Synergy of empirical breeding, marker-assisted selection, and genomics to increase crop yield potential

This paper was presented as part of the symposium entitled "Post-Green Revolution Trends in Crop Yield Potential: Increasing, Stagnant or Greater Resistance to Stress." In this presentation, we have focused on (i) uses of marker technology in determining the genetic basis of phenotypic expression and the manipulation of phenotypic variation in plants. This included the use of markers in understanding heterosis, in attempts to improve hybrid predictions, in quantitative trait locus (QTL) identification and mapping, in marker-assisted selection (MAS), and in enhancing breeding success in the development of improved lines and hybrids; (ii) the role of genomics in developing a precise understanding of the genetic basis of phenotypic expression which will then provide more precision in the manipulation of phenotypic variation; and (iii) some attempts to integrate marker technology and genomics into empirical breeding strategies. In addition, we have focused on what has been successful as well as what has fallen short of expectations, and have suggested some of the possible reasons for the lack of success. Because of page limitations, we could not include an exhaustive review of the plant literature and have limited many of our examples to investigations in maize (Zea mays L).