Combining ability of carrot (Daucus carota L.) lines and heritability of yield and its quality components

The purpose of this research was to investigate the combining ability of inbred lines in terms of traits important for the development of hybrid carrot cultivars with high yields and better root quality. The experimental plant material consisted of 15 inbred lines that were crossed in an incomplete diallel design to produce 34 hybrids. It was observed that the variation of general combining ability (GCA), specific combining ability (SCA) and reciprocal effects (RE) were significant for all of the tested characters, except SCA for sugars. Among the tested lines, the RFO had the most positive GCA for the yield; at the some time, the RFO line had negative GCA for carotenes and dry matter content. A significant positive GCA was found for all traits, except monosaccharides and nitrates, for the 2163 line. Most of the crosses based on the RFO and 2163 lines yielded well; additionally, the hybrids based on 2163 presented high levels of quality characters. The ratio of GCA:SCA indicated that the quality traits were mainly affected by additive gene effects, but the yield was controlled more by non-additive gene effects. Heritability in a broad sense presented a higher environmental influence for yield than the quality characters of carrot roots.