WE NEED TO PREDICT WHERE NEW WEEDS WILL GO AND HOW THEY WILL BEHAVE. MAKING THESE PREDICTIONS IS CRUCIAL TO WEED MANAGEMENT AND CONTROL. BIOLOGISTS HAVE SHOWN THAT PLANTS, INCLUDING WEEDS, CAN EVOLVE RAPIDLY OVER SHORT PERIODS OF TIME. THE CAPACITY FOR WEEDS TO CHANGE MAY THWART OUR ABILITY TO PREDICT THEIR SPREAD AND IMPACT. STINKWORT (DITTRICHIA GRAVEOLENS) IS A NOXIOUS WEED THAT WAS INTRODUCED TO CALIFORNIA FROM EUROPE IN 1984. IT HAS ALREADY SPREAD ACROSS 40 COUNTIES, AND IT IS INVADING RANGELANDS AND THREATENS AGRICULTURAL RESOURCES SUCH AS VINEYARDS. THE USDA CATEGORIZES STINKWORT AS A "HIGH RISK" WEED, AND YET SURPRISINGLY LITTLE IS KNOWN ABOUT ITS BIOLOGY. OUR OVERARCHING GOAL IS TO STUDY THE EVOLUTIONARY FORCES INFLUENCING THE INVASION OF STINKWORT, WITH THREE OBJECTIVES:1. USE GENOMIC TOOLS TO RECONSTRUCT THE HISTORY OF THE SPREAD OF THIS NOVEL WEED AND STUDY HOW ITS GENOME HAS CHANGED WITH INVASION.2. STUDY HOW THIS WEED HAS EVOLVED, INCLUDING ADAPTATION TO THE CALIFORNIA ENVIRONMENT, ADAPTATION TO MICROBES IN THE SOIL (INCLUDING PATHOGENS), AND EVOLUTION OF TRAITS THAT MAKE IT SPREAD FASTER THAN EVER. 3. EXPLORE HOW EVOLUTIONARY CHANGES WILL AFFECT WHERE THE WEED CAN GROW, ITS RATE OF SPREAD, AND HOW AGGRESSIVELY IT WILL COMPETE WITH OTHER PLANTS IN GRASSLANDS AND RANGELANDS.OUR STUDY WILL FOCUS ON STINKWORT ACROSS MULTIPLE INVASION FRONTS ACROSS CALIFORNIA AND WILL ADDRESS KEY PRACTICAL CONCERNS OF LAND MANAGERS. OUR PROJECT INTEGRATES DIVERSE APPROACHES INCLUDING WHOLE-GENOME SEQUENCING, GREENHOUSE EXPERIMENTS, FIELD EXPERIMENTS, AND HABITAT SUITABILITY MODELING FOR RISK ASSESSMENT. WE ARE ACTIVELY CONSULTING AND COLLABORATING WITH WEED MANAGERS, AND WE HAVE USED THEIR PRIORITIES TO SHAPE OUR QUESTIONS AND APPROACHES. OUR PROJECT WILL CULMINATE IN A REGIONAL WORKSHOP ON STINKWORT BEST MANAGEMENT PRACTICES.