IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
artículos
Título:
Classical and molecular cytogenetics and DNA content in Maihuenia and Pereskia (Cactaceae)
Autor/es:
LAS PEÑAS M. L.; URDAMPILLETA J. D.; LOPEZ-CARRO B.; SANTIÑAQUE F.; KIESLING R.; BERNARDELLO G.
Revista:
PLANT SYSTEMATICS AND EVOLUTION
Editorial:
SPRINGER WIEN
Referencias:
Lugar: Viena; Año: 2014 vol. 300 p. 549 - 558
ISSN:
0378-2697
Resumen:
The family Cactaceae is divided into four subfamilies. We studied species of the subfamilies Pereskioideae (five species of the southern clade) and all species of Maihuenioideae using molecular cytogenetic techniques and DNA content. Mitotic chromosomes were analyzed for Pereskia aculeata, P. bahiensis, P. grandifolia, P. nemorosa, P. sacharosa, Maihuenia poepeggii, and M. patagonica, using the Feulgen technique, CMA/DAPI fluorescent chromosome banding, fluorescence in situ hybridization (FISH, probes of 5S rDNA and pTa71 for 18-5.8-26S rDNA), and DNA content by flow cytometry (FC) technique. The karyotypes were highly symmetrical, most of the pairs being m. CMA/DAPI banding revealed the presence of CMA+/DAPI- bands associated with NORs in the first m pair of all species. The co-localization of 18-5.8-26S rDNA loci with CMA+/DAPI-/NORs blocks allowed the identification of homeologous chromosome pairs between species of both subfamilies. FISH using probe 5S rDNA was applied for the first time in two subfamilies of Cactaceae. Diploid species had always one m pair carrying 5S rDNA genes, with pericentromeric location in different chromosome pairs. In the tetraploid cytotype of M. patagonica, the 5S rDNA probe hybridized to two pairs. The 2C DNA content obtained by FC varied two-fold (from 1.85 to 2.52 pg), with significant differences between species. Karyotype analysis allowed us to detect slight differences between the taxa examined, indicating that speciation would be accompanied by small changes in karyotype structure. However, karyotypes can be distinguished by a combination of cytogenetic features. Our results showed that both genera are closely related, although no data are available about the Northern Pereskioideae.