Selection of carrot genotypes for phenotypic root characters

We studied the efficiency of selecting carrot genotypes based on phenotypic root characters. Eleven genotypes were evaluated, which included four breeding populations (09; 14; 16 and 17), one open-pollinated cultivar (BRS Planalto), five experimental hybrids (17; 20; 03; 27 and 31) and a commercial hybrid (Juliana). The experiment was carried out during the summer crop of 2014 (sown January 30th and harvested after 113 days) in Uberlandia, Minas Gerais State, Brazil. A randomized block design with four replications was used. We estimated genotypic values, direct gains, the effect of direct selection on other characters, and gains related to the selection index of the distance to the biotype. We determined that the simultaneous selection of total root mass, commercially-viable root mass, root diameter, high percentage of cylindrical roots, high percentage of roots without green shoulders and high percentage of dark-orange roots led to positive gains in all characters. Direct selection produced the greatest gains in each character; however, total root mass, percentage of cylindrical roots, percentage of roots without green shoulders and percentage of dark-orange roots led to lower gains in other characters. The best genotypes considering all characters were populations 14, 16 and 17.