SMALL GRAIN QUALITY AND MOLECULAR BIOLOGY

Objective 1. The Impact of Rht Allelic Variation upon Wheat Growth and Development. The overall goal here being to determine the degree to which wheat growth and development can be modified by Rht allelic variation. Ultimately, we hope to demonstrate that several new alleles are superior to those currently being utilized and that one or more of the new alleles are deployed in breeding programs.MilestonesCreation and testing of new Rht alleles in each of several different source populations. This has entailed creation and initial characterization of EMS lines created in the standard height variety Fortuna and in the semi-dwarf variety Alpowa for hexaploid wheat. For durum wheat, it has involved creation, identification and testing of Rht alleles in EMS populations created in Divide and Kronos.Characterization of a subset of the new Rht alleles in vitro and in segregating populations in different wheat varieties. Demonstration that one or more of the new Rht alleles is superior to currently utilized Rht dwarfing genes at the agronomic or product quality levels.Objective 2. Increasing Wheat Tillering and Yield by Optimizing TB1 Expression. The overall goal of this objective is to determine the optimal level of TB1 expression required for optimal tillering, plant biomass, and seed yield for both forage and seed yield applications in durum and hexaploid wheat.MilestonesCreation of and testing of new TB1 alleles in each of two source populations. This will entail the testing of alleles created in Kronos and Divide for durum wheat and in Alpowa and Cadenza for hexaploid wheat.We will characterize the impact of mutations in one or more TB1 alleles by creating backcross populations in semi-dwarf and standard height and semi-dwarf durum, spring, and winter wheat.We anticipate demonstrating that mutations in one or more TB1 genes is associated with increased biomass and protein content equal or higher than control varieties.Objective 3. Understanding the Role of Leaf Starch in Whole Plant Metabolism and Product Quality.The overall goal of this objective is to assess the degree to which plant growth and productivity is limited by normal levels of seed and leaf starch biosynthesis. We hope to identify key stages at which selection for increased leaf and/or seed starch biosynthesis would yield improved agronomic yield.MilestonesCompletion of yield studies designed to determine the relative role of leaf starch biosynthesis in overall plant growth.Identification of chromosome regions associated with increased leaf starch.Ability to select for increased leaf starch and improved whole plant productivity via selection for variation in genes that impact leaf starch content.Agronomic, product quality, and nutritional testing of durum seed with increased amylose, protein, and dietary fiber.Assessment of the usefulness and importance of the trait to wheat breeding programs.