Genetic variation for glutenin and gliadins associated with quality in durum wheat (Triticum turgidum L. ssp. turgidum) landraces from Spain

The allelic variation at seven prolamin loci involved in quality has been studied in a set of durum wheat landraces from all the Spanish regions where this crop has been traditionally cultivated. The genetic variability was higher than that found in other germplasm collections. All the loci, except Glu-B2, displayed a genetic variability higher than 0.62, with Glu-3 the most polymorphic. In total, five alleles were studied at Glu-A1, nine at Glu-B1, 15 at Glu-A3, 18 at Glu-B3, two at GluB2, and eight at Gli-A1 and Gli-B1. New allelic variants not previously identified in durum wheat were detected. The 30 different genotypes of B low-molecular-weight (B-LMW) glutenin subunits analysed, of which 25 are novel, provide an important source of genetic variability for quality breeding. Protein patterns for convars. durum and turgidum, and for the North and South of Spain were identified for the loci with significant influence on quality. Higher variability was observed in convar. turgidum and in the North zone than in convar. durum and the South, respectively, mainly for the Glu-B1 and Glu-B3. Also, convar. turgidum appeared to be a valuable source for new alleles for the LMW glutenin subunits. Wheats from the South were, however, more diverse for prolamins encoded at Glu-A3. Additional key words: convar. durum, convar. turgidum, germplasm, LMW patterns, prolamin alleles, quality breeding.