Research is underway to understand resistance mechanisms in Asian ash species and to develop hybrids to incorporate resistance from Asian species into North America ash species. These efforts include:
- Forest Service Seed Collection in Natural Areas
- Identification, Selection and Testing of Lingering Ash
- Development of Novel Forest Service Hybrids of American ash with resistant Asian ash trees
We are also testing the incorporation of Baccillus thuringensis genes into native ash.
The Northern Research Station also searches for resistance to plant pathogens, such as Beech Bark Disease and Dutch Elm Disease.
The Pacific Southwest Research Station has funded studies seeking resistance in tanoak to the Sudden Oak Death pathogen, Phytophthora ramorum.
White pine blister rust, introduced to the U.S. in the early 1900's, has been the focus of resistance breeding efforts at the Rocky Mountain Research Station. At first only the economically important timber species — western white pine, sugar pine, and eastern white pine — were studied. In recent years, an appreciation for the ecological importance of high elevation white pine species has led the Forest Service to identify resistant “plus trees” and protect them where feasible from mountain pine beetle attack. Seeds are being collected to represent the range of geographic variation and tested for resistance.
The Southern Research Station has for many years studied and identified resistance sources in families of slash and loblolly pine. Further reading: