TY  - PRO
AU  - Herrera-Foessel,S.A.
AU  - D Singh,D.
AU  - Huerta-Espino,J.
AU  - Burgueño,J.
AU  - Singh,R.P.
AU  - Dreisigacker,S.
AU  - Bhavani,S.
AU  - Pawan Kumar Singh
AU  - Crossa,J.
TI  - Identification of chromosomal regions determining leaf rust, yellow rust and stem rust resistances in CIMMYT germplasm through association mapping
PY  - 2009///
N1  - Poster Abstract
N2  - A historical set of 170 bread wheat (Triticum  aestivum) lines originating from the CIMMYT 1st, 6th, 10th, 20th and 24th elite spring wheat yield trials (ESWYT) were evaluated for resistance to leaf rust (LR) (caused by Puccinia triticina) and stripe rust (YR) (P. striiformis f. sp. tritici) in field trials established in Mexico in 2007, and to stem rust (SR) (P. graminis f. sp. tritici) in Kenya in the off- and main seasons in 2008 under high disease pressure using prevalent races. In addition, leaf rust resistance genes present in these wheat lines were postulated from seedling reaction data obtained in the greenhouse using 13 Mexican P. triticina races. The ESWYT set was used previously for identifying genomic regions associated with resistance to the three rusts and other traits utilizing phenotypic data collected between 1979 and 2004, and genotypic data generated through Diversity Array Technology markers (DArTs) (813 in total) together with 831 other markers. In this study, association analyses were conducted using new rust data and the previously available genotypic data. We used the mixed model for association analyses incorporating the relationship matrix comprising the coefficients of parentage among lines and the population structures. This increases the power of detecting more reliable marker-trait associations. Results reveal that markers identified to be associated with resistance to all three rusts were located on chromosome arms 1AS, 1AL, 3BS, 3BL, 4AL, 4BL, 5BS, 5BL, 6BS, 7AS, 7BL, and 7DS. Additional markers associated with rust resistance were located on the short arms of 1B (LR, YR), 2A (YR), 2B (SR), 2D (LR), 4B (LR, SR), 4D (LR), 5A (YR), 6A (SR), 7B (SR), and on the long arms of 1B (YR, SR), 1D (YR, SR), 2A (SR), 2B (LR, SR), 3A (LR, SR), 5A (LR), 6A (LR, SR), and 7A (LR, SR). The identified genomic regions carrying resistance genes are being verified through further genetic analyses
ER  -