2004 Annual Report 4.What were the most significant accomplishments this past year? This report serves to document research conducted under a Specific Cooperative Agreement between ARS and Texas A&M University. Additional details of this research can be found in the report of the parent project 6406-21000-010-00D, Germplasm Enhancement and Genetic Improvement of Cotton. Dr. David Stelly is the TA&MU cooperator. This project is developing chromosome substitution lines with specific G. barbadense chromosomes or chromosome arms substituted into G. hirsutum via a backcross procedure. Seventeen chromosome substitution lines were released as germplasm in 2004. We have begun research to sbustitute G. tomentosum chromosomes into G. hirsutum.