Mapping and validation of a major QTL for yellow pigment content on 7AL in durum wheat (Triticum turgidum L. ssp durum)
Résumé
Yellow pigment content in durum wheat (Triticum turgidum L. ssp. durum) is an important criterion for both pasta bright yellow color and human health because of antioxidant properties of carotenoids involved in this pigmentation. In the present study, QTLs for yellow pigment content in durum wheat were mapped in a population of 140 RILs developed from a intraspecific cross between a released variety (PDW 233) and a landrace (Bhalegaon 4). This trait was evaluated in one location for 3 years and in two more locations for one additional year (five different year x location combinations further called "environments"). Yellow pigment content was highly heritable across the five different environments. Analysis of variance showed the significant effect of genotype, environment and genotype x environment interaction on the trait. Five different QTLs linked to yellow pigment content were identified on chromosome 1A, 3B, 5B, 7A and 7B across five different environments. The strongest one located on the distal part of the long arm of chromosome 7A, QYp.macs-7A, explained 55.22% of the variation in the trait, while, remaining four QTLs explained 5-8.75% of phenotypic variation in yellow pigment content. Marker analysis revealed significant association of one ISSR and one AFLP fragment with the trait. These two markers were linked to the major QTL QYp.macs-7A and were converted into SCAR markers. These SCAR markers were further validated on another population as well as 38 diverse genotypes so as to prove their potential in marker assisted selection. These markers will be very useful for the marker assisted breeding of durum wheat for higher yellow pigment content.