Examining the Needle in the Haystack: Evolutionary Relationships in the Mistletoe Genus Loranthus (Loranthaceae)

2021 ◽  
Vol 46 (2) ◽  
pp. 403-415
Author(s):  
Daniel L. Nickrent ◽  
Huei-Jiun Su ◽  
Ruo-Zhu Lin ◽  
Mohan Prasad Devkota ◽  
Jer-Ming Hu ◽  
...  

Abstract— The genus Loranthus (Loranthaceae) consists of ca. nine Old World species distributed from eastern Asia to Europe. Loranthus, the type of the family, has had a complex taxonomic history that continues today, partly because most mistletoes in the family have resided in this genus. For this reason, there are over 1800 Loranthus species names, the vast majority of which are synonyms for mistletoes in other genera. The present work sampled representatives of nine species considered bona fide members of the genus. Using complete plastome sequences, nuclear ribosomal DNA, and mitochondrial 26S rDNA, phylogenetic gene trees were generated to assess interspecific relationships. The Loranthus plastomes ranged in size from 121 to 125 kb and exhibited the quadripartite structure seen in most Santalales. These plastomes have lost or pseudogenized 24 genes, including all of the NADH dehydrogenase complex, thus reducing the genomes to ca. 90 functional genes. Cladistic analyses of morphological characters were conducted and these trees compared to the molecular trees, thus informing which taxonomic characters best define clades and characterize species within the genus. Two major clades in Loranthus were identified. The Europaeus clade includes the deciduous species L. europaeus, L. grewingkii, L. lambertianus, and L. tanakae mostly distributed above 30° N latitude. The Odoratus clade, mostly distributed below 30° N latitude, included L. guizhouensis, L. kaoi, L. odoratus, and L. pseudo-odoratus. The latter four species are genetically closely related, show percurrent (vs. pseudo-dichotomous) branching, and have evergreen leaves. Unisexual flowers have apparently evolved independently in each of the two clades. Future work should focus upon the species delimitation in the Odoratus clade and whether hybridization is occurring among any members.

1998 ◽  
Vol 11 (4) ◽  
pp. 321 ◽  
Author(s):  
Austin R. Mast

Despite considerable research interest in the subtribe Banksiinae (Banksia L.f. and Dryandra R.Br.), no strongly supported phylogenetic hypothesis for the relationship between the genera exists, nor have molecular characters been sampled for phylogenetic reconstruction at any level. In this study, DNA sequence characters were sampled from chloroplast DNA (cpDNA; the trnL intron, the trnL 3′ exon, and the spacer between the trnL 3′ exon and trnF) and nuclear ribosomal DNA (nrDNA; both internal transcribed spacers) of 18 species of Banksia and five of Dryandra, with six outgroup taxa from the subfamily Grevilleoideae. The molecular characters provided the opportunity to code taxa outside of Banksia for cladistic comparison with the genus—an opportunity not previously provided by morphological characters. Cladistic analyses, using parsimony, explored the effects of various weightings of transition to transversion events and base substitution to insertion and deletion events to determine which relationships in the cladograms were robust. The trnL/trnF and ITS characters strongly supported a paraphyletic Banksia with respect to a monophyletic Dryandra. The molecular results supported a single root for Thiele and Ladiges’(1996) unrooted morphological cladogram along the branch between the Isotylis to B. fuscolutea clade and the Grandes to B. tricuspis clade. George’s (1981) subgenus Banksia and section Banksia appeared dramatically non-monophyletic. The distribution of eastern taxa at derived positions on the molecular cladograms suggested considerable cladogenesis in the the genus prior to the formation of the Nullarbor Plain during the Tertiary.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4633 ◽  
Author(s):  
Michael Haas ◽  
Roger A. Burks ◽  
Lars Krogmann

Jewel wasps (Hymenoptera: Chalcidoidea) are extremely species-rich today, but have a sparse fossil record from the Cretaceous, the period of their early diversification. Three genera and three species,Diversinitus attenboroughigen. & sp. n., Burminata caputaeriagen. & sp. n. andGlabiala barbatagen. & sp. n. are described in the family Diversinitidae fam. n., from Lower Cretaceous Burmese amber. Placement in Chalcidoidea is supported by the presence of multiporous plate sensilla on the antennal flagellum and a laterally exposed prepectus. The new taxa can be excluded from all extant family level chalcidoid lineages by the presence of multiporous plate sensilla on the first flagellomere in both sexes and lack of any synapomorphies. Accordingly, a new family is proposed for the fossils and its probable phylogenetic position within Chalcidoidea is discussed. Morphological cladistic analyses of the new fossils within the Heraty et al. (2013) dataset did not resolve the phylogenetic placement of Diversinitidae, but indicated its monophyly. Phylogenetically relevant morphological characters of the new fossils are discussed with reference to Cretaceous and extant chalcidoid taxa. Along with mymarid fossils and a few species of uncertain phylogenetic placement, the newly described members of Diversinitidae are among the earliest known chalcidoids and advance our knowledge of their Cretaceous diversity.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4783 ◽  
Author(s):  
Yuanmeng Miles Zhang ◽  
Julia Stigenberg ◽  
Jacqueline Hope Meyer ◽  
Barbara Jo-Anne Sharanowski

BackgroundParasitic wasps in the family Braconidae are important regulators of insect pests, particularly in forest and agroecosystems. Within Braconidae, wasps in the tribe Euphorini (Euphorinae) attack economically damaging plant bugs (Miridae) that are major pests of field and vegetable crops. However, the evolutionary relationships of this tribe have been historically problematic. Most generic concepts have been based on ambiguous morphological characters which often leads to misidentification, complicating their use in biological control.MethodsUsing a combination of three genes (COI,28S, andCAD) and 80 taxa collected worldwide, we conducted Bayesian inference using MrBayes, and maximum likelihood analyses using RAxML and IQ-Tree on individual gene trees as well as the concatenated dataset.ResultsThe monophyly of the tribe Euphorini and the two generaPeristenusandLeiophronwere confirmed using maximum likelihood and Bayesian inference. The subgeneric classifications ofLeiophron sensu latowere not supported, and the monotypic genusMamawas also not supported.DiscussionEuphoriella,Euphoriana,Euphorus, andMamasyn. n,have been synonymized underLeiophron. Mama mariaesyn. nwas placed as a junior synonym ofLeiophron reclinator. The generic concepts ofPeristenusandLeiophronwere refined to reflect the updated phylogeny. Further we discuss the need for revising Euphorini given the number of undescribed species within the tribe.


2011 ◽  
Vol 20 (1) ◽  
pp. 161-173
Author(s):  
A.P. Kassatkina

Resuming published and own data, a revision of classification of Chaetognatha is presented. The family Sagittidae Claus & Grobben, 1905 is given a rank of subclass, Sagittiones, characterised, in particular, by the presence of two pairs of sac-like gelatinous structures or two pairs of fins. Besides the order Aphragmophora Tokioka, 1965, it contains the new order Biphragmosagittiformes ord. nov., which is a unique group of Chaetognatha with an unusual combination of morphological characters: the transverse muscles present in both the trunk and the tail sections of the body; the seminal vesicles simple, without internal complex compartments; the presence of two pairs of lateral fins. The only family assigned to the new order, Biphragmosagittidae fam. nov., contains two genera. Diagnoses of the two new genera, Biphragmosagitta gen. nov. (type species B. tarasovi sp. nov. and B. angusticephala sp. nov.) and Biphragmofastigata gen. nov. (type species B. fastigata sp. nov.), detailed descriptions and pictures of the three new species are presented.


2020 ◽  
Author(s):  
Fernando Lopes ◽  
Larissa R Oliveira ◽  
Amanda Kessler ◽  
Yago Beux ◽  
Enrique Crespo ◽  
...  

Abstract The phylogeny and systematics of fur seals and sea lions (Otariidae) have long been studied with diverse data types, including an increasing amount of molecular data. However, only a few phylogenetic relationships have reached acceptance because of strong gene-tree species tree discordance. Divergence times estimates in the group also vary largely between studies. These uncertainties impeded the understanding of the biogeographical history of the group, such as when and how trans-equatorial dispersal and subsequent speciation events occurred. Here we used high-coverage genome-wide sequencing for 14 of the 15 species of Otariidae to elucidate the phylogeny of the family and its bearing on the taxonomy and biogeographical history. Despite extreme topological discordance among gene trees, we found a fully supported species tree that agrees with the few well-accepted relationships and establishes monophyly of the genus Arctocephalus. Our data support a relatively recent trans-hemispheric dispersal at the base of a southern clade, which rapidly diversified into six major lineages between 3 to 2.5 Ma. Otaria diverged first, followed by Phocarctos and then four major lineages within Arctocephalus. However, we found Zalophus to be non-monophyletic, with California (Z. californianus) and Steller sea lions (Eumetopias jubatus) grouping closer than the Galapagos sea lion (Z. wollebaeki) with evidence for introgression between the two genera. Overall, the high degree of genealogical discordance was best explained by incomplete lineage sorting resulting from quasi-simultaneous speciation within the southern clade with introgresssion playing a subordinate role in explaining the incongruence among and within prior phylogenetic studies of the family.


2000 ◽  
Vol 77 (11) ◽  
pp. 1569-1579
Author(s):  
W A Charlton

Wiesneria triandra (Dalzell) Micheli is an unusual annual plant of the Alismataceae with spike-like inflorescences bearing unisexual flowers. Shoot development follows the sympodial pattern of other Alismataceae, but the cycle is so condensed that initiation of each foliage leaf is followed by inflorescence formation. The plant develops a tufted habit by the formation of an unusual accesory bud adjacent to each inflorescence. Male flowers have three sepals, three petals, three stamens, and usually three carpellodes; female flowers have a similar perianth, three staminodes, and three or more carpels. Up to the first three carpels, floral parts are arranged in alternating trimerous whorls. Additional carpels may occur above and between those of the first whorl. The androecium is particularly unusual for the Alismataceae since it has conventional alternation of stamens with petals rather than the antipetalous pairs of stamens commonly perceived in the family, but the phylogenetic postion of Wiesneria within the family (as revealed by other studies) indicates that the apparently conventional androecium of Wiesneria represents a derived state rather than a primitive one. The unisexual flowers also represent a derived state.


2014 ◽  
Vol 46 (1) ◽  
pp. 51-67 ◽  
Author(s):  
Zuzana FERENCOVA ◽  
Paloma CUBAS ◽  
Pradeep Kumar DIVAKAR ◽  
M. Carmen MOLINA ◽  
Ana CRESPO

AbstractThe importance of the anatomy and fine morphology of reproductive structures for the systematics of the family Parmeliaceae is highlighted by the new genus Notoparmelia, described here for Australasian species of Parmelia. These species were known to form a monophyletic lineage but correlated characters for its delimitation were lacking. A major characteristic used here for the circumscription of this genus is the overlooked apothecial anatomy. The proper exciple is reduced to one layer formed exclusively by large hyphae without any clear branching pattern and embedded in an abundant polysaccharide matrix. This feature differs from the rest of Parmeliaceae which have a stratified three-layered proper exciple composed of a thin hyaline layer, intermediate layer and basal cortex-like structure. The anatomy of proper exciple, together with the thickness of spore walls and other morphological characters such as lobe morphology, pseudocyphellae and rhizine type, allow a precise diagnosis of the new genus. The area of distribution is also useful for characterizing this genus. Sixteen new combinations are proposed.


2021 ◽  
Vol 22 (9) ◽  
pp. 4677
Author(s):  
Judit Danis ◽  
Mark Mellett

The nucleotide-binding domain and leucine-rich-repeat-containing family (NLRs) (sometimes called the NOD-like receptors, though the family contains few bona fide receptors) are a superfamily of multidomain-containing proteins that detect cellular stress and microbial infection. They constitute a critical arm of the innate immune response, though their functions are not restricted to pathogen recognition and members engage in controlling inflammasome activation, antigen-presentation, transcriptional regulation, cell death and also embryogenesis. NLRs are found from basal metazoans to plants, to zebrafish, mice and humans though functions of individual members can vary from species to species. NLRs also display highly wide-ranging tissue expression. Here, we discuss the importance of NLRs to the immune response at the epidermal barrier and summarise the known role of individual family members in the pathogenesis of skin disease.


2005 ◽  
Vol 26 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Francisca do Val ◽  
Paulo Nuin

AbstractThe systematics and phylogenetic relationships of the family Leptodactylidae are controversial as is the intrafamilial phylogeny of the leptodactylids. Here we analyze the relationships of the leptodactylid subfamily Hylodinae. This subfamily has been considered to be monophyletic and composed of three genera, Hylodes, Crossodactylus and Megaelosia. In the present study 49 characters were used, based on different studies on Leptodactylidae phylogeny. Maximum parsimony methods with unweighted and successively weighted characters were used to estimate the phylogeny of the Hylodinae. Upon analysis, the data provided further evidence of the monophyletic status of the three genera, with Megaelosia being the basal genus and the other two genera being sister taxa. The analysis with successive weighting results in a more resolved topology of the species subgroups of the genus Hylodes and separates this genus from Crossodactylus and confirms that the hylodines are monophyletic.


Phytotaxa ◽  
2014 ◽  
Vol 186 (4) ◽  
pp. 188 ◽  
Author(s):  
Ying-Ying Zhou ◽  
HONG-WEI ZHANG ◽  
JIANG-QIN HU ◽  
Xiao-Feng Jin

Sinalliaria is described here as a new genus of the family Brassicaceae from eastern China, based on the morphological characters and molecular sequences. Sinalliaria differs from the related genus Orychophragmus in having basal leaves petiolate, simple or rarely with 1‒3 lateral lobes (not pinnatisect); cauline leaves petiolate, cordate at base (not sessile, auriculate or amplexicaul at base); petals obovate to narrowly obovate, claw inconspicuous (not broadly obovate, with a claw as along as sepal); siliques truncate (not long-beaked) at apex. The microscopic characters of seed testa also show significant differences between Sinalliaria and Orychophragmus. Phylogenetic evidence from DNA sequences of nuclear ribosomal ITS and plastid region trnL-trnF indicates that Sinalliaria is a distinct group related to Orychophragmus and Raphanus, but these three genera do not form a clade. The new genus Sinalliaria is endemic to eastern China and has only one species and one variety. The new combinations, S. limprichtiana (Pax) X. F. Jin, Y. Y. Zhou & H. W. Zhang and S. limprichtiana var. grandifolia (Z. X. An) X. F. Jin, Y. Y. Zhou & H. W. Zhang are proposed here.


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