Abstract:

To advance molecular marker-assisted breeding of high yellow pigment (YP) wheat, this study validated the effectiveness of molecular markers associated with key enzymes (PSY, PDS, ZDS, and LCYE) in the YP biosynthesis pathway and oxidative enzymes (LOX, POD) responsible for flour bleaching. This was achieved by measuring flour YP content in 46 wheat varieties (lines). Functional markers YP7A and YP7B2 at the Psy-A1 and Psy-B1 loci, as well as dominant complementary functional markers LOX16 and LOX18 at the Lox-B1 locus, detected distinct allelic variations across the 46 wheat varieties (lines). The differences in mean flour YP content between these allelic variants reached highly significant levels (P<0.01). However, codominant functional markers YP4B1 and YP4B2 at the Pds-B1 locus showed no significant correlation (P=0.063) between allelic variations and flour YP content. Similarly, codominant functional markers POD3A1 and POD3A2 at the Pod-A1 locus revealed no significant differences in YP content between allelic variants, though Pod-A1a materials (low POD activity) exhibited slightly higher mean YP content compared to Pod-A1b materials (high POD activity). Functional markers YP7A, YP7B2, LOX16, and LOX18 are recommended for molecular marker-assisted breeding of high-yellow pigment wheat, whereas codominant markers YP4B1, YP4B2, POD3A1, and POD3A2 should be applied cautiously in such breeding programs.

Key words: wheat, yellow-pigment content, yellow-pigment related gene, molecular marker, allelic variation, marker-assisted breeding