ARS | Publication request: Progressing from putative QTLs to marker assisted selection in breeding

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 1, 2003
Publication Date: November 1, 2003
Citation: McClung, A.M., Pinson, S.R., Shank, A.R., Chen, M., Bergman, C.J., Fjellstrom, R.G. 2003. Progressing from putative QTLs to marker assisted selection in breeding [abstract]. Agronomy Abstracts. 2003 CDROM.

Technical Abstract: Our goal has been to develop DNA markers for traits that are relevant to the development of commercial cultivars and can be used in narrow-based breeding programs. This process usually begins with identifying putative chromosomal regions that are associated with the trait of interest and have been identified in wide crosses used as mapping populations. These polymorphic regions are then tested across a survey germplasm known to differ for the trait of interest to see how broadly useful these markers may be. Then crosses using narrow-based parents that are polymorphic and differ for the trait are evaluated to fine-tune the markers. Our initial focus has been to develop markers for relatively simply inherited traits that are commonly used by breeders like semidwarfism, grain quality traits associated with conventional and specialty markets, photoperiodism, and race-specific disease resistance genes. We have worked with other public breeding programs to transfer this marker technology to them with the goal of enhancing selection efficiency and decreasing cultivar development time. These markers have been used to verify F1 progeny, expedite backcrossing, eliminate residual variability during seed purification, fingerprint common commercial cultivars and eliminate seed mixtures and outcrosses, discard progeny during early generations that do not possess desirable alleles, screen for traits during off-seasons, and select for genes that would be obscured by the environment or other genes. Our next goals will include developing markers for more complexly inherited and environmentally sensitive traits like seedling vigor, reduced water use efficiency and resistance to other diseases.