| The study of near isogenic wheat lines from the varieties Saratovskaya, Pegaso, Halberd, Fiorello, Avocet, G-22, and Chinese Spring is described in this dissertation. The main objectives were to evaluate isogenic wheat lines as suitable materials to establish protein composition/functionality relationship, and to investigate the functionality of certain groups of proteins that may be targeted in breeding programs. The results confirm the potential of natural and chromosomally engineered near isogenic lines in understanding the effects of proteins coded at specified loci. Wheat lines single null at Gli-2 loci may be useful in breeding programs to manipulate dough properties towards a controlled change in strength, tailoring the functionality to precisely meet end-use requirements. High molecular weight glutenin subunits having one less cysteine residue had molecular weight distribution shifted to lower values. This is reflected in weaker dough properties and poorer breadmaking performance. This study showed more evidence that both Gli-1 and Gli-2 loci may code for modified gliadins that act as chain terminators, which reduce the molecular size of glutenins and decrease dough strength. |
