A partir de cette page vous pouvez :
Retourner au premier écran avec les dernières notices... |
Résultat de la recherche
1 résultat(s) recherche sur le mot-clé ' phénologie'
trié(s) par (Pertinence décroissant(e), Titre croissant(e)) Affiner la recherche Générer le flux rss de la recherche
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)
[article]
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