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A multi-level analysis to evaluate the extinction risk of and conservation strategy for the aquatic fern Marsilea quadrifolia L. in Europe / I. Bruni in Aquatic Botany, vol. 111 (Année 2013)
[article]
Titre : A multi-level analysis to evaluate the extinction risk of and conservation strategy for the aquatic fern Marsilea quadrifolia L. in Europe Type de document : Livre Auteurs : I. Bruni, Auteur ; Rodolfo Gentili, Auteur ; F. (de) Mattia, Auteur ; P. Cortis, Auteur ; G. Rossi, Auteur ; M. Labra, Auteur Année de publication : 2013 Article en page(s) : pp. 35-42 Langues : Anglais Mots-clés : herbicide restauration génétique agrosystème génétique biologie de la conservation plante aquatique Résumé : "This study investigated the conservation status of Marsilea quadrifolia, an endangered fern founding paddy fields, irrigation ditches and ponds. An evaluation at the European level based on IUCN criteria showed that the extent of occurrence (EOO) of M. quadrifolia has decreased from5,930,000 km2 to 5,774,000 km2 during the past decade, whereas its area of occupancy (AOO) has decreased from 620 to 400 km2 (approximately 35.5%). These findings allowed the species to be upgraded from the IUCN classification of Near Threatened to Vulnerable. The agricultural chemical treatments seem to be the main extinction cause of M. quadrifolia, therefore we performed toxicological with 7 most common rice herbicides. Young plantlets were incubated for 96h with each herbicide at three different concentrations : TQ (Tale Quale, chosen in accordance with the suggested dose for rice fields described on the product label), 1:100 and1:1.000. Results suggested that survival of the plantlets depended on the herbicide and concentration used, and ranged between 0 and 80%, and no survival at ambient concentrations for 4(Aura, Aura + Dash, Clincher and Viper) out of the 8 chosen herbicides. We conclude that herbicides represent one of the principal threats to the survival of this species. Finally, a DNA analysis using the AFLP approach was employed to identify the most suitable genetic pool for plant reintroduction efforts. The data show that the analysed populations of M. quadrifolia suffered from low genetic variability (Nei’s gene diversity varied from 0.025 to 0.036). However, the analysis of the distribution of genetic variability suggested that 4 populations were characterised by different genetic traitst that are useful in defining a genetic pool for plant conservation. This study highlights a strategy for implementing a plan of action for species growing in agro-ecosystems based on an integrated approach that is able to clarify the species conservation status, the principal threat factor and the genetic pool to be used for species conservation and reintroduction." (source : auteur) Type de publication : périodique Référence biblio : Bruni I., Gentili R., Mattia F. (de), Cortis P., Rossi G., Labra M., 2013 - A multi-level analysis to evaluate the extinction risk of and conservation strategy for the aquatic fern Marsilea quadrifolia L. in Europe. Aquatic Botany, 111 : 35-42. ID PMB : 58984 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=58984
in Aquatic Botany > vol. 111 (Année 2013) . - pp. 35-42[article]Exemplaires
Cote Localisation Disponibilité aucun exemplaire The effect of weeds on the numbers of hoverfly (Diptera: Syrphidae) adults and the distribution and composition of their eggs in winter wheat / S.E. Cowgill in The Annals of applied Biology, vol. 123, n°3 (Décembre 1993)
[article]
Titre : The effect of weeds on the numbers of hoverfly (Diptera: Syrphidae) adults and the distribution and composition of their eggs in winter wheat Type de document : Livre Auteurs : S.E. Cowgill, Auteur ; S.D. Wratten, Auteur ; N.W. Sotherton, Auteur Année de publication : 1993 Article en page(s) : pp. 499-515 Langues : Anglais Mots-clés : Syrphidae plante messicole herbicide lutte biologique Résumé : "The abundance and species composition of syrphid adults in herbicide-treated and untreated headlands was recorded in a replicated within-field experiment conducted over a two-year period. The highest numbers of the most abundant syrphid species, Episyrphus balteatus, were recorded in the untreated headland strips. Analysis of the behaviour of the adult flies showed that they were retained in the untreated strips because they were foraging on the flowering non-crop plants.
The distribution of syrphid eggs between herbicide treated and untreated headland replicates was examined. A significant positive relationship between the numbers of eggs per aphid and weed density was detected during June in the second year of the study. This is in part attributed to the tendency of Melanostoma females to oviposit on non-crop plants.
The implications of the implementation of a modified herbicide regime in the headlands of cereal fields for the biological control of cereal aphids by syrphid larvae is discussed." (source : auteurs)Type de publication : périodique Référence biblio : Cowgill S.-E., Wratten S.-D., Sotherton N.-W., 1993 - The effect of weeds on the numbers of hoverfly (Diptera: Syrphidae) adults and the distribution and composition of their eggs in winter wheat. The Annals of applied Biology, 123 (3) : 499-515. ID PMB : 62745 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=62745
in The Annals of applied Biology > vol. 123, n°3 (Décembre 1993) . - pp. 499-515[article]Exemplaires
Cote Localisation Disponibilité aucun exemplaire