1a. Objectives (from AD-416)
Agronomically important genes for wheat will be identified and deployed using a genetic approach in wheat and Arabidopsis. The genetic mechanisms by which the plant hormones abscisic acid (ABA) and gibberellin (GA) control pre-harvest sprouting, stand establishment, and drought and cold tolerance in wheat and Arabidopsis. Spring and winter wheat cultivars with durable resistance to stripe rust, soilborne disease, cold and drought, and improved end-use quality will be developed.
1b. Approach (from AD-416)
Multiple approaches will be employed. The genetic diversity of wheat plants will be increased using wide crosses to wheat relatives and thorough mutagenesis and selection of new traits. We will determine whether ABA sensitivity controls grain dormancy and tolerance to preharvest sprouting using wheat mutants with increased and decreased sensitivity to ABA. The degree to which preharvest sprouting, drought tolerance and cold tolerance depends upon ABA sensitivity will be determined using association mapping, and wheat mutants with increased and decreased ABA sensitivity. The mechanisms by which GA signaling controls seed dormancy and plant height using Arabidopsis as a model system to determine exactly how GA response genes control gene expression during seed germination. New sources of genes giving superior end-use quality, disease resistance, and resistance to cold and drought conditions will be identified through characterization of material from the USDA-ARS National Small Grains Germplasm Collection. New approaches for deployment of these genes through the identification of new molecular markers, use of molecular markers to score segregation in breeding lines, employment of Bayesian statistics, and classical statistical plant breeding. Documents SCA with WSU.
3. Progress Report
Hormonal regulation of wheat stress responses. This project examines the genetic mechanisms by which the plant hormones abscisic acid (ABA) and gibberellin (GA) control pre-harvest sprouting, stand establishment, and drought and cold tolerance in wheat and Arabidopsis. Spring and winter wheat cultivars with durable resistance to stripe rust, soilborne disease, cold and drought, and improved end-use quality are being developed. During the current funding year, a Doubled Haploid mapping population was developed for the purpose of finding markers linked to the Rhizoctonia resistance gene in Scarlet-Rz1. Collaborative work was conducted to examine the drought tolerance of ABA hypersensitive wheat plants in the field. Collaborative work was also conducted to develop breeder-friendly markers for stripe rust resistance. A polyclonal antibody to wheat Rht1 DELLA protein was developed for future work in examining the role of GA signaling in wheat. In Arabidopsis, progress was made in examining the phosphorylation of the DELLA protein RGL2. Progress on this project was tracked through weekly meetings with the Washington State University graduate students and postdoctoral fellows conducting the research, and through quarterly meetings with WSU professor/collaborator Dr. K. Kidwell. This research is relevant to NP301 Component 2 “Crop Informatics, Genomics, and Genetic Analyses” and to National Program Problem Statements NP301 2C: Genetic Analyses and Mapping of Important Traits, and NP302 2B: Understanding Plant Interactions with Their Environment.