Genetic diversity in puroindolines and grain softness proteins in Australian and overseas wheat germplasm and implications for grain texture

Grain hardness in the hexaploid wheat species Triticum aestivum is one of the most important factors determining end-use quality and commercial value of the world trade of wheat. While mutations in the two puroindoline genes have been associated with grain hardness, there is insufficient understanding regarding genetic factors associated with grain texture. This investigation resulted in the identification of: limited puroindoline diversity present in Australian hard wheat germplasm; potential variation and diversity of the puroindoline genes in overseas landraces and the polyploid wheats; the diverse variation in sequence and gene copy number of the Gsp-1 genes which have potential for a similar structure and role as the grain hardness related puroindolines genes.