Monday, November 5, 2007 - 2:15 PM
80-3
Comparative and Translational Genomics Strategies for Breaking the Domestication Bottleneck and Problem Solving in Hybrid Sunflower Breeding Programs.
Steve Knapp, University of Georgia, Center for Applied Genetic Technologies, 111 Riverbend Road, Athens, GA 30602
The genomics revolution has supplied the technology and strategies for cataloging allelic diversity, identifying functionally important DNA polymorphisms and loci and elucidating genetic mechanisms underlying economically important traits, and sequencing genomes on a scale previously not envisioned in plants. Here, we highlight the role genomics has played in understanding the nature and structure of allelic diversity in elite and exotic germplasm, identifying novel alleles not found in elite single-cross hybrids, broadening genetic diversity and transferring novel alleles across species barriers, elucidating the genetics of economically important traits, and supplying DNA polymorphisms for enhancing marker-assisted selection (MAS) in sunflower. While the number of functionally important DNA polymorphisms and phenotypic-genotypic associations are ever increasing in sunflower and other economically important plants, the simultaneous manipulation of numerous loci affecting multiple complex traits through MAS is still enormously challenging because the scale of analysis required for identifying recombinants is often inadequate and cost-prohibitive, the usual suspects (e.g., genotype by environment interactions) complicate selection and the design and implementation of MAS beyond simple trait loci and large-effect QTL, and, when linked loci are under selection, progress can only be achieved by introducing repulsion linkages and breaking and reconstituting coupling linkages built up through several generations of selection. Genomics advances should yield an increasingly greater understanding and resolution of loci necessary for identifying recombinants and building ‘designer’ genotypes through MAS.