Plant & Animal Genomes XVI Conference Plant & Animal Genomes XVI ConferenceJanuary 12-16, 2008
Town & Country Convention Center
San Diego, CA
José Crossa1, Juan Burgueño, Susanne Dreisigacker, Mateo Vargas, Sybil A. Herrera-Foessel, Morten Lillemo†, Ravi P. Singh, Richard Trethowan‡, Marilyn Warburton*, Jorge Franco¶, Matthew Reynolds*, Jonathan H. Crouch and Rodomiro Ortiz
International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6-641, 06600
México, D.F., Mexico.
† Department of Plant and Environmental Sciences, Norwegian Univ. of Life Sciences, P.O.
Box 5003, N-1432 Ås, Norway.
‡ University of Sydney, PMB 11, Camden NSW 2570, Australia.
¶ Facultad de Agronomía, Universidad de la República del Uruguay, Av. Garzón 780 CP 12900,
Montevideo, Uruguay.
ABSTRACT
Linkage disequilibrium can be used for identifying associations between traits of interest and genetic markers. This study used mapped Diversity Array Technology (DArT) markers to find associations with stem rust, leaf rust, yellow rust, powdery mildew, and grain yield in five historical wheat international multi-environment trials from the International Maize and Wheat Improvement Center (CIMMYT). Two linear mixed models were used to assess marker-trait associations incorporating information on population structure and covariance between relatives. An integrated map containing 813 DArT markers and 831 other markers was constructed. Several linkage disequilibrium clusters bearing multiple host plant resistance genes were found. Most of the associated markers were found in genomic regions where previous reports had found genes or quantitative trait loci (QTLs) encoding the same traits, and many new chromosome regions for host plant resistance and grain yield were identified in the wheat genome. Phenotyping across environments and years allowed modeling genotype environment interaction, thereby making possible the identification of markers contributing to both additive and additive additive interaction effects of traits.