Composition of and variation in high- and low-molecular weight glutenin subunits, and omega gliadins in Ethiopian tetraploid wheat germplasm

Abstract

A collection of 120 Ethiopian tetraploid wheat accessions was analysed for high-molecular weight (HMW) glutenin subunit, low-molecular weight (LMW) glutenin subunit and omega gliadin composition by SDS–PAGE. For the HMW glutenin subunits, a new allelic variant, 2****, was detected which has not been previously described at the Glu-A1 locus. A high proportion of Glu-A1x banding pattern was observed in durum wheat. For the Glu-B1 locus four different banding patterns were detected. Among those HMW glutenin subunits, 7+8 were the most common, while subunits 14+15 and 6+8 were found to be rare. A high degree of variation was evident for the LMW glutenin subunits and D-zone omega gliadins. The association of the composition of the gluten with quality has been discussed. This wide variation can be used in improving the quality of wheat and to widen its genetic base.

Quality assessment with HPLC in released varieties of tetraploid (Triticum durum Desf.) wheat from Ethiopia and Spain

“…One variety was found showing the 2**** subunit, previously reported in Ethiopian durum wheat by (Hailu et al 2006). A larger variation was seen in the composition of LMW-GS, which also corresponds to previous investigations (Hailu et al 2006).…”

“…Furthermore Glu-A3a and Glu-A3d have been correlated to good pasta quality (Branlard et al 2003). Equivalence models for allelic composition, LMW patterns and quality have been developed (Payne et al 1984;Nieto-Taladriz et al 1997) and these models have also been adapted to the Ethiopian durum wheat material (Hailu et al 2006). Applying this model indicate a good quality as related to LMW-GS of several of the Ethiopian varieties, i.e.…”

“…The gliadin and glutenin subunits were extracted from individually ground grains and the proteins were separated on 10% polyacrylamide gels in the presence of sodium dodecyl sulphate (SDS-PAGE) (Hailu et al 2006). Then, in order to determine the gluten composition, the gels were stained with Coomassie Brilliant Blue R-250 solution at-least overnight according to Johansson et al (1993) and de-stained in 8% (w/v) trichloroacetic acid (TCA) for a day.…”

Variation in gluten strength and yellow pigment in Ethiopian tetraploid wheat germplasm

“…The diversity in Ethiopian tetraploid wheat has been studied using agro-morphological traits (Hailu et al 2006a;Bechere et al 1996;Belay et al 1997;Belay et al 1993;Negassa 1986;Tesemma et al 1991), isozymes (Tsegaye et al 1996;Asins and Carbonnel 1989), storage proteins (Hailu et al 2006b;Messele 2001), as well as chromosome morphology and structure (Belay et al 1994). However, very little emphasis has been placed on improving the pasta quality of the tetraploid wheat in the country.…”

Farmers perception of pesticide use and genetic erosion of landraces of tetraploid wheat (Triticum spp.) in Ethiopia

“…However, the factories that produce pasta, spaghetti and macaroni in Ethiopia are mainly using durum wheat imported from Asia, as the local production of tetraploid wheat fails to meet domestic processing demand for the product in terms of quality and quantity. Quality analysis (Hailu et al 2006(Hailu et al , 2010 indicates that the quality of some of the landraces available in Ethiopia is comparable to that of released varieties. Productivity could be increased, but under normal production conditions the landraces are assumed to be lowyielding.…”