Deceptive morphological variation in Hirschmanniella mucronata (Nematoda: Pratylenchidae) and a polytomous key to the genus

Nematology ◽  
2015 ◽  
Vol 17 (4) ◽  
pp. 377-400 ◽  
Author(s):  
Kimkhuy Khun ◽  
Wilfrida Decraemer ◽  
Marjolein Couvreur ◽  
Gerrit Karssen ◽  
Hanne Steel ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Morphological Variation ◽  
Species Delimitation ◽  
Single Species ◽  
Valid Species ◽  
Diagnostic Features ◽  
Sister Relationship ◽  
Species Inquirenda ◽  
Phylogenetic Framework ◽  
Stylet Length

Hirschmanniella mucronatapopulations isolated from two Cambodian provinces were characterised using morphological, morphometric and molecular criteria. Examination of 1024 specimens from 60 different paddy fields revealed high intraspecific variation in morphology and morphometrics, especially in tail terminus shape and stylet length. Sequence results confirmed that morphologically divergent individuals represent a single species, suggesting that neglecting morphological variation has led to an overestimation ofHirschmannielladiversity in former studies. Phylogenetic analysis of the SSU, D2-D3, LSU and ITS1-5.8S-ITS2 regions revealed three concordant clades,H. mucronatahaving a sister relationship withH. kwazunaandH. loofi. Plotting the diagnostic features, including tail terminus shape, stylet length and lip region morphology on the phylogenetic framework, revealed that none of them supported the clades and represented convergent features. All three molecular markers were able to discriminate allHirschmanniellaspecies, but the D2-D3 region was the easiest, fastest and most successful region to be amplified. Species delimitation and the diagnostic features ofHirschmanniellawere re-evaluated.Hirschmanniella abnormalis and H. exactaare considered to be junior synonyms ofH. oryzaeandH. mannaiaspecies inquirenda. Finally, a list of valid species with indication of synonyms and a polytomous key are provided.

scholarly journals Taxonomic Revision of the Genus Lactifluus (Russulales, Basidiomycota) of South Korea

2021 ◽  
Author(s):  
Hyun Lee ◽  
Komsit Wissitrassameewong ◽  
Myung Soo Park ◽  
Jonathan J. Fong ◽  
Annemieke Verbeken ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Morphological Variation ◽  
North American ◽  
Species Delimitation ◽  
Taxonomic Revision ◽  
Molecular Data ◽  
Similar Species ◽  
Cryptic Diversity ◽  
Intraspecific Morphological Variation

Abstract Lactifluus (Pers.) Roussel is an ectomycorrhizal genus that was recently recognized to be distinct from the genus Lactarius. To date, 216 Lactifluus species have been reported worldwide. Misidentification of Lactifluus species is common because of intraspecific morphological variation, cryptic diversity, and the limited number of taxonomic keys available. Molecular data are indispensable for species delimitation; a multilocus phylogenetic analysis showed that most Asian Lactifluus species are not conspecific with morphologically similar species present on other continents. In particular, Korea has misused European and North American Lactifluus names. In this study, we evaluated the taxonomy of Lactifluus in Korea using both morphological and multilocus molecular (ITS, nrLSU, rpb1, and rpb2) data. We examined 199 Lactifluus specimens collected between 1980 and 2016, and a total of 24 species across the four Lactifluus subgenera were identified. All Korean species are distinct and clearly separated from European and North American species. Five taxa corresponded to previously described species from Asia and the remaining 19 taxa are confirmed as new species. Herein, we provide keys to the Korean Lactifluus species within their subgenera, molecular phylogenies, a summary of diversity, and detailed description of the new species.

A new taxonomic arrangement for Paleorhinus scurriensis

2012 ◽  
Vol 103 (3-4) ◽  
pp. 251-263 ◽  
Author(s):  
Michelle R. Stocker
Keyword(s):  
Phylogenetic Analysis ◽  
Single Species ◽  
Cranial Morphology ◽  
Late Triassic ◽  
Morphological Description ◽  
Diagnostic Features ◽  
Anatomical Features ◽  
Cladistic Analyses ◽  
Single Genus ◽  
Multiple Species

ABSTRACTThe paraphyletic genus ‘Paleorhinus’ is understood currently as a cosmopolitan phytosaur taxon from the Late Triassic. There is no consensus regarding the number of species of ‘Paleorhinus,’ with multiple species and genera synonymised into a single genus or even a single species at various points in its published history. The taxonomy is confounded by historical descriptions without the benefit of comparisons to more recently collected specimens, emphasis on plesiomorphic cranial morphology as diagnostic features of the genus, and lack of cladistic analyses. When included in a recent explicitly cladistic phylogenetic analysis, the holotype of ‘Paleorhinus’ scurriensis (TTU P-00539) was found to be the earliest-branching phytosaur with respect to other North American specimens previously referred to ‘Paleorhinus,’ and is generically distinct from Paleorhinus. ‘Paleorhinus’ scurriensis differs from all known phytosaurs in five unambiguous characters: basitubera widely separated mediolaterally; ridge present on lateral surface of jugal; thickened shelf present along posteroventral edge of expanded pterygoid-quadrate wing; ‘septomaxillae’ separated and excluded from internarial septum; and nasal swelling present posterior to posterior borders of nares. This detailed morphological description of an early-branching phytosaur taxon is a first step towards resolving long-standing issues surrounding specific anatomical features and relationships among early members of the clade.

scholarly journals Assessing the molecular diversity of Hildaea (Poaceae, Panicoideae): reaching a compromise between the splitter and the lumper

2019 ◽  
Vol 192 (1) ◽  
pp. 121-147
Author(s):  
Christian Silva ◽  
Cristiane Snak ◽  
Gerrit Davidse ◽  
Cássio Van Den Berg ◽  
R Patrícia Oliveira
Keyword(s):  
Phylogenetic Analysis ◽  
Morphological Variation ◽  
Species Delimitation ◽  
Molecular Diversity ◽  
Nuclear Data ◽  
Morphological Characters ◽  
Middle Ground ◽  
Old World ◽  
Western Africa ◽  
Possible Cause

Abstract The taxonomy of some groups of plants is challenging, and the strict use of morphological characters may not be enough to solve problems of species delimitation. Hildaea, a genus of tropical grasses recently segregated from Ichnanthus section Foveolatus, is mostly composed of species with obscure boundaries. This group was revised by two authors, Rogers and Stieber, with distinct opinions. The former recognized > 30 taxa, whereas the latter reduced this number to six. In the present study, we re-evaluate current and previous classifications through a comprehensively sampled phylogenetic analysis using plastid (ndhF) and nuclear data (ETS and ITS). Our results demonstrate that the diversity in Hildaea is a middle ground between the splitter and the lumper, indicating that several taxa currently treated as synonyms should be reinstated. Old World Hildaea were found to belong to two clades, one including species from Asia and Oceania, and another including species from the Neotropics and from western Africa. Topological incongruences suggest that hybridization may be a possible cause for the morphological variation observed and also an important evolutionary driver.

High diversity of fish ectoparasitic monogeneans (Dactylogyrus) in the Iberian Peninsula: a case of adaptive radiation?

Parasitology ◽  
2020 ◽  
Vol 147 (4) ◽  
pp. 418-430
Author(s):  
Michal Benovics ◽  
Yves Desdevises ◽  
Radek Šanda ◽  
Jasna Vukić ◽  
Mathilde Scheifler ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Iberian Peninsula ◽  
Adaptive Radiation ◽  
Species Delimitation ◽  
Single Species ◽  
European Regions ◽  
Local Fauna ◽  
Almost All ◽  
High Degree ◽  
High Diversity

AbstractThe epicontinental fauna of the Iberian Peninsula is strongly influenced by its geographical history. As the possibilities for dispersion of organisms into and from this region were (and still are) limited, the local fauna consists almost exclusively of endemic species. Almost all Iberian freshwater fishes of the families Leuciscidae and Cyprinidae are endemic and on-going research on these taxa continually uncovers new species. Nevertheless, information on their host-specific parasites remains scarce. In this study, we investigate the diversity and phylogenetic relationships in monogeneans of the genus Dactylogyrus (gill ectoparasites specific to cyprinoid fish) in the Iberian Peninsula. Twenty-two species were collected and identified from 19 host species belonging to Cyprinidae and Leuciscidae. A high degree of endemism was observed, with 21 Dactylogyrus species reported from Iberia only and a single species, D. borealis, also reported from other European regions. Phylogenetic analysis split the endemic Iberian Dactylogyrus into two well-supported clades, the first encompassing Dactylogyrus parasitizing endemic Luciobarbus spp. only, and the second including all Dactylogyrus species of endemic leuciscids and four species of endemic cyprinids. Species delimitation analysis suggests a remarkable diversity and existence of a multitude of cryptic Dactylogyrus species parasitizing endemic leuciscids (Squalius spp. and representatives of Chondrostoma s.l.). These results suggest a rapid adaptive radiation of Dactylogyrus in this geographically isolated region, closely associated with their cyprinoid hosts. Moreover, phylogenetic analysis supports that Dactylogyrus parasites colonized the Iberian Peninsula through multiple dispersion events.

scholarly journals Plastome Characterization and Phylogenomic Analysis Yield New Insights into the Evolutionary Relationships among the Species of the Subgenus Bryocles (Hosta; Asparagaceae) in East Asia

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1980
Author(s):  
Ji-Young Yang ◽  
Mi-Jung Choi ◽  
Seon-Hee Kim ◽  
Hyeok-Jae Choi ◽  
Seung-Chul Kim
Keyword(s):  
Phylogenetic Analysis ◽  
East Asia ◽  
Rna Editing ◽  
Phylogenetic Inference ◽  
Evolutionary Relationships ◽  
Phylogenomic Analysis ◽  
Diagnostic Features ◽  
Sister Relationship ◽  
Species Circumscription ◽  
Hybridization And Introgression

The genus Hosta, which has a native distribution in temperate East Asia and a number of species ranging from 23 to 40, represents a taxonomically important and ornamentally popular plant. Despite its taxonomic and horticultural importance, the genus Hosta has remained taxonomically challenging owing to insufficient diagnostic features, continuous morphological variation, and the process of hybridization and introgression, making species circumscription and phylogenetic inference difficult. In this study, we sequenced 11 accessions of Hosta plastomes, including members of three geographically defined subgenera, Hosta, Bryocles, and Giboshi, determined the characteristics of plastomes, and inferred their phylogenetic relationships. We found highly conserved plastomes among the three subgenera, identified several mutation hotspots that can be used as barcodes, and revealed the patterns of codon usage bias and RNA editing sites. Five positively selected plastome genes (rbcL, rpoB, rpoC2, rpl16, and rpl20) were identified. Phylogenetic analysis suggested (1) the earliest divergence of subg. Hosta, (2) non-monophyly of subg. Bryocles and its two sections (Lamellatae and Stoloniferae), (3) a sister relationship between H. sieboldiana (subg. Giboshi) and H. ventricosa (subg. Bryocles), and (4) reciprocally monophyletic and divergent lineages of H. capitata in Korea and Japan, requiring further studies of their taxonomic distinction.

scholarly journals Revision of the Tanzanian dicynodont Dicynodon huenei (Therapsida: Anomodontia) from the Permian Usili Formation

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7420 ◽  
Author(s):  
Christian F. Kammerer
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
South African ◽  
Single Species ◽  
Sharp Contrast ◽  
Valid Species ◽  
Late Permian ◽  
A New Species

A single species of the dicynodontoid dicynodont Dicynodon is currently recognized from the late Permian Usili Formation of Tanzania: Dicynodon huenei Haughton, 1932. Restudy of the known Tanzanian materials of D. huenei demonstrates that they represent two distinct morphotypes, here considered separate taxa. The holotype of D. huenei is not referable to Dicynodon and instead is transferred to the genus Daptocephalus (but retained as a valid species, Daptocephalus huenei comb. nov.). A number of published dicynodontoid specimens from the Usili Formation, however, are referable to Dicynodon, and are here recognized as a new species (Dicynodon angielczyki sp. nov.) Dicynodon angielczyki can be distinguished from its South African congener Dicynodon lacerticeps by the presence of an expansion of the squamosal and jugal beneath the postorbital bar and a curved, posterolateral expansion of the squamosal behind the temporal fenestra. Inclusion of Dicynodon angielczyki and D. huenei in a phylogenetic analysis supports their referral to Dicynodon and Daptocephalus (respectively). These results indicate higher basinal endemism in large late Permian dicynodonts than previously thought, a sharp contrast to the cosmopolitanism in the group in the earliest Triassic.

A taxonomic revision of Stenoglottis (Orchideae, Orchidoideae, Orchidaceae)

Phytotaxa ◽  
2020 ◽  
Vol 456 (3) ◽  
pp. 219-243 ◽  
Author(s):  
DEAN P. PHILLIPS ◽  
BENNY BYTEBIER
Keyword(s):  
Phylogenetic Analysis ◽  
Morphological Variation ◽  
Species Delimitation ◽  
Taxonomic Revision ◽  
Diagnostic Characters

Based on a published morphological and phylogenetic analysis, species delimitation in Stenoglottis is here revised, and five species (six taxa) are now recognized: S. fimbriata (with two varieties), S. longifolia, S. inandensis, S. woodii, and S. macloughlinii. Stenoglottis fimbriata subsp. saxicola and S. zambesiaca are synonymised here with S. fimbriata, S. modesta is reduced in rank to S. fimbriata var. modesta and S. molweniensis is synonymised with S. longifolia. The three spurred species, S. inandensis, S. woodii and S. macloughlinii, are retained. We include revised descriptions, diagnoses and a morphological key, in which characteristics of the floral spurs, labella, leaves, bracts, and auricles contribute most clearly to distinguishing the taxa. Distributions maps and photos showing important diagnostic characters and morphological variation are also presented.

Rhizocarpon smaragdulum, a new monosporic yellow-thalline species and some additional species of the genus Rhizocarpon from the Altai Mountains (Siberia)

2017 ◽  
Vol 49 (5) ◽  
pp. 457-466 ◽  
Author(s):  
Evgeny A. DAVYDOV ◽  
Lidia S. YAKOVCHENKO
Keyword(s):  
Phylogenetic Analysis ◽  
Phylogenetic Tree ◽  
Altai Mountains ◽  
Additional Species ◽  
Sister Relationship

AbstractRhizocarpon smaragdulum Davydov & Yakovchenko sp. nov. is described and a phylogenetic analysis (ITS, mtSSU) is presented, confirming its distinctiveness and indicating a sister relationship with R. suomiense and R. subgeminatum. The species is unique among yellow Rhizocarpon species in having a single hyaline ascospore per ascus. The phylogenetic tree suggests that the number of ascospores per ascus has been reduced in Rhizocarpon more than once during the course of its evolution. Two new distributional records are also reported: Rhizocarpon atroflavescens is new for Siberia and R. norvegicum is new for the Altai Mountains. Rhizocarpon norvegicum in this region grows on rocks and is also lichenicolous on Acarospora bullata.

Molecular Systematics of Tribe Physarieae (Brassicaceae) Based on Nuclear ITS, LUMINIDEPENDENS, and Chloroplast ndhF

2021 ◽  
Author(s):  
Sara Fuentes-Soriano ◽  
Elizabeth A. Kellogg
Keyword(s):  
Sequence Data ◽  
Plastid Dna ◽  
Sister Relationship ◽  
Data Set ◽  
Woody Perennial ◽  
History Of ◽  
Nuclear Its ◽  
Phylogenetic Framework ◽  
Phylogenetic Hypotheses ◽  
Relationship Of

Physarieae is a small tribe of herbaceous annual and woody perennial mustards that are mostly endemic to North America, with its members including a large amount of variation in floral, fruit, and chromosomal variation. Building on a previous study of Physarieae based on morphology and ndhF plastid DNA, we reconstructed the evolutionary history of the tribe using new sequence data from two nuclear markers, and compared the new topologies against previously published cpDNA-based phylogenetic hypotheses. The novel analyses included ca. 420 new sequences of ITS and LUMINIDEPENDENS (LD) markers for 39 and 47 species, respectively, with sampling accounting for all seven genera of Physarieae, including nomenclatural type species, and 11 outgroup taxa. Maximum parsimony, maximum likelihood, and Bayesian analyses showed that these additional markers were largely consistent with the previous ndhF data that supported the monophyly of Physarieae and resolved two major clades within the tribe, i.e., DDNLS (Dithyrea, Dimorphocarpa, Nerisyrenia, Lyrocarpa, and Synthlipsis)and PP (Paysonia and Physaria). New analyses also increased internal resolution for some closely related species and lineages within both clades. The monophyly of Dithyrea and the sister relationship of Paysonia to Physaria was consistent in all trees, with the sister relationship of Nerisyrenia to Lyrocarpa supported by ndhF and ITS, and the positions of Dimorphocarpa and Synthlipsis shifted within the DDNLS Clade depending on the employed data set. Finally, using the strong, new phylogenetic framework of combined cpDNA + nDNA data, we discussed standing hypotheses of trichome evolution in the tribe suggested by ndhF.

Species delimitation of colour polymorphic Cladophorus (Coleoptera: Lycidae) from New Guinea

Zootaxa ◽  
2017 ◽  
Vol 4320 (3) ◽  
pp. 505 ◽  
Author(s):  
ROMANA KALOUSOVA ◽  
LADISLAV BOCAK
Keyword(s):  
Phylogenetic Analysis ◽  
Mitochondrial Dna ◽  
Related Species ◽  
Species Delimitation ◽  
Morphological Differentiation ◽  
Morphological Characters ◽  
Molecular Data ◽  
Closely Related Species ◽  
Dna Fragment ◽  
Colour Patterns

Cladophorus Guérin-Méneville, 1830 are endemic Papuan net-winged beetles which take part in highly diverse Müllerian mimicry rings. Available specimens were sequenced for cox1–tRNA-Leu–cox2 mitochondrial DNA fragment and the species delimitations were based on the genetic distance, phylogenetic analysis, and morphology. Three earlier described species were identified in the recently collected material and further 10 species are described: C. pallescens sp. nov., C. bicolor sp. nov., C. craterensis sp. nov., C. motykai sp. nov., C. mindikensis sp. nov., C. kailakiensis sp. nov., C. manokwarensis sp. nov., C. haiaensis sp. nov., C. humeralis sp. nov., and C. boceki sp. nov. DNA-based identifications provided some ambiguous results and closely related species could not be robustly delimited using solely molecular data. Additionally, the species limits were based on clearly defined morphological characters and the morphological differentiation was found unlinked from the genetic divergence. Colour patterns cannot be used for identification because all species available in more specimens were polymorphic and followed various local co-mimics. The Papuan fauna of Cladophorus is very diverse and the closely related species regularly occur in limited regions. Differentiation within restricted ranges is therefore considered as the main speciation mode. 

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