeå.
Zhang Y, Fournier J, Pointing SB, Hyde KD (2008). Are Melanomma pulvi-pyrius and Trematosphaeria pertusa congeneric? Fungal Diversity 33:47 –60.
Zhang Y, Schoch CL, Fournier J, Crous PW, Gruyter J de, et
al. (2009). Multi-locus phylogeny of the
Pleosporales: a taxonomic, ecological and evolutionary reevaluation.
Studies in Mycology 64:85
–102.
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70 % are shown above or below the branches.
Black circles indicate branches with Bayesian posterior probabilities 
