Cytogenetic Studies in Mexican Populations of Species of Crotalaria L. (Leguminosae-Papilionoideae).

Abstract

Chromosome numbers and karyotypes of four Mexican species of Crotalaria are reported. A new cytotype for C. spectabilis (2n=16) was found, characterized by the presence of two metacentric chromosomes with a satellite. C. longirostrata and C. pumila had similar karyotypes 2n=32. C. incana two difierent cytotypes were observed for the Mexican populations: the first, 8m+6sm with satellites in two pairs of submetacentric chromosomes and the second with an additional pair of metacentrics with double constrictions. Differences between the meiotic behavior of the two cytotypes are reported and the chiasmata frequency and recombination index are given. A spontaneous formation of subchromatic bridges in AI in the four populations of C. incana was found, these being the first records for the genus Crotalaria.