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Diaspore bank analysis of Baltic coastal waters / Petra Nowak in Botany letters, vol. 165, n°1 (Année 2018)
[article]
Titre : Diaspore bank analysis of Baltic coastal waters Type de document : texte imprimé Auteurs : Petra Nowak, Auteur ; Tim Steinhardt, Auteur ; Ulla Von Ammon, Auteur ; Henning Rohde, Auteur ; Arne Schoor, Auteur ; Anja Holzhausen, Auteur ; Ralf Schaible, Auteur ; Hendrik Schubert, Auteur Année de publication : 2018 Article en page(s) : pp. 159-173 Langues : Anglais (eng) Catégories : [habitats/milieux] 1 - Habitats littoraux et halophile
[Thèmes] Charophytes / CharacéesMots-clés : eutrophisation restauration germination diaspore oospore Résumé : "The coastal waters are important transition zones for terrestrial nutrient and pollutant runoff and the open Sea. During the last decades, eutrophication has negatively influenced macrophyte communities of the coastal ecosystems, making restoration activities inevitable. This study analysed recent macrophyte vegetation and the reproductive potential through the sediment diaspore reservoir along the German Baltic Sea coastline. Salinity was identified to be the responsible factor for shifts in the macrophyte community with most commonly found species like Stuckenia pectinata or Myriophyllum spicatum. In contrast, the oospores of small charophytes (e.g. Tolypella nidifica) clearly dominated the sediment diaspore bank. The germination rates differed in the recent vegetation composition and the diaspore bank composition with Zannichellia palustris as the dominant species. However, several species not visually detected at the respective sites were represented in the diaspore bank and germinated at a low rate (e.g. Chara contraria and Lamprothamnium papulosum). The maximal germination frequency corresponded to the sediment layer in which diaspore density was the highest (5–15 cm). In conclusion, the germinable diaspores were observed at all sites. Considering the differences between the diaspore composition, recent vegetation and germination success, we have illustrated the potential of the diaspore banks for the restoration of the macrophyte communities after at least mid-term periods of disturbance." (source : auteurs) Type de publication : périodique Référence biblio : Nowak P., Steinhardt T., Von Ammon U., Rohde H., Schoor A., Holzhausen A., Schaible R., Schubert H., 2018 - Diaspore bank analysis of Baltic coastal waters. Botany letters, 165 (1) : 159-173. Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=67244
in Botany letters > vol. 165, n°1 (Année 2018) . - pp. 159-173[article]Exemplaires(1)
Cote Localisation Disponibilité P0177-6 Brest Exclu du prêt Reproductive biology of Sorghum halepense (L.) Pers. (Poaceae; Panicoideae; Andropogoneae) in relation to invasibility / Rajdavinder Kaur in Flora, vol. 229 (Année 2017)
[article]
Titre : Reproductive biology of Sorghum halepense (L.) Pers. (Poaceae; Panicoideae; Andropogoneae) in relation to invasibility Type de document : texte imprimé Auteurs : Rajdavinder Kaur, Auteur ; Amarjit Singh Soodan, Auteur Année de publication : 2017 Article en page(s) : pp. 32-49 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Sorghum halepense
[Thèmes] Pollinisation, pollen, nectar
[Thèmes] ReproductionMots-clés : diaspore endozoochorie xénogamie phénologie florale Résumé : "Sorghum halepense (L.) Pers. is the most aggressive grass weed of the world resulting from an efficient system of its reproduction and propagation through a combination of vegetative and sexual means. However, reproductive biology of the species is not understood in sufficient details and had serious gaps of information on its pollen and pollination system, breeding behaviour, fruit and dispersal biology. The species was found to be chasmogamous with an andromonoecious sexual system of well-developed bisexual and male spikelets in pairs and terminal triads. Precocious extrusion of receptive stigmas preceding anther dehiscence, abundant pollen of high fertility and longevity and a high pollen-ovule ratio strongly indicate xenogamy in the species. Laser Confocal Microscopy revealed rapid germination of pollen and growth of pollen tubes down the pistil to the ovule which caused high fruit set and facilitated the amphimictic cycle. The present study is presumably the first report on the role of several insect pollinators mainly from the order Diptera (Isomyia paurogonita Fang & Fan.) and Hymenoptera (Hylaeus sp., Sphecodes ephippius Linnaeus , Megachile sp.). The visitation time of insect pollinators closely synchronized with peak anthesis resulting in high pollen loads. Breeding experiments revealed significantly higher fruit set in open pollinated in comparison to bagged synflorescences. The diaspore enclosed a well-developed caryopsis surrounded by accessory bracts along with persistent pedicels and a rachis segment preparing them for dispersal through autochory and endozoochory. Thus, cosmopolitan and invasive nature of S. halepense could be attributed to a combination of xenogamous breeding system, high seed production and efficient fruit dispersal through resistant diaspores. This study on the reproductive system of S. halepense shall provide a framework for developing management strategies both for the control of this invasive grass species as also for its propagation as a fodder crop in vacant rangelands." (source : auteurs) Type de publication : périodique Référence biblio : Kaur R., Soodan A., 2017 - Reproductive biology of Sorghum halepense (L.) Pers. (Poaceae; Panicoideae; Andropogoneae) in relation to invasibility. Flora, 229 : 32-49. Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=66240
in Flora > vol. 229 (Année 2017) . - pp. 32-49[article]Exemplaires(0)
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