Heterosis and Combining Ability Studies in Sorghum (Sorghum bicolor (L.) Moench) Over the Environments

In the field of plant breeding, the most important breakthrough has been considered as ‘heterosis’. Exploitation of heterosis on commercial scale and the systematic varietal improvement through hybridization are the main tools to increase the sorghum production. The success in the development of superior hybrids and/or varieties depends on the choice of parents for hybridization and amount and type of genetic variability present in the base population to be improved. Verma and Kumar (1974) and Joshi (1979) emphasized that greater attention should be paid on the choice of parents for hybridization. This should be based not only on per se performance, as has been done generally, but also on adaptability, genetic diversity, and combining ability. Selection of parents for hybridization can be made with the help of combining ability analysis (Sprague and Tatum, 1942).