scholarly journals A duplicate gene rooting of seed plants and the phylogenetic position of flowering plants

2010 ◽  
Vol 365 (1539) ◽  
pp. 383-395 ◽  
Author(s):  
Sarah Mathews ◽  
Mark D. Clements ◽  
Mark A. Beilstein

Flowering plants represent the most significant branch in the tree of land plants, with respect to the number of extant species, their impact on the shaping of modern ecosystems and their economic importance. However, unlike so many persistent phylogenetic problems that have yielded to insights from DNA sequence data, the mystery surrounding the origin of angiosperms has deepened with the advent and advance of molecular systematics. Strong statistical support for competing hypotheses and recent novel trees from molecular data suggest that the accuracy of current molecular trees requires further testing. Analyses of phytochrome amino acids using a duplicate gene-rooting approach yield trees that unite cycads and angiosperms in a clade that is sister to a clade in which Gingko and Cupressophyta are successive sister taxa to gnetophytes plus Pinaceae. Application of a cycads + angiosperms backbone constraint in analyses of a morphological dataset yields better resolved trees than do analyses in which extant gymnosperms are forced to be monophyletic. The results have implications both for our assessment of uncertainty in trees from sequence data and for our use of molecular constraints as a way to integrate insights from morphological and molecular evidence.

The Auk ◽  
2004 ◽  
Vol 121 (1) ◽  
pp. 224-229
Author(s):  
J. Jordan Price ◽  
Scott M. Lanyon

Abstract The accuracy with which avian song features indicate phylogenetic relationships has rarely been investigated. In a previous study of vocal evolution in oropendolas (Price and Lanyon 2002a), we estimated the phylogenetic position of the Green Oropendola (Psarocolius viridis) using characters derived from oropendolas' elaborate courtship songs. Here, we test that estimate using mitochondrial DNA sequence data. The position of the Green Oropendola determined from molecular data is remarkably close to that based solely on song characters; both data sets support a close relationship between P. viridis and members of the genus Gymnostinops. Numerous morphological differences yet low genetic divergence among the species in question suggest that rapid diversification has occurred in the group. The fact that this position has not been proposed previously for P. viridis underscores the effectiveness of song characters for phylogenetic reconstruction.


2011 ◽  
Vol 43 (6) ◽  
pp. 561-567 ◽  
Author(s):  
K. PAPONG ◽  
G. KANTVILAS ◽  
H. T. LUMBSCH

AbstractThe phylogenetic placement of the genus Maronina was studied, based chiefly on phenotypic characters such as thallus colour and anatomy, secondary chemistry, the anatomy of the excipulum and the ascus-type. DNA sequence data of mitochondrial and nuclear ribosomal loci from some of the species support the hypothesis that Maronina is nested within Protoparmelia. Hence, Maronina is reduced to synonymy with Protoparmelia. Comparison of genetic distances suggests that the two varieties within M. orientalis should be regarded as distinct species. Consequently, the new combinations Protoparmelia australiensis (Hafellner & R. W. Rogers) Kantvilas et al., P. corallifera (Kantvilas & Papong) Kantvilas et al., P. hesperia (Kantvilas & Elix) Kantvilas et al., P. multifera (Nyl.) Kantvilas et al., and P. orientalis (Kantvilas & Papong) Kantvilas et al. are proposed.


IMA Fungus ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Adans A. Colmán ◽  
Harry C. Evans ◽  
Sara S. Salcedo-Sarmiento ◽  
Uwe Braun ◽  
Kifle Belachew-Bekele ◽  
...  

AbstractDigitopodium hemileiae was described originally in 1930 as Cladosporium hemileiae; growing as a mycoparasite of the coffee leaf rust (CLR), Hemileia vastatrix, in a sample of diseased leaves of Coffea canephora collected in the Democratic Republic of Congo. No cultures from this material exist. More recently, the type material was re-examined and, based on morphological features, considered to be incorrectly placed in Cladosporium. The new genus Digitopodium was erected to accommodate this species. Interest in fungal antagonists of H. vastarix, as potential biocontrol agents of CLR, led to comprehensive surveys for mycoparasites, both in the African centre of origin of the rust, as well as in its South American exotic range. Among the rust specimens from Ethiopia, one was found to be colonized by a fungus congeneric with, and similar to, D. hemileiae. Pure cultures obtained from the Ethiopian material enabled a molecular study and for its phylogenetic position to be elucidated, based on DNA sequence data from the ITS and LSU regions. Molecular data showed that two members of the recently erected genus Hyalocladosporiella (Herpotrichiellaceae: Chaetothyriales) are congeneric with Digitopodium from Ethiopia and morphologically similar to both D. hemileiae and the two Ethiopian isolates. These isolates were found to be morphologically and genetically identical to H. tectonae, described previously from Brazil. Thus, species of Hyalocladosporiella are re-allocated to Digitopodium here; including D. tectonae, and a novel species, D. canescens, recently found in Brazil growing as a mycoparasite of Puccinia thaliae. The potential use of D. hemileiae and D. tectonae for classical biological control of CLR is discussed.


2018 ◽  
Vol 32 (6) ◽  
pp. 1316 ◽  
Author(s):  
Jahnavi Joshi ◽  
Gregory D. Edgecombe

Integrative taxonomy assesses the congruence between different lines of evidence for delimiting species, such as morphological, molecular or ecological data. Herein molecular phylogenetics is used to test monophyly and determine the phylogenetic position of the Old World tropical centipede genus Ethmostigmus Pocock, 1898, and to define species boundaries for Ethmostigmus in peninsular India. A phylogeny of the family Scolopendridae based on DNA sequence data for three markers from 427 specimens sampling in all major lineages (144 individuals generated in this study) recovers Ethmostigmus as a monophyletic group, but relationships among the genera in its subfamily Otostigminae are poorly supported. Two species delimitation methods for DNA sequence data and phylogeny are integrated with morphology and geographic data to propose a well-supported species hypothesis for Ethmostigmus on the peninsular Indian plate. Five species of Ethmostigmus are recognised in peninsular India, of which E. coonooranus Chamberlin, 1920 and three new species, namely, E. agasthyamalaiensis, sp. nov., E. sahyadrensis, sp. nov. and E. praveeni, sp. nov., occur in the Western Ghats, a biodiversity hotspot. The lesser-known Eastern Ghats harbour one species, E. tristis (Meinert, 1886), which has been nearly unreported for 130 years. This study highlights the value of an integrative approach to systematics, especially in underexplored, high biodiversity regions and where morphological variation is limited among closely related species.


2009 ◽  
Vol 34 (3) ◽  
pp. 580-594 ◽  
Author(s):  
Anthony R. Magee ◽  
Ben-Erik van Wyk ◽  
Patricia M. Tilney ◽  
Stephen R. Downie

Generic circumscriptions and phylogenetic relationships of the Cape genera Capnophyllum, Dasispermum, and Sonderina are explored through parsimony and Bayesian inference analyses of nrDNA ITS and cpDNA rps16 intron sequences, morphology, and combined molecular and morphological data. The relationship of these genera with the North African genera Krubera and Stoibrax is also assessed. Analyses of both molecular data sets place Capnophyllum, Dasispermum, Sonderina, and the only southern African species of Stoibrax (S. capense) within the newly recognized Lefebvrea clade of tribe Tordylieae. Capnophyllum is strongly supported as monophyletic and is distantly related to Krubera. The monotypic genus Dasispermum and Stoibrax capense are embedded within a paraphyletic Sonderina. This complex is distantly related to the North African species of Stoibrax in tribe Apieae, in which the type species, Stoibrax dichotomum, occurs. Consequently, Dasispermum is expanded to include both Sonderina and Stoibrax capense. New combinations are formalized for Dasispermum capense, D. hispidum, D. humile, and D. tenue. An undescribed species from the Tanqua Karoo in South Africa is also closely related to Capnophyllum and the Dasispermum–Sonderina complex. The genus Scaraboides is described herein to accommodate the new species, S. manningii. This monotypic genus shares the dorsally compressed fruit and involute marginal wings with Capnophyllum, but is easily distinguished by its erect branching habit, green leaves, scabrous umbels, and fruit with indistinct median and lateral ribs, additional solitary vittae in each marginal wing, and parallel, closely spaced commissural vittae. Despite the marked fruit similarities with Capnophyllum, analyses of DNA sequence data place Scaraboides closer to the Dasispermum–Sonderina complex, with which it shares the erect habit, green (nonglaucous) leaves, and scabrous umbels.


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.


Phytotaxa ◽  
2018 ◽  
Vol 350 (1) ◽  
pp. 42 ◽  
Author(s):  
GALINA V. DEGTJAREVA ◽  
MICHAEL G. PIMENOV ◽  
TAHIR H. SAMIGULLIN

The systematic position of three Apiaceae-Apioideae taxa, Pinacantha porandica, Ladyginia bucharica and Peucedanum mogoltavicum, from Middle Asia and Afghanistan, is clarified based on nrITS DNA sequence data. In the molecular phylogenetic tree, the monotypic Pinacantha is placed in unresolved position within the Ferulinae. Although there is no morphological information on essential characters, we propose a new position of Pinacantha porandica within the genus Ferula. As a result a new combination Ferula porandica is proposed, with a new section Pinacantha to accommodate it. The attribution of Peucedanum mogoltavicum to Ferula has been confirmed, its correct name being Ferula lithophila. The genus Ladyginia should not be included in Ferula, its closest relatives being Mozaffariania and Glaucosciadium from the Glaucosciadium Clade.


Author(s):  
Todd McLay ◽  
Gareth D. Holmes ◽  
Paul I. Forster ◽  
Susan E. Hoebee ◽  
Denise R. Fernando

The rainforest genus Gossia N.Snow & Guymer (Myrtaceae) occurs in Australia, Melanesia and Malesia, and is capable of hyperaccumulating the heavy metal manganese (Mn). Here, we used nuclear ribosomal and plastid spacer DNA-sequence data to reconstruct the phylogeny of 19 Australian species of Gossia and eight New Caledonian taxa. Our results indicated that the relationship between Gossia and Austromyrtus (Nied.) Burret is not fully resolved, and most Australian species were supported as monophyletic. Non-monophyly might be related to incomplete lineage sorting or inaccurate taxonomic classification. Bark type appears to be a morphological synapomorphy separating two groups of species, with more recently derived lineages having smooth and mottled ‘python’ bark. New Caledonian species were well resolved in a single clade, but were not the first diverging Gossia lineage, calling into doubt the results of a recent study that found Zealandia as the ancestral area of tribe Myrteae. Within Australia, the evolution of multiple clades has probably been driven by well-known biogeographic barriers. Some species with more widespread distributions have been able to cross these barriers by having a wide range of soil-substrate tolerances. Novel Mn-hyperaccumulating species were identified, and, although Mn hyperaccumulation was not strongly correlated with phylogenetic position, there appeared to be some difference in accumulation levels among clades. Our study is the first detailed phylogenetic investigation of Gossia and will serve as a reference for future studies seeking to understand the origin and extent of hyperaccumulation within the Myrteae and Myrtaceae more broadly.


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