Wild species 17 species of tomatoes and their wild relatives Mutants Mostly single gene mutations Induced and spontaneous Miscellaneous genetic stocks Introgression lines Landraces A collection of genetic stocks and wild relatives of tomato C. M. Rick T G R C Tomato Genetics Resource Center Total ≈ 3,600 accessions
Wild Species From Columbia to Chile Also the Galapagos Islands Ranges overlap S. chilense Moyle 2008 Evolution
Extreme Xerophytes grafting allows growth in the greenhouse S. sitiens The Atacama Desert – one of the driest places on Earth
Wet Conditions (photo C. Rick) S. ochranthum on a stream bank S. juglandifolium seedlings
Galapagos Island Species Little or no morphological variation S. cheesmaniae accessions Charley Rick
Variation within Species S. peruvianum fruit from a single population photo C. Jones
Valuable Traits in Wild Species Bacterial and fungal resistance Gemini virus resistance Drought and salinity tolerance Cold tolerance and insect resistance
S. lycopersicoides, grows to 3,600m in Andes of S. Peru and N. Chile (photo C. Jones)
Mutants in Cultivated Tomato Leaf morphologies and colors Growing habits Hormone deficiencies Floral differences: i.e. male steriles “Lazy” “Ghost”
“Lanata, Wooly” “Curl”
Some mutations are lethal or sterile in the homozygote and must be maintained through the heterozygote “double dwarf” “extreme dwarf”
Pollinations “Buzz” pollinating Hand pollinating Tailored to the mating system: outcrossers and selfers 50 plants/accession grown for outcrossers
Germplasm Evaluation Germination Testing Purity, Identity & Diversity
Seed Regeneration
Seed Processing Fruit is blended and fermented for 48 hours Seeds are flattened on paper to dry Packaged and placed in storage
Seed Storage Working collection stored at 6°C Germ tested after 10 years Long term seed stored at -20°C USDA TGRC
Seed Distribution Annual activity requests from researchers in over 30 countries approx. 5,000 seed samples distributed utilization rate of ~ 100% seed provided gratis Common uses breeding genetics and genomics leaf development fruit ripening fruit biochemistry evolutionary studies education
Threats to Wild Tomatoes in Native Area agriculture urbanization herbivores mining
Department of Plant Sciences tgrc.ucdavis.edu