Abstract
Thirty-one clover species with significant agronomic value, originating from Eurasia, Africa and America, were analyzed to reveal their nuclear DNA content and propidium iodide/4,6-diamidino-2-phenylindole (PI/DAPI) ratio. Chromosome numbers of the same accessions were determined for calculation of 1Cx genome size values, and the relationships between species were studied based on ITS-rDNA analysis. The nuclear DNA content of the majority of species was determined for the first time and revealed large variations among investigated species. The somatic nuclear DNA content ranged from 0.688 pg ( T. ligusticum) to 7.375 pg ( T. burchellianum), exhibiting a 10.7-fold difference. Since polyploidy is characteristic of several species of the genus Trifolium, 1Cx values provided the most informative measure of interspecific DNA content variation. Analysis of nuclear DNA content based on 1Cx-values within the Lotoidea section revealed that the basic genome size values of six African and American species were twice those of the six Eurasian species of the same section. Measurements of nuclear DNA content using propidium iodide/DAPI staining highly correlated ( r = 0.99), the average PI/DAPI ratio of 29 species was 1.043. Clustering based on ITS polymorphisms showed high relationship with botanical sections with the only exemption in the section Lotoidea, which was divided mainly according to its origin (American, African or Eurasian). Genome size data and the ITS clustering were highly correlated in sections Chronosemium, Involucrarium and Vesicaria and varied approximately two-fold within sections Trifolium, Lotoidea (African origin) and Lotoidea (Eurasian origin).
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call