The nuclear DNA content, the proportion of A+T base pairs, the chromosomal positions of 5S and 25S rRNA genes, as well as of DAPI (4',6-diamidino-2-phenylindole) bands are described for seven species belonging to three different sect ions of the genus Lathyrus. These data and chromosome measurements allowed to establish precise idiograms and to discriminate most of the chromosome pairs of the seven species. The karyotypic features correlate well with the phylogenetic distances between these species.Key words: Lathyrus karyotypes, 5S/25S rDNA loci, FISH, DAPI banding pattern, nuclear DNA content.
