Nuclear DNA amount variation in Cyamopsis D.C. (Fabaceae)

Abstract

In the present work 4C DNA amount has been determined in 3 species of Fabaceous genus Cyamopsis involving 14 accessions. At intraspecific level 10 collections of C. tetragonoloba, 2 collections each of C. senegalensis and C. serrata did not show any significant variation. Within the genus Cyamopsis, C. serrata possessing symmetrical karyotype is a primitive species with 20.35 pg of DNA and more advanced species having asymmetrical karyotype has 18.19 pg DNA and recently evolved cultivated crop species has 10.05 pg of DNA. Two fold DNA amount variation is apparent without any numerical changes in chromosome number, as all the Cyamopsis species share a common chromosome number of 2n=2x=14. Thus evolution of genome size within small African genus Cyamopsis has occurred through loss of DNA.