The karyotype of Nothoscordum arenarium Herter (Gilliesioideae, Alliaceae): a populational and cytomolecular analysis
| Autor: | Helga Winge, Marcelo Guerra, Luiz Gustavo Rodrigues Souza, Orfeo Crosa |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: |
lcsh:QH426-470
Heterochromatin Population Robertsonian translocation Chromosomal translocation CMA/DAPI staining medicine.disease_cause Plant Genetics Polyploid Centromere Genetics medicine education Molecular Biology education.field_of_study Heterocromatina biology heterochromatin Karyotype biology.organism_classification 5S and 45S rDNA lcsh:Genetics Nothoscordum Research Article América do Sul |
| Zdroj: | Genetics and Molecular Biology v.32 n.1 2009 Genetics and Molecular Biology Sociedade Brasileira de Genética (SBG) instacron:SBG Repositório Institucional da UFRGS Universidade Federal do Rio Grande do Sul (UFRGS) instacron:UFRGS Genetics and Molecular Biology, Vol 32, Iss 1, Pp 111-116 (2009) Scopus-Elsevier Genetics and Molecular Biology, Volume: 32, Issue: 1, Pages: 111-116, Published: 23 JAN 2009 |
| Popis: | The genus Nothoscordum Kunth comprises approximately 20 species native to South America. Karyologically, the genus is remarkable for its large chromosomes and Robertsonian translocations. Variation in chromosome number has been recorded in a few polyploid species and it is unknown among diploids. This study presents the chromosome number and morphology of 53 individuals of seven populations of N. arenarium Herter (2n = 10). In addition, karyotype analyses after C-banding, staining with CMA and DAPI, and in situ hybridization with 5S and 45S rDNA probes were performed in six individuals from one population. All individuals exhibited 2n = 10 (6M + 4A), except for one tetraploid (2n = 20, 12M + 8A) and one triploid (2n = 15, 9M + 6A) plant. C-banding revealed the presence of CMA(+) /DAPI (-) heterochromatin in the short arm and in the proximal region of the long arm of all acrocentric chromosomes. The 45S rDNA sites co-localized with the CMA (+) regions of the acrocentrics short arms, while the 5S rDNA probe only hybridized with the subterminal region of a pair of metacentric chromosomes. A change in the pattern of CMA bands and rDNA sites was observed in only one individual bearing a reciprocal translocation involving the long arm of a metacentric and the long arm of an acrocentric chromosome. These data suggest that, despite isolated cases of polyploidy and translocation, the karyotype of N. arenarium is very stable and the karyotypic instability described for other species may be associated with their polyploid condition. |
| Databáze: | OpenAIRE |
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