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Towards an integrated understanding of charophyte biology and paleobiology / Mary Beilby in Botany letters, vol. 165, n°1 (Année 2018)
[article]
Titre : Towards an integrated understanding of charophyte biology and paleobiology Type de document : Livre Auteurs : Mary Beilby, Auteur ; S. Schneider, Auteur ; Andrzej Puckacz, Auteur ; Carles Martin-Closas, Auteur Année de publication : 2018 Article en page(s) : pp. 7-10 Langues : Anglais Mots-clés : charophyte molecular genetics physiology ecology paleobotany Résumé : "In this special issue, we present an overview of the presentations given at the 7th Meeting of the International Research Group on charophytes held in Astana in 2016. Charophytes, understood as the members of extant Charales and their direct ancestors (fossil orders Sycidiales and Moellerinales), represent a significant plant group that provides an iconic research system for many diverse fields, such as evolution, ecology, electrophysiology, phytoremediation and management of wetlands. Charophytes have been proposed as one of the closest ancestors of land plants. Their fossil record goes back to 425 Ma (million years ago), but the rise of the oldest living charophyte genera is dated from ca 155–125 Ma. An example of vegetations already dominated by early Characeae has been recently found in China, dating back to that time. The definition of charophyte species has been a matter of debate, since the morphology of these plants shows a great plasticity. The elucidation of charophyte taxonomy is of major importance for the definition of endangered species. New light is shed by the use of genetic coding for the distinction of problematic species within the Chara genus. Climate change is one of the major concerns in the present scenario of disturbance of charophyte habitats. Specific adaptations, including changes in thallus morphology, parthenogenesis and enhanced production of oospores, develop when charophyte habitats become unstable, desiccate or increase their salinity. Brackish charophytes are also a subject of special attention, since they include species highly specialized in particular niches and highly vulnerable to extreme salinities reached through habitat desiccation. The chemistry of water controls the distribution of species, even at the biogeographic scale. Experiments, related to the transport of ions across the charophyte cell membrane, provide an understanding of how charophytes adapt physiologically to those changes." Type de publication : périodique Référence biblio : Beilby M., Schneider S., Puckacz A., Martin-Closas C., 2018 - Towards an integrated understanding of charophyte biology and paleobiology. Botany letters, 165 (1) : 7-10. Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=67139
in Botany letters > vol. 165, n°1 (Année 2018) . - pp. 7-10[article]Exemplaires
Cote Localisation Disponibilité P0177-6 Brest Exclu du prêt Viability assessment and estimation of the germination potential of charophyte oospores : testing for site and species specificity / Anja Holzhausen in Botany letters, vol. 165, n°1 (Année 2018)
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Titre : Viability assessment and estimation of the germination potential of charophyte oospores : testing for site and species specificity Type de document : Livre Auteurs : Anja Holzhausen, Auteur ; Christian Porsche, Auteur ; Hendrik Schubert, Auteur Année de publication : 2018 Article en page(s) : pp. 147-158 Langues : Anglais Mots-clés : charophyte desiccation diaspore dormance irradiance TTC test Résumé : "Anthropogenic disturbance over several decades has caused aquatic ecosystems to deteriorate, raising concerns about their condition and, consequently, prompting restorative activities. The recovery of submerged vegetation (notably charophytes) is a crucial requirement for the restoration of eutrophic aquatic systems. The success of this action often depends on the availability and germinability of aquatic plant diaspores. To characterize the potential of the diaspore bank for the restoration of charophyte stands, we investigated viability, germination potential and conditions for dormancy breaking of the oospores in three independent studies. The viability of the oospores was determined by means of the triphenyltetrazolium chloride (TTC) test. The germination potential of the diaspore banks from seven locations was estimated for potential irradiance dependency and the impact of factors influencing the dormancy status was assessed. For the latter aspect, the germination experiments were conducted with solitary oospores from plants and diaspore banks, pretreated under different temperature and desiccation regimens. The results showed species-specific differences in dormancy breakage and germination of 10 charophyte species. Five of the species tested, Chara filiformis Hertzsch, Lychnothamnus barbatus (Meyen) Leonh., Tolypella glomerata (Desvaux) Leonh., Nitella mucronata (A.Braun) Miq. in Hall and Nitella flexilis (L.) C. Agardh/Nitella opaca (C. Agardh ex Bruz.) C. Agardh, exhibited light-dependent germination. The irradiances where maximum germination was achieved correspond well to the species’ distribution within the vertical irradiance gradient in their habitats." Type de publication : périodique Référence biblio : Holzhausen A., Porsche C., Schubert H., 2018 - Viability assessment and estimation of the germination potential of charophyte oospores : testing for site and species specificity. Botany letters, 165 (1) : 147-158. Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=67243
in Botany letters > vol. 165, n°1 (Année 2018) . - pp. 147-158[article]Exemplaires
Cote Localisation Disponibilité P0177-6 Brest Exclu du prêt The life cycle of a parthenogenetic population of Chara canescens from an interdunal Mediterranean pond / Sara Calero in Botany letters, vol. 165, n°1 (Année 2018)
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Titre : The life cycle of a parthenogenetic population of Chara canescens from an interdunal Mediterranean pond Type de document : Livre Auteurs : Sara Calero, Auteur ; Maria Rodrigo, Auteur Année de publication : 2018 Article en page(s) : pp. 55-65 Langues : Anglais Mots-clés : charophyte phénologie reproduction cycle de vie oogonia maturation oospore size brackish pond Résumé : "Chara canescens lives in shallow brackish waters in the northern hemisphere. It has been described as an annual species that mostly reproduces by parthenogenesis, being the only species of Chara able to do so. However, much is still unknown about its life cycle and the differences between the sexual and the parthenogenetic populations. We monitored the life cycle of a parthenogenetic population growing in a brackish interdunal pond in the Albufera de València Natural Park (Spain). Approximately 30 specimens were harvested every 15–30 days throughout 2015. The longest polar axis and the largest equatorial diameter were measured, and the isopolarity index was calculated for the oogonia and the oospores. The non-swollen and the swollen oogonia were distinguished by size. This population had a short life cycle, but two types of shoots with different life history traits were found. A few small individuals overwintered underneath the emergent vegetation. In early March, new shoots appeared from the germinating oospores, growing fast and colonizing more open waters. The first oogonia appeared in April, enlarging and ripening along the first five whorls of the shoots. The oospores were produced in less than 15 days after the first oogonia emergence. The ripe oospores were small (average size ± SD: 392 ± 34 × 219 ± 24 μm; isopolarity index: 181 ± 22). Parthenogenetic reproduction lasted 5 months. No new fructifications were produced from September onwards. Although the oospores were smaller than those described in the literature for the species, they were clearly viable and enabled the persistence of the population through the winter." Type de publication : périodique Référence biblio : Calero S., Rodrigo M., 2018 - The life cycle of a parthenogenetic population of Chara canescens from an interdunal Mediterranean pond. Botany letters, 165 (1) : 55-65. Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=67224
in Botany letters > vol. 165, n°1 (Année 2018) . - pp. 55-65[article]Exemplaires
Cote Localisation Disponibilité P0177-6 Brest Exclu du prêt