Summary
Emerald ash borer (EAB) continues to advance at an alarmingly fast pace, putting green ash at risk of extinction. Tests done on “lingering ash,” the rare surviving trees found in areas under long-term EAB attack, are evidence that these trees are capable of mounting a defense against EAB. A collaborative project between Forest Service researchers and members of the Hardwood Genomics Project demonstrated measurable differences in patterns of gene expression between lingering ash trees and trees that are fully susceptible to EAB, both before and after EAB larvae have fed upon their inner bark tissues. The study identified hundreds of genes that may prove useful in future research on the specific molecular mechanisms responsible for the defenses lingering ash use against EAB. Different lingering ash trees use different types of defense responses; the goal of the Forest Service’s green ash breeding program is to combine the different defenses to produce progeny that can combat EAB even more effectively than their lingering ash parents. Forest Service researchers are collaborating with university partners to integrate genomics tools like those developed by the Hardwood Genomics project into the green ash breeding program to accelerate restoration of green ash in EAB-impacted landscapes throughout the U.S.
