scholarly journals Pollen morphology of tribesAptosimeaeandMyoporeaesupports the phylogenetic pattern in early-branchingScrophulariaceaerevealed by molecular studies

2015 ◽  
Vol 45 (2) ◽  
pp. 209-222 ◽  
Author(s):  
Sergei L. Mosyakin ◽  
Zoya M. Tsymbalyuk
Keyword(s):  
Pollen Morphology ◽  
Phylogenetic Pattern ◽  
Molecular Studies

Diplazoptilon (Asteraceae) is merged with Saussurea based on evidence from morphology and molecular systematics

Phytotaxa ◽  
2015 ◽  
Vol 236 (1) ◽  
pp. 53 ◽  
Author(s):  
Qian Yuan ◽  
Yanchao Bi ◽  
Yousheng Chen
Keyword(s):  
Molecular Systematics ◽  
Pollen Morphology ◽  
Morphological Characters ◽  
Systematic Position ◽  
Monotypic Genus ◽  
Molecular Analyses ◽  
Molecular Studies ◽  
Micromorphological Characters

Diplazoptilon is a monotypic genus belonging to the Saussurea group (Asteraceae, Cardueae). We undertake micromorphological and molecular studies to discuss the systematic position of this genus. The achene of Diplazoptilon picridifolium is obconical, 4-angled, with a small crown on the apical rim. The pollen of D. picridifolium are spheroidal, narrowly tricolpate, with the exine reticulate and shortly spinulate. The micromorphological characters of D. picridifolium are well in accordance with those of the genus Saussurea. Our molecular analyses demonstrate that Diplazoptilon and Saussurea form a strongly supported clade. Taking into account the great similarities in achene, pappus and pollen morphology between Diplazoptilon and Saussurea, it is reasonable to merge Diplazoptilon with Saussurea. From our molecular work and the gross-morphological characters, D. picridifolium should be a member of Saussurea subgen. Saussurea sect. Strictae. There are more than one species with a plumose outer pappus in the genus Saussurea, and the occurrences the plumose outer pappus in the genus Saussurea may have had parallel origins.

Systematic relevance of the pollen morphology for the Rondeletia complex (Cinchonoideae, Rubiaceae)

2020 ◽  
Vol 194 (3) ◽  
pp. 290-307
Author(s):  
Alejandro Torres-Montúfar ◽  
Elia Ramírez-Arriaga ◽  
Enrique Martínez-Hernández ◽  
Helga Ochoterena
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pollen Morphology ◽  
Morphological Characters ◽  
Palynological Data ◽  
Molecular Studies ◽  
Close Relationship ◽  
Relationship Of ◽  
Scanning Electron

Abstract Seventeen morphologically related genera have been considered as the Rondeletia complex, traditionally in Rondeletieae. Molecular studies agree that this is a polyphyletic group and some genera have been transferred to Guettardeae. Nevertheless, no solid morphological characters support this hypothesis. Our aim is to explore pollen morphology to see if this source of characters has systematic value. Our study uses light and scanning electron microscopy for 30 species of both tribes representing 14 genera. The most important characters are polar outline, endoaperture type and nexine discontinuities. Our results do not permit diagnosis of tribes, but they show that the genera formerly included in the Rondeletia complex, but now placed in Guettardeae, have nexine discontinuities in polar areas: endofissures (Rogiera) or endocracks (Arachnothryx complex: Arachnothryx-Gonzalagunia-Javorkaea-Renistipula). Palynological data also confirm a close relationship of Rondeletia with Stevensia, corroborating their synonymy, and of Arachnothryx with Gonzalagunia-Javorkaea-Renistipula, providing evidence of their close relationship. We conclude that pollen is a useful source of characters for supporting main lineages, but further research is still necessary for other genera, including Blepharidium, Machaonia, Mazaea and additional Rondeletia spp.

Persepolium (Polygoneae): A new genus in Polygonaceae based on conventional Maximum Parsimony and Three-taxon statement analyses of a comprehensive morphological dataset

Phytotaxa ◽  
2017 ◽  
Vol 314 (2) ◽  
pp. 151 ◽  
Author(s):  
OLGA V. YURTSEVA ◽  
ELENA E. SEVEROVA ◽  
EVGENY V. MAVRODIEV
Keyword(s):  
Life History ◽  
Maximum Parsimony ◽  
Pollen Morphology ◽  
New Genus ◽  
Taxonomic Revision ◽  
Molecular Studies ◽  
Pollination Mode

Recent molecular studies revealed the polyphyletic nature of the broadly defined genus Polygonum. This paper includes a standard maximum parsimony (MP) and three-taxon statement analyses (3TA) as well as a taxonomic revision of Polygonum sect. Avicularia subsect. Spinescentia (Polygonaceae) as compared with two closely related taxa: genus Atraphaxis s.s., and genus Bactria. In total, 27 characters, including life history, habit, morphology of the shoots, leaf blades, ocreas, perianth, achene, ultrasculpture of perianth and achene surfaces, as well as pollen morphology, were analyzed, illustrated, and discussed in detail. Both the standard MP and 3TA confirm that monophyletic Polygonum subsect. Spinescentia is sister to the narrowly defined Atraphaxis. The genus Persepolium (Polygonum subsect. Spinescentia), with the circumscription of five species, is established as new to science as a result of this study. Possible transformations of perianth and thyrse morphology are discussed within the framework of the Principle of variable proportions by Troll in connection with a shift of pollination mode in the group of taxa studied.

Darwin's two competing phylogenetic trees: marsupials as ancestors or sister taxa?

2012 ◽  
Vol 39 (2) ◽  
pp. 217-233 ◽  
Author(s):  
J. David Archibald
Keyword(s):  
Fossil Record ◽  
Evolutionary Biology ◽  
Phylogenetic Trees ◽  
Charles Darwin ◽  
The Other ◽  
Charles Lyell ◽  
Single Origin ◽  
Molecular Studies ◽  
Richard Owen ◽  
First Time

Studies of the origin and diversification of major groups of plants and animals are contentious topics in current evolutionary biology. This includes the study of the timing and relationships of the two major clades of extant mammals – marsupials and placentals. Molecular studies concerned with marsupial and placental origin and diversification can be at odds with the fossil record. Such studies are, however, not a recent phenomenon. Over 150 years ago Charles Darwin weighed two alternative views on the origin of marsupials and placentals. Less than a year after the publication of On the origin of species, Darwin outlined these in a letter to Charles Lyell dated 23 September 1860. The letter concluded with two competing phylogenetic diagrams. One showed marsupials as ancestral to both living marsupials and placentals, whereas the other showed a non-marsupial, non-placental as being ancestral to both living marsupials and placentals. These two diagrams are published here for the first time. These are the only such competing phylogenetic diagrams that Darwin is known to have produced. In addition to examining the question of mammalian origins in this letter and in other manuscript notes discussed here, Darwin confronted the broader issue as to whether major groups of animals had a single origin (monophyly) or were the result of “continuous creation” as advocated for some groups by Richard Owen. Charles Lyell had held similar views to those of Owen, but it is clear from correspondence with Darwin that he was beginning to accept the idea of monophyly of major groups.

On Riccia marginata and related species (Ricciaceae, Marchantiophyta)

2012 ◽  
Vol 46 ◽  
pp. 298-305 ◽  
Author(s):  
A. D. Potemkin ◽  
T. Ahti
Keyword(s):  
Related Species ◽  
Lake Ladoga ◽  
Leningrad Region ◽  
Sem Images ◽  
North Shore ◽  
The North ◽  
Molecular Studies ◽  
The Future ◽  
The Town

Riccia marginata Lindb. was described by S. O. Lindberg (1877) from the outskirts of the town of Sortavala near the north shore of Lake Ladoga, Republic of Karelia, Russia. The species has been forgotten in most recent liverwort accounts of Europe, including Russia. Lectotypification of R. marginata is provided. R. marginata shares most characters with R. beyrichiana Hampe ex Lehm. It differs from “typical” plants of R. beyrichiana in having smaller spores, with ± distinctly finely areolate to roughly papillose proximal surfaces and a narrower and shorter thallus, as well as in scarcity or absence of marginal hairs. It may represent continental populations of the suboceanic-submediterranean R. beyrichiana, known in Russia from the Leningrad Region and Karelia only. The variability of spore surfaces in R. beyrichiana is discussed and illustrated by SEM images. A comparison with the spores of R. bifurca Hoffm. is provided. The question how distinct R. marginata is from R. beyrichiana needs to be clarified by molecular studies in the future, when adequate material is available. R. marginata is for the time being, provisionally, included in R. beyrichiana.

Evolution of Angiosperm Pollen: 8. Lamiids

2020 ◽  
Vol 105 (3) ◽  
pp. 323-376
Author(s):  
Li-E Yang ◽  
Lu Lu ◽  
Kevin S. Burgess ◽  
Hong Wang ◽  
De-Zhu Li
Keyword(s):  
Maximum Likelihood ◽  
Pollen Morphology ◽  
Pollen Size ◽  
State Transitions ◽  
Character State ◽  
Evolutionary Mechanisms ◽  
Pollen Characters ◽  
Exine Ornamentation ◽  
Shape Class ◽  
Pollen Character

Lamiids, a clade composed of approximately 15% of all flowering plants, contains more than 50,000 species dispersed across 49 families and eight orders (APG IV, 2016). This paper is the eighth in a series that analyzes pollen characters across angiosperms. We reconstructed a maximum likelihood tree based on the most recent phylogenetic studies for the Lamiids, comprising 150 terminal genera (including six outgroups) and covering all eight orders and 49 families within the clade. To illustrate pollen diversity across the Lamiids, pollen grains from 22 species (22 genera in 14 families) were imaged under light, scanning, and transmission electron microscopy. Eighteen pollen characters that were documented from previous publications, websites, and our new observations were coded and optimized onto the reconstructed phylogenetic tree using Fitch parsimony, maximum likelihood, and hierarchical Bayesian analysis. Pollen morphology of the Lamiids is highly diverse, particularly in shape class, pollen size, aperture number, endoaperture shape, supratectal element shape, and tectum sculpture. In addition, some genera show relatively high infrageneric pollen variation within the Lamiids: i.e., Coffea L., Jacquemontia Choisy, Justicia L., Pedicularis L., Psychotria L. nom. cons., Sesamum L., Stachytarpheta Vahl, and Veronica L. The plesiomorphic states for 16 pollen characters were inferred unambiguously, and 10 of them displayed consistent plesiomorphic states under all optimization methods. Seventy-one lineages at or above the family level are characterized by pollen character state transitions. We identified diagnostic character states for monophyletic clades and explored palynological evidence to shed light on unresolved relationships. For example, palynological evidence supports the monophyly of Garryales and Metteniusaceae, and sister relationships between Icacinaceae and Oncothecaceae, as well as between Vahliales and Solanales. The evolutionary patterns of pollen morphology found in this study reconfirm several previously postulated evolutionary trends, which include an increase in aperture number, a transition from equatorially arranged apertures to globally distributed ones, and an increase in exine ornamentation complexity. Furthermore, there is a significant correlation between pollen characters and a number of ecological factors, e.g., pollen size and pollination type, pollen ornamentation and pollination type, and shape class and plant growth form. Our results provide insight into the ecological, environmental, and evolutionary mechanisms driving pollen character state changes in the Lamiids.

New Findings on Scrophularia sect. Mimulopsis (Scrophulariaceae) from Iran

2019 ◽  
Vol 27 (4) ◽  
pp. 238-247
Author(s):  
Massoud Ranjbar ◽  
Narges Rahchamani
Keyword(s):  
New Species ◽  
Pollen Morphology ◽  
Conservation Status ◽  
Morphological Characters ◽  
Northern Iran ◽  
Distribution Maps ◽  
New Findings ◽  
Tehran Province ◽  
Micromorphological Characters ◽  
A New Species

Scrophularia dianatnejadii Ranjbar & Rahchamani, a new species from Tehran Province in northern Iran, is described and illustrated. It is closely related to S. amplexicaulis Benth. and shares with it some diagnostic morphological characters such as habit, plant indument, phyllotaxy, and corolla shape and color. Both species are placed in Scrophularia L. sect. Mimulopsis Boiss. Macro- and micromorphological characters of the two are examined and compared. Pollen morphology of these species is investigated using SEM. Detailed descriptions, illustrations, distribution maps, and conservation status of both species are provided.

Pollen morphology of selected tundra plants from the high Arctic of Ny-Ålesund, Svalbard

2013 ◽  
Vol 23 (2) ◽  
pp. 103-115 ◽  
Author(s):  
Yifeng YAO ◽  
Qi ZHAO ◽  
Subir BERA ◽  
Xiaoli LI ◽  
Chengsen LI
Keyword(s):  
Pollen Morphology ◽  
High Arctic
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