Karyotypic studies in the genus Crotalaria Linn.

Abstract

Karyotypic analyses were made using root tip mitoses in 29 collections representing 27 species of the genus Crotalaria (Leguminosae). It was found that karyotype asymmetry was of a low order. It was also concluded that if C. incana with 2n=14 is derived from the taxa having 2n=16, a secondary trend from asymmetric to symmetric karyotype will have to be presumed. Since karyotypic differences could be found within a species, minor differences in karyotype should not be considered to have a strong bearing on taxonomy without giving due consideration to morphological differences.It was concluded that evolution in the genus must have taken place due to changes in individual genes or gene complexes due to mutations or gene recombinations. Structural changes in chromosomes, if any, did not change the karyotypes in any significant manner.