Intraspecific Karyotypic Variability Among Accessions ofPsoralea corylifoliaL.-A Medicinally Important Plant

Abstract

Psoralea corylifolia L. is a traditional healer used in skin diseases of human beings. The karyotypes of 8 accessions of P. corylifolia L. were examined to explore the intrapopulation chromosome structural variations. Although all the accessions exhibited a chromosome number of 2n=22, they could be differentiated by their karyotype formulae and quantitative parameters of the karyotypes. Significant differences were noted among accessions in the number of metacentric, submetacentric and subtelocentric chromosomes, chromosome length, total haploid complement, arm ratio and centromeric index. Accession IC 111239 showed highest tendency towards karyotype symmetry, whereas accession IC 11228 presented the most asymmetrical nature confirming more heterogeneity. The present investigation also traces for the first time structural chromosomal polymorphism among P. corylifolia accessions, and emphasizes the possible mechanisms underlying the origin and establishment of this variation. The widespread karyotypic variability seems to have originated through repeated interchanges involving a number of non-homologous chromosomes. Phenetic representation of genetic relationship on the basis of karyotype data separated the accessions in two groups, which reveal intraspecific chromosome polymorphism.