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3 résultat(s) recherche sur le mot-clé 'Phenotypic plasticity' 
trié(s) par (Pertinence décroissant(e), Titre croissant(e)) Affiner la recherche Générer le flux rss de la rechercheInstability of morphological features used for classification of Thymus pulegioides infraspecific taxa / Kristina Loéiene in Acta botanica Hungarica, vol. 48, n°3-4 (Septembre 2006)
Titre : Instability of morphological features used for classification of Thymus pulegioides infraspecific taxa Type de document : Livre Auteurs : Kristina Loéiene, Auteur Année de publication : 2006 Article en page(s) : pp. 345-360 Langues : Anglais Mots-clés : Thymus pulegioides environmental factors habitat inflorescences leaves phenotypic plasticity Résumé : "The stability of morphological features, traditionally used for the infraspecific classification of Thymus pulegioides L., was studied. The individual plants of T. pulegioides were collected from different habitats and cultivated under the same field conditions by cloning them annually for five years. The results of the cultivation experiment indicated that most of the investigated morphological features including length of leaves, length/width ratio of leaves and length of inflorescences were unstable. A conclusion was approached that the natural variation of the investigated morphological characters of T. pulegioides is not genetically fixed. It is phenotypic plasticity of plants, which depends on environmental conditions. Therefore the morphological characters, used at the “traditional” infraspecific classifications of T. pulegioides, cannot be used as the reliable diagnostic indicators of the infraspecific taxa of the species." Type de publication : périodique Référence biblio : Loéiene K., 2006 - Instability of morphological features used for classification of Thymus pulegioides infraspecific taxa. Acta botanica Hungarica, 48 : 345-360. DOI : 10.1556/ABot.48.2006.3-4.9 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=68003
in Acta botanica Hungarica > vol. 48, n°3-4 (Septembre 2006) . - pp. 345-360[article]Exemplaires
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Titre : Fitness and growth of the ephemeral mudflat species Cyperus fuscus in river and anthropogenic habitats in response to fluctuating water-levels Type de document : Livre Auteurs : Jörg Böckelmann, Auteur ; Karin Tremetsberger, Auteur ; Katerina Sumberova, Auteur ; Heinrich Grausgruber, Auteur ; Karl-Georg Bernhardt, Auteur Année de publication : 2017 Article en page(s) : pp. 135-149 Langues : Anglais Catégories : [habitats/milieux] ZH - Zones humides Mots-clés : Flooding Isoëto-Nanojuncetea Secondary habitats Phenotypic plasticity Soil seed bank végétation Résumé : "Cyperus fuscus is a representative of threatened ephemeral wetland plant communities in summer-dry shoreline habitats. We compared variation and plasticity in traits related to fitness and growth of plants germinating from the soil seed bank and established plants from river and secondary anthropogenic habitats. Plants from sites at rivers, fishponds and fish storage ponds were cultivated and selfed to get homogenous seed material for a germination and an environmental manipulation experiment involving three different water regimes. Differences in traits and their plasticities were evaluated by means of linear mixed models. Cyperus fuscus followed a low-oxygen escape strategy when flooded. Seeds of plants derived from the soil seed bank germinated faster than seeds of plants derived from established plants suggesting that short-term selection of genotypes is mediated by the particular conditions on the site during germination. The experiment revealed significant differences between river and secondary habitats as well as between the soil seed bank and established plants. For example, plants from river habitats produced the highest number of culms with inflorescences. The difference was most evident under partial submergence. Plants from fish storage ponds rapidly reached the reproductive phase, but produced less culms with inflorescences. This seemingly allows them to cope with numerous and irregular disturbances and intensive substrate moisture changes. Our results suggest that populations have adapted to conditions at secondary habitats provided by fish farming during the last centuries." Type de publication : périodique Référence biblio : Böckelmann J., Tremetsberger K., Sumberova K., Grausgruber H., Bernhardt K.-G., 2017 - Fitness and growth of the ephemeral mudflat species Cyperus fuscus in river and anthropogenic habitats in response to fluctuating water-levels. Flora, 234 : 135-149. DOI : 10.1016/j.flora.2017.07.012 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=66243
in Flora > vol. 234 (Année 2017) . - pp. 135-149[article]Exemplaires
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Titre : Morphological adaptations of Chara baltica and Chara liljebladii (Characeae) under different light conditions Type de document : Livre Auteurs : Petra Nowak, Auteur ; Hendrik Schubert, Auteur ; Anja Holzhausen, Auteur ; Veronika Sommer, Auteur ; Ralf Schaible, Auteur Année de publication : 2018 Article en page(s) : pp. 67-75 Langues : Anglais Catégories : [Thèmes] Algues
[Thèmes] Charophytes / Characées
[Thèmes] EcologieMots-clés : Phenotypic plasticity light acclimation Résumé : "Individuals within wild populations differ substantially in their fitness as a result of either genetic differences or acclimation. Within the Charophyte algae, the two taxa Chara baltica and C. liljebladii predominate at different water depths of the same habitat. The two taxa are mainly distinguished by quantitative characteristics, pointing to light acclimation. In particular, they differ by a length of the internode and the bract cells, as well as the cortication type. Genetic analyses revealed that individuals of both morphotypes are genetically identical, and hence may belong to the same species. In the present paper, we tested a hypothesis that C. liljebladii is a low-light phenotype of C. baltica. Can a C. baltica phenotype be transferred into a C. liljebladii (and vice versa) by manipulation of the environmental conditions such as irradiance? We observed significant changes in the morphology of C. baltica: decreasing the irradiance significantly increased the growth of the branchlets and internodal cells. Consequently, the plants grew larger, changing their morphology in the direction of the C. liljebladii morphotype. In the reverse experiment, subjecting C. liljebladii to increasing irradiances, the individuals had slightly better growth, but none of the analysed morphological characteristics changed significantly. Both taxa have thus shown different adaptations to light limitation. Their morphologies cannot be transferred into each other by environmental factors. Thus, the presence of the different morphologies reflects the ecological characteristics of their habitats, such as light availability or turbidity." (source : auteurs) Type de publication : périodique Référence biblio : Nowak P., Schubert H., Holzhausen A., Sommer V., Schaible R., 2018 - Morphological adaptations of Chara baltica and Chara liljebladii (Characeae) under different light conditions. Botany letters, 165 (1) : 67-75. ID PMB : 67226 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=67226
in Botany letters > vol. 165, n°1 (Année 2018) . - pp. 67-75[article]Exemplaires
Cote Localisation Disponibilité P0177-6 Brest Exclu du prêt
