Estimation of genome size in Brachiaria species

Genome sizes of five cultivars of four Brachiaria species were estimated by flow cytometry to evaluate their utility as breeding material. Genome sizes expressed as C values differed among these cultivars (615-1953 Mbp C-1), increasing with increased ploidy level. Genome sizes given as Cx values were larger in apomictic polyploids (651-817 Mbp Cx-1) than in sexual diploids (615 Mbp Cx-1). Additionally, genome sizes expressed as Cx values tended to decrease with increasing ploidy levels in apomictic cultivars. Our findings indicate that genome size depends on ploidy level and reproductive mode in Brachiaria. The information is useful for research on the construction of DNA libraries, genetic maps, biodiversity and evolution of Brachiaria species.