Resumen

TAPIA-PASTRANA, Fernando  y  JIMENEZ-SALAZAR, Anahid. Karyotypes of Cologania grandiflora and Erythrina americana (Leguminosae-Papilionoideae- Phaseoleae) of Reserva Ecológica del Pedregal de San Ángel, Mexico. Rev. Mex. Biodiv. [online]. 2011, vol.82, n.3, pp. 776-781. ISSN 1870-3453.

Meristematic root cells from Cologania grandiflora and Erythrina americana from Reserva Ecológica del Pedregal de San Ángel, Distrito Federal, Mexico, were analyzed cytogenenetically using a surface-spreading and air-drying method. The somatic chromosome numbers were determined. Chromosome morphology and others quantitative features of the karyotypes obtained for first time in C. grandiflora (2n= 44= 26m + 18sm) and E. americana (2n= 42= 36m + 4sm + 2st^sat) and also the first in both genera. Cologania and Erythrina are recognized as stabilized polyploids and the finding of just one pair of chromosomes with satellites (nucleolar dominance) in the species analyzed here supports the view of allopolyploid origin of these taxa.

Palabras llave : allopolyploid; karyotype; Cologania; Erythrina; satellites; surface-spreading and air-drying.