QTLs for Semolina and Pasta Color in Durum Wheat

ZHANG, W.; CERVIGNI, G.; CARRERA, A.; PICCA, A.; VIVIANA ECHENIQUE; MANTHEY, F.Y7; HELGUERA, M.; CHAO, S.; DUBCOVSKY, J.

San Diego, California

Conferencia; XIV Plant and Animal Genome Conference; 2006

Technical Abstract: Bright yellow color is an important factor for the production of good-quality pasta products. Pasta color depends on the abundance of carotenoid pigments in the grain and on the loss of these pigments during processing, due mainly to the activity of lipoxygenases (LOX). A population of recombinant inbred lines (RIL) was produced by crossing the durum wheat experimental line UC1113 (intermediate color values) with the good yellow color variety Kofa. A total of 228 molecular markers were arranged on 14 linkage groups covering a total length of 1780-cM. LOX activity, semolina color and dry pasta color were measured in each line for two years and the averages were used for QTL analysis. Using Composite Interval Mapping (CIM), we identified one QTL for LOX activity, three for semolina color, and four for pasta color. The major QTL for LOX activity was detected on chromosome 4B, with a peak at the XLpx-B1 locus. Plants carrying the Kofa allele showed a 70% decrease in LOX activity relative to plants with the UC1113 allele. The XLpx-B1 locus also has a significant effect on dry pasta color but not on semolina color. Three additional QTLs were identified in chromosomes 1B, 6A, and 7A that simultaneously affect dry pasta and semolina color; suggesting that they were associated with the amount of yellow pigment in the grain rather than with its degradation during pasta production. The results from a factorial ANOVA using the alleles at each of the four QTL loci as factors confirmed the CIM results.