Molecular breeding of durum wheat cultivars for pasta quality

The quality of durum wheat (Triticum durum) is defined as its degree of suitability for pasta production. In order to meet the demand of pasta industry for high quality raw material, existing durum varieties should be first improved in terms of quality-associated genes or quantitative trait loci (QTLs). In this study, important QTLs (Gli-B1 locus encoding γ-gliadin 45 protein and Glu-B3 locus encoding LMW-2 type glutenins) that affect cooking quality of pasta were transferred to two durum wheat cultivars (Salihli-92 and Kiziltan-91) through marker-assisted selection (MAS) and backcross breeding. A Canadian durum wheat cultivar with a high quality, Kyle, was used as the donor parent. Each F1 and backcross (BC) plants were backcrossed four times to the recurrent parents, and backcrosses carrying the targeted QTLs were selected by linked molecular markers, i.e. DNA markers, acidic polyacrylamide gel electrophoresis (A-PAGE) and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Quality analyses were performed on the kernels and semolinas of inbred backcross lines (BC4F4) and of parental cultivars to assess the effects of the transferred QTLs. Both advanced breeding lines (ABLs) had higher protein contents (14.9 and 15.8%) than their recurrent parents (14.0-14.8%). Also, SDS-sedimentation volumes (32.7 and 28.2 ml) of the ABLs were significantly higher (P < 0.05) than their parents. It was found that the transfer of Gli-B1 locus containing γ-gliadin 45 and Glu-B3 locus containing LMW-2 type glutenins to the advanced breeding lines led to increases in their pasta-quality associated properties.