Identification of Glu-B1 alleles in bread wheat cultivars using PCR

Abstract

High dough strength is used as a predictor of good quality bread wheat and it has been attributed largely to the type of allele present at the Glu-D1 locus, where the Glu-D1d allele is most favorable. Recently, it has been observed that cultivars with over expressed subunit Bx7OE at the Glu-B1 have enhanced dough strength. In order to implement recently developed PCR assay for Glu-B1 x-type allele discrimination in marker-assisted selection, a set of wheat cultivars from 11 countries was analyzed. The PCR results matched the known Glu-B1 HMW GS genotypes of the cultivars possessing subunits Bx7 or Bx17. It was shown that this molecular marker also differentiated some other Glu-B1 alleles: Bx6, Bx13, Bx20 and Bx22. These results create the opportunity for an improved method of polymorphism scoring at the Glu-B1 in bread wheat germplasm. .Zahvaljujuci jedinstvenim karakteristikama polimernog proteina - glutena, brasno hlebne psenice ima sposobnost razvoja viskoznih i elasticnih osobina testa. Kvalitativnim karakteristikama glutena u najvecem procentu doprinose proteinski produkti Glu-1 lokusa, od kojih lokus Glu-B1 pokazuje najvecu alelnu varijabilnost. Alelna kompozicija Glu-B1 lokusa dvadesetosam genotipova heksaploidne psenice je analizirana primenom PCR-zasnovanih markera sa ciljem ocene preciznosti i fleksibilosti metode u svetlu njene implementacije u programe marker asistirane selekcije psenice. Na osnovu analize velicine produkata amplifikacije, utvrdjeno je da od 4 genotipa nosilaca 7+8 subjedinice, samo sorta Centurk poseduje jacu ekspresiju subjedinice 1Bx7. Pored vec poznatih literaturnih nalaza o mogucnosti razlikovanja i alela Glu-B1i, odgovornog za sintezu HMW gluteninske subjedinice 17+18, elektroforetskim razdvajanjem na 6% nedenaturisucem PAA gelu, na osnovu svoje mobilnosti mogli su se razlikovati i aleli Glu-B1d (subjedinica 6+8), Glu-B1f (subjedinica 13+16), Glu-B1e (subjedinica 20) i Glu-B1k (subjedinica 22). Prezentovani rezultati otvaraju mogucnost za efikasnu primenu ovog tipa markera u proucavanju polimorfnosti Glu-B1 lokusa u germ plazmi heksaploidne psenice. .