scholarly journals Why morphology matters: the negative consequences of hasty descriptions of putative novelties in asexual ascomycetes

IMA Fungus ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ondřej Koukol ◽  
Gregorio Delgado

ABSTRACTRecent progress in the discovery of fungal diversity has been enabled by intensive mycological surveys in centres of global biodiversity. Descriptions of new fungal species have been almost routinely based on phenotypic studies coupled with single or multigene phylogenetic analyses of DNA sequence data. However, high accessibility of sequencing services together with an increasing amount of available molecular data are providing easier and less critical support for taxonomic novelties without carefully studying the phenotype, particularly morphology. As a result, the accelerated rate of species descriptions has been unfortunately accompanied by numerous cases of overlooking previously described and well documented species, some of them that have been known for more than a century. Here, we critically examined recent literature, phenotypic and molecular data, and detected multiple issues with putative novelties of asexual Ascomycota traditionally known as hyphomycetes. In order to fix these taxonomic problems, three new combinations within the genera Pleopunctum, Camposporium and Sporidesmium, and two new names in Camposporium are proposed. Moreover, three genera, Aquidictyomyces, Fusiconidium and Pseudohelminthosporium, together with nine species are reduced to synonymy. The examples outlined here clearly show the relevance of morphology in modern phylogenetic studies and the importance of more stringent ‘quality controls’ during biodiversity studies documenting the extensive fungal diversity in a speedy manner.

Phytotaxa ◽  
2014 ◽  
Vol 161 (2) ◽  
pp. 157 ◽  
Author(s):  
Sinang Hongsanan ◽  
Putarak Chomnunti ◽  
Pedro W. Crous ◽  
Ekachai Chukeatirote ◽  
Kevin D. Hyde

The order Microthyriales comprises foliar biotrophs, epiphytes, pathogens or saprobes that occur on plant leaves and stems. The order is relatively poorly known due to limited sampling and few in-depth studies. There is also a lack of phylogenetic data for these fungi, which form small black spots on plant host surfaces, but rarely cause any damage to the host. A "Microthyriaceae"-like fungus collected in central Thailand is described as a new genus, Chaetothyriothecium (type species Chaetothyriothecium elegans sp. nov.). Phylogenetic analyses of LSU gene data showed this species to cluster with other members of Microthyriales, where it is related to Microthyrium microscopicum the type of the order. The description of the new species is supplemented by DNA sequence data, which resolves its placement in the order. Little molecular data is available for this order, stressing the need for further collections and molecular data.


2004 ◽  
Vol 17 (2) ◽  
pp. 145 ◽  
Author(s):  
Randall L. Small ◽  
Richard C. Cronn ◽  
Jonathan F. Wendel

Molecular data have had a profound impact on the field of plant systematics, and the application of DNA-sequence data to phylogenetic problems is now routine. The majority of data used in plant molecular phylogenetic studies derives from chloroplast DNA and nuclear rDNA, while the use of low-copy nuclear genes has not been widely adopted. This is due, at least in part, to the greater difficulty of isolating and characterising low-copy nuclear genes relative to chloroplast and rDNA sequences that are readily amplified with universal primers. The higher level of sequence variation characteristic of low-copy nuclear genes, however, often compensates for the experimental effort required to obtain them. In this review, we briefly discuss the strengths and limitations of chloroplast and rDNA sequences, and then focus our attention on the use of low-copy nuclear sequences. Advantages of low-copy nuclear sequences include a higher rate of evolution than for organellar sequences, the potential to accumulate datasets from multiple unlinked loci, and bi-parental inheritance. Challenges intrinsic to the use of low-copy nuclear sequences include distinguishing orthologous loci from divergent paralogous loci in the same gene family, being mindful of the complications arising from concerted evolution or recombination among paralogous sequences, and the presence of intraspecific, intrapopulational and intraindividual polymorphism. Finally, we provide a detailed protocol for the isolation, characterisation and use of low-copy nuclear sequences for phylogenetic studies.


Phytotaxa ◽  
2017 ◽  
Vol 323 (1) ◽  
pp. 27 ◽  
Author(s):  
VLADIMIR E. FEDOSOV ◽  
ALINA V. FEDOROVA ◽  
ELENA A. IGNATOVA ◽  
MICHAEL S. IGNATOV

The genus Seligeria is revised based on morphological and DNA sequence data of nuclear ITS and chloroplastic trnL-F. Fifteen species from most infrageneric units of the genus are recovered in two well supported phylogenetic clusters that are also distinctive in morphology. The clade with the type species of the genus, S. pusilla, includes also S. donniana, S. brevifolia, S. calcarea, S. patula, S. tristichoides, S. trifaria, and S. oelandica. These species are characterized by short, cupulate or turbinate capsules widened towards the mouth, and the lack of a stem central strand. Another clade includes species with rather long, mainly ovate to cylindrical capsules and more or less developed stem central strand: S. campylopoda, S. recurvata, S. subimmersa, S. diversifolia, and S. polaris. These two clusters do not show sister relationships, but the second one appears more closely related to the Blindia clade. To resolve the apparent paraphyly, the latter phylogenetic group is segregated in a genus Blindiadelphus. In some aspects of morphology and ecology it is intermediate between Seligeria s. str. and Blindia, but differs from both genera in subquadrate upper leaf cells and thin- to moderately thick-walled rectangular exothecial cells. Molecular phylogenetic analyses revealed heterogeneity within the specimens previously referred to Blindiadelphus campylopodus, indicating a presence in Asian Russia of an undescribed species that is described here as Blindiadelphus sibiricus. It differs from B. campylopodus by the larger spores and typically rounded leaf apices. The isotype specimen of S. galinae appeared to be nearly identical to S. donniana in the sequences of ITS and trnL-F, and examination of morphology revealed no substantial differences between these species. Thus, we consider S. galinae as a synonym of S. donniana. The genus Blindiadelphus includes species of Seligeria subg. Blindiadelphus and S. subg. Cyrtoseligeria, which however are found intermingled in the molecular phylogenetic analysis. Thus the genus Blindiadelphus is accepted without any infrageneric taxa. The phylogenetic tree is congruent with the subdivision of the genus Seligeria s.str into subg. Seligeria, subg. Anodon, subg. Megalosporia and one newly established subgenus Robustidontia for S. brevifolia.


Author(s):  
Pradeep K. Divakar ◽  
Ana Crespo

Several obligately sexualy reproducing lichen-forming fungal species are disjunctly distributed in pantropical regions. Here, we aim to re-examine species boundaries within the sexually reproducing, disjunctly distributed species, Hypotrachyna intercalanda. We gathered a three-locus DNA sequence data set of Hypotrachyna subgen. Parmelinopsis, especially including the samples from India, and these data were analysed in a phylogenetic framework. Our results show that specimens of H. intercalanda, as currently circumscribed, do not form a monophyletic group but fall into two well-supported independent clades. Morphological and chemical features were re-evaluated. Corroborating with the phenotypic features, the sample recovered in clade 2 occurring in southern India are described as a new species, viz. Hypotrachyna upretii Divakar and A. Crespo sp. nov. Our study adds a further example of a previously overlooked, geographically distinct, lineage that was uncovered using molecular data. Additionally, our study underlines the need of critical reexamination of phenotypic features of samples falling into different clades.


Zootaxa ◽  
2011 ◽  
Vol 3138 (1) ◽  
pp. 1 ◽  
Author(s):  
JOSEPH R. MENDELSON III ◽  
DANIEL G. MULCAHY ◽  
TYLER S. WILLIAMS ◽  
JACK W. SITES JR.

We combine mitochondrial and nuclear DNA sequence data with non-molecular (morphological and natural history) data to conduct phylogenetic analyses and generate an evolutionary hypothesis for the relationships among nearly every species of Mesoamerican bufonid in the genus Incilius. We collected a total of 5,898 aligned base-pairs (bp) of sequence data from mitochondrial (mtDNA: 12S–16S, cyt b, ND2–CO1, including tRNAsTRP–TYR and the origin of light strand replication; total 4,317 bp) and nuclear (CXCR4 and RAG1; total 1,581 bp) loci from 52 individual toads representing 37 species. For the non-molecular data, we collected 44 characters from 29 species. We also include Crepidophryne, a genus that has not previously been included in molecular analyses. We present results of parsimony and Bayesian analyses for these data separately and combined. Relationships based on the non-molecular data were poorly supported and did not resolve a monophyletic Incilius (Rhinella marina was nested within). Our molecular data provide significant support to most of the relationships. Our combined analyses demonstrate that inclusion of a considerably smaller dataset (44 vs. 5,898 characters) of non-molecular characters can provide significant support where the molecular relationships were lacking support. Our combined results indicate that Crepidophryne is nested within Incilius; therefore, we place the former in the synonymy of the latter taxon. Our study provides the most comprehensive evolutionary framework for Mesoamerican bufonids (Incilius), which we use as a starting point to invoke discussion on the evolution of their unique natural history traits.


Phytotaxa ◽  
2019 ◽  
Vol 399 (1) ◽  
pp. 100 ◽  
Author(s):  
GUI-ZHEN CHEN ◽  
GUO-QIANG ZHANG ◽  
JIE HUANG ◽  
MENG WANG ◽  
WEN-HUI RAO ◽  
...  

A new orchid species, Cymbidium shidianense (Orchidaceae; Cymbidieae), from Yunnan Province, China, is described and illustrated based on morphological and molecular analyses. This new species is similar in morphology to C. cyperifolium, but it differs in its larger pseudobulbs, rigid leaves, broader pale green sepals, petals with darkly coloured veins and set of V-shaped blotches on the lip midlobe. A phylogenetic analyses based on nuclear ribosomal ITS and plastid (matK, rbcL) DNA sequence data support C. shidianense as related to C. cyperifolium.


2021 ◽  
Vol 9 (4) ◽  
pp. 706
Author(s):  
Martina Réblová ◽  
Miroslav Kolařík ◽  
Jana Nekvindová ◽  
Andrew N. Miller ◽  
Margarita Hernández-Restrepo

Zanclospora (Chaetosphaeriaceae) is a neglected, phialidic dematiaceous hyphomycete with striking phenotypic heterogeneity among its species. Little is known about its global biogeography due to its extreme scarcity and lack of records verified by molecular data. Phylogenetic analyses of six nuclear loci, supported by phenotypic data, revealed Zanclospora as highly polyphyletic, with species distributed among three distantly related lineages in Sordariomycetes. Zanclospora is a pleomorphic genus with multiple anamorphic stages, of which phaeostalagmus-like and stanjehughesia-like are newly discovered. The associated teleomorphs were previously classified in Chaetosphaeria. The generic concept is emended, and 17 species are accepted, 12 of which have been verified with DNA sequence data. Zanclospora thrives on decaying plant matter, but it also occurs in soil or as root endophytes. Its global diversity is inferred from metabarcoding data and published records based on field observations. Phylogenies of the environmental ITS1 and ITS2 sequences derived from soil, dead wood and root samples revealed seven and 15 phylotypes. The field records verified by DNA data indicate two main diversity centres in Australasia and Caribbean/Central America. In addition, environmental ITS data have shown that Southeast Asia represents a third hotspot of Zanclospora diversity. Our data confirm that Zanclospora is a rare genus.


Phytotaxa ◽  
2014 ◽  
Vol 176 (1) ◽  
pp. 184 ◽  
Author(s):  
Huang Zhang ◽  
Kevin D. Hyde ◽  
Yongchang Zhao ◽  
ERIC H.C. MCKENZIE ◽  
Dequn Zhou

Lophiostoma vaginatispora comb. nov. was collected from submerged wood in a stream in Northern Thailand. The species is characteristic by immersed to erumpent ascomata, with slot-like ostioles, with long, branched and numerous periphyses, an unequally thick peridium where the upper part is narrower than the lower part, and 1-septate, narrowly fusiform ascospores with a thick surrounding papilionaceous sheath. The placement of this species in Lophiostoma is based on morphological characters and phylogenetic analyses of the partial nuclear ribosomal 18S small subunit and 28S large subunit DNA sequence data. Lophiostoma vaginatispora is distinguished from other Lophiostoma species in possessing a wide papilionaceous sheath.


2021 ◽  
Vol 9 (3) ◽  
pp. 666
Author(s):  
Niccolò Forin ◽  
Alfredo Vizzini ◽  
Federico Fainelli ◽  
Enrico Ercole ◽  
Barbara Baldan

In a recent monograph on the genus Rosellinia, type specimens worldwide were revised and re-classified using a morphological approach. Among them, some came from Pier Andrea Saccardo’s fungarium stored in the Herbarium of the Padova Botanical Garden. In this work, we taxonomically re-examine via a morphological and molecular approach nine different Roselliniasensu Saccardo types. ITS1 and/or ITS2 sequences were successfully obtained applying Illumina MiSeq technology and phylogenetic analyses were carried out in order to elucidate their current taxonomic position. Only the ITS1 sequence was recovered for Rosellinia areolata, while for R. geophila, only the ITS2 sequence was recovered. We proposed here new combinations for Rosellinia chordicola, R. geophila and R. horridula, while for R. ambigua, R. areolata, R. australis, R. romana and R. somala, we did not suggest taxonomic changes compared to the current ones. The name Rosellinia subsimilis Sacc. is invalid, as it is a later homonym of R. subsimilis P. Karst. & Starbäck. Therefore, we introduced Coniochaeta dakotensis as a nomen novum for R. subsimilis Sacc. This is the first time that these types have been subjected to a molecular study. Our results demonstrate that old types are an important source of DNA sequence data for taxonomic re-examinations.


Plant Disease ◽  
2003 ◽  
Vol 87 (11) ◽  
pp. 1329-1332 ◽  
Author(s):  
J. Roux ◽  
H. Myburg ◽  
B. D. Wingfield ◽  
M. J. Wingfield

Cryphonectria cubensis is an economically important pathogen of commercial Eucalyptus spp. Differences have been reported for disease symptoms associated with Cryphonectria canker in South Africa and other parts of the world, and recent DNA-based comparisons have confirmed that the fungus in South Africa is different from that in South America and Australasia. During a disease survey in the Republic of Congo, Cryphonectria canker was identified as an important disease on Eucalyptus grandis and E. urophylla. In this study, we compared Congolese and South African isolates of C. cubensis using DNA sequence data and pathogenicity under greenhouse conditions. The β-tubulin and internal transcribed spacer (ITS) region sequences show that C. cubensis in Congo is different from the fungus in South Africa and that Congolese isolates group most closely with South American isolates. Furthermore, pathogenicity tests showed that a South African isolate was more aggressive than two Congolese isolates. We conclude that two distinct Cryphonectria spp. occur in Africa and hypothesize that the fungus in the Congo probably was introduced into Africa from South America. Both fungi are important pathogens causing disease and death of economically important plantation trees. However, they apparently have different origins and must be treated separately in terms of disease management and quarantine considerations.


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