2006 Annual Report 4d.Progress report. This subordinate project is associated with the parent project 6225-21000-008-00D, Use of Diverse Germplasm for Genetic Improvement of Rice. This report serves to document research conducted under Specific Cooperative Agreement No. 58-6225-4-019 between ARS and the University of Puerto Rico. Research was conducted on the development of early maturing and short-statured germplasm possessing grain characteristics typical of basmati and jasmine rice cultivars. In addition, selections in an indica—based germplasm development program were made and various mutation breeding projects were evaluated. The winter nursery was also used to advance the development of a mapping population and increase seed of late-maturing, core collection, and low inventory lines from the National Small Grains Germplasm Collection. Utilization of this winter nursery saves researchers a year in genetic improvement cycles and enables seed production of long season, photoperiod-sensitive lines that do not set seed at the DBNRRC in Stuttgart, AR.