wild species 17 species of tomatoes and their wild relatives mutants mostly single gene mutations...
Post on 19-Dec-2015
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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. RickC. M. Rick
T G R CT G R CTomato Genetics Resource CenterTomato 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 SpeciesS. 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 DistributionAnnual activity•300 - 500 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