La plasticité phénotypique des caractères anatomiques foliaires chez le Festuca rubra L. (Pcaceae)

1996 ◽  
Vol 74 (11) ◽  
pp. 1708-1718 ◽  
Author(s):  
Martin Dubé ◽  
Pierre Morisset
Keyword(s):  
Phenotypic Plasticity ◽  
Analysis Of Variance ◽  
Leaf Anatomy ◽  
Salt Marshes ◽  
Festuca Rubra ◽  
Transplantation Experiment ◽  
Plasticité Phénotypique ◽  
Almost All

The phenotypic plasticity of nine anatomical leaf characters of Festuca rubra was studied through a transplantation experiment. Twelve genotypes from four habitats (salt marshes, coastal rocks, coastal sands, and ruderal places) were submitted to five treatments in a garden. An analysis of variance shows that almost all these characters were modified by treatments. Nevertheless, in most cases, the greatest part of the variation observed was genetic rather than plastic. Morever, it appears that genotypes responded quite differently to the treatments. The use of these characters in the taxonomy of F. rubra is discussed. Keywords: Festuca rubra, leaf anatomy, phenotypic plasticity.

scholarly journals An Anatomical Study of Scilla (Scilloideae) Section Chionodoxa and Scilla bifolia in Turkey1

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
H. YILDIRIM ◽  
K. YETISEN ◽  
A. ÖZDEMIR ◽  
C. ÖZDEMIR
Keyword(s):  
Numerical Analysis ◽  
Numerical Methods ◽  
Analysis Of Variance ◽  
Leaf Anatomy ◽  
Pearson Correlation ◽  
Anatomical Study ◽  
Anatomical Variations ◽  
Vascular Bundles ◽  
Single Row ◽  
Scilla Bifolia

ABSTRACT In the present study Scilla luciliae, S. forbesii, S. sardensis, S. siehei, Scilla x allenii and S. bifolia are compared anatomically. Some differences have been found in root, scape, and leaf anatomy of the taxa, and commented. S. luciliae, S. forbesii, S. sardensis and S. siehei have a metaxylem at the center of the root, others have 3-4 number metaxylem. Vascular bundles in two row in S. luciliae and S. forbesii in a single row in S. sardensis, Scilla x allenii and S. bifolia though in three rows in S. siehei. Aerenchyma tissue is present in mesophyll of five taxa leaf except S. sardensis. The anatomical variations in the taxa have been investigated by means of numerical methods (Analysis of variance and Pearson correlation). By the analysis of the investigated taxa from 12 anatomy related characters, it has been also found that the results from numerical analysis of anatomy characters can provide additional evidences, which correspond to the anatomy for the recognition of the taxa.

Ventilatory response to 8 h of isocapnic and poikilocapnic hypoxia in humans

1995 ◽  
Vol 78 (3) ◽  
pp. 1092-1097 ◽  
Author(s):  
L. S. Howard ◽  
P. A. Robbins
Keyword(s):  
Analysis Of Variance ◽  
Ventilatory Response ◽  
Progressive Increase ◽  
Nasal Catheter ◽  
Partial Pressures ◽  
End Tidal ◽  
Almost All ◽  
And Control

Almost all studies of the effects of prolonged hypoxia on ventilation (VE) in humans have been performed with the end-tidal PCO2 (PETCO2) left uncontrolled. The purpose of this study was to compare the effects of 8 h of hypoxia with PETCO2 held constant with 8 h of hypoxia with PETCO2 left uncontrolled. Ten subjects completed the study. Each was seated inside a chamber in which the inspired gas could be controlled so as to maintain the desired partial pressures of end-tidal gases (sampled via nasal catheter) constant (see L.S.G.E. Howard et al. J. Appl. Physiol. 78:1088–1091, 1995.). Three 8-h protocols were employed: 1) isocapnic hypoxia, at an end-tidal PO2 of 55 Torr with PETCO2 held at the subject's resting value; 2) poikilocapnic hypoxia, at the same end-tidal PO2; and 3) control, where the inspired gas was air. VE was measured (over 3 min) at 0 and 20 min and at hourly intervals between 1.5 and 7.5 h. There was a rise in VE during isocapnic hypoxia [from an initial VE of 16.2 +/- 1.3 (SE) l/min to a final VE of 24.8 +/- 1.6 l/min], which was significant compared with poikilocapnic hypoxia and control values (P < 0.001, analysis of variance). There was no significant progressive rise in VE during poikilocapnic hypoxia compared with control values. These results show that isocapnic hypoxia produces a progressive increase in VE when sustained over an 8-h period. The onset of this response is faster than has been noted in studies of the progressive rise in VE associated with the poikilocapnic hypoxia of altitude.

scholarly journals Phenotypic plasticity at fine-grained spatial scales: the scorched mussel Perumytilus purpuratus growing on Patagonian rocky salt-marshes

2020 ◽  
Vol 84 (4) ◽  
pp. 393-401
Author(s):  
Yamila Gonzalez Giorgis ◽  
María Cruz Sueiro ◽  
Federico Márquez
Keyword(s):  
Phenotypic Plasticity ◽  
Environmental Conditions ◽  
Range Expansion ◽  
Salt Marshes ◽  
Spatial Scales ◽  
Shell Shape ◽  
Patch Type ◽  
Fine Grained ◽  
Perumytilus Purpuratus ◽  
Ecological Range

Understanding phenotypic plasticity of species at different spatial scales is vital in the current context of an increasing pace of environmental changes. Through this knowledge, it is possible to predict their potential to adapt and/or evolve in face of new environmental conditions such as climate change, and/or to understand their ecological range expansion. In Patagonian rocky salt-marshes, one of the most abundant invertebrate species is the scorched mussel Perumytilus purpuratus. In this system, this mussel can be found inhabiting both vegetated and non-vegetated patches, which differ in critical environmental conditions. We performed a field study evaluating whether mussels growing in vegetated patches differ in shell shape from those growing in adjacent non-vegetated patches. We sampled individuals from both patch types and assessed their shell shape and size using geometric morphometrics. The results showed that mussels from vegetated patches had shells that were more dorsoventrally expanded, anterodorsally restricted and globose in shape than those from non-vegetated patches, which showed the opposite traits resulting in a more elongated shell. The differences found could be driven by the different conditions of temperature, desiccation rate, wave action and population density to which mussels are exposed in each patch type. These results revealed the striking phenotypic plasticity of shell form of this native species at a fine-grained scale, which could be one of the explanations for its success in its ecological range expansion.

scholarly journals Transgressivity in Key Functional Traits Rather Than Phenotypic Plasticity Promotes Stress Tolerance in A Hybrid Cordgrass

Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 594
Author(s):  
Blanca Gallego-Tévar ◽  
Brenda J. Grewell ◽  
Rebecca E. Drenovsky ◽  
Jesús M. Castillo
Keyword(s):  
Phenotypic Plasticity ◽  
Sea Level Rise ◽  
Stress Tolerance ◽  
Sea Level ◽  
San Francisco ◽  
Functional Traits ◽  
Salt Marshes ◽  
Parental Species ◽  
Expression Patterns ◽  
Phenotypic Expression

Hybridization might promote offspring fitness via a greater tolerance to environmental stressors due to heterosis and higher levels of phenotypic plasticity. Thus, analyzing the phenotypic expression of hybrids provides an opportunity to elucidate further plant responses to environmental stress. In the case of coastal salt marshes, sea level rise subjects hybrids, and their parents, to longer tidal submergence and higher salinity. We analyzed the phenotypic expression patterns in the hybrid Spartina densiflora x foliosa relative to its parental species, native S. foliosa, and invasive S. densiflora, from the San Francisco Estuary when exposed to contrasting salinities and inundations in a mesocosm experiment. 37% of the recorded traits displayed no variability among parents and hybrids, 3% showed an additive inheritance, 37% showed mid-parent heterosis, 18% showed best-parent heterosis, and 5% presented worst-parent heterosis. Transgressivity, rather than phenotypic plasticity, in key functional traits of the hybrid, such as tiller height, conveyed greater stress tolerance to the hybrid when compared to the tolerance of its parents. As parental trait variability increased, phenotypic transgressivity of the hybrid increased and it was more important in response to inundation than salinity. Increases in salinity and inundation associated with sea level rise will amplify the superiority of the hybrid over its parental species. These results provide evidence of transgressive traits as an underlying source of adaptive variation that can facilitate plant invasions. The adaptive evolutionary process of hybridization is thought to support an increased invasiveness of plant species and their rapid evolution.

scholarly journals Assessment of per se performance, combining ability, hybrid vigour and reaction to major diseases in pigeonpea [Cajanus cajan (L.) Millsp.]

2016 ◽  
Vol 8 (2) ◽  
pp. 588-596
Author(s):  
Yamanura Yamanura ◽  
R. Lokesha ◽  
V. Kantharaju ◽  
S. Muniswamy
Keyword(s):  
Analysis Of Variance ◽  
Seed Yield ◽  
Combining Ability ◽  
Performance Standard ◽  
Hybrid Vigour ◽  
Male Sterile ◽  
Additive Gene ◽  
Standard Heterosis ◽  
Per Se ◽  
Almost All

An experiment was carried out using seven cytoplasmic-genetic male sterile (CGMS) lines as females and seven diversified testers as males in a line × tester design. The analysis of variance for parents, females x males, hybrids and parents vs hybrids showed significant differences for almost all characters studied indicating the presence of sufficient variability among parents. Analysis of variance for combining ability revealed that mean squares due to females and line x tester interaction were significant for most of the characters. Thereby it is suggested that the variation in hybrids in respect of seed yield may be strongly influenced by the female lines. Analysis of variance revealed that the ratio of variance due to GCA to SCA was less than unity for all the characters indicating that these traits may be under the influence of non additive gene action and these characters are more likely to be improved through heterosis breeding. The gca effects of parents revealed that ICPA-2043, ICPA-2047, ICPA-2078, AKT-9913, BDN-2 and GRG-811 were good general combiners for seed yield and it’s direct compo-nents. The top three crosses exhibiting high specific combing ability effects along with their Per se performance, standard heterosis and gca status of the parents indicated that the cross combinations ICPA-2092 x GRG-811, ICPA-2043 x ICP-7035 and ICPA-2047 x RVKP-261 were good specific combiners for seed yield. These parental combinations are being used for exploitation of hybrid vigour. The good general combiners (ICPA-2043, ICPA-2047, ICPA-2078, AKT-9913, BDN-2 and GRG-811) and promising crosses viz. ICPA-2047 x GRG-811 and ICPA-2047 x BDN-2 were resistant for SMD and Fusarium wilt diseases, having high mean performance, positive sca effects for seed yield were identified from the present investigation and these may be useful in future breeding program.

Genus Oscillatoria Vaucher (Cyanoprokaryota) in Maldah District, West Bengal, India

2017 ◽  
Vol 3 (01) ◽  
pp. 53-63
Author(s):  
Pratibha Gupta
Keyword(s):  
Salt Marshes ◽  
West Bengal ◽  
Water System ◽  
Common Species ◽  
Water Ecosystem ◽  
Oscillatoria Chalybea ◽  
Almost All ◽  
Oscillatoria Agardhii ◽  
Cold Lakes ◽  
Oscillatoria Rubescens

Genus Oscillatoria Vaucher is the ubiquitous Cyanoprokaryote, growing in almost all habitats in fresh-water ecosystem like bils, dighis, lakes, ponds, wetlands, and marine water system like - salt marshes and pans, estuaries, brackish waters and ocean. It also occurs on inter-tidal rocks, snow and even in cold lakes underneath 5 m of ice pack as well as in thermal springs. During systematic investigations recorded altogether 25 species, 4 variety and 2 forms from Maldah District viz. Oscillatoria acuta Bürhl and Biswas, Oscillatoria agardhii Gomont, Oscillatoria amoena (Kütz.) Gomont, Oscillatoria amphibia C.Agardh ex Gomont, Oscillatoria amphigranulata Goor, Oscillatoria angusta Koppe, Oscillatoria chalybea G.Mertens ex Gomont, Oscillatoria formosa Bory ex Gomont, Oscillatoria formosa f. loktakensis Brühl and Biswas, Oscillatoria geitleriana Elenkin, Oscillatoria geminata Menegh. ex. Gomont, Oscillatoria limnetica Lemmerm., Oscillatoria limosa C.Agardh ex Gomont, Oscillatoria minnesotensis Tilden, Oscillatoria okenii C.Agardh ex Gomont, Oscillatoria ornata var. crassa C.B.Rao, Oscillatoria perornata f. attenuata Skuja, Oscillatoria princeps Vaucher ex Gomont, Oscillatoria prolifica Gomont, Oscillatoria proteus Skuja, Oscillatoria pseudogeminata var. unigranulata Biswas, Oscillatoria quadripunctulata Brühl and Biswas, Oscillatoria raoi DeToni, Oscillatoria redekei Goor, Oscillatoria rubescens DC. ex Gomont, Oscillatoria splendida Grev. ex Gomont, Oscillatoria subbrevis Schmidle, Oscillatoria tenuis C.Agardh ex Gomont, Oscillatoria tenuis var. natans Gomont, Oscillatoria tenuis var. tergestina Rabenh. ex Gomont and Oscillatoria willei N.L.Gardner. However, Oscillatoria subbrevis Schmidle, Oscillatoria tenuis C.Agardh ex Gomont are the most common species followed by Oscillatoria amphigranulata Goor, Oscillatoria acuta Bürhl and Biswas, Oscillatoria amphibia C.Agardh ex Gomont, Oscillatoria amphigranulata Goor in water bodies of Malda District. Oscillatoria redekei Goor is reported new from India.

Morphological and leaf anatomical variation in Festuca rubra sensu lato (Poaceae) from eastern Quebec

1987 ◽  
Vol 65 (6) ◽  
pp. 1065-1077 ◽  
Author(s):  
Martin Dubé ◽  
Pierre Morisset
Keyword(s):  
Salt Marshes ◽  
Anatomical Variation ◽  
Similarity Analysis ◽  
Festuca Rubra ◽  
Classification Problems ◽  
Geographical Factors ◽  
Variation Patterns ◽  
Character Variation ◽  
Anatomical Characters ◽  
Weak Structure

The variation of 52 morphological and anatomical characters was analysed in 32 populations of Festuca rubra L. sensu lato from salt marshes, coastal rocks, coastal sands, and anthropogenic sites in eastern Quebec. The results show that the variation of characters is essentially continuous within and between populations, that some populations are much more variable than others, and that on the whole, character variation patterns are mainly related to ecological rather than geographical factors. The weak structure revealed by a similarity analysis of populations is the source of the classification problems within this species.

scholarly journals A transplantation experiment yields no evidence for phenotypic plasticity in shell band width in Cepaea nemoralis

2020 ◽  
Author(s):  
Menno Schilthuizen ◽  
Ruth K. Scheid ◽  
Lia J. J. den Daas
Keyword(s):  
Phenotypic Plasticity ◽  
Evolutionary Biology ◽  
Band Width ◽  
Model Species ◽  
Habitat Types ◽  
Colour Variation ◽  
Cepaea Nemoralis ◽  
Transplantation Experiment ◽  
The Common ◽  
Spiral Bands

AbstractThe common European grove snail, Cepaea nemoralis (Helicidae), has been a model species in genetics and evolutionary biology for over a century thanks largely to its genetic shell colour polymorphism. Although most aspects of its shell colour variation are known to be purely genetic, with little or no phenotypic plasticity involved, the width of the spiral bands has been suspected to display a certain amount of plasticity. To test this, we conducted a transplantation experiment, in which 548 growing banded snails were marked and transplanted, either within the same habitat (open or closed vegetation, displaying 19% and 61% band fusion, respectively) or between habitat types. The numbers recaptured were low: 8%, 5% after removal of individuals that had not grown. Based on these samples, we did not find any substantial influence of transplantation on band width.

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