Geneticist Richard Olsen and horticulturist Sue Bentz of USDA's Agricultural Research Service (ARS) teamed up with Forest Service entomologist Mike Montgomery to breed and select these tolerant hybrids. Olsen and Bentz work in the U.S. National Arboretum's Floral and Nursery Plants Research Unit in Beltsville, Md. The arboretum is located in Washington, D.C., and is operated by ARS, the principal intramural scientific research agency of USDA.
Over the past few decades, two hemlocks native to the United States-Tsuga canadensis and Tsuga caroliniana-have been under attack by the small sucking insect Adelges tsugae, also known as the hemlock woolly adelgid (HWA). Originally from Asia, this aphid relative has spread to forests and backyards in 17 eastern states, killing hemlock trees and devastating natural ecosystems.
Under the direction of ARS geneticist Denny Townsend (now retired), the arboretum began a breeding program in the 1990s to develop hemlock hybrids tolerant to HWA. The scientists crossed hemlock species native to the United States with germplasm-collected in Asia-of hemlocks that have shown tolerance to the insect. Now, 10 years later, Olsen and Bentz have developed 140 hemlock hybrids, 108 of which are suitable for testing.
In 2006, Olsen and his colleagues began a multi-year field trial to test each hybrid's degree of tolerance to HWA. Testing more than 170 trees, the researchers artificially infested the hybrids by attaching HWA-infested branches to the hybrids' lower branches and securing them with mesh bags to prevent the insects from escaping. They found the species T. chinensis and its hybrids to be most tolerant to HWA.
Details of the scientists' studies have been published in the Journal of Economic Entomology, the Journal of Arboriculture and the Journal of the American Society for Horticultural Science.
The hybrids are appealing not only due to their tolerance, but because they have good vigor and shape. Still, the researchers have several years of testing to complete before they can release these hybrids.
Read more about this research in the November/December 2010 issue of Agricultural Research magazine.
USDA is an equal opportunity provider, employer and lender. To file a complaint of discrimination, write: USDA, Director, Office of Civil Rights, 1400 Independence Ave., S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice), or (202) 720-6382 (TDD).
Stephanie Yao | Newswise Science News
Faba fix for corn's nitrogen need
11.04.2018 | American Society of Agronomy
Wheat research discovery yields genetic secrets that could shape future crops
09.04.2018 | John Innes Centre
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
20.04.2018 | Physics and Astronomy
20.04.2018 | Interdisciplinary Research
20.04.2018 | Physics and Astronomy