2019 ASHS Annual Conference

ARS scientists in Charleston, SC have been working to breed broccoli adapted to high temperature environments for more than two decades. This effort has employed a recurrent selection approach, and progress in developing germplasm increasingly tolerant to this abiotic stress has been slow and incremental. Observations and experience over the years have confirmed the original hypothesis that adaptation to high temperatures is a quantitative trait controlled by many genes with relatively small effects. Recent studies have identified significant quantitative trait loci (QTL) associated with the trait, and candidate genes that may be associated with expression have been proposed. Research has also identified factors that may limit additional gains made in this breeding effort; however, some progress can still be expected in future selection cycles.