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Ajouter le résultat dans votre panierLocal genetic population structure in an endangered plant species, Silene tatarica (Caryophyllaceae) / N. Tero in Heredity, 94 (2005)
Titre : Local genetic population structure in an endangered plant species, Silene tatarica (Caryophyllaceae) Type de document : Imprimé Auteurs : N. Tero ; J. Aspi ; P. Siikamäki ; A. Jäkäläniemi Année de publication : 2005 Article en page(s) : 478-487 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Génétique et écologie (dynamique, démographique, sélection) Mots-clés : Silene tartarica Résumé : Genetic substructuring in plant populations may evolve as a consequence of sampling events that occur when the population is founded or regenerated, or if gene dispersal by pollen and seeds is restricted within a population. Silene tatarica is an endangered, perennial plant species growing along periodically disturbed riverbanks in northern Finland. We investigated the mechanism behind the microspatial genetic structure of S. tatarica in four subpopulations using amplified fragment length polymorphism markers. Spatial autocorrelation revealed clear spatial genetic structure in each subpopulation, even though the pattern diminished in older subpopulations. Parentage analysis in an isolated island subpopulation indicated a very low level of selfing and avoidance of breeding between close relatives. The mean estimated pollen dispersal distance (24.10 m; SD=10.5) was significantly longer and the mean seed dispersal distance (9.07 m; SD=9.23) was considerably shorter than the mean distance between the individuals (19.20 m; SD=13.80). The estimated indirect and direct estimates of neighbourhood sizes in this subpopulation were very similar, 32.1 and 37.6, respectively. Our results suggested that the local spatial genetic structure in S. tatarica was attributed merely to the isolation-by-distance process rather than founder effect, and despite free pollen movement across population, restricted seed dispersal maintains local genetic structure in this species. Lien pérenne : DOI : 10.1038/sj.hdy.6800642 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=148686
in Heredity > 94 (2005) . - 478-487Tero, N., Aspi, J., Siikamäki, P., Jäkäläniemi, A. 2005 Local genetic population structure in an endangered plant species, Silene tatarica (Caryophyllaceae). Heredity, 94: 478-487.Documents numériques
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Titre : Patterns of pollen dispersal in a small population of Pinus sylvestris L. revealed by total-exclusion paternity analysis Type de document : Imprimé Auteurs : Juan José Robledo-Arnuncio ; Luis Gil Année de publication : 2005 Article en page(s) : 13-22 Langues : Anglais (eng) Mots-clés : Pinus sylvestris L., 1753 Résumé : Patterns of pollen dispersal were investigated in a small, isolated, relict population of Pinus sylvestris L., consisting of 36 trees. A total-exclusion battery comprising four chloroplast and two nuclear microsatellites (theoretical paternity exclusion probability EP=0.996) was used to assign paternity to 813 seeds, collected from 34 trees in the stand. Long-distance pollen immigration accounted for 4.3% of observed matings. Self-fertilization rate was very high (0.25), compared with typical values in more widespread populations of the species. The average effective pollen dispersal distance within the stand was 48 m (or 83 m excluding selfs). Half of effective pollen was dispersed within 11 m, and 7% beyond 200 m. A strong correlation was found between the distance to the closest tree and the mean mating-distance calculated for single-tree progenies. The effective pollen dispersal distribution showed a leptokurtic shape, with a large and significant departure from that expected under uniform dispersal. A maximum-likelihood procedure was used to fit an individual pollen dispersal distance probability density function (dispersal kernel). The estimated kernel indicated fairly leptokurtic dispersal (shape parameter b=0.67), with an average pollen dispersal distance of 135 m, and 50% of pollen dispersed beyond 30 m. A marked directionality pattern of pollen dispersal was found, mainly caused by the uneven distribution of trees, coupled with restricted dispersal and unequal male success. Overall, results show that the number and distribution of potential pollen donors in small populations may strongly influence the patterns of effective pollen dispersal. Lien pérenne : DOI : 10.1038/sj.hdy.6800542 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=149167
in Heredity > 94 (2005) . - 13-22Robledo-Arnuncio, Juan José, Gil, Luis 2005 Patterns of pollen dispersal in a small population of Pinus sylvestris L. revealed by total-exclusion paternity analysis. Heredity, 94: 13-22.Documents numériques
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