Seed micro-morphology and its systematic significance in Gypsophila (Caryophyllaceae) and allied genera
TL;DR: Seed-coat characters support the separation of Gypsophila and Saponaria to some extent but disagree with recognition of Ankyropetalum as a genus separate from Gypsphila.
Abstract: In order to examine the systematic application of seed-coat micro-morphology in Gypsophila and allied genera, seed surfaces of 30 species and two varieties representing four genera of tribe Caryophylleae were examined with scanning electron microscope. The seeds of examined species range between 0.5–2.1 mm in length and 0.3–2.4 mm in diameter. The exomorphology of the seed coat shows two distinctive cell patterns. The epidermis is constructed either of elongated polygonal or of broad polygonal cells. The elongated type is the most common among the studied species, but the variation in alignment of testa cells, their size and shape as well as the density of protuberances may provide further information and useful diagnostic characters at generic and specific rank. The testa cells in Gypsophila and Saponaria are shallowly undulate, deeply undulate, lobed and armed at anticlinal walls. Deeply undulate anticlinal walls were observed in both Gypsophila and Ankyropetalum and a few species of Saponaria. Non- or indistinctly grooved anticlinal walls is the more common type in Allochrusa. Seed-coat characters support the separation of Gypsophila and Saponaria to some extent but disagree with recognition of Ankyropetalum as a genus separate from Gypsophila.
Citations
More filters
TL;DR: Palynological characters of 18 species belonging to seven genera of the traditional subfamily Alsinoideae including Arenaria, Cerastium, Eremogone, Lepyrodiclis, Minuartia, Sabulina and Stellaria were studied in detail using light and scanning electron microscopy and a dichotomous key has been developed for quick and easy identification.
Abstract: Palynological characters of 18 species belonging to seven genera of the traditional subfamily Alsinoideae including Arenaria, Cerastium, Eremogone, Lepyrodiclis, Minuartia, Sabulina and Stellaria were studied in detail using light and scanning electron microscopy. Pollen grains of subfamily Alsinoideae are subspheroidal or prolate, pantoporate and 20.04 to 51.4 µm in size, prominent and sunken apertures uniformly distributed on the pollen surface. Two types of pollen grain ornamentation were observed, i.e. microechinate-punctate or microechinate-perforate. Echini are present on the surface of the pollen of all investigated species with medium, dense, or sparse echinodensity. These species exhibit variation in polar view, equatorial diameter, number of apertures, exine thickness, diameter of pore, appendages per pore, pore ornamentation, echini arrangement, echinidensity and shape of pollen. Based on qualitative characters, a dichotomous key has been developed for quick and easy identification. The...
47 citations
Cites background from "Seed micro-morphology and its syste..."
...…by different researchers (Erdtman 1952; Chanda 1962; McNeill & Bassett 1974; Ghazanfar 1984; Bittrich 1993; Taia 1994; Punt & Hoen 1995; Yildiz 2001a, 2001b; Perveen & Qaiser 2006; Poyraz & Ataşlar 2010; Yildiz et al. 2010; Amini et al. 2011; Mostafavi & Mehregan 2014; Ullah et al. 2018c, 2018d)....
[...]
...Palynology of the family Caryophyllaceae has been studied by different researchers (Erdtman 1952; Chanda 1962; McNeill & Bassett 1974; Ghazanfar 1984; Bittrich 1993; Taia 1994; Punt & Hoen 1995; Yildiz 2001a, 2001b; Perveen & Qaiser 2006; Poyraz & Ataşlar 2010; Yildiz et al. 2010; Amini et al. 2011; Mostafavi & Mehregan 2014; Ullah et al. 2018c, 2018d)....
[...]
TL;DR: The results explained that SEM morphology of seeds provide important data about affinity among taxa and give potential characters in delimitation of members of subfamily Alsinoideae at generic and species level.
Abstract: Seed micromorphology of 13 species, belonging to four genera of subfamily Alsinoideae (Caryophyllaceae) were investigated with scanning electron microscopy (SEM), in order to assess their diagnostic significance at generic level and provide additional evidence on species delimitation, as well as correct identification and phylogenetic position. Genera and species of subfamily Alsinoideae exhibit great variation in ultrastructure and a high diversity of novel micromorphological characters were observed. Variation in seed shape, color, hilum, anticlinal wall, epidermal cell, cell surface, margins, and quantitative characters as length and width were studied in detail, compared, illustrated, and their taxonomic significant were discussed. Seed shapes of the species were classified as reniform, round, angular, subcircular, subreniform, and elliptical pyriform, with sub-central, central, basal, and nearly basal hilum. Wavy, irregular, tetragonal, and elongated epidermal cells structure has been observed as an exomorphological character. The present findings show that the micromorphology of subfamily Alsinoideae provides taxonomic information and is helpful to distinguish different species. The results also explained that SEM morphology of seeds provide important data about affinity among taxa and give potential characters in delimitation of members of subfamily Alsinoideae at generic and species level. A principal component analysis allowed to highlight the most outsiders among seed micromorphology with a possible explanation. Taxonomic keys were developed based on micromorphological characters to delimit the species and useful for their quick identification within subfamily Alsinoideae.
39 citations
Cites background or methods from "Seed micro-morphology and its syste..."
...…that is, seed color, seed shape, hilum, anticlinal wall, epidermal cell, cell surface, margins of cell, length, and width were studied to be important in distinguishing plant entities at different taxonomic level (Amini et al., 2011; Kanwal et al., 2012; Minuto et al., 2006; Mitra Arman, 2013)....
[...]
...length, and width were studied to be important in distinguishing plant entities at different taxonomic level (Amini et al., 2011; Kanwal et al., 2012; Minuto et al., 2006; Mitra Arman, 2013)....
[...]
...The studied samples were evaluated for diagnostic seed surface features like shape, size, hilum, anticlinal wall, epidermal cell, and cell margins using the terminology described in previous studies on Caryophyllaceae (Amini et al., 2011; Arabi et al., 2017; Crow, 1979)....
[...]
...In Caryophyllaceae special consideration has been made on the application of seed surface micromorphology in delimitation of allied genera of the family (Amini et al., 2011; Kanwal et al., 2012; Sadeghian et al., 2014)....
[...]
TL;DR: Both macro‐ and micromorphological characters can provide basis for classification and delimitation of genus Eucalyptus.
Abstract: Seed shape, surface cells shape, arrangement, anticlinal wall pattern, and periclinal wall protuberances were recorded for nine species of Eucalyptus (Myrtaceae) using scanning electron microscopy to determine the importance of seed morphological characters as an additional tool for identification. Most of the seeds were found ovate and some seeds were elliptic and cuboid in shape. Almost reticulate regular seed surface patterns were observed. Four types of surface cells were examined; diamond, elliptic, oblong, and irregular. Majority of the seeds showed raised anticlinal wall level and diversity from wavy to puzzle in pattern. Periclinal wall may be glabrous or having protuberances that were rhombus and bullate in shape. Both macro- and micromorphological characters can provide basis for classification and delimitation of genus Eucalyptus. RESEARCH HIGHLIGHTS: Seeds quantitative characters of nine Eucalyptus species as seed length, width, and weight. Macromorphological characters of seeds including seed color, helium position, and seed shape. Micromorphological characters include seed surface, periclinal wall, and anticlinal wall investigation under scanning electron microscope. Ultra-seed sculpturing features as an additional tool in identification.
28 citations
TL;DR: The main goal of the present study was to re-assess the monophyly of the genera currently recognized in this tribe using molecular phylogenetic data and propose a new classification system matching both molecular phylogenetics and morphological evidence.
Abstract: Assigning correct names to taxa is a challenging goal in the taxonomy of many groups within the Caryophyllaceae. This challenge is most serious in tribe Caryophylleae since the supposed genera seem to be highly artificial, and the available morphological evidence cannot effectively be used for delimitation and exact determination of taxa. The main goal of the present study was to re-assess the monophyly of the genera currently recognized in this tribe using molecular phylogenetic data. We used the sequences of nuclear ribosomal internal transcribed spacer (ITS) and the chloroplast gene rps16 for 135 and 94 accessions, respectively, representing all 16 genera currently recognized in the tribe Caryophylleae, with a rich sampling of Gypsophila as one of the most heterogeneous groups in the tribe. Phylogenetic trees were reconstructed using maximum parsimony and Bayesian inference methods. The results show that most of the large genera of Caryophylleae are not monophyletic. As a result, we propose a new classification system matching both molecular phylogenetic and morphological evidence. The main taxonomic conclusions include: (1) the description of three new genera, (2) treating five small genera as synonyms, (3) resurrecting the genus Heterochroa with six species, and (4) proposing 23 new combinations plus 2 replacement names at the specific level. As a result, we recognize 14 genera in Caryophylleae. A diagnostic key to all genera of Caryophylleae is provided.
27 citations
TL;DR: This analysis suggests that Allochrusa, Diaphanoptera, Ochotonophila and Scleranthopsis are nested within Acanthophyllum but that the traditionally recognized sections of Acanthophllum are monophyletic after reassignment of a few species.
Abstract: Despite being one of the larger genera of Caryophyllaceae with about 60 cushion-forming subshrubby species, Acanthophyllum is represented poorly in previous molecular phylogenetic studies. The genus is an important component of the subalpine steppe flora in Central to Southwest Asia. Although the placement of Acanthophyllum in the tribe Caryophylleae and a close relationship to Allochrusa has already been suggested, the monophyly of the genus and its subgeneric taxa, as well as its relation to other closely related genera, have not been addressed. We have assembled datasets of nuclear ribosomal internal transcribed spacer (ITS) sequences and intron sequences of the chloroplast gene rps16 for 47 Acanthophyllum species and 63 species of 12 additional genera from Caryophylleae. Phylogenetic analyses were performed using maximum parsimony, maximum likelihood and Bayesian methods. Our analysis suggests that Allochrusa, Diaphanoptera, Ochotonophila and Scleranthopsis are nested within Acanthophyllum but that the traditionally recognized sections of Acanthophyllum are monophyletic after reassignment of a few species. Emarginate petals may be a synapomorphy for one of the two basal clades of Acanthophyllum. Moreover, non-monophyly of the genera Gypsophila and Diaphanoptera is suggested by the present study. The age of the crown clade of Acanthophyllum s.l. is estimated to be 11.1 Ma by *BEAST species tree analysis.
24 citations
References
More filters
TL;DR: There is evidence that these features may be seen primarily under the aspects of reduced ability of plants to contaminate and as temperature control mechanisms of the surfaces, and some evidence for their systematic applicability above the family level.
Abstract: Based on SEM examinations of about 5000 species of seed plants, this is a survey of their epidermal surface characters with an aim to application in taxonomy. Surface characters may be grouped into four categories: (1) Cellular arrangement or cellular pattern. (2) Shape of cells (the “primary sculpture” of a surface). (3) Relief of outer cell walls (the “secondary sculpture” superimposed on the primary sculpture), caused mainly by cuticular striations and superficially visible wall inclusions and wall thickenings. (4) Epicuticular secretions (the “tertiary sculpture” superimposed on the secondary sculpture), i.e. mainly waxes and related substances.
The systematic applicability is discussed for each of these structural groups. Epidermal characters are only slightly influenced by environmental conditions. Their high structural diversity provides most valuable criteria for the classification between species and family level. There is also some evidence for their systematic applicability above the family level.
The possible evolutionary–ecological significance of surface sculpturing is discussed briefly. There is evidence that these features may be seen primarily under the aspects of reduced ability of plants to contaminate and as temperature control mechanisms of the surfaces.
642 citations
TL;DR: The joint usage ofrps16 intron and ITS sequences provides a powerful tool for resolving many of the difficult taxonomic issues in the tribeSileneae.
Abstract: Intron sequences of the chloroplast generps16 from 46 species were used to examine phylogenetic relationships indicated by nrDNA ITS sequence variation in the tribeSileneae (Caryophyllaceae, Caryophylloideae). This region has previously not been utilized for phylogenetic purposes but the results presented here suggest that it is a consistent and valuable complement to the ITS sequences. Therps16 intron trees are largely congruent with the ITS trees. All the major hypotheses suggested by the ITS data are supported, often at similar bootstrap levels. The joint usage ofrps16 intron and ITS sequences provides a powerful tool for resolving many of the difficult taxonomic issues in the tribeSileneae.
579 citations
TL;DR: This work investigates the phylogeny of the Caryophyllaceae by means of analyzing plastid and nuclear sequence data with parsimony and Bayesian methods and describes a mode of tracing a stable phylogenetic signal in ITS sequences.
Abstract: Caryophyllaceae is a principally holarctic family including around 2200 species often classified into the three subfamilies Alsinoideae, Caryophylloideae, and Paronychioideae. Complex and possibly homoplasious morphological characters within the family make taxa difficult to delimit and diagnose. To explore part of the morphological evolution within the family, we investigated the phylogeny of the Caryophyllaceae by means of analyzing plastid and nuclear sequence data with parsimony and Bayesian methods. We describe a mode of tracing a stable phylogenetic signal in ITS sequences, and a significant common signal is shared with the plastid data. Parsimony and Bayesian analyses yield some differences in tree resolution. None of the subfamilies appear monophyletic, but the monophyly of the Caryophylloideae is not contradicted. Alsinoideae are paraphyletic, with Arenaria subg. Eremogone and Minuartia subg. Spergella more closely related to the Caryophylloideae. There is strong support for the inclusion of Spergula-Spergularia in an Alsinoideae-Caryophylloideae clade. Putative synapomorphies for these groupings are twice as many stamens as number of sepals and a caryophyllad-type of embryogeny. Paronychioideae form a basal grade, where tribe Corrigioleae are sister to the rest of the family. Free styles and capsules with simple teeth are possibly plesiomorphic for the family.
151 citations
TL;DR: The phylogenies reveal that the closest relatives to Schiedea are a pair of widespread, largely Arctic taxa, Honckenya peploides and Wilhelmsia physodes, and are not reflective of natural groups; this study proposes abandoning this classification in favor of a new system that recognizes major lineages of the molecular phylogeny at the tribal level.
Abstract: Understanding the relationships within the Caryophyllaceae has been difficult, in part because of arbitrarily and poorly defined genera and difficulty in determining phylogenetically useful morphological characters. This study represents the most complete phylogenetic analysis of the family to date, with particular focus on the genera and relationships within the large subfamily Alsinoideae, using molecular characters to examine the monophyly of taxa and the validity of the current taxonomy as well as to resolve the obscure origins of divergent taxa such as the endemic Hawaiian Schiedea. Maximum parsimony and maximum likelihood analyses of three chloroplast gene regions (matK, trnL‐F, and rps16) from 81 newly sampled and 65 GenBank specimens reveal that several tribes and genera, especially within the Alsinoideae, are not monophyletic. Large genera such as Arenaria and Minuartia are polyphyletic, as are several smaller genera. The phylogenies reveal that the closest relatives to Schiedea are a pair of wid...
140 citations
TL;DR: The relationships within the tribe Sileneae (Caryophyllaceae, Caryophylloideae) were deduced from nucleotide sequence variation in the nuclear ribosomal DNA, and Polyschemone, previously often misplaced in Lychnis, is apparently closely related to Silene acaulis.
Abstract: The relationships within the tribe Sileneae (Caryophyllaceae, Caryophylloideae) were deduced from nucleotide sequence variation in the nuclear ribosomal DNA. The internal transcribed spacer (ITS) regions and the intervening 5.8S gene were sequenced for 76 ingroup and five outgroup taxa. The relationships were analysed more closely for 26 of these, with the addition of 822 aligned positions from the 28S gene. Drypis appears not to belong in Sileneae, and perhaps not even in Caryophylloideae. Agrostemma is sister group to the rest of the tribe. Eudianthe (Silene coeli-rosa and S. laeta) and Petrocoptis are clearly separated from the core Silene. Steris (Viscaria), Silene sect. Heliosperma, sect. Rupifraga, and sect. Compactae together form a strongly supported clade, as do Lychnis plus Uebelinia. Cucubalus, Melandrium, and Gastrolychnis are nested within a weakly supported "Silene". Polyschemone, previously often misplaced in Lychnis, is apparently closely related to Silene acaulis. Within the core Silene, three main groups can be identified, corresponding roughly to three of Rohrbach's (1869) five main generic subdivisions, S. subg. Behen, sect. Cincinnosilene, and sect. Botryosilene. Pleconax, Melandrium, Cucubalus, and Gastrolychnis nest within S. subg. Behen, but the monophyly of this group is weakly supported. Members of S. sect. Dichasiosilene are scattered over all three groups, indicating that dichasium is plesiomorphic within the group.
132 citations