PIs: Katrien M. Devos (University of Georgia) and Elizabeth A. Kellogg (University of Missouri - Saint Louis)
CoPI: Jeffrey Bennetzen (University of Georgia)
Setaria viridis or green foxtail is a ubiquitous weed that was introduced from Eurasia during the past 500 years. It is often found in and around cultivated fields and the extensive herbicide pressure imposed by agricultural weed control has led to the development of herbicide resistant genotypes. Resistance to four different types of herbicides has been identified in S. viridis. Under continued herbicide application, the genome region that carries the resistance will be under strong selection and this is expected to lead to reduced variation at the herbicide resistance locus and surrounding genome region. The project aims to compare the genetic variation at the whole genome level with the variation present in and around three herbicide resistance genes. To achieve this objective, S. viridis accessions will be collected from North America and Canada, where herbicide resistance has previously been observed. S. viridis accessions from around the world will be obtained from national and international germplasm repositories. The plants will be tested for herbicide resistance. Cutting edge molecular techniques, including high-throughput sequencing, will be used to analyze the genetic variation. The project will provide new insights into the diversity of green foxtail worldwide, the history and origin of green foxtail introductions into North America, the nature of the mutations that give rise to herbicide resistance, how the resistance spreads through populations and the effects of intense directional selection on genome evolution.
The project provides a vehicle for training students at the undergraduate, graduate and post-doctoral level in independent research. In addition, the project data will be used as hands-on teaching materials in graduate courses taught by the PIs. The project also aims to provide a link between weed scientists, germplasm curators and geneticists with an interest in green foxtail. To raise awareness of the research interests of the different groups and to facilitate collaborations, the project will organize a workshop to discuss available green foxtail collections, maintenance of those stocks, genomic tools and common goals. All sequence data produced by this project will be made publicly available through GenBank. Germplasm can be obtained from the University of Georgia and the USDA-ARS Germplasm Resources Information Network (GRIN) (www.ars-grin.gov).
