Comparative anatomy of absorbing roots and anchoring roots in three species of Cyclanthaceae (Monocotyledoneae)

1992 ◽  
Vol 70 (12) ◽  
pp. 2384-2404 ◽  
Author(s):  
George J. Wilder ◽  
Jeffrey R. Johansen
Keyword(s):  
Key Words ◽  
Vascular Tissue ◽  
Comparative Anatomy ◽  
Root Anatomy ◽  
Tracheary Elements ◽  
Sieve Elements ◽  
Quantitative Characteristics ◽  
Root Types ◽  
Absorbing Roots

Absorbing roots and anchoring roots of Asplundia sp., Evodianthus fiinifer, and Thoracocarpus bissectus differ from one another anatomically in at least 15 quantitative characteristics and in additional related respects. Differences are diverse, involving both stelar and extrastelar tissues. Absorbing roots are significantly greater in diameter, have more vascular tissue, exhibit broader tracheary elements and sieve elements, and have other characteristics supporting the hypothesis that those features logically interpretable as optimizing conduction in xylem and phloem predominate in the absorbing roots. The three species also differ significantly from each other according to the anatomy of their absorbing roots, with T. bissectus having the most distinctive anatomy. Statistical and nonstatistical approaches to analysis of the data provided very consistent results, both in regard to differences between the two root types under study and to differences between taxa. Key words: absorbing roots, anchoring roots, Asplundia, Cyclanthaceae, Evodianthus, root anatomy, Thoracocarpus.

Vascular system of the floret of Phleum pratense

1988 ◽  
Vol 66 (9) ◽  
pp. 1818-1829 ◽  
Author(s):  
Thompson Demetrio Pizzolato
Keyword(s):  
Vascular Tissue ◽  
Vascular System ◽  
Sieve Tube ◽  
Sieve Element ◽  
Phleum Pratense ◽  
Tracheary Elements ◽  
Sieve Elements ◽  
Circular Component

Two bundles occur in the rachilla at the floret base. The anterior bundle supplies the vascular tissue for the lemma median trace, and the posterior supplies that for its two extreme laterals. The intermediate laterals of the lemma connect at the anterior bundle, and the two palea traces join near the posterior bundle to the traces for the extreme lemma laterals. Near these connections sieve elements of the two rachilla bundles link, forming the lower component of the sieve-element plexus. The xylem discontinuity begins above the anterior bundle. An upper, circular component of the sieve-element plexus surrounds the discontinuity. The sieve elements of the lodicules join the anterior of the upper plexus. The upper plexus becomes trilobed as it merges with the stamen traces. Three pistil bundles including sieve elements and tracheary elements of the xylem discontinuity join the upper plexus. These pistil bundles unite into a circular pistil plexus surrounding the discontinuity. The anterior sieve tube of the pistil joins the anterior of the pistil plexus. Sieve elements emerge from the posterolateral portions of the plexus toward the styles and leave a placental bundle of sieve elements and tracheary elements of the xylem discontinuity in the pistil posterior.

scholarly journals Root morpho-physiology changes during the habitat transition from soil to canopy of the aroid vine Rhodospatha oblongata

2020 ◽  
Author(s):  
Arinawa Liz Filartiga ◽  
Dulce Mantuano ◽  
Ricardo Cardoso Vieira ◽  
Karen Lucia Gama de Toni ◽  
Gustavo M Vasques ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Water Absorption ◽  
Root Anatomy ◽  
Water Retention Capacity ◽  
Outer Cortex ◽  
Retention Capacity ◽  
Physiological Basis ◽  
Root Region ◽  
Aerial Roots ◽  
Root Types

Abstract Background and Aims The aroid vine Rhodospatha oblongata is characterized by a habitat change from terrestrial to canopy, relying on aerial roots at maturity to obtain water and nutrients from the forest soil. We hypothesize that morpho-physiological acclimation occurs in roots as they grow under atmospheric conditions. These changes would guarantee the whole plant survival of aroid vines in the new and potentially stressful habitat of the canopy. Methods Terrestrial and aerial roots were compared on a morpho-physiological basis. Root anatomy, water balance, water absorption capacity via fluorescent tracer, and photochemical activity via chlorophyll fluorescence were measured. Key Results While thin fasciculate roots occur on terrestrial crawling individuals, two clearly distinct aerial roots (anchor and feeder) are produced on canopy individuals, which are both adhered to the host trunk. The color of both aerial roots change during development from red and brownish to striped and green at maturity. Color changes are induced by the replacement of epidermis, exodermis, and outer cortex by an inner layer of lignified cork on the root region exposed to the atmosphere. In the root region that is in contact with the host, covering substitutions do not occur and both exodermis and lignified cork, along with several epidermal hairs, appear. Water retention capacity was higher in green roots than in other root types. Rehydration capacity via water absorption by hairs of aerial roots was confirmed by fluorescence. Chlorophyll fluorescence data indicated low levels of photosynthetic capacity in both root types. Conclusions Plants should evolve strategies to survive stress situations. The transition from soil to canopy imposes abiotic changes and potentially stressful situations to R. oblongata. We conclude that the morpho-physiological changes observed represent an important strategy that permits the maintenance of aroid roots and the survival of R. oblongata in the canopy.

Advances in understanding plant root anatomy and nutrient acquisition

2021 ◽  
pp. 99-126
Author(s):  
Dimitris L. Bouranis ◽  
◽  
Styliani N. Chorianopoulou ◽  
Keyword(s):  
Plant Root ◽  
Agricultural Productivity ◽  
Environmental Issues ◽  
Nutrient Acquisition ◽  
Root Anatomy ◽  
Aerenchyma Formation ◽  
Root Types

In this chapter root anatomical traits and trait states, and nutrient acquisition mechanisms, along with the environmental issues affecting nutrient acquisition are summarized. Then, the whole range of adaptations of root anatomical traits, and its impact on nutrient acquisition are discussed. Combinations of anatomical traits lead to suggestions of root ideotypes potentially capable of supporting agricultural productivity under different edaphic constraints. Spatiotemporal aerenchyma formation in the various root types of maize under nitrate, phosphate or sulfate deprivation is discussed in a case study.

Time course of anatomical changes to stem vascular tissues of alfalfa, Medicago sativa, from probing injury by the potato leafhopper, Empoasca fabae

1995 ◽  
Vol 73 (2) ◽  
pp. 288-298 ◽  
Author(s):  
Carol L. Ecale ◽  
Elaine A. Backus
Keyword(s):  
Time Course ◽  
Vascular Tissue ◽  
Wound Response ◽  
Tracheary Elements ◽  
Insect Feeding ◽  
Phloem Tissue ◽  
Cross Sectional ◽  
Standard Duration ◽  
Total Cross Sectional Area ◽  
Xylem Tissue

We used a videomicrography technique to apply standard-duration pulses of leafhopper probing damage to alfalfa stems, or manually punctured stems with an implement resembling leafhopper stylets, to compare damage induction and chronicle the plant's anatomical responses over time. Plants were examined at 0.5, 1, 2, 4, and 8 days after probing. Leafhopper probing occurred primarily in phloem tissue: stylets damaged and deposited sheath saliva primarily in phloem. Between days 1 and 4, collapsed phloem cells and sheath saliva deposits were dissolved and removed as surviving cells adjacent to stylet pathways underwent enlargement and division. By day 8, phloem tissue assumed a near-normal appearance when viewed in cross section, although it is not known whether phloem functionality was restored. In contrast, xylem tissue suffered reduction in size, quantity, and total cross-sectional area of mature tracheary elements. These effects to vascular tissue may be responsible for all subsequent symptoms of hopperburn in alfalfa. Damage to phloem and xylem in mechanically punctured stems was slight and was similar for all time points. Key words: plant wound response, plant vascular development, phloem, xylem, hopperburn, insect feeding behaviour.

COMPARATIVE ANATOMICAL STUDIES IMPLY ADAPTIVE VARIATIONS OF RUMINANT DIGESTIVE PHYSIOLOGY

1984 ◽  
Vol 64 (5) ◽  
pp. 203-205 ◽  
Author(s):  
R. R. HOFMANN
Keyword(s):  
Key Words ◽  
Food Quality ◽  
Seasonal Changes ◽  
Digestive System ◽  
Comparative Anatomy ◽  
Digestive Physiology ◽  
Anatomical Studies ◽  
Ruminant Species

Anatomical studies of 51 ruminant species show adaptive variations in all digestive system portions related to food quality. Morphophysiological variations have an evolutionary base, involve seasonal changes and require differentiated physiological methods. Key words: Comparative anatomy, morphophysiological adaptation

Structural Aspects of the Pathways of Nutrient Flow to the Developing Embryo and Cotyledons of Pisum sativum L

1976 ◽  
Vol 24 (6) ◽  
pp. 711 ◽  
Author(s):  
AR Hardham
Keyword(s):  
Vascular Tissue ◽  
Embryo Sac ◽  
Phloem Tissue ◽  
Sieve Elements ◽  
Boundary Wall ◽  
Surface Areas ◽  
Pisum Sativum L ◽  
Large Numbers ◽  
Pea Seed ◽  
Structural Aspects

The pea seed requires large quantities of nutrient during its growth and development. In the early stages a large proportion of this nutrient is obtained from the endosperm surrounding the embryo in the embryo sac. A number of structural specializations, such as increased surface areas of the embryo sac boundary wall and the extra-embryonic wall and breakdown of the inner ovular cells, may aid in the passage of nutrient to the developing embryo. This study has shown that the amount of vascular tissue in the funicle and ovule increases markedly between the time of cotyledon initiation and the commencement of storage protein synthesis and deposition. Large numbers of transfer cells are associated with the sieve elements in the pod and funicle, but not in the ovule. Also, the numbers of xylem and sieve elements in the funicle decrease as the strand passes from the pod to the ovule. Two strands of phloem tissue were found to branch from the main vascular bundle in the ovule and to sweep across the base of the seed and around either side of the narrow tubular arm of the embryo sac which contains the radicle.

OCT-indications for antiangiogenic therapy of macular edema in postthrombotic retinopathy

2021 ◽  
pp. 322-324
Author(s):  
E.V. Kabardina ◽  
◽  
I.P. Shurygina ◽  
◽  
◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Statistical Analysis ◽  
Macular Edema ◽  
Key Words ◽  
Temporal Lobe ◽  
Antiangiogenic Therapy ◽  
Central Zone ◽  
Quantitative Characteristics ◽  
Quantitative Indicators

Purpose. To develop OCT-indications for antiangiogenic therapy of macular edema in post-thrombotic retinopathy. Material and methods. The study included 300 patients (121 women, 179 men) who had suffered upper temporal lobe thrombosis with macular edema in the period from 1 to 3 months and received antiangiogenic therapy. The age of the patients ranged from 42 to 73 years (the average age was 58.5±1.2 years). The duration of follow-up was 2 years. All patients underwent an OCT - study using the device "Heidelberg Spectralis" (Germany). We used a program for creating a map of the macular region with the interpretation of quantitative indicators of the macular region: height and volume. Results. According to the results of the study, a statistical analysis of the initial quantitative characteristics of macular edema in patients with positive dynamics of treatment with antiangiogenic therapy drugs was performed. As a result of the analysis, statistically significant values were identified: the thickness of the central zone of the retina and the average macular volume, which were used in the development of objective criteria, which allowed us to calculate the coefficient of indications for antiangiogenic therapy of macular edema in post-thrombotic retinopathy according to the author's formula (RF Patent No. 2706303). Conclusions. In the course of the conducted studies, the author's formula was proposed, which clarifies the reliability of OCT indications for the expediency of antiangiogenic therapy of macular edema in post-thrombotic retinopathy. Key words: intravitreal drugs, macular edema, post-thrombotic retinopathy, optical coherence tomography.

Vascular-tissue relations in the lungs in experimental superinvasive opisthorchiasis

2021 ◽  
Author(s):  
M.S. Shvedsky ◽  
G.S. Solovyov ◽  
V.V. Matvienko ◽  
V.A. Shidin ◽  
O.G. Solovyova ◽  
...  
Keyword(s):  
Key Words ◽  
Structural Changes ◽  
Vascular Tissue ◽  
Interstitial Tissue ◽  
Late Period ◽  
Epithelial Proliferation ◽  
Initial Stage

Structural changes in the lungs in superinvasive opisthorchiasis at various stages of invasion were studied. The morphology of permanent epithelial proliferation at the initial stage and their decrease in the late period were revealed. With the formation of granulomas in the interstitial tissue of the respiratory organs, with changes in the chronic period towards the formation of sclerotic foci. Key words: superinvasive opisthorchiasis (CO), metacercariae, acinus, terminal bronchioles (TB), cell infiltrates, pneumocytes.

Comparative morphology and anatomy of absorbing roots and anchoring roots in three species of Cyclanthaceae (Monocotyledoneae)

1992 ◽  
Vol 70 (1) ◽  
pp. 38-48 ◽  
Author(s):  
George J. Wilder
Keyword(s):  
Key Words ◽  
Root Morphology ◽  
Comparative Morphology ◽  
Base Length ◽  
Aerial Parts ◽  
Host Trees ◽  
General Restriction ◽  
Absorbing Roots

Asplundia sp., Evodianthus funifer, and Thoracocarpus bissectus are root-climbing lianas that each have absorbing roots and anchoring roots. On stems appressed to the trunks of host trees, both types of roots arise mainly from internodes, generally emerging from those halves of stem surfaces facing the trunks (Asplundia sp., E. funifer), and may form nonreplacement roots and replacement roots. Aerial portions of absorbing roots differ from anchoring roots according to direction of growth, abundance of nonreplacement roots, diameter 1 cm distal to base, length, abundance, and color (T. bissectus). In all species the anchoring roots (with or without replacement roots) are interpretable as determinate because on long specimens their distal portions appear anatomically narrowed and reduced. In contrast, aerial parts of absorbing roots are indeterminate. The determinate aspects of anchoring roots and the general restriction (on stems appressed to tree trunks) of roots to trunk-facing stem surfaces are advantageous as means for conserving biomass. Key words: roots, root morphology, root dimorphism, Cyclanthaceae.

INFLUENCES OF SEASONAL TEMPERATURE ON NITROGEN AND SULFUR MINERALIZATION/IMMOBILIZATION IN A MAPLE-BIRCH FOREST FLOOR IN CENTRAL ONTARIO

1989 ◽  
Vol 69 (3) ◽  
pp. 501-514 ◽  
Author(s):  
N. W. FOSTER
Keyword(s):  
Soil Temperature ◽  
Ammonium Nitrate ◽  
Key Words ◽  
Forest Floor ◽  
Late Summer ◽  
Seasonal Temperature ◽  
Net Mineralization ◽  
Net Release ◽  
Sulfur Mineralization ◽  
Absorbing Roots

Net mineralization of sulfur (S) and nitrogen (N) and nitrification in an F(Oe) horizon were examined over a 16-wk period (May to September) with (a) buried bags, (b) lysimeters and (c) closed flasks at 10, 20 or 30 °C. The amount of [Formula: see text] plus [Formula: see text] extracted from soil held at 33 kPa tension over 16 wk, when extrapolated to the mass of soil in the field, was 30 kg ha−1 N and 9 kg ha−1[Formula: see text] at constant 20 °C in the flasks, and 33 kg ha−1 N and 4 kg ha−1[Formula: see text] in buried bags (mean daily temperature 15.2 °C). On the basis of lysimeter data there was a net release of only 8 kg ha−1 N and a net retention of 3 kg ha−1[Formula: see text] under field conditions, with fluctuating temperature and moisture and actively absorbing roots. Nitrate recovered from the three types of experiment was equivalent to 18, 36, and 4 kg ha−1 N, respectively. Mineralization appeared to be particularly sensitive to temporal changes in average daily temperatures in the field. The late-summer peak in mean daily forest-floor temperature triggered a shift from net mineralization to net immobilization of N. Key words: Soil temperature, forest floor, sulfate, ammonium, nitrate

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