title: Karyotype characterization and evolution in South American species of Lathyrus (Notolathyrus, Leguminosae) evidenced by heterochromatin and rDNA mapping.
abstract: Notolathyrus is a section of South American endemic species of the genus Lathyrus. The origin, phylogenetic relationship and delimitation of some species are still controversial. The present study provides an exhaustive analysis of the karyotypes of approximately half (10) of the species recognized for section Notolathyrus and four outgroups (sections Lathyrus and Orobus) by cytogenetic mapping of heterochromatic bands and 45S and 5S rDNA loci. The bulk of the parameters analyzed here generated markers to identify most of the chromosomes in the complements of the analyzed species. Chromosome banding showed interspecific variation in the amount and distribution of heterochromatin, and together with the distribution of rDNA loci, allowed the characterization of all the species studied here. Additionally, some of the chromosome parameters described (st chromosomes and the 45S rDNA loci) constitute the first diagnostic characters for the Notolathyrus section. Evolutionary, chromosome data revealed that the South American species are a homogeneous group supporting the monophyly of the section. Variation in the amount of heterochromatin was not directly related to the variation in DNA content of the Notolathyrus species. However, the correlation observed between the amount of heterochromatin and some geographical and bioclimatic variables suggest that the variation in the heterochromatic fraction should have an adaptive value.
authors.affiliation: Instituto de Botánica del Nordeste (UNNE-CONICET), Facultad de Ciencias Agrarias, CC 209, 3400, Corrientes, Argentina. laurachalup@gmail.com.
authors.forename: Laura
authors.initials: L
authors.lastname: Chalup
authors.affiliation: Instituto de Botánica del Nordeste (UNNE-CONICET), Facultad de Ciencias Agrarias, CC 209, 3400, Corrientes, Argentina.
authors.forename: Sergio Sebastián
authors.initials: SS
authors.lastname: Samoluk
authors.affiliation: Instituto de Botánica del Nordeste (UNNE-CONICET), Facultad de Ciencias Agrarias, CC 209, 3400, Corrientes, Argentina.|Facultad de Ciencias Exactas y Naturales y Agrimensura (UNNE), Av. Libertad 5460, 3400, Corrientes, Argentina.
authors.forename: Viviana Solís
authors.initials: VS
authors.lastname: Neffa
authors.affiliation: Instituto de Botánica del Nordeste (UNNE-CONICET), Facultad de Ciencias Agrarias, CC 209, 3400, Corrientes, Argentina.|Facultad de Ciencias Exactas y Naturales y Agrimensura (UNNE), Av. Libertad 5460, 3400, Corrientes, Argentina.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Seijo
mesh_terms: D014128:Chromomycin A3 / Q000737:chemistry; D002874:Chromosome Mapping; D018744:DNA, Plant / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics*; D019143:Evolution, Molecular; D006570:Heterochromatin / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D007211:Indoles / Q000737:chemistry; D059785:Karyotype; D027807:Lathyrus / Q000145:classification / Q000235:genetics*; D013020:South America
chemical_list: D018744:DNA, Plant; D004275:DNA, Ribosomal; D006570:Heterochromatin; D007211:Indoles; C007293:DAPI; D014128:Chromomycin A3
keywords: Heterochromatin; Karyotype; Lathyrus; rDNA loci