Chromosome numbers and meiotic studies in species of Senecio (Asteraceae) from Argentina

Autores
López, Mariana G.; Wulff, Arturo F.; Poggio, Lidia; Xifreda, Cecilia Carmen
Año de publicación
2005
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Meiotic chromosome counts, chromosomal behaviour and meiotic configurations of ten taxa of Senecio from Argentina were examined. Most counts are original: S. crepidifolius DC., S. francisci Phil. and S. octolepis Griseb. var. saltensis (Hicken) Cabrera & Zardini have 2n = 40, and S. chrysolepis Phil., 2n = 80 + 8B. We confirmed previous reports for S. deferens Griseb. (2n = 40 + 4B), S. filaginoides DC. var. filaginoides (2n = 40), S. hieronymi Griseb. (2n = 40 + 7B), S. pampeanus Cabrera (2n = 40) and S. rudbeckiifolius Meyen & Walp. (2n = 40 + 7B). In S. bracteolatus Hook. & Arn. var. bracteolatus, we found a new number (2n = 40) that differs from the one cited previously. In four species, numerical polymorphisms for B-chromosomes were observed. Several of the analysed species presented secondary bivalent association. This phenomenon, together with other evidence, supports x = 5 as the basic chromosome number. The number of chiasmata and their positions were also surveyed, with the finding that open bivalents were the most frequent meiotic figures and terminal chiasmata the preferential position. These features are related to recombination rate, and the success and persistence of these polyploids. We discuss some systematic and evolutionary aspects in the light of cytogenetic data and conclude that polyploidy is the major force modelling the chromosome evolution within this genus. 
Laboratorio de Etnobotánica y Botánica Aplicada
Materia
Botánica
Basic chromosome number
Bivalent structure
Polyploidy
Recombination
Secondary association
Secondary cycle of polyploidy
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/137561

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oai_identifier_str oai:sedici.unlp.edu.ar:10915/137561
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network_name_str SEDICI (UNLP)
spelling Chromosome numbers and meiotic studies in species of Senecio (Asteraceae) from ArgentinaLópez, Mariana G.Wulff, Arturo F.Poggio, LidiaXifreda, Cecilia CarmenBotánicaBasic chromosome numberBivalent structurePolyploidyRecombinationSecondary associationSecondary cycle of polyploidyMeiotic chromosome counts, chromosomal behaviour and meiotic configurations of ten taxa of Senecio from Argentina were examined. Most counts are original: S. crepidifolius DC., S. francisci Phil. and S. octolepis Griseb. var. saltensis (Hicken) Cabrera & Zardini have 2n = 40, and S. chrysolepis Phil., 2n = 80 + 8B. We confirmed previous reports for S. deferens Griseb. (2n = 40 + 4B), S. filaginoides DC. var. filaginoides (2n = 40), S. hieronymi Griseb. (2n = 40 + 7B), S. pampeanus Cabrera (2n = 40) and S. rudbeckiifolius Meyen & Walp. (2n = 40 + 7B). In S. bracteolatus Hook. & Arn. var. bracteolatus, we found a new number (2n = 40) that differs from the one cited previously. In four species, numerical polymorphisms for B-chromosomes were observed. Several of the analysed species presented secondary bivalent association. This phenomenon, together with other evidence, supports x = 5 as the basic chromosome number. The number of chiasmata and their positions were also surveyed, with the finding that open bivalents were the most frequent meiotic figures and terminal chiasmata the preferential position. These features are related to recombination rate, and the success and persistence of these polyploids. We discuss some systematic and evolutionary aspects in the light of cytogenetic data and conclude that polyploidy is the major force modelling the chromosome evolution within this genus. Laboratorio de Etnobotánica y Botánica Aplicada2005info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf465-474http://sedici.unlp.edu.ar/handle/10915/137561enginfo:eu-repo/semantics/altIdentifier/issn/1095-8339info:eu-repo/semantics/altIdentifier/issn/0024-4074info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1095-8339.2005.00415.xinfo:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-10-15T11:24:14Zoai:sedici.unlp.edu.ar:10915/137561Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-10-15 11:24:15.125SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Chromosome numbers and meiotic studies in species of Senecio (Asteraceae) from Argentina
title Chromosome numbers and meiotic studies in species of Senecio (Asteraceae) from Argentina
spellingShingle Chromosome numbers and meiotic studies in species of Senecio (Asteraceae) from Argentina
López, Mariana G.
Botánica
Basic chromosome number
Bivalent structure
Polyploidy
Recombination
Secondary association
Secondary cycle of polyploidy
title_short Chromosome numbers and meiotic studies in species of Senecio (Asteraceae) from Argentina
title_full Chromosome numbers and meiotic studies in species of Senecio (Asteraceae) from Argentina
title_fullStr Chromosome numbers and meiotic studies in species of Senecio (Asteraceae) from Argentina
title_full_unstemmed Chromosome numbers and meiotic studies in species of Senecio (Asteraceae) from Argentina
title_sort Chromosome numbers and meiotic studies in species of Senecio (Asteraceae) from Argentina
dc.creator.none.fl_str_mv López, Mariana G.
Wulff, Arturo F.
Poggio, Lidia
Xifreda, Cecilia Carmen
author López, Mariana G.
author_facet López, Mariana G.
Wulff, Arturo F.
Poggio, Lidia
Xifreda, Cecilia Carmen
author_role author
author2 Wulff, Arturo F.
Poggio, Lidia
Xifreda, Cecilia Carmen
author2_role author
author
author
dc.subject.none.fl_str_mv Botánica
Basic chromosome number
Bivalent structure
Polyploidy
Recombination
Secondary association
Secondary cycle of polyploidy
topic Botánica
Basic chromosome number
Bivalent structure
Polyploidy
Recombination
Secondary association
Secondary cycle of polyploidy
dc.description.none.fl_txt_mv Meiotic chromosome counts, chromosomal behaviour and meiotic configurations of ten taxa of Senecio from Argentina were examined. Most counts are original: S. crepidifolius DC., S. francisci Phil. and S. octolepis Griseb. var. saltensis (Hicken) Cabrera & Zardini have 2n = 40, and S. chrysolepis Phil., 2n = 80 + 8B. We confirmed previous reports for S. deferens Griseb. (2n = 40 + 4B), S. filaginoides DC. var. filaginoides (2n = 40), S. hieronymi Griseb. (2n = 40 + 7B), S. pampeanus Cabrera (2n = 40) and S. rudbeckiifolius Meyen & Walp. (2n = 40 + 7B). In S. bracteolatus Hook. & Arn. var. bracteolatus, we found a new number (2n = 40) that differs from the one cited previously. In four species, numerical polymorphisms for B-chromosomes were observed. Several of the analysed species presented secondary bivalent association. This phenomenon, together with other evidence, supports x = 5 as the basic chromosome number. The number of chiasmata and their positions were also surveyed, with the finding that open bivalents were the most frequent meiotic figures and terminal chiasmata the preferential position. These features are related to recombination rate, and the success and persistence of these polyploids. We discuss some systematic and evolutionary aspects in the light of cytogenetic data and conclude that polyploidy is the major force modelling the chromosome evolution within this genus. 
Laboratorio de Etnobotánica y Botánica Aplicada
description Meiotic chromosome counts, chromosomal behaviour and meiotic configurations of ten taxa of Senecio from Argentina were examined. Most counts are original: S. crepidifolius DC., S. francisci Phil. and S. octolepis Griseb. var. saltensis (Hicken) Cabrera & Zardini have 2n = 40, and S. chrysolepis Phil., 2n = 80 + 8B. We confirmed previous reports for S. deferens Griseb. (2n = 40 + 4B), S. filaginoides DC. var. filaginoides (2n = 40), S. hieronymi Griseb. (2n = 40 + 7B), S. pampeanus Cabrera (2n = 40) and S. rudbeckiifolius Meyen & Walp. (2n = 40 + 7B). In S. bracteolatus Hook. & Arn. var. bracteolatus, we found a new number (2n = 40) that differs from the one cited previously. In four species, numerical polymorphisms for B-chromosomes were observed. Several of the analysed species presented secondary bivalent association. This phenomenon, together with other evidence, supports x = 5 as the basic chromosome number. The number of chiasmata and their positions were also surveyed, with the finding that open bivalents were the most frequent meiotic figures and terminal chiasmata the preferential position. These features are related to recombination rate, and the success and persistence of these polyploids. We discuss some systematic and evolutionary aspects in the light of cytogenetic data and conclude that polyploidy is the major force modelling the chromosome evolution within this genus. 
publishDate 2005
dc.date.none.fl_str_mv 2005
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info:eu-repo/semantics/publishedVersion
Articulo
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/137561
url http://sedici.unlp.edu.ar/handle/10915/137561
dc.language.none.fl_str_mv eng
language eng
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info:eu-repo/semantics/altIdentifier/issn/0024-4074
info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1095-8339.2005.00415.x
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
465-474
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