The effectiveness of phenotypic characters for characterization and evaluation of dissimilarity, and the genetic distance among improved carrot populations and cultivars were observed. The essays were carried out in Brasília, Brazil. Three improved carrot populations (712467, 712473 and 712464), and three cultivars (Brasília, BRS Esplanada and BRS Planalto) belonging to the Brasília group, were evaluated in the summers of 2008, 2009, 2010, in a complete randomized block design with two replications and plots of 1 m². At 100 days after sowing, in each plot, 25 roots were harvested and evaluated individually for diameter of root xylem, and some characters that are part of the standard descriptors and protection of carrot cultivars. We performed estimates of repeatability and the necessary number of evaluations to characterize the populations, the phenotypic and genotypic dissimilarity, and the coefficients of determination (R²) according to different numbers of evaluations. Except for the character root tip format, the other characters studied which are part of the standard descriptors of carrot, are not effective to both processes of characterization and distinction of carrot populations belonging to Brasília group. It is not expect to occur great heterotic effects when crossing the processing populations BRS Esplanada and 712464. For the in natura cultivars evaluated, it may be possible to obtain heterotic effects only when the Brasília cultivar is used in the crosses.
Daucus carota; plant variety protection; repeatability
