derived from contributes strong yellowness to durum wheat but may cause yield loss in Japan.

Strong yellow color, caused by carotenoid accumulation, in semolina flour made from durum wheat ( L. subsp. (Desf.)) is one of the most important traits for pasta production. The first step in the carotenoid biosynthesis pathway, which is catalyzed by phytoene synthase (PSY), is a bottleneck, and allelic variation of in durum wheat produces different yellow pigment contents (YPC) in seeds. Durum wheat carrying leaf rust resistance gene , which was translocated from wheat relative chromosome 7E to durum wheat chromosome 7A, is known to produce high YPC, and the causal gene is presumed to be , which is tightly linked to . In this study, produced higher YPC than alleles, such as , and , in durum wheat. Segregation analysis demonstrated that is located at the locus on chromosome 7A. In a 2-year field test of near-isogenic materials, was accompanied by yield loss with decreases in grain number per spike, test weight and thousand-kernel weight under moisture conditions typical of wheat-growing areas of Japan. Thus, has the potential to contribute high YPC in durum wheat breeding programs, although the applicable cultivation environments are limited.