scholarly journals Symmetry breaking of the cellular lobes closely relates to phylogenetic structure within green microalgae of theMicrasteriaslineage (Zygnematophyceae)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6098 ◽  
Author(s):  
Jiri Neustupa ◽  
Jan Stastny

Green microalgae of theMicrasteriaslineage are unicellular microorganisms with modular morphology consisting of successively differentiated lobes. Due to their morphological diversity and peculiar morphogenesis, these species are important model systems for studies of cytomorphogenesis and cellular plasticity. Interestingly, the phylogenetic structure of theMicrasteriaslineage and most other Desmidiales is poorly related to the traditional morphological characters used for delimitation of taxa. In this study, we focused on symmetry breaking between adjacent cellular lobes in relation to phylogeny of the studied species. While pronounced morphological asymmetry between the adjacent lobes is typical for some species, others have been characterized by the almost identical morphologies of these structures. We asked whether there is any detectable average shape asymmetry between the pairs of lobes and terminal lobules in 19Micrasteriasspecies representing all major clades of this desmidiacean lineage. Then, we evaluated whether the asymmetric patterns among species are phylogenetically structured. The analyses showed that the phylogeny was in fact strongly related to the patterns of morphological asymmetry between the adjacent cellular lobes. Thus, evolution of the asymmetric development between the adjacent lobes proved to be the key event differentiating cellular shape patterns ofMicrasterias. Conversely, the phylogeny was only weakly related to asymmetry between the pairs of terminal lobules. The subsequent analyses of the phylogenetic morphological integration showed that individual hierarchical levels of cellular morphology were only weakly coordinated with regard to asymmetric variation among species. This finding indicates that evolutionary differentiation of morphogenetic processes leading to symmetry breaking may be relatively independent at different branching levels. Such modularity is probably the key to the evolvability of cellular shapes, leading to the extraordinary morphological diversity of these intriguing microalgae.

2012 ◽  
Vol 10 (1) ◽  
pp. 19-44 ◽  
Author(s):  
Alfy Morales-Cazan ◽  
James S. Albert

The systematics and taxonomy of poeciliid fishes (guppies and allies) remain poorly understood despite the relative importance of these species as model systems in the biological sciences. This study focuses on testing the monophyly of the nominal poeciliine tribe Heterandriini and the genus Heterandria, through examination of the morphological characters on which the current classification is based. These characters include aspects of body shape (morphometrics), scale and fin-ray counts (meristics), pigmentation, the cephalic laterosensory system, and osteological features of the neurocranium, oral jaws and suspensorium, branchial basket, pectoral girdle, and the gonopodium and its supports. A Maximum Parsimony analysis was conducted of 150 characters coded for 56 poeciliid and outgroup species, including 22 of 45 heterandriin species (from the accounted in Parenti & Rauchenberger, 1989), or seven of nine heterandriin species (from the accounted in Lucinda & Reis, 2005). Multistate characters were analyzed as both unordered and ordered, and iterative a posteriori weighting was used to improve tree resolution. Tree topologies obtained from these analyses support the monophyly of the Middle American species of "Heterandria," which based on available phylogenetic information, are herein reassigned to the genus Pseudoxiphophorus. None of the characters used in previous studies to characterize the nominal taxon Heterandriini are found to be unambiguously diagnostic. Some of these characters are shared with species in other poeciliid tribes, and others are reversed within the Heterandriini. These results support the hypothesis that Pseudoxiphophorus is monophyletic, and that this clade is not the closest relative of H. formosa (the type species) from southeastern North America. Available morphological data are not sufficient to assess the phylogenetic relationships of H. formosa with respect to other members of the Heterandriini. The results further suggest that most tribe-level taxa of the Poeciliinae are not monophyletic, and that further work remains to resolve the evolutionary relationships of this group.


2021 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Vina Eka Aristya

<p class="Abstract" align="center"><strong>ABSTRAK</strong></p><p class="Abstract"><em>Sesamum indicum</em> L. adalah salah satu tanaman alternatif penghasil minyak nabati penting. Pendekatan pemuliaan melalui induksi mutasi berusaha untuk menghasilkan variabilitas baru populasi wijen, yang secara umum tersusun dari individu homozigot. Karakter morfologi berguna untuk mengidentifikasi galur dan memastikan hasil pemuliaan mutasi. Tujuan penelitian ini adalah untuk mengevaluasi keragaman morfologi wijen hasil mutasi berdasarkan 26 karakter kualitatif. Penggalian informasi dengan metode analisis kelompok juga dikaji untuk menggambarkan variabilitas genetik pada 57 galur mutan wijen (jenis hitam dan putih) generasi M4 dan M5. Penelitian ini dilakukan dalam dua tahap: tahap pertama terdiri 18 galur generasi M4, dievaluasi pada Maret-Agustus 2015; tahap kedua terdiri atas 39 galur M5, ditanam pada November 2015 hingga April 2016. Pemeriksaan penampilan kualitatif mengikuti panduan <em>descriptor list</em> untuk wijen. Secara umum, penilaian representatif dari sifat kualitatif pada galur mutan wijen generasi M4 akan diikuti oleh keturunan generasi M5. Dendrogram dibangun untuk membedakan galur menjadi kelompok berdasarkan matriks tingkat kemiripan. Struktur populasi utama dari 57 galur berdasarkan sifat kualitatif dikategorikan dalam dua kelompok besar. Materi genotipe kelompok I diklasifikasikan menjadi dua sub-kelompok, terdiri 17 dan 31 galur. Sub-kelompok ini menjadi bagian distribusi genotipe terbesar. Kelompok II tersusun oleh 9 galur, mayoritas dari M4. Nilai korelasi antar karakter bervariasi antara 0,7176 hingga 1,0. Keragaman morfologi antar galur wijen dipengaruhi oleh sifat genetik dibandingkan faktor lingkungan. Studi ini membantu seleksi galur terpilih berdasarkan kestabilan fenotipe. Evaluasi keragaman struktur populasi wijen mutan bermanfaat untuk program pemuliaan.</p><p class="Abstract" align="center"><strong>ABSTRACT</strong></p><p class="Abstract"><em>Sesamum indicum</em> L. is one of the alternative crops that produces vegetative oil. The plant breeding approach through mutation induction could produce new genetic variability in sesame populations, which are generally composed of homozygous individuals. The study aims were to determine the diversity of sesame-mutant lines based on 26 qualitative characters. Cluster analysis method was carried out to describe the genetic variability of 57 sesame mutant lines (consist of black and white types) 4<sup>th</sup> (M4) and 5<sup>th</sup> generations (M5). The study was done in two phases, the first phases consisted of 18 M4 lines planted in March-August 2015; the second phase consisted 39 M5 lines planted in November 2015 to April 2016. Analyses of qualitative morphological characters followed the descriptors list for sesame. In general, a representative assessment of qualitative traits in M4 lines will be followed by the offspring of M5. Dendrogram showed that the 57 mutant lines categorized into two major clusters. Cluster I were composed of two sub-clusters, consisting 17 and 31 lines. This sub-cluster was the largest part of the genotype distribution. Cluster II composed of 9 lines, where M4 were the majority. The correlation value between characters ranged from 0.7176 up to 1.0. Morphological diversity among lines were largely influenced by genetic rather than environmental factors. This study supports the selection of lines based on phenotype stability. Evaluation of the structural diversity of mutant-sesame populations could be applied in sesame-breeding programs.</p>


2019 ◽  
pp. 54-78
Author(s):  
Yaroslav Tsytsiura

The article presents the results of a long-term study of the features of the phytocenology of agrophytocenoses of oil radish using different methods for assessing their condition and studying the tactics of the plant vitality strategy. A comprehensive assessment was made of the effect of changes in row spacing, seeding rates and fertilizer rates on the formation of various plant morphotypes, the variability of morphological characters and the general characteristics of plant viability. Three idiotypes of the plant oil radish were identified in a vertical study of agrophytocenosis, on the basis of which a detailed analysis of the variability of each group and a statistical assessment of the reliability of its existence were carried out. The features of the morphological integration of each tier are analyzed and its impact on the formation of the overall field productivity is evaluated. Based on the modular and vitality grouping, the effectiveness and feasibility of combining various options for plant density and fertilizer in the range of 30-90 kg of active substance per 1 ha were evaluated. Conclusions are drawn about the desired model of agrophytocenosis of oil radish based on the characteristics of its vital tactics and the goals of its growing. Grouping was carried out according to a variety of morphological traits of plants in the population and the possibilities of applying the basic patterns of phytocenology in their application to radish oilseed plants were evaluated. Through the use of regression analysis, the influence of climatic conditions on the formation of various morphological types of plants and the nature of the relationship of plants of oil radish in cenoses of various densities against the background of various fertilizer options has been evaluated. The main promising areas for further research on the peculiarities of creating highly productive and highly adaptable agrophytocenoses of oil radish have been outlined.


2021 ◽  
pp. 1-24
Author(s):  
Mariana F. Lindner ◽  
Augusto Ferrari ◽  
Adriano Cavalleri

Abstract Holopothrips is a diverse group of thrips associated to galls in the Neotropics, with a variety of host plants and wide morphological diversity. Relationships to other Neotropical groups have been proposed, but are still untested, and the monophyly of the genus remains doubtful. Here, we perform a phylogenetic analysis of Holopothrips, based on morphological characters. A total of 87 species were included in the matrix and eight analyses were carried out, but all of them failed to recover Holopothrips as a monophyletic grouping. Bremer and Bootstrap support values were low, and the topologies varied among all analyses, with uncertain internal relations for the ingroup. These results indicate that the relationships for Holopothrips species, and the proposed related genera, are more complex than previously reported; and morphological characters may not be enough to recover the evolutionary story within this group. We also discuss the influences of different character coding, continuous characters and weighting schemes in our results.


2020 ◽  
Vol 189 (4) ◽  
pp. 1249-1312 ◽  
Author(s):  
Alberto Sánchez-Vialas ◽  
Mario García-París ◽  
José L Ruiz ◽  
Ernesto Recuero

Abstract Delimiting species boundaries is a complex challenge usually hindered by overlooked morphological diversification or misinterpretation of geographically structured phenotypic variability. Independent molecular data are extremely useful to characterize and understand such morphological diversity. Morphological and molecular variability of the non-phoretic and apterous, widely distributed, giant blister beetles of the genus Berberomeloe, were investigated within and between lineages across most of the distributional range of the genus. We used two mtDNA gene fragments to characterize genetic variability and to produce a time-calibrated phylogeny of the genus. Our results reveal several mitochondrial lineages, allopatrically, parapatrically and sympatrically distributed. Most clades are not distinguishable between each other based on morphometrics. However, no morphometric overlap is observed between two closely related clades, one of them occurring in sympatry with a distantly congeneric species (B. insignis), suggesting that sympatry could trigger morphological diversification. Although most species share a morphometric space, they can be morphologically identified by a combination of easily observed characteristic qualitative features. Based on the concordance between mtDNA clades and morphological units, we describe six new species of Berberomeloe (B. castuo sp. nov., B. comunero sp. nov., B. indalo sp. nov, B. yebli sp. nov., B. payoyo sp. nov. and B. tenebrosus sp. nov.), revalidate two taxa (B. maculifrons comb. nov. and B. laevigatus comb. nov.) and redefine B. majalis.


2020 ◽  
Vol 193 (3) ◽  
pp. 287-315 ◽  
Author(s):  
Ekaterina A Shepeleva ◽  
Mikhail I Schelkunov ◽  
Michal Hroneš ◽  
Michal Sochor ◽  
Martin Dančák ◽  
...  

Abstract Thismia is a genus of &gt; 80 mycoheterotrophic species characterized by a peculiar appearance and complex floral morphology. A significant proportion of the species and morphological diversity of Thismia has only been uncovered in the past two decades, and new discoveries continue to be made. Given that many new data have recently become available, and the most comprehensive taxonomic revision of the genus from 1938 addresses less than half of the currently known species, previous hypotheses for species relationships and infrageneric taxonomic classification in Thismia was in need of review. Extensive molecular phylogenetic studies of Thismia at the genus level have never been presented. We investigate the phylogenetic relationships of 41 species (and one variety) of Thismia from the Old World. Our study comprises 68 specimens (for 28 of which the data were newly generated), including outgroup taxa broadly representing Thismiaceae (= Burmanniaceae p.p. sensuAPG IV, 2016), and is based on two nuclear and one mitochondrial marker. We use maximum likelihood and Bayesian inference to infer relationships among the taxa. We also constructed a morphological dataset of 12 mostly floral characters, comparing these characters to hypotheses based on molecular evidence to identify putative synapomorphies for major clades and to discuss hypotheses regarding the evolution of structural traits in the genus. Our analyses indicate that the majority of currently accepted infrageneric taxa of Thismia are polyphyletic. We find support for the monophyly of the Old World group, in which we recognize five well-supported lineages (clades); the only New World species studied appears to be related to the Neotropical genus Tiputinia. Ancestral state reconstructions demonstrate that the evolution of most morphological characters was homoplastic, but we identify characters that provide each of the five clades of Old World Thismia with a unique morphological description. The geographical distribution of the species under study is also shown to be consistent with the major clades. Our investigation provides a phylogenetic basis for the development of a novel sectional classification of Thismia reflecting morphological and geographical traits.


2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Carolina C. Siliprandi ◽  
Víctor M. Tuset ◽  
Antoni Lombarte ◽  
Marc Farré ◽  
Carmen L. D. B. Rossi-Wongtschowski

ABSTRACT Morphological characters of species are essential for assessing the functional structure of a fish assemblage, since differences between them, for example in body shape, are related to many functional and ecological traits (e.g., swimming, search for food, striking and capturing prey, evading predators, spawning). Globally, tidal flats are relevant to fish assemblages by offering feeding, refuge, and reproduction grounds. To analyze the morphofunctional structure of the fish assemblage from a tidal flat on the Brazilian coast, we conducted standardized sampling using nine different fishing gears. The geometric morphometric method was applied to describe the fish shapes and verify the morphological structure of the assemblage. Here, we present the influence/susceptibility of each gear type on the morphological diversity of the fish assemblage. The results indicated that beach seine, otter trawl, marginal encircling gillnet, and fish traps, together, were the most effective gears to represent the maximum morphological variability of fish inhabiting that tidal flat. Moreover, the assemblage showed high morphological redundancy considered as a resistance of the ecosystem for avoiding functional diversity loss, emphasizing the importance of complementary gear use when determining fish assemblages in a conservation context.


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