Chromosome studies in Argentinian species of Stemodia L. (Scrophulariaceae)

Chromosome studies were carried out on 5 Argentinian species of Stemodia. First chromosome counts are presented for S. ericifolia (2n=22), S. lanceolata (2n=22), S. stricta (2n=44) and S. hyptoides (2n=66), while the number 2n=22 of S. verticillata is confirmed. These numbers constitute the first re...

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Detalles Bibliográficos
Autores: Sosa, María de las Mercedes, Seijo, José Guillermo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2002
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/39332
Acceso en línea:http://hdl.handle.net/11336/39332
Access Level:acceso abierto
Palabra clave:CHROMOSOME NUMBERS
KARYOTYPES
POLYPLOIDY
STEMODIA
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descripción
Sumario:Chromosome studies were carried out on 5 Argentinian species of Stemodia. First chromosome counts are presented for S. ericifolia (2n=22), S. lanceolata (2n=22), S. stricta (2n=44) and S. hyptoides (2n=66), while the number 2n=22 of S. verticillata is confirmed. These numbers constitute the first reports for South American species of Stemodia. In addition, the karyograms of S. lanceolata and S. verticillata are the first descriptions for the genus. Diploid species showed regular meiotic behaviour and pollen viability was high in all the accessions analysed. These results suggest that 2 different mechanisms would be implicated in chromosome diversification of Stemodia. The first one implicates variation in genome size with karyotype formulae conservation and the second, polyploidy. Chromosome data provided here are discussed in relation to growth habit, morphological characters and taxonomic position of the species.