scholarly journals Morphological characters of the seed coat in selected species of the genus Hypericum L. and their taxonomic value

2016 ◽  
Vol 44 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Piotr Szkudlarz ◽  
Zbigniew Celka

Abstract Eight Hypericum species are native to Poland: H. elegans Stephan ex Willd., H. hirsutum L., H. humifusum L., H. maculatum Crantz, H. montanum L., H. perforatum L., H. pulchrum L., and H. tetrapterum Fr. Only seeds of H. elegans were investigated in detail in Poland before, so here we present results of qualitative and quantitative analyses of seed morphology of the other 7 species, based on characters like seed length, width, and shape, seed coat sculpture, shape of epidermal cells of the testa, and number of epidermal cells along the seed axis. The results show that seeds of the studied species are small, 0.56-1.15 mm long and 0.26-0.49 mm wide. In SEM images, seed coat sculpture is reticulate in 5 species, papillate in H. hirsutum, and cup-shaped in H. pulchrum. The differences are caused by the varied final development of the testa epidermis, which constitutes the outer layer of the seed coat. The mean number of epidermal cells along the seed axis ranges from 22 to 33. Results of cluster analysis, based on the agglomeration method and including also published data on seeds of H. elegans, show that the variation in the investigated characters of seeds is reflected in the taxonomic division of the genus into sections.

2018 ◽  
Vol 50 (1) ◽  
pp. 39-52
Author(s):  
Małgorzata Mazur ◽  
Magdalena Gawlak ◽  
Elżbieta Sandurska ◽  
Tomasz Kałuski ◽  
Katarzyna Marcysiak

Abstract The study was conducted on five species of Veronica L. subsection Agrestes occurring in Central Europe: Veronica agrestis L., V. polita Fr., V. opaca Fr., V. persica Poir. and V. filiformis Sm. These species are very similar morphologically and are often misidentified. Last thorough studies of morphology and micromorphology of their seeds were conducted in 1960s. Based on 48 herbarium specimens, we examined SEM images of 422 seeds. We found that 22 of the 30 studied morphological traits differentiated five species at statistical level and V. agrestis and V. persica differed with the greatest number of features from other species. Our measurements of seed size were not fully congruent with previous studies, suggesting dependence of these features on external conditions. Seeds were usually cochlidiospermous and ovoid with a reticulate-verrucate seed coat, but these features were, at the same time, quite variable. The results of discriminant function confirmed that some characters of the seed size, shape and coat sculpture could be taxonomically useful in distinguishing species of Veronica subsect. Agrestes. In addition, we believe that similarity of the examined seeds may confirm unity of this group and the need of identifying a subsection.


2020 ◽  
Vol 45 (3) ◽  
pp. 478-482
Author(s):  
Steven R. Manchester

Abstract—The type material on which the fossil genus name Ampelocissites was established in 1929 has been reexamined with the aid of X-ray micro-computed tomography (μ-CT) scanning and compared with seeds of extant taxa to assess the relationships of these fossils within the grape family, Vitaceae. The specimens were collected from a sandstone of late Paleocene or early Eocene age. Although originally inferred by Berry to be intermediate in morphology between Ampelocissus and Vitis, the newly revealed details of seed morphology indicate that these seeds represent instead the Ampelopsis clade. Digital cross sections show that the seed coat maintains its thickness over the external surfaces, but diminishes quickly in the ventral infolds. This feature, along with the elliptical chalaza and lack of an apical groove, indicate that Ampelocissites lytlensis Berry probably represents Ampelopsis or Nekemias (rather than Ampelocissus or Vitis) and that the generic name Ampelocissites may be useful for fossil seeds with morphology consistent with the Ampelopsis clade that lack sufficient characters to specify placement within one of these extant genera.


Author(s):  
D. G. Melnikov ◽  
L. I. Krupkina

Based on the published data of molecular phylogenetic studies of the tribe Cariceae Dumort. genera (Cyperaceae), obtained by an international collaboration (The Global Carex Group, 2016; et al.), and morphological characters of the genera (Kukkonen, 1990; and others), new nomenclatural combinations and replacement names in the genus Carex L. are published for 11 species, one subspecies and two sections previously included in the genus Kobresia Willd.


2007 ◽  
Vol 55 (6) ◽  
pp. 618 ◽  
Author(s):  
Kim N. Hamilton ◽  
Sarah E. Ashmore ◽  
Rod A. Drew ◽  
Hugh W. Pritchard

Combinational traits of seed size and seed-coat hardness in Citrus garrawayi (F.M.Bailey) (syn. of Microcitrus garrowayi) were investigated as markers for estimation of seed morphological and physiological maturity. Seed size (length) and coat hardness correlated well with changes in seed coat and embryo morphological development, dry-weight accumulation, decreases in moisture content and a significant increase in germinability. Seed moisture content decreased from 82 ± 1% in immature seeds to 40 ± 1% at seed maturation. The outer integument of immature seeds consisted of thin-walled epidermal fibres from which outgrowths of emerging protrusions were observed. In comparison, mature seed coats were characterised by the thickening of the cell walls of the epidermal fibres from which arose numerous protrusions covered by an extensive mucilage layer. Immature seeds, with incomplete embryo and seed-coat histodiffereniation, had a low mean germination percentage of 4 ± 4%. Premature seeds, with a differentiated embryonic axis, were capable of much higher levels of germination (51 ± 10%) before the attainment of mass maturity. Mature seeds, with the most well differentiated embryonic axis and maximum mean dry weight, had the significantly highest level of germination (88 ± 3%).


2015 ◽  
Vol 28 (3) ◽  
pp. 124 ◽  
Author(s):  
Renata Piwowarczyk

Holoparasitic genera within family Orobanchaceae are characterised by greatly reduced vegetative organs; therefore, seed micromorphology has proved to be a useful complementary taxonomic criterion. Seeds of 160 samples from 54 localities of 26 taxa of the Orobanche and Phelipanche genera occurring in central Europe, specifically from Poland, the Czech Republic, Austria and Slovakia, supplemented by samples from Spain, France and Ukraine, were investigated using scanning electron microscopy. Thirteen quantitative or qualitative morphological characters of seeds were analysed. The following three types of periclinal wall sculpture of seeds were identified: veined and fibrillar in Phelipanche; with oval or elliptic perforations (pitted) in almost all species of Orobanche; with outer periclinal wall smooth, granular or rugged (very rarely visibly pitted), impeding vision of the inner one, occurring only in O. gracilis Sm. and O. coerulescens Stephan in Willd. The influence of different hosts on the features of seeds of eight species is also presented, as well as relationships between seed morphology and taxonomic classification, including problematic taxa. The best diagnostic features include type of ornamentation of the periclinal wall, perforation diameter (in pitted sculpture), fibrillar diameter (in fibrillar sculpture) and width of anticlinal walls. Size and shape of the seeds and cells and the presence of median troughs are variable; however, these features can be helpful when using larger samples. The usefulness of micromorphological studies on seeds of Orobanche and Phelipanche is demonstrated.


Phytotaxa ◽  
2021 ◽  
Vol 502 (2) ◽  
pp. 191-207
Author(s):  
SHIVANI KASHYAP ◽  
CHANDAN KUMAR SAHU ◽  
ROHIT KUMAR VERMA ◽  
LAL BABU CHAUDHARY

Due to large size and enormous morphological plasticity, the taxonomy of the genus Astragalus is very complex and challenging. The identification and grouping of species chiefly based on macromorphological characters become sometimes difficult in the genus. In the present study, the micromorphology of the seeds of 30 species belonging to 14 sections of Astragalus from India has been examined applying scanning electron microscopy (SEM) along with light microscopy (LM) to evaluate their role in identification and classification. Attention was paid to colour, shape, size and surface of seeds. The overall size of the seeds ranges from 1.5–3.2 × 0.8–2.2 mm. The shape of the seeds is cordiform, deltoid, mitiform, orbicular, ovoid and reniform. The colour of seeds varies from brown to blackish-brown to black. Papillose, reticulate, ribbed, rugulate and stellate patterns were observed on the seed coat surface (spermoderm) among different species. The study reveals that the seed coat ornamentations have evolved differently among species and do not support the subgeneric and sectional divisions of the genus. However, they add an additional feature to the individual species, which may help in identification in combination with other macro-morphological features.


2012 ◽  
Vol 9 (5) ◽  
pp. 1873-1884 ◽  
Author(s):  
G. M. Santos ◽  
A. Alexandre ◽  
J. R. Southon ◽  
K. K. Treseder ◽  
R. Corbineau ◽  
...  

Abstract. Plants absorb and transport silicon (Si) from soil, and precipitation of Si within the living plants results in micrometric amorphous biosilica particles known as phytoliths. During phytolith formation, a small amount of carbon (<2%) can become occluded in the silica structure (phytC) and therefore protected from degradation by the environment after plant tissue decomposition. Since the major C source within plants is from atmospheric carbon dioxide (CO2) via photosynthesis, the current understanding is that the radiocarbon (14C) content of phytC should reflect the 14C content of atmospheric CO2 at the time the plant is growing. This assumption was recently challenged by 14C data from phytoliths extracted from living grasses that yielded ages of several thousand years (2–8 kyr BP; in radiocarbon years "Before Present" (BP), "Present" being defined as 1950). Because plants can take up small amounts of C of varying ages from soils (e.g., during nutrient acquisition), we hypothesized that this transported C within the plant tissue could be attached to or even embedded in phytoliths. In this work, we explore this hypothesis by reviewing previously published data on biosilica mineralization and plant nutrient acquisition as well as by evaluating the efficiency of phytolith extraction protocols from scanning electron microscope (SEM) images and energy dispersive spectrometer (EDS) analyses from harvested grasses phytolith concentrates. We show that current extraction protocols are inefficient since they do not entirely remove recalcitrant forms of C from plant tissue. Consequently, material previously measured as "phytC" may contain at least some fraction of soil-derived C (likely radiocarbon-old) taken up by roots. We also suggest a novel interpretation for at least some of the phytC – which enters via the root pathway during nutrient acquisition – that may help to explain the old ages previously obtained from phytolith concentrates.


2011 ◽  
Vol 73 (4) ◽  
pp. 293-300 ◽  
Author(s):  
Irmina Maciejewska-Rutkowska ◽  
Leszek Bednorz

This paper presents the results of the study on seed morphology of five Polish species of the genus <em>Sorbus</em> L. (<em>S. aria</em> (L.) Crantz, <em>S. aucuparia</em> L. Emend. Hedl., <em>S. chamaemespilus</em> (L.) Crantz, <em>S. intermedia</em> (Ehrh.) Pers. and <em>S. torminalis</em> (L.) Crantz). Observations and measurements were carried out with stereoscope and scanning microscopes. Four types of seed microsculpture were distinguished on the ground of SEM observations. The key to determine Polish species, based on morphological characters of seeds is given too.


2021 ◽  
Vol 912 (1) ◽  
pp. 012103
Author(s):  
Elimasni ◽  
R A Nasution

Abstract Abstrak. Loquat (Eriobotrya japonica Lindl.) is a flowering plant that belongs to the Rosacea family. The loquat has many health benefits. Cultivation and information about loquat plants in Indonesia are still limited, so they are rarely found and known by the public. Limited information and data regarding loquat plants is also an obstacle to the development of loquat plants. Research on loquat plants aims to analyze the morphological characters in three districts, namely, Karo, Dairi, and Simalungun districts. This research was conducted using a descriptive method. The analysis of the morphological characteristics of loquat plants using morphological data scoring into binary data. The similarity between individuals was analyzed using clusters with the NTSYS program version 2.0 with the UPGMA method of the SimQual function. Morphological Observation Results Loquat plants (Eriobotrya japonica Lindl.) in Karo, Dairi, and Simalungun Districts have uniform characters in the morphology of stems, leaves, and flowers. However, the observed fruit and seed morphology showed different characters. Different characters exist in the shape of the fruit and seeds. The morphological similarity level of loquat plants was grouped at a similarity coefficient value of 95%. Clusters I and II have the highest similarity with a coefficient value of 100%. Cluster III has the lowest similarity with a coefficient value of 97%.


Phytotaxa ◽  
2021 ◽  
Vol 484 (1) ◽  
pp. 44-74
Author(s):  
OLGA V. YURTSEVA ◽  
N.K. BADMAEVA ◽  
EVGENY V. MAVRODIEV

Maximum Likelihood (ML) and Bayesian analyses (BI) applied for 3-plastid loci (cpDNA trnL(UAA) intron, trnL–trnF IGS, and rpl32–trnL(UAG) IGS regions) / 55 tips of Atraphaxis revealed a subclade of two endemics from Transbaikalia (Dahuria) which are often mistaken for A. pungens and A. frutescens but phylogenetically distant from both. Atraphaxis selengensis is a species new to science which inhabits dune sands along the Selenga and Chikoy rivers and has specific morphology of perianth, fruits, ochreas, leaf blades, and pollen. Atraphaxis davurica inhabits stony mountain steppe in Buryatia and Chita region and differs from A. pungens and A. frutescens by longer ochreas, fruits, styles and stigmas extended to ends. Two varieties recognized by Ledebour in plants from Russian Transbaikalia have no clear morphological and molecular distinctions, but the plants from Khentei-Chikoy Highlands subtly differ in leaf ratio (length/width), bark colour, and a single-nucleotide substitution in trnL–F region. These plants are described as A. davurica var. chikoensis var. nov. Morphological descriptions of A. selengensis and A. davurica are supplied with LM and SEM images and a distributional map. Atraphaxis frutescens and A. pungens are absent from Russian Transbaikalia but distributed in Altai, Tuva, Khakassia, Mongolia and China.


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