Identification of QTL for carotenoid pigment and yellow color in durum wheat.

RONCALLO, P.F.; CERVIGNI, G.; AKKIRAJU P; GOMEZ P; CARRERA, A.; MIRANDA R; HELGUERA, M.; VIVIANA ECHENIQUE

Saint Louis, Missouri, US

Congreso; 9th International Plant Molecular Biology Congress (IPMB); 2009

The desirable bright yellow colour of durum wheat grain and pasta products is due to the presence of carotenoid pigments and their enzymatic degradation by lipoxygenases. The aim of this work was to map quantitative trait loci (QTL) associated with carotenoid pigment content (CPC) and bright yellow color in durum wheat. A mapping population of 93 RILs derived from the cross between the variety Kofa (high color) and the line UC1113 (intermediate color) was evaluated during two consecutive years 2006 and 2007 in three environments of Argentina (Cabildo, Barrow and Balcarce). A randomized complete block design with three replicates was used. Whole meal samples were analyzed for CPC using a microtest and yellow color was evaluated with a colorimeter Minolta. QTL was identified using CIM method on a framework of 269 genetic markers map. The genotype effect was strong and highly significant for both traits. CPC and yellow color showed high narrow sense heritability in each environment (h2 >0.95). A high number of significant QTL related to the CPC and yellow color were identified, mostly located on chromosomes 1BL, 2AS, 4AL, 5AS, 5AL 5BL, 6AL, 7AS, 7AL, 7BS, 7BL. A new QTL was identified on the short arm of chromosome 7A associated to the CPC and yellow color. ANOVA analyses showed that 1BL, 4AL, 6AL and 7BL QTL have significant interaction effects. The QTL found in chromosome 6AL explained most of the phenotypic variation for both traits and their flanking markers could be efficiently used to select superior genotypes.