ALTHOUGH SWITCHGRASS IS A DESIRABLE BIOFUELS CROP, IT IS ALSO A HIGHLY-OUTCROSSING, WIND-POLLINATED SPECIES NATIVE TO THE AREA WHERE IT WILL BE GROWN. AGRICULTURAL CULTIVATION OF GENETICALLY ENGINEERED (GE) SWITCHGRASS RAISES THE POSSIBILITY THAT THE INTRODUCED TRAITS MAY MOVE INTO NATURAL POPULATIONS WITH POTENTIAL UNINTENDED ENVIRONMENTAL IMPACTS. THUS, AN EFFECTIVE REPRODUCTIVE CONFINEMENT SYSTEM IS NEEDED. RESEARCH DEVELOPING AN EFFECTIVE BIOCONTAINMENT SYSTEM IN GE SWITCHGRASS WILL BE PERFORMED TO MEET THIS NEED. THIS RESEARCH IS DIRECTLY RELEVANT TO PROGRAM AREA 1 TO MINIMIZE THE ENVIRONMENTAL RISK OF GE ORGANISMS AND SPECIFICALLY THE DEVELOPMENT OF EFFECTIVE BIO-CONFINEMENT STRATEGIES TO LIMIT GENE TRANSFER (GENE FLOW) OR OUTCROSSING TO SEXUALLY COMPATIBLE ORGANISMS OF THE FY2017 BRAG REQUEST FOR APPLICATIONS.THE REPRODUCTIVE BIOCONTAINMENT SYSTEM WILL DEPLOY A TWO-PART FLORAL STERILITY SYSTEM THAT WILL BE ACTIVATED IN HYBRID PLANTS. THE INITIAL PARENTAL GE SWITCHGRASS PLANTS WILL BE FERTILE BECAUSE THE CONTAINMENT SYSTEM WILL BE HELD INACTIVE. CROSSING SELECTED GE SWITCHGRASS PLANTS WILL GENERATE HYBRID PLANTS WITH ACTIVE REPRODUCTIVE CONTAINMENT. THOSE PLANTS WILL NOT PRODUCE ANY FLOWERS AND BE COMPLETELY STERILE, BLOCKING THE CROP'S ABILITY TO PRODUCE SEED AND/OR CROSS WITH NATIVE SWITCHGRASS PLANTS THAT MAY BE GROWING NEARBY. THIS STRATEGY WILL NOT ONLY GENERATE REPRODUCTIVELY CONTAINED SWITCHGRASS, BUT CAN ALSO EASILY BE INCORPORATED INTO A BREEDING STRATEGY FOR THE DEVELOPMENT HYBRID SWITCHGRASS CULTIVARS FOR AGRICULTURAL DEPLOYMENT ENABLING THE USE OF GE SWITCHGRASS AS AN ALTERNATIVE RENEWABLE SOURCE OF ENERGY.