Molecular analysis of gliadin and glutenin genes in T. durum cv. Lira. A model system to analyse the molecular bases of quality differences in durum wheat cultivars

Abstract

As a model system to study the molecular bases of differences between high- and lowquality durum wheat cultivars, designated as biotypes γ-45 and γ-42, respectively, the cultivar Lira, which contains both biotypes, was examined. Polymerase chain reaction analysis of biotypes 42 and 45 was carried out by using oligonucleotide primers from flanking nucleotide sequences coding for α-, β- and γ-gliadin and for high molecular weight (HMW) and low molecular weight (LMW) glutenins. A different amplified band for γ-gliadin sequences was observed between the two biotypes. Southern blot analysis of the same biotypes showed different hybridization patterns for both γ-gliadin and LMW glutenin genes. The hybridization patterns of LMW glutenin sequences revealed the presence of additional bands in biotype 45, suggesting that the quantitative differences in LMW glutenins between biotypes 42 and 45, considered responsible for their quality differences, are most probably due to a higher number of LMW genes in biotype 45. This conclusion seems also to be supported by the results obtained in other durum wheat cultivars belonging to types 42 and 45.