Project Number: 5348-21000-030-04
Start Date: Aug 29, 2011
End Date: Jul 31, 2014
This project will identify loci controlling preharvest sprouting tolerance and seedling emergence. It is likely that loci providing dormancy will give better preharvest sprouting tolerance, but have a negative impact on emergence unless dormancy breaking treatments are used. Cooperator will examine the ability of wheat to emerge from deep planting, to germinate under water-limited conditions, and develop dormancy breaking conditions. ARS' research program will take a complimentary approach by examining the dormancy status of wheat varieties and elucidating the role of ABA and GA hormone signaling in the control of seed germination using wheat and Arabidopsis. ARS and the cooperator will collaborate to examine how seed dormancy and emergence properties correlate and to develop a strategy to breed for wheat that will have sufficient dormancy to resist sprouting while at the same break dormancy quickly enough to avoid problems with emergence. This will be achieved in part through assessing breeding program germplasm and wheat mutants for these properties using after-ripening time course experiments, PEG plating assays, RT-PCR analysis of ABA and GA signaling related gene expression, and strategic crosses for breeding. As part of the collaboration on the subject of drought and cold tolerance, ARS and the cooperator will use experiments under controlled greenhouse conditions to assess the mechanisms of wheat survival of these stresses. They will integrate this data, their own field data, and field data from the cooperator's program to devise new breeding strategies. Finally, both ARS and the cooperator will examine the loci providing stripe and stem rust resistance within their breeding programs. This will be achieved through test crosses, greenhouse rust infection assays to determine whether resistance genes are specific to particular rust races, and through collaborative breeding efforts.