2007 Annual Report 1a.Objectives (from AD-416) The objective of this cooperative project is to conduct research on the genetic improvement and physiology of rice, and other relevant research investigations of mutual benefit to DBNRRC and University of Arkansas Rice Research and Extension Center-Stuttgart, AR (Cooperator) using services and facilities of DBNRRC as follows: specialized equipment for laboratory and field-oriented experiments; specialized laboratory, greenhouse, office or other facilities as required for the research; and commitment of personnel and their necessary travel to conduct the cooperative research. 1b.Approach (from AD-416) Numerous rice plants will be propagated in soil-filled, flooded pots and grown to. 1)the seedling stage for marker-assisted selection procedures; and. 2)the flowering stage/maturity for crossing purposes, for grain filling physiology experiments, and for anther culture experiments. 3.Progress Report This report serves to document research conducted under a non-funded cooperative agreement between ARS and the University of Arkansas. Additional details of research can be found in the report for the parent project 6225-21000-008-00D, Use of Diverse Germplasm for Genetic Improvement of Rice. In FY2007, greenhouses at DBNRRC were used in cooperative rice research projects with University of Arkansas scientists. Major activities included an evaluation of volatile chemicals emitted from rice plants involved in the attraction of stink bugs, an important pest of rice, as well as studies to evaluate silica content and starch enzyme activity in several rice cultivars. More than 16,000 rice seedlings from UA breeding programs were grown in the greenhouse for subsequent DNA testing. More than 70,000 marker analyses were conducted in the DBNRRC Genomics Core Facility in cooperation with University scientists for marker-assisted selection projects involving milling quality and disease resistance, and for marker confirmation of gene flow between rice and weedy rice. Research progress was monitored through the year via frequent meetings between ARS and University researchers to discuss data results and drafting of manuscripts for publication.