Los cariotipos de Cologania grandiflora y Erythrina americana (Leguminosaer Papilionoideae-Phaseoleae) de la Reserva Ecológica del Pedregal de San Ángel, México

Abstract

Meristematic root cells from Cologania grandiflora and Erythrina americana from Reserva Ecologica del Pedregal de San Angel, Distrito Federal, Mexico, were analyzed cytogenenetically using a surface-spreading and airdrying 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.