Data/hora: 05/06/2024 08:46:53

Provedor de dados: | 74
País: | Brazil
Título: | Intrachromosomal karyotype asymmetry in Orchidaceae
Autores: | Medeiros-Neto,Enoque; Nollet,Felipe; Moraes,Ana Paula; Felix,Leonardo P.
Data: | 2017-09-01
Ano: | 2017
Palavras-chave: | Asymmetry index; Karyotype symmetry; Chromosome; Cytogenetic; Evolution.
Resumo: | Abstract The asymmetry indexes have helped cytotaxonomists to interpret and classify plant karyotypes for species delimitation efforts. However, there is no consensus about the best method to calculate the intrachromosomal asymmetry. The present study aimed to compare different intrachromosomal asymmetry indexes in order to indicate which are more efficient for the estimation of asymmetry in different groups of orchids. Besides, we aimed to compare our results with the Orchidaceae phylogenetic proposal to test the hypothesis of Stebbins (1971). Through a literature review, karyotypes were selected and analyzed comparatively with ideal karyotypes in a cluster analysis. All karyotypes showed some level of interchromosomal asymmetry, ranging from slightly asymmetric to moderately asymmetric. The five tested intrachromosomal asymmetry indexes indicated Sarcoglottis grandiflora as the species with the most symmetrical karyotype and Christensonella pachyphylla with the most asymmetrical karyotype. In the cluster analysis, the largest number of species were grouped with the intermediary ideal karyotypes B or C. Considering our results, we recommend the combined use of at least two indexes, especially Ask% or A1 with Syi, for cytotaxonomic analysis in groups of orchids. In an evolutionary perspective, our results support Stebbins’ hypothesis that asymmetric karyotypes derive from a symmetric karyotypes.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572017000400610
Editor: | Sociedade Brasileira de Genética
Relação: | 10.1590/1678-4685-gmb-2016-0264
Formato: | text/html
Fonte: | Genetics and Molecular Biology  v.40 n.3 2017
Fonte: | info:eu-repo/semantics/openAccess