Published in Probe Volume 6 (Final): July 1996
The C.M. Rick Tomato Genetic Resources Center (TGRC), located at the University of California, Davis, is a genebank of wild relatives, monogenic mutants, and miscellaneous genetic stocks of tomato. It is currently curated by Dr. Roger T. Chetelat in the Department of Vegetable Crops.
The genebank was founded by Dr. Charles Rick, who collected many of the wild species accessions in South America and whose research program produced many of the marker and cytogenetic stocks. Before its establishment, stocks were shared informally under the auspices of the Tomato Genetics Cooperative (TGC), a group of tomato researchers interested in genetics, linkage, mapping, and breeding. Rick served as publisher of the TGCs annual report, which included lists of available stocks and their sources. In 1976, Rick received a National Science Foundation grant to support maintenance of the collection, then named the Tomato Genetic Stocks Center. It was renamed in 1990 to honor Ricks contributions and indicate that it contains resources beyond stocks.
Researchers at the TGRC and worldwide continue to collect wild species and construct new genetic stocks. In recent years, the collection has grown by about 100-200 items per year.
The TGRC currently houses 1,059 accessions of wild species, which include representatives of all nine Lycopersicon species, as well as four related Solanum species. Monogenic mutants (963 accessions) include spontaneous and induced mutations affecting all aspects of plant development, introgressed disease resistance genes, and protein marker stocks. Miscellaneous genetic stocks (1,187 accessions) include linkage tester stocks, trisomics, translocations, Latin American varieties, and various types of interspecific prebreds.
New genetic stocks include collections of monogenic mutants nearly isogenic in uniform genetic backgrounds, a library of introgressed alien chromosome segments, and dominant resistance genes for emerging diseases. In the future, TGRC researchers hope to incorporate transgenic germplasm, such as antisense and transposon insertion mutants.
Seed samples are distributed free to researchers worldwide, for a wide variety of research projects. A major area of activity is the use of wild germplasm for disease resistance, with new useful resistances being reported each year. Researchers have discovered resistance to at least 42 major diseases in exotics ad have bred 20 of them into horticultural tomatoes. Other traits of economic interest include insect resistance, abiotic stress tolerance, and improved horticultural and fruit characteristics. TGRC stocks are also cited frequently in studies of tomato physiology and development, genetics, and molecular genetics.
TGRC researchers conduct ongoing projects in several areas. Currently, they are using molecular marker techniques to identify chromosome segments of two previously inaccessible Solanum species introgressed into a tomato background.
Researchers also maintain a computer database, which includes passport information on all accessions, with detailed collection notes for wild species, a list of the known mutants of tomato, records of seed requests, and a growing library of digital images for tomato stocks. Information is periodically uploaded to the genome database SolGenes. Stock lists are also available electronically (e-mail: tgrc@vegmail.ucdavis.edu) and are published annually in the Tomato Genetics Cooperative Report.
For further information, contact:
Dr. Roger T. Chetelat
Department of Vegetable Crops
University of California
Davis, CA 95616
Phone: (916) 752-6726
Fax: (916) 752-9659
E-mail:
chetelat@vegmail.ucdavis.edu