Nuclear DNA variation in Phaseolus

There are highly significant differences in nuclear DNA amount between eight species of Phaseolus; Phaseolus dumosus, for example has 60% more DNA than Phaseolus lathyroides. The total nuclear mass and the nucleolar mass also vary significantly between species but the ratios of DNA to the total mass and the nucleolar mass are constant throughout. © 1974 Springer-Verlag.