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Auteur Douglas E. Soltis (1953-) |
Documents disponibles écrits par cet auteur (6)
Affiner la rechercheMatK and rbcL gene sequence data indicate that Saxifraga (Saxifragaceae) is polyphyletic / Douglas E. Soltis in American Journal of Botany, 83 (3) (1996)
Titre : MatK and rbcL gene sequence data indicate that Saxifraga (Saxifragaceae) is polyphyletic Type de document : Imprimé Auteurs : Douglas E. Soltis (1953-) ; Robert Kuzoff ; Elena Conti ; Richard Gornall ; Keith Ferguson Année de publication : 1996 Article en page(s) : 371-382 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Phylogénie (liens existant entre espèces apparentées) Mots-clés : Saxifraga Résumé : The large genus Saxifraga, which consists of ≈400 morphologically and cytologically diverse species, has long been considered taxonomically complex. Phylogenetic analysis of over 2500 bp of chloroplast sequence data derived from matK and rbcL was employed to examine relationships among sections of Saxifraga, the segregate genera Zahlbrucknera, Saxifragopsis, and Cascadia, and the relationships of these taxa to other Saxifragaceae sensu stricto. Phylogenetic trees resulting from separate analyses of the matK and rbcL sequences were highly congruent; phylogenetic analysis of a combined matK–rbcL data matrix was therefore also conducted. Our analyses indicate that Saxifraga is polyphyletic, comprising two well-differentiated clades. One clade, Saxifraga sensu stricto, is the sister to the remainder of the family and consists of Saxifraga sections Irregulares, Heterisia, Trachyphyllum, Cymbalaria, Mesogyne, Xanthizoon, Porphyrion, Ciliatae, Cotylea, Ligulatae, Saxifraga, and Gymnopera. With the exception of Gymnopera, the species-rich sections of this clade are monophyletic. Also part of this clade is the problematic Zahlbrucknera paradoxa, which is allied with members of section Saxifraga. A second major clade of Saxifraga species, Micranthes sensu lato, comprises the large section Micranthes, as well as the segregate genus Cascadia, and S. tolmiei of section Merkianae. This clade is allied with the Heuchera, Darmera, and Chrysosplenium-Peltoboykinia groups of genera. The segregate genus Saxifragopsis is only distantly related to species of Saxifraga, and is instead the sister to Astilbe. The monotypic Oresitrophe is confirmed as a member of the Darmera group of genera. These results suggest that the floral features used to define Saxifraga may simply be symplesiomorphic in these well-separated Saxifraga lineages. Furthermore, the enormous cytological diversity encompassed by Saxifraga likely represents two independent instances of extensive aneuploidy and polyploidy in Saxifragaceae. Identifiant : DOI : 10.1002/j.1537-2197.1996.tb12717.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=138298
in American Journal of Botany > 83 (3) (1996) . - 371-382Soltis, Douglas E. (1953-), Kuzoff, Robert, Conti, Elena, Gornall, Richard, Ferguson, Keith 1996 MatK and rbcL gene sequence data indicate that Saxifraga (Saxifragaceae) is polyphyletic. American Journal of Botany, 83(3): 371-382.Documents numériques
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article (1996)URL
Titre : Molecular evidence for polyploid origins in Saxifraga (Saxifragaceae) : the narrow arctic endemic S. svalbardensis and its widespread allies Type de document : Imprimé Auteurs : Christian Brochmann (1953-) ; Xiang ; Brunsfeld ; Douglas E. Soltis (1953-) ; Pamela S. Soltis (1957-) Année de publication : 1998 Article en page(s) : 135-143 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Variabilité, analyse de l'ADN, polymorphisme Mots-clés : Saxifraga Saxifraga svalbardensis Résumé : The recently described polyploid Saxifraga svalbardensis is endemic to the arctic archipelago of Svalbard. We investigated relationships among four closely related species of Saxifraga in Svalbard and tested three previously proposed hypotheses for the origin of S. svalbardensis: (1) differentiation from the morphologically and chromosomally variable polyploid S. cernua; (2) hybridization between the diploid S. hyperborea and S. cernua; and (3) hybridization between the tetraploid S. rivularis and S. cernua. Fifteen populations were analyzed using random amplified polymorphic DNAs (RAPDs) and nucleotide sequences of the chloroplast gene matK and the internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA). RAPD and matK data suggest that S. svalbardensis has originated from a hybrid with S. rivularis as the maternal parent and S. cernua as the paternal parent, possibly a single time, whereas ITS data could not be used to discriminate among the hypotheses. The data also suggest that the diploid S. hyperborea is a progenitor of the tetraploid S. rivularis. The four populations examined of S. svalbardensis were virtually identical for RAPD and ITS markers, whereas S. cernua showed high levels of variation, suggesting that the latter polyploid either has formed recurrently or has undergone considerable differentiation since its origin. Identifiant : DOI : 10.2307/2446562 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=138291
in American Journal of Botany > 85 (7) (07/1998) . - 135-143Brochmann, Christian (1953-), Xiang, Brunsfeld, Soltis, Douglas E. (1953-), Soltis, Pamela S. (1957-) 1998 Molecular evidence for polyploid origins in Saxifraga (Saxifragaceae) : the narrow arctic endemic S. svalbardensis and its widespread allies. American Journal of Botany, 85(7): 135-143.Documents numériques
Article (1998)URL
Titre : Phylogenetic inference in Saxifragaceae sensu stricto en Gilia (Polemoniaceae) using matK sequences Type de document : Imprimé Auteurs : Leigh A. Johnson ; Douglas E. Soltis (1953-) Année de publication : 1995 Article en page(s) : 149-175 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Phylogénie (liens existant entre espèces apparentées)
[CBNPMP-Thématique] Variabilité, analyse de l'ADN, polymorphismeEn ligne : https://www.biodiversitylibrary.org/page/27995517 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=138296
in Annals of the Missouri Botanical Garden > 82 (1995) . - 149-175Johnson, Leigh A., Soltis, Douglas E. (1953-) 1995 Phylogenetic inference in Saxifragaceae sensu stricto en Gilia (Polemoniaceae) using matK sequences. Annals of the Missouri Botanical Garden, 82: 149-175.
Titre : Phylogenic relationships in tribe Cardueae (Asteraceae) based on ITS sequences Type de document : Imprimé Auteurs : Alfonso Susanna de la Serna (1955-) ; Núria Garcia-Jacas ; Douglas E. Soltis (1953-) ; Pamela S. Soltis (1957-) Année de publication : 1995 Article en page(s) : 1056-1068 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Phylogénie (liens existant entre espèces apparentées)
[CBNPMP-Thématique] Variabilité, analyse de l'ADN, polymorphismeRésumé : The Cardueae pose vexing systematic problems at several taxonomic levels. Tribal delimitation is controversial, with views ranging from a broadly defined Cardueae comprising subtribes Echinopsidinae, Carlininae, Carduinae, and Centaureinae to a more restrictive Cardueae (comprising only Carduinae and Centaureinae) with tribal rank also given to Echinopsideae (or Echinopeae) and Carlineae. Furthermore, the circumscription of groups within a broad Cardueae is also controversial, with divergent views emphasizing differences in floral or achene morphology; the distinction between Carduinae and Centaureinae is particularly weak. The generic limits of Centaurea, comprising 500–600 species and great diversity in both chromosome number and pollen morphology, are also unclear. Patterns of morphological, chromosomal, and pollen diversity in Centaurea do not completely support either the current taxonomy or any of the proposed modifications. Clearly, the Cardueae in general and Centaurea in particular require a phylogenetic approach to resolve problems of taxonomic circumscription and rank and to understand patterns of pollen and chromosomal evolution. We therefore analyzed DNA sequences of the internal transcribed spacers (ITS) of the nuclear ribosomal RNA genes (rDNA) of 35 taxa to reconstruct the phylogeny of Cardueae and assess 1) the positions of Echinopsidinae and Carlininae, 2) the circumscription of the Carduinae-Centaureinae complex, and 3) the limits of Centaurea and related genera. Phylogenetic analysis of ITS sequence variation strongly supports the monophyly of Cardueae relative to outgroup taxa from Mutisieae and Cichorieae. Both Carlininae and Echinopsidinae occupy basal branches in Cardueae. Carduinae are paraphyletic, forming a basal grade in the tribe. The Centaureinae, however, form a well-supported clade. As typically circumscribed, Centaurea is paraphyletic, comprising species of several other genera in addition to those currently recognized as Centaurea. Proposed evolutionary trends in pollen morphology and, to a lesser extent, base chromosome numbers are largely supported by the ITS phylogeny for Cardueae. Identifiant : DOI : 10.1002/j.1537-2197.1995.tb11571.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=138299
in American Journal of Botany > 82 (8) (1995) . - 1056-1068Susanna de la Serna, Alfonso (1955-), Garcia-Jacas, Núria, Soltis, Douglas E. (1953-), Soltis, Pamela S. (1957-) 1995 Phylogenic relationships in tribe Cardueae (Asteraceae) based on ITS sequences. American Journal of Botany, 82(8): 1056-1068.Documents numériques
article (1995)URL
Titre : The distribution of selfing rates in homosporous ferns Type de document : Imprimé Auteurs : Douglas E. Soltis (1953-) ; Pamela S. Soltis (1957-) Année de publication : 1992 Article en page(s) : 97-100 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Biologie de la reproduction
[CBNPMP-Thématique] Ptéridophytes, fougèresMots-clés : Dryopteris Résumé : The models of Lande and Schemske predict that among species in which the selfing rate is largely under genetic control and not subject to tremendous environmental variation, the distribution of selfing rates should be bimodal. When this prediction was tested empirically using data from the literature for species of angiosperms and gymnosperms, the distribution of outcrossing rates for all species was clearly bimodal. To provide another empirical test of the prediction, we analyzed mating-system data for 20 species of Pteridophyta (ferns). Homosporous ferns and their allies are unique among vascular plants because three types of mating are possible: intragametophytic selfing (selfing of an individual gametophyte); intergametophytic selfing (analogous to selfing in seed plants); and intergametophytic crossing (analogous to outcrossing in seed plants). The distribution of intragametophytic selfing rates among species of homosporous ferns is clearly uneven. Most species of homosporous ferns would be classified as extreme outcrossers. In contrast, a few species are nearly exclusively inbreeding. In only a few populations of Dryopteris expansa and Hemionitis palmata and a single population of Blechnum spicant do we see convincing evidence of a mixed mating system. The uneven distribution of selfing rates we observed for homosporous ferns, coupled with a corresponding bimodality of the magnitude of genetic load, strongly supports the model. Identifiant : DOI : 10.1002/j.1537-2197.1992.tb12628.x Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=137523
in American Journal of Botany > 79 (1) (1992) . - 97-100Soltis, Douglas E. (1953-), Soltis, Pamela S. (1957-) 1992 The distribution of selfing rates in homosporous ferns. American Journal of Botany, 79(1): 97-100.Documents numériques
article (1992)URL
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