Diversidade da Heterocromatina na subtribo Laeliinae (Epidendroideae: Orchidaceae), com ênfase no gênero Cattleya Lindl.

• Ano de defesa: 2015
• Autor(a) principal: Souza, Bruno César Querino de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraíba; Brasil; Fitotecnia e Ciências Ambientais; Programa de Pós-Graduação em Agronomia; UFPB
• Palavras-chave em Português: Laeliinae; Heterochromatic; Cattleya; Heterocromatica; Conteúdo de DNA nuclear; Nuclear DNA content; CIENCIAS AGRARIAS::AGRONOMIA
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/tede/8228

The subtribe Laeliinae comprises about 2000 species in 38 genera, exclusively neotropical and is considered the third largest family of subtribe. Cytological features most species with basic chromosome number x = 20 and karyotype evolution mainly associated with polyploidy. This study aimed performed a comparative cytogenetic analysis in 42 species of Laeliinae subtribe based on banding fluorochromes with CMA/DAPI, and estimate the nuclear DNA content of many of these species through citmetria of flow. All species presented 2n = 40 except Cattleya nobilior with 2n = 42 and the polyploid C. elongata, C. crispata, Encyclia alboxanthina, E. jenischiana, E. seidelii, Laelia gouldiana and Prosthechea faresiana (2n = 80). We observed two blocks CMA+/DAPI terminals in all species. The DNA content of species ranged from 2C = 3.45 pg in Brassavola nodosa to 2C = 7.96 pg in C. guttata. The leaf tissues of the analyzed representatives presented endoreduplication cycles in most species. Our data suggest that although it occurs an apparent macrostructural stable karyotype (2n = 40) in the species of the subtribe Laeliinae as well as the genus Cattleya studied, they present a pattern of diversification of heterochromatin consistent with the phylogenetic clusters and identify possible sinapomorphies that allow better understanding of taxonomically complex species.