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1.
J Eukaryot Microbiol ; 64(6): 829-842, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28397389

RESUMO

We investigate the cyst-theca relationship of Impagidinium caspienense. Through an incubation experiment, we succeeded in examining the motile stage. Additional molecular analysis of single-cyst PCR (LSU and SSU rDNA) reveal that the cyst is related to the species Gonyaulax baltica Ellegaard et al. (). The ability of this species to belong to two types of cyst-based genera (spiniferate and impagidinioid) suggests that environmental (particularly salinity) and not genetic factors explain the formation of both morphotypes by G. baltica, which provides evidence for heterospory in this species. The affiliation to G. baltica demonstrates that I. caspienense is not endemic to the Caspian Sea. The phylogenetic position of several other gonyaulacoid species is also documented: Impagidinium pallidum, Ataxiodinium choane, Pyxidinopsis psilata, Spiniferites belerius, and Spiniferites ramosus. The LSU and SSU rDNA based phylogenies suggest that the genera Impagidinium and Spiniferites are not monophyletic, and that P. psilata and A. choane are close to Gonyaulax verior and Gonyaulax polygramma, respectively. In addition, this study accentuates the importance of cyst morphology in the classification of the Gonyaulacales.


Assuntos
Dinoflagellida/classificação , Dinoflagellida/isolamento & purificação , Sedimentos Geológicos/parasitologia , Análise por Conglomerados , DNA de Protozoário/química , DNA de Protozoário/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dinoflagellida/genética , Dinoflagellida/fisiologia , Locomoção , Microscopia , Oceanos e Mares , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico/genética , RNA Ribossômico 18S/genética , Análise de Sequência de DNA
2.
Mar Pollut Bull ; 205: 116551, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38878413

RESUMO

The Caspian Sea, the world's largest enclosed water body, experiences significant transformations in its physico-chemical properties and a decline in bioresources due to extensive anthropogenic activities. These activities include the discharge of diverse pollutants and bio-physical alterations such as over-fishing, hunting, and physical alterations to rivers. While acute manifestations such as a fall in the Caspian water levels and wetland desiccation are more overt, the pervasive impact of human activities contributes to a likely irreversible decline in environmental quality that we aim to spotlight in this discussion in order to facilitate its restoration.


Assuntos
Monitoramento Ambiental , Oceanos e Mares , Conservação dos Recursos Naturais , Áreas Alagadas
3.
Bot J Linn Soc ; 177(2): 278-289, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25821246

RESUMO

The domestication of the one-grained einkorn (Triticum monococcum) in the Near East is relatively well known. However, an independent two-grained einkorn-like domestication has been archaeobotanically detected and scarce information is available. Triticum urartu, a wild wheat, was not fully described until the 1970s because the phenology does not allow it to be distinguished easily from wild einkorn (Triticum boeoticum subsp. thaoudar), although a genetic separation exists. Both species are mostly two grained and could potentially be the relatives of the extinct two-grained form. Pollen grains of several genetically well-identified wheat species, including T. urartu and T. boeoticum subsp. thaoudar, were studied by measuring the grain diameter and examining the exine sculpturing with phase-contrast microscopy and scanning electron microscopy to gain an insight into differences enabling taxonomic identification. This work showed that, although T. urartu pollen is smaller on average, grain diameter is not sufficient because of the size overlap between the species, but T. urartu presents a different exine sculpturing (scabrate) from other Triticum spp. (aerolate). This outcome is useful for taxonomists and archaeobotanists. First, it will allow a simple re-classification of herbarium materials. Second, further research could establish whether T. urartu was cultivated.

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