2004 Annual Report 4.What were the most significant accomplishments this past year? D. Progress Report: This report serves to document research conducted under a specific cooperative agreement between ARS and ICARDA, Allepo, Syria. Additional details of research can be found in the report for the parent CRIS (6217-21000-006-00D, Genetic Improvement of Insect Pest Resistance in Wheat, Barley, and Sorghum). Fifty advanced breeding lines developed in Stillwater, Oklahoma, were shipped to ICARDA in Aleppo, Syria, for testing against the Syrian population of Russian wheat aphid (RWA), known to be virulent to U.S. developed wheat cultivars having resistance to the U.S. RWA population. Tests were carried out in glass houses and field plots in Aleppo, Syria. Results of these tests showed several wheat breeding lines developed at Stillwater were highly resistant to the Syrian RWA population, in addition to being resistant to the U.S. RWA population. At least seven wheat lines exhibited no leaf rolling and low levels of chlorosis following RWA feeding tests. Both of these traits are key to developing wheat cultivars with resistance to RWA. Additional tests are ongoing to confirm these results. Some of these advanced breeding lines are already being targeted as sources of RWA resistance for use in breeding programs at ICARDA. Information gained from these tests will be used to select for new resistance genes to be used in U.S. breeding programs.