Generating novel milling and baking properties in bread wheat via the development of novel puroindoline and glutenin alleles

Abstract

The lack of natural allelic variation in genes impacting wheat quality limits the ability to make improvements based on selection among natural variation. Improvements to wheat quality can be made by generating new alleles in quality related genes via ethyl methane sulfonate mutagenesis. A series of novel puroindoline alleles were selected because each imparted a unique level of grain hardness. The impact of each allele upon wheat milling properties was tested by creating isolines in two wheat varieties. The results demonstrated that specific levels of grain hardness associated with individual puroindoline alleles result in modified break and total flour yield and modified flour particle size. A similar project was undertaken to create modified forms of several glutenin genes, which impact wheat flour mixing properties. The creation of novel glutenin alleles resulted in major loss of gluten function in nonsense mutations, while missense mutations generally did not significantly impact protein quality traits. Generating novel alleles in genes that have limited natural allelic variation is worthwhile, which is reinforced with the unique milling properties created in the puroindoline study. However, the application of EMS mutagenesis may not be equally useful for all genes impacting quality traits, since the generation of novel glutenin alleles did not result in significant improvements to wheat protein quality.