scholarly journals Morphoanatomy of the underground system of Androtrichum trigynum (Cyperaceae)

Rodriguésia ◽  
2012 ◽  
Vol 63 (2) ◽  
pp. 305-319
Author(s):  
Roberta Andressa Pereira ◽  
Ana Claudia Rodrigues
Keyword(s):  
Adventitious Roots ◽  
Atlantic Coast ◽  
Root Apex ◽  
Southwestern Atlantic ◽  
Coastal Regions ◽  
Outer Cortex ◽  
Anatomical Features ◽  
Thin Walls ◽  
Intercalary Meristem ◽  
Underground System

Androtrichum has only one species, A. trigynum (Spr.) Pfeiffer, occurring in coastal regions of the southwestern Atlantic coast. It presents an underground system consisting of rhizomes and adventitious roots. The rhizome is thickened, plagiotropic, sympodial, and floral scapes and roots arise from it. From the stem promeristem, the protoderm, procambium and ground meristem are differentiated. At the apex region, the intercalary meristem and primary thickening meristem (PTM) are observed. The adventitious roots originate from the PTM, and present root apex with closed organization. The young epidermis has papillose cells, and meristematic endoderm activity is observed. In a mature root, the outer cortex, or hypodermis, and the internal cortex can be identified. The endoderm presents radially elongated cells with thin walls and the pericycle is biseriate. The anatomical features observed in the present study are found in other species of Cyperaceae and some xeromorphic characters can be identified.

Anatomy of vegetative organs with an emphasis on the secretory structures of two species of Aldama (Asteraceae–Heliantheae)

Botany ◽  
2013 ◽  
Vol 91 (6) ◽  
pp. 335-342 ◽  
Author(s):  
Tuane Oliveira ◽  
Aline Bertolosi Bombo ◽  
Beatriz Appezzato-Da-Glória
Keyword(s):  
Adventitious Roots ◽  
Glandular Trichomes ◽  
Diagnostic Value ◽  
Aromatic Plants ◽  
Secretory Structures ◽  
Vegetative Organs ◽  
Anatomical Features ◽  
Anatomical Analysis ◽  
Secretory Cavities ◽  
Underground System

Aldama arenaria (Baker) E.E.Schill. & Panero and Aldama robusta (Gardner) E.E.Schill. & Panero are aromatic plants, morphologically very similar and usually confused on the analysis of exsiccates. The present study aimed to identify the secretory structures present in vegetative organs and to survey for anatomical features with diagnostic value between A. arenaria and A. robusta based on an examination of these organs. Aldama arenaria and A. robusta exhibit hydathodes in the dentate ornamentations of the leaf margins and apices in addition to glandular trichomes, secretory cavities and ducts, all of which vary with respect to type and location in each species. Xylopodia and adventitious roots constitute the underground system. The xylopodium is covered by epidermis or by suberised cells resulting from periclinal divisions of parenchyma cells. The tuberisation process of adventitious roots results mainly from hypertrophy and hyperplasia of medullary cells, especially in A. arenaria. Through anatomical analysis, useful features for distinction between A. arenaria and A. robusta in exsiccates and fresh materials were identified, and these features were related mainly to the position and frequency of secretory structures.

scholarly journals Insights of the life history in the porcellanid crab Petrolisthes armatus (Gibbes, 1850) (Crustacea: Anomura: Porcellanidae) from the Southwestern Atlantic coast

2017 ◽  
Vol 61 (2) ◽  
pp. 78-89 ◽  
Author(s):  
Marcelo Antonio Amaro Pinheiro ◽  
Marcio Camargo Araujo João ◽  
Maria Helena Arruda Leme ◽  
Akeme Milena Ferreira Matsunaga ◽  
Juliana Priscila Piva Rio ◽  
...  
Keyword(s):  
Life History ◽  
Atlantic Coast ◽  
Southwestern Atlantic ◽  
Petrolisthes Armatus

scholarly journals BIOGEOGRAPHIC SHELL SHAPE VARIATION INTROPHON GEVERSIANUS(GASTROPODA: MURICIDAE) ALONG THE SOUTHWESTERN ATLANTIC COAST

Palaios ◽  
2018 ◽  
Vol 33 (11) ◽  
pp. 498-507 ◽  
Author(s):  
MARIANO E. MALVÉ ◽  
MARCELO M. RIVADENEIRA ◽  
SANDRA GORDILLO
Keyword(s):  
Atlantic Coast ◽  
Shell Shape ◽  
Southwestern Atlantic ◽  
Shape Variation

scholarly journals Longitudinal Pattern of Aerenchyma Formation Using the Ti-Gompertz Model in Rice Adventitious Roots

2021 ◽  
Vol 12 ◽  
Author(s):  
Yun Chen ◽  
Guoming Li ◽  
Buhong Zhao ◽  
Yajun Zhang ◽  
Kun Liu ◽  
...  
Keyword(s):  
Adventitious Roots ◽  
Goodness Of Fit ◽  
Gompertz Model ◽  
Root Apex ◽  
Information Criterion ◽  
Ordinary Least Squares ◽  
Parameter Estimates ◽  
Aerenchyma Formation ◽  
Root Aerenchyma ◽  
Longitudinal Pattern

The longitudinal pattern of root aerenchyma formation of its relationship with the function of adventitious roots in rice remains unclear. In this study, the percentage of the aerenchyma area to the cross-sectional area (i.e., aerenchyma percentage) was fit with four non-linear models, namely, W0-Gompertz, Ti-Gompertz, logistic, and von Bertalanffy. Goodness-of-fit criteria such as the R2, the Akaike information criterion (AIC), and the Bayesian information criterion (BIC) were used to select the model. The bias of the parameters was evaluated using the difference between the ordinary least squares-based parameter estimates and the mean of 1,000 bootstrap-based parameter estimates and the symmetry of the distributions of these parameters. The results showed that the Ti-Gompertz model, which had a high goodness-of-fit with an R2 close to 1, lower AIC and BIC values, parameter estimates close to being unbiased, and good linear approximation, provided the best fit for the longitude pattern of rice aerenchyma formation with different root lengths among the competing models. Using the second- and third-order derivatives according to the distance from the root apex, the critical points of Ti-Gompertz were calculated. The rapid stage for aerenchyma formation was from the maximum acceleration point (1.38–1.76 cm from the root apex) to the maximum deceleration point (3.13–4.19 cm from the root apex). In this stage, the aerenchyma percentage increased by 5.3–15.7% per cm, suggesting that the cortical cells tended to die rapidly for the aerenchyma formation rather than for the respiration cost during this stage. Meanwhile, the volume of the aerenchyma of the entire roots could be computed using the integral function of the Ti-Gompertz model. We proposed that the longitudinal pattern of root aerenchyma formation modeled by the Ti-Gompertz model helped to deeply understand the relationship between the anatomical traits and physiological function in rice adventitious roots.

Population dynamics of the mud shrimp Upogebia omissa (Crustacea: Gebiidea: Upogebiidae) from the southwestern Atlantic coast of Brazil

2020 ◽  
Vol 36 ◽  
pp. 101281
Author(s):  
Larissa Bacelar Costa ◽  
Nídia Melo Marinho ◽  
Paulo V.V.C. Carvalho ◽  
Monica Lucia Botter-Carvalho
Keyword(s):  
Population Dynamics ◽  
Atlantic Coast ◽  
Southwestern Atlantic ◽  
Mud Shrimp

scholarly journals Undercover speciation of wentletraps (Caenogastropoda: Epitoniidae) in the Southwestern Atlantic

Zootaxa ◽  
2017 ◽  
Vol 4286 (1) ◽  
pp. 41
Author(s):  
DIEGO G. ZELAYA ◽  
MARINA GÜLLER
Keyword(s):  
New Species ◽  
Atlantic Coast ◽  
Intraspecific Variability ◽  
Shell Morphology ◽  
Southwestern Atlantic ◽  
Number Of Species ◽  
Anatomical Characters ◽  
Three New Species ◽  
First Time ◽  
Species Being

Despite being one of the most speciose families, Epitoniidae still remains at present as one of the least understood gastropod families worldwide. This is a consequence of most of the species being only known from shell morphology, added to the wide intraspecific variability of this character and the fact that shell morphology has proven to have frequent examples of parallelisms and convergences among different (unrelated) species. Knowledge of other morphological and anatomical characters in this group is still in its first steps, and such information is currently available for a limited number of species, thus being difficult (when not impossible) to evaluate its taxonomic value. The aim of this study is to re-evaluate the diversity of Epitoniidae occurring in the Atlantic coast of Patagonia. As part of this study, the validity of only four of the six species described / reported from this area could be confirmed: Epitonium georgettinum, E. striatellum, E. fabrizioi and “Cirsotrema” magellanicum. In addition, three new species were recognized and are described herein: Epitonium evanidstriatum, “Cirsotrema” ctenodentatum and “Cirsotrema” strebeli. Information on the shell (including the protoconch), operculum, radula and jaw for these species is here provided, in most cases for the first time. A neotype for Scalaria magellanica is here designated. Furthermore, “Cirsotrema” georgeanum is here proposed as a replacement name for Scalaria fenestrata Strebel, 1908 (not Meneghini in de Stefani, 1875, nor Scalaria fenestrata Wöhrmann, 1889); and that taxon is regarded as a full species, instead of as a synonym of “Cirsotrema” magellanicum, as suggested in some previous publications. This study reveals that the usage of isolated (either morphological or anatomical) characters is usually insufficient for identifying some of the species from Patagonia; however, if these characters are combined, all species may be clearly recognized. 

Yulebacaulis normanii gen. et sp. nov., a new fossil tree fern from south-eastern Queensland, Australia

1991 ◽  
Vol 4 (2) ◽  
pp. 421 ◽  
Author(s):  
WD Tidwell ◽  
AC Rozefelds
Keyword(s):  
New Genus ◽  
Western Siberia ◽  
Small Animals ◽  
New Genus And Species ◽  
Tree Fern ◽  
Outer Cortex ◽  
Cortical Cells ◽  
Anatomical Features ◽  
Faecal Pellets ◽  
Parenchyma Cells

Although possibly reworked, a silicified specimen consisting of outer cortex, petioles, aphlebiae and roots was collected from the Lower Cretaceous Mooga Sandstone or Tertiary sediments which lie topographically above the site near Yuleba, Queensland, and represents the new genus and species Yulebacaulis normanii. The petioles in this specimen lack stipular wings and epidermal trichomes or scales. Its clepsydroid-shaped petiolar vascular strands are oblong, straight and elongated tangential to the missing stele. Clusters of parenchyma cells at the ends of the strands form 'peripheral loops' and, at higher levels of the petioles, the 'loops' open, freeing C-shaped aphlebiae traces. Non-filiforrn aphlebiae produced by the petioles are numerous. Yulebacaulis normanii is anatomically similar to Asterochlaenopsis kirgisica (Stenzel) Sahni from the Permian of western Siberia. They differ by the peripheral loops in Y. normanii remaining open after the C-shaped traces depart, rather than staying closed as in A. kirgisica. The trace also begins as a loop in A. kirgisica and not in Y. normanii. Aphlebiae fork repeatedly in the former species and only twice in the latter. Faecal pellets produced by some small animals are present between the petioles, in the aphlebiae, and in borings in the inner and outer cortices of some petioles of Y. normanii. Based upon the size ranges of the faecal pellets, three different animals may have been involved. The pellets are loosely packed, almost filling the galleries, and appear to have been deposited by the animals as they fed upon the cortical cells. The anatomical features of Yulebacaulis are very close to some members of the Zygopteridales. If it is Early Cretaceous in age, then by assigning this genus to this group the age of this order would be extended from Upper Palaeozoic into the mid-Mesozoic.

Subterranean structures and mycotrophy of the achlorophyllous Triuris hyalina (Triuridaceae)

1998 ◽  
Vol 76 (12) ◽  
pp. 2011-2019 ◽  
Author(s):  
Stephan Imhof
Keyword(s):  
Arbuscular Mycorrhiza ◽  
Adventitious Roots ◽  
Sustainable Use ◽  
Root Anatomy ◽  
Root Structure ◽  
Outer Cortex ◽  
Short Cell ◽  
External Hyphae ◽  
Xylem Elements ◽  
Inner Cortex

Triuris hyalina Miers, an unusual achlorophyllous plant, was investigated for subterranean morphology, root anatomy, and mycotrophy. Stems with scale leaves extend subterraneously to a depth of 15 cm. Pairs of adventitious roots develop at the scale leaves and clumps of apparently radiating roots, formed by accumulations of side shoot and scale leaf developments, occur. Roots consist of epidermis, short cell exodermis, three distinct layers of cortex parenchyma, endodermis, and an extremely reduced central cylinder with one or two central tracheidal xylem elements. The fungus associated with T. hyalina roots exhibits thick-walled, 6-9 µm thick, aseptate external hyphae. It penetrates the epidermis by developing appressoria and enters the cortex solely through the short cells of the exodermis. In the cortex cells, the aseptate hyphae start to coil. In the outer cortex layer, hyphae are thin, frequently branched, and most densely coiled. In the middle cortex layer they are thicker and less densely coiled, and mostly appear degenerated to clumps of amorphous fungal material. The inner cortex layer rarely becomes colonized. Vesicles occur in the outer and the middle cortex layers. This mycorrhizal pattern is interpreted as an adaption to attain a sustainable use from the endophyte. It is suggested that the mycorrhiza in Triuris hyalina be interpreted as a type of arbuscular mycorrhiza (AM). Implications for systematics and ecology are discussed.Key words: Triuris, Triuridaceae, root structure, anatomy, arbuscular mycorrhiza, myco-heterotrophy.

Sign in / Sign up

Export Citation Format

Share Document