scholarly journals Phylogenetic placement of enigmatic Astianthus (Bignoniaceae) based on molecular data, wood and bark anatomy

2021 ◽  
Vol 99 (2) ◽  
pp. 398-412
Author(s):  
Marcelo R. Pace ◽  
Brenda Hernández-Hernández ◽  
Esteban M. Martínez Salas ◽  
Lúcia G. Lohmann ◽  
N. Ivalu Cacho

Background: Astianthus is a monospecific arborescent genus of Bignoniaceae that occur in the Pacific Coast of central Mexico and northern Central America, where it grows in dense populations along riversides. Its phylogenetic placement has remained controversial since Astianthus has unusual morphological characters such as a four-loculed ovary, and simple, pulvinate, verticillate leaves. Methods: Here we used three plastid markers ndhF, rbcL, and trnL-F, wood, and bark anatomical data to investigate the phylogenetic placement of Astianthus and assign it to one of Bignoniaceae’s main clades. Results: Our molecular phylogenetic analyses indicated that Astianthus belongs in tribe Tecomeae s.s., where other charismatic Neotropical Bignoniaceae genera such as Campsis and Tecoma are currently placed. Wood and bark anatomy support this placement, as Astianthus reunites a unique combination of features only known from members of Tecomeae s.s., such as storied axial parenchyma, the co-occurrence of homo- and heterocellular rays, septate fibers, and scattered phloem fibers in the bark. Conclusions: The placement of Astianthus within Tecomeae s.s. provides further support to previous proposals for the Neotropical origin of this Pantropical tribe.

2021 ◽  
Vol 307 (2) ◽  
Author(s):  
Pau Carnicero ◽  
Núria Garcia-Jacas ◽  
Llorenç Sáez ◽  
Theophanis Constantinidis ◽  
Mercè Galbany-Casals

AbstractThe eastern Mediterranean basin hosts a remarkably high plant diversity. Historical connections between currently isolated areas across the Aegean region and long-distance dispersal events have been invoked to explain current distribution patterns of species. According to most recent treatments, at least two Cymbalaria species occur in this area, Cymbalaria microcalyx and C. longipes. The former comprises several intraspecific taxa, treated at different ranks by different authors based on morphological data, evidencing the need of a taxonomic revision. Additionally, some populations of C. microcalyx show exclusive morphological characters that do not match any described taxon. Here, we aim to shed light on the systematics of eastern Mediterranean Cymbalaria and to propose a classification informed by various sources of evidence. We performed molecular phylogenetic analyses using ITS, 3’ETS, ndhF and rpl32-trnL sequences and estimated the ploidy level of some taxa performing relative genome size measures. Molecular data combined with morphology support the division of traditionally delimited C. microcalyx into C. acutiloba, C. microcalyx and C. minor, corresponding to well-delimited nrDNA lineages. Furthermore, we propose to combine C. microcalyx subsp. paradoxa at the species level. A group of specimens previously thought to belong to Cymbalaria microcalyx constitute a well-defined phylogenetic and morphological entity and are described here as a new species, Cymbalaria spetae. Cymbalaria longipes is non-monophyletic, but characterized by being glabrous and diploid, unlike other eastern species. The nrDNA data suggest at least two dispersals from the mainland to the Aegean Islands, potentially facilitated by marine regressions.


Phytotaxa ◽  
2019 ◽  
Vol 392 (1) ◽  
pp. 45 ◽  
Author(s):  
ZHUN XU ◽  
NENG WEI ◽  
YING TAN ◽  
SHUAI PENG ◽  
VERONICAH MUTELE NGUMBAU ◽  
...  

Paris lihengiana (Melanthiaceae), a new species from Yunnan Province, China, is described and illustrated based on evidence from morphological characters and molecular phylogeny. It differs from other species of Paris in its pubescent stem, pedicel and abaxial leaf surface, as well as other characters. Molecular phylogenetic analysis of 33 taxa in Paris was conducted based on nuclear ribosomal ITS and six plastid markers. Paris lihengiana is supported as a new species by both morphological characters and molecular data.


2015 ◽  
Vol 29 (6) ◽  
pp. 591 ◽  
Author(s):  
Marco Gebiola ◽  
Antonio P. Garonna ◽  
Umberto Bernardo ◽  
Sergey A. Belokobylskij

Doryctinae (Hymenoptera : Braconidae) is a large and diverse subfamily of parasitic wasps that has received much attention recently, with new species and genera described and phylogenies based on morphological and/or molecular data that have improved higher-level classification and species delimitation. However, the status of several genera is still unresolved, if not controversial. Here we focus on two related groups of such genera, Dendrosoter Wesmael–Caenopachys Foerster and Ecphylus Foerster–Sycosoter Picard & Lichtenstein. We integrated morphological and molecular (COI and 28S–D2 genes) evidence to highlight, by phylogenetic analyses (maximum likelihood and Bayesian) and a posteriori morphological examination, previously overlooked variation, which is here illustrated and discussed. Monophyly of Dendrosoter and Caenopachys and the presence of synapomorphic morphological characters support synonymy of Caenopachys under Dendrosoter. Low genetic differentiation and high variability for putatively diagnostic morphological characters found in both C. hartigii (Ratzeburg) and C. caenopachoides (Ruschka) supports synonymy of D. caenopachoides under D. hartigii, syn. nov. Morphological and molecular evidence together also indicate independent generic status for Sycosoter, stat. rev., which is here resurrected. This work represents a further advancement in the framework of the ongoing effort to improve systematics and classification of the subfamily Doryctinae.


Phytotaxa ◽  
2018 ◽  
Vol 345 (1) ◽  
pp. 35 ◽  
Author(s):  
BIAO XU ◽  
UWE BRAUN ◽  
SHANHE ZHANG ◽  
HUI YANG ◽  
ZHI CAO ◽  
...  

Bauhinia species are popular ornamental and medicinal plants with a pantropical distribution. In December 2016, powdery mildew symptoms were found on B. blakeana and B. purpurea in Guangdong, China. Based on ITS and 28S rDNA sequences, as well as morphological characters, the powdery mildew was identified as Erysiphe lespedezae. Previous records of powdery mildews on Bauhinia spp. are discussed. Based on morphological and molecular phylogenetic analyses of type material, Pseudoidium caesalpiniacearum is reduced to synonymy with E. lespedezae. To our best knowledge, this is the first report of E. lespedezae causing powdery mildew on B. purpurea in China, and B. blakeana as a new host. A detailed morphological description and molecular data are provided herein.


Neodiversity ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 56-94
Author(s):  
Luciano P. Queiroz ◽  
◽  
Ana C.S. Oliveira ◽  
Cristiane Snak

The Galactia clade is one of three major lineages of the papilionoid legume tribe Diocleae. It comprises eight genera and approximately 140 species almost entirely restricted to the Americas. Establishing stable generic boundaries within this clade has been a challenge because of its tortuous taxonomic history and the broad polyphyly of the genera of the so-called Galactia-Camptosema-Collaea complex. Previous molecular phylogenetic studies revealed some well-supported lineages, but did not advance towards any new taxonomic arrangements. We carried out maximum parsimony and Bayesian phylogenetic analyses of a combined dataset including our previously published multilocus molecular data (nrITS and ETS and plastid trnK/matK and trnT-Y regions) and 82 morphological characters. The resulting topologies largely concur with those previously reported based on molecular data only, where Camptosema and Galactia appear as broadly polyphyletic, with species scattered among five (Camptosema) and seven (Galactia) of the twelve lineages that are newly recognized here at genus level. We are therefore proposing the following new taxonomic rearrangements within the Galactia clade: descriptions of the new genera Caetangil, Cerradicola, Mantiqueira, and Nanogalactia; resurrection of Betencourtia; and the subsuming of Neorudolphia into Rhodopis and of Camptosema sect. Macropetalum into Cratylia.


2020 ◽  
Vol 61 (1) ◽  
Author(s):  
Jian-Sheng Wang ◽  
Yi-Fei Lu ◽  
Yue-Liang Xu ◽  
Shui-Hu Jin ◽  
Xiao-Feng Jin

Abstract Background Southeast Asia, together with tropical Africa, Madagascar, South India and Sri Lanka, and the eastern Himalayas, are the five primary hotspots of species diversity of Impatiens (Balsaminaceae). China is also rich in Impatiens species, especially in the limestone karsts or ‘Danxia’ landforms. With zygomorphic flowers and diverse corolla morphology and color, the species in Impatiens are well-known for their ornamental use, but they are also notorious in taxonomy. During the preparation of revision of Impatiens in Zhejiang and adjacent regions, an unknown species was collected from Mt. Wuyi in Fujian Province, Southeast China. Results Phylogenetic analyses based on nuclear ITS, chloroplast atpB-rbcL and trnL-F sequences, together with micromorphology of pollen grains and seed coats, strongly supported the close relationship of the new species with Impatiens platysepala Y.L.Chen and I. chloroxantha Y.L.Chen. In turn, both molecular data and morphological characters also were sufficient to distinguish the new species from the other two counterparts. Conclusions Our detailed morphological observations and molecular phylogenetic analyses support the recognition of Impatiens wuyiensis as a species new to science.


2019 ◽  
Vol 94 ◽  
Author(s):  
S.V. Shchenkov ◽  
S.A. Denisova ◽  
G.A. Kremnev ◽  
A.A. Dobrovolskij

Abstract The phylogenetic position of most xiphidiocercariae from subgroups Cercariae virgulae and Cercariae microcotylae remains unknown or unclear, even at the family level. In this paper, we studied the morphology and molecular phylogeny of 15 microcotylous and virgulate cercariae (11 new and four previously described ones). Based on morphological and molecular data, we suggested five distinct morphological types of xiphidiocercariae, which are a practical alternative to Cercariae virgulae and Cercariae microcotylae subgroups. Four of these types correspond to actual digenean taxa (Microphallidae, Lecithodendriidae, Pleurogenidae and Prosthogonimidae), while the fifth is represented by Cercaria nigrospora Wergun, 1957, which we classified on the basis of molecular data for the first time. We reassessed the relative importance of morphological characters used for the classification of virgulate and microcotylous cercariae, and discussed the main evolutionary trends within xiphidiocercariae. Now stylet cercariae can be reliably placed into several sub-taxa of Microphalloidea on the basis of their morphological features.


Nematology ◽  
2018 ◽  
Vol 20 (1) ◽  
pp. 81-95 ◽  
Author(s):  
Daniel Leduc ◽  
Frederic Sinniger

Because of their relatively simple body plan, the number of morphological characters used to differentiate between closely related nematode genera is often limited. In addition, boundaries among genera sometimes become blurred due to the appearance of new trait combinations as more new species are described. Molecular phylogenetic analyses can address the shortcomings of morphological taxonomy by clarifying relationships among closely related species and genera and can help identify which morphological characters are taxonomically informative. Here, we describeLaxus sakihariiaesp. n. from shallow subtidal sands on Sesoko Island in the Okinawa prefecture, investigate phylogenetic relationships with other stilbonematine species and genera based on SSU rDNA sequences, and provide the first LSU rDNA sequence for the subfamily. The new species can be easily distinguished from all other species of the genus by the presence in the male of subventral and ventral rows of stout and spine-like setae in the pre- and postcloacal regions. This feature suggests affinities with the closely related genusLeptonemella, although the SSU consensus tree clearly shows that the new species forms a monophyletic clade together with the otherLaxusspecies for which sequences are available. The structure of the cephalic capsule inL. sakihariiaesp. n., which consists of a block layer between the median and basal zones of the cephalic cuticle, is consistent with the placement of this species. This trait is not currently used as a diagnostic feature, but our finding suggests that the structure of the cephalic capsule may be taxonomically useful for differentiating between some stilbonematine genera.


2009 ◽  
Vol 22 (1) ◽  
pp. 1 ◽  
Author(s):  
James O. Indsto ◽  
Peter H. Weston ◽  
Mark A. Clements

Diuris is a terrestrial orchid genus of at least 61 and possibly more than 100 species, restricted to Australia except for one species endemic in Timor. Distinctive species groups have respective eastern and western centres of distribution. Although species affinities have been vaguely understood for many years, no formal infrageneric treatment has been undertaken as Diuris possesses few reliable morphological characters for a classification system. We have undertaken cladistic parsimony and Bayesian phylogenetic analyses of Diuris by using the ITS1–5.8S–ITS2 region of nuclear rDNA and morphological characters, with a subset of samples also studied by amplified fragment length polymorphism (AFLP) as an independent test of phylogenetic relationships. Four major clades with strong bootstrap support were resolved and are named here according to a recently published classification; D. sulphurea forms a lineage (subg. Paradiuris) of its own that is well supported as the sister to the rest of Diuris. Two other major eastern clades contained species related to D. maculata (subg. Xanthodiuris) and D. punctata (subg. Diuris), respectively. Although these latter two subgenera are genetically well resolved, there is minimal genetic variation at species level, consistent with recent, rapid speciation. A fourth clade (subg. Hesperodiuris) has a centre of distribution in Western Australia, and has more genetic and morphological variation than the eastern subgenera. Total evidence analysis provides support for the western clade being sister group to the two eastern subgenera Diuris and Xanthodiuris; however, this relationship was not resolved by molecular data. Hybridisation is known to be common among species within subgenera Diuris and Xanthodiuris. Instances of incongruence between different datasets were found suggestive of hybridisation events between species of different sections of Diuris.


Zootaxa ◽  
2009 ◽  
Vol 2174 (1) ◽  
pp. 51-62 ◽  
Author(s):  
P. A. DINGHI ◽  
V. CONFALONIERI ◽  
M. M. CIGLIANO

The Dichroplini genera Scotussa, Leiotettix, Ronderosia, Atrachelacris, Chlorus, Eurotettix and Dichromatos have been grouped into the “Paranaense-Pampeano” informal genus group, based on characters of the male genitalia. However, recent molecular phylogenetic analyses showed weak support values or no support at all for this group. In this study, we used molecular and morphological characters to test the monophyly of this informal genus group. Morphological characters included aspects of the general morphology, and male and female genitalia as well. Whereas the molecular data was based on one mitochondrial gene: cytochrome oxidase I. Independent and combined phylogenetic analyses of the data were performed under both unweighted and implied weighting parsimony. Our results showed that, when only molecular data is considered, the “Paranaense-Pampeano” informal genus group is not recovered. However, the group is monophyletic according to morphological and combined analyses. The “Paranaense-Pampeano” informal genus group is considered to be a natural clade; therefore, we propose the genus group name Scotussae. As a final remark, the molecular data provided in most cases the same evidence of relationships as morphology.


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