Resistance Screening Center

The Resistance Screening Center evaluates seedling materials for resistance to disease - primarily fusiform rust and pitch canker as a service to tree improvement specialists, seed orchard managers, scientists, and others in government agencies, research institutions, and private industry. Testing enables clients to obtain information on the relative resistance of their materials, in much less time than is possible in field progeny tests. By using information from these tests, trees producing disease resistant progeny are identified.

Background

• Center established in 1973 to meet the threat of fusiform rust.

• Additional disease resistance screening procedures developed as disease problems increased or changed. (Pitch canker disease, pitch canker seed fungi, chestnut blight, dogwood anthracnose, butternut canker decline, brown spot needle blight, white pine blister rust, specific gravity.)

• Thousands of seedlots have been screened and millions of seedlings evaluated for disease resistance over the years.

• An Ad Hoc Technical steering committee meets every 1-2 years to review current testing procedures and make recommendations for future direction.

Project Highlights

• Fusiform Rust - Pine seed are germinated, transplanted, and grown under optimum greenhouse conditions for inoculation. Pine plants may also be provided by the client in the form of somatic embryogenesis plants, clonal plants, or rooted cuttings. At the same time, the fungus is cultivated by germinating, transplanting, inoculating the alternate host, and harvesting basidiospores. Pine seedlings are then inoculated using a controlled basidiospore suspension system. After incubation and continued maintenance in the greenhouse, seedlings are evaluated for relative resistance. Results are available to clients in less than one year. This service is available for a fee.

• Pitch Canker - Pine seed or plants provided by the client are germinated, transplanted, and grown under optimum greenhouse conditions for inoculation. The fungus is cultured in the laboratory for spore production. At inoculation, seedlings are decapitated and inoculated with a spray suspension. After incubation and maintenance in the greenhouse, seedlings are evaluated for relative resistance. Results are available to clients in less than one year. This service is available for a fee and currently includes CAMCORE, Rayonier Company, SAPPI, and WGFTP as clients.

• Seed Fungi Screening for Pitch Canker Disease- Seed are screened in a laboratory environment for the presence of pitch canker disease. Clients using this service are involved in providing seed to foreign countries, which will only accept disease free seed.

• Chestnut Blight - Greenhouse screening techniques have been developed and evaluated on American chestnut, Chinese chestnut, crosses and backcrosses of the same. This is in cooperation with TACF and the SRS.

• Butternut Canker - Field plantings have been installed and have been evaluated for canker development. Natural planting sites have been identified and are being evaluated for growth, disease incidence and severity, and nut production. These studies are in cooperation with the University of Tennessee, SRS, and the NFS.

• Dogwood Anthracnose - Screening techniques are available to screen for Discula distructiva.

• Specific Gravity Testing - Laboratory determinations of specific gravity on superior tree candidates are available for the NFS Tree Improvement Program.

• The Center is operated by a staff of three technicians and the work load is planned accordingly with a minimal budget. Fees for service supplement the purchase of supplies and maintenance.

• The RSC has the flexibility to modify current screening procedures to accommodate specialized requests. This allows researchers to use the RSC as an additional experimental tool.

• In a research assistance capacity, the RSC has played an important role in newly developed understanding of genetic interactions in the pine-fusiform rust pathosystem and will continue to do so in the foreseeable future.

• By using information from the Resistance Screening Center tests, trees producing resistant progeny can be identified or questions may be answered concerning such things as the nature of pathogen variation or the effectiveness of fungicides.

• The RSC remains open to service screening work or research endeavors in an effort to improve forest health.

Conclusions/Future Direction

Since it's beginning, the RSC has screened nearly 15,000 seedlots and evaluated over 1.8 million seedlings. The Center's flexibility in adapting or modifying its standard test design to accommodate client requests allows it to continue as a valuable tool for tree improvement researchers, scientists, and industry. With support and direction from the Resistance Screening Center Steering Committee, the Center will continue to operate and contribute to the tree improvement industry.

FHP Contact:

Josh Bronson
USDA Forest Service
Resistance Screening Center
1579 Brevard Road
Asheville, NC 28806
Phone: 828-667-5089 ext 102
Email: jjbronson@fs.fed.us

Back

USDA Forest Service - Forest Health Protection, Southern Region
Last Modified: Monday, 14 January 2013 at 09:40:57 EST