In an ARS research plot in South Carolina, geneticist Mark Farnham collects broccoli for heat-tolerance evaluations.
Photo by USDA-ARS U.S. Vegetable Laboratory.
Traditionally, broccoli is a cool-weather crop. Agricultural Research Service (ARS) scientists are looking to change that by developing new varieties that grow in warm temperatures.
ARS plant geneticist Mark Farnham and his team in Charleston, South Carolina, have developed and characterized the genetic sources of broccoli’s heat tolerance. Theoretical and Applied Genetics published these results in March 2017.
The team, led by ARS geneticist Sandra Branham, evaluated a group of broccoli plants Farnham developed for the ability to tolerate heat stress and identified genetic markers associated with heat resistance.
An important finding from this research is that the resistance trait is controlled by many genes. Now, public and private broccoli breeders are interested in using these markers to help speed development of heat-tolerant broccoli.
Farnham is working with scientists at land-grant universities along the Eastern Seaboard who are growing his broccoli in warm-temperature field trials. Once they verify that his broccoli will do well under adverse conditions, the broccoli will become available for research purposes or for use by commercial seed companies and breeders.
Encountering high temperatures is the main factor limiting where and when broccoli is grown. Heat-tolerant broccoli will expand future growth possibilities, helping to meet the demand for this nutritious vegetable.
Total U.S. annual broccoli consumption (fresh and frozen) grew from about 1 pound per person in the 1960s to about 8 to 9 pounds per person today. One cup of broccoli provides more than 100 percent of our daily requirement for vitamins C and K and is a good source of fiber, vitamin A, folate, and potassium.
Read more about this research in the September 2017 issue of AgResearch.