POLYMORPHISM OF OMEGA-GLIADINS IN DURUM-WHEAT AS REVEALED BY THE 2-STEP APAGE SDS-PAGE TECHNIQUE

Polymorphism of omega-gliadins was studied in 243 durum wheats from 27 countries using the two-step one-dimensional APAGE/SDS-PAGE technique . A total of 12 bands of different mobility were observed, and four of them were found to be different from those previously detected by Khe lfi et al. (1992) in bread wheat. Fifteen alleles, six coded by the Gl i-A1 locus and nine coded by the Gli-B1 locus, were identified, accoun ting for 19 different electrophoretic patterns. Seven new alleles were detected: two at the Gli-A1 locus and five at the Gli-B1 locus. The p olymorphism found at the GW-A1 and Gli-B1 loci was slightly greater th an that found in bread wheat. Allelic differences between both species were higher at the Gli-B1 locus. A comparison of the frequencies of a lleles in both species was carried out. The null allele, Gli-Ale, was more common in durum wheat than in bread wheat. The GW-B1b allele, pre sent in 60% of the bread wheats, was found in only 2% of the durum whe ats and Gli-B1e, very common in durum wheat (45%), was rare in bread w heat (4%). The Gli-B1IV/allele, common in durum wheat (28%), was not d etected in bread wheat.