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Projects |
Movies of standard lab procedures
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Breeding and mutation analyses in tomato have resulted in a
diverse germplasm collection, which provides a rich resource for studies on
fruit morphology. Fruit morphological changes occur during ovary
formation and/or during fruit formation. Therefore, tomato
varieties displaying altered fruit shapes provide unique insights into
developmental processes controlling ovary and fruit growth and
maturation. Understanding the molecular and genetic bases of
diversity in fruit form will allow insights into evolutionary
processes of tomato domestication and selection. In addition, developmental processes that regulate ovary and
fruit formation can be further investigated by utilizing genes that
alter fruit shape. A historical overview of the origin of tomato and where
and when the different morphologies were first recorded is described
here (Tomato Fruit Morphology).
In our laboratory, the basis of tomato fruit shape variation is studied by a multi-tiered approach. First, we perform genetic analyses to identify loci that control fruit shape. Loci that have been selected are fine-mapped to identify genes underlying the trait. Second, we conduct developmental analyses to describe when changes in fruit shape occur during ovary and/or fruit growth. In addition, we want to determine which tissues(s) in the ovary or fruit are displaying altered growth characteristics that permit changes in final fruit shape. Third, we take a molecular approach to identify genes with altered expression due to allelic variation at fruit shape loci. This information will allow insights into networks of genes and biochemical processes potentially downstream from fruit shape loci, and help determine how fruit morphology is regulated. Fourth, we take a computational/database approach by developing software to semi-automatically quantify fruit morphological characteristics. The analysis of these shape characteristics is then integrated with gene expression and genotype information. Much of our current efforts are devoted to the identification and characterization of SUN, a gene controlling tomato fruit elongation. SUN controls fruit elongation by a redistribution of fruit mass via elongation of the septum, and the largest differences in shape are observed 10-14 days post anthesis. Stay tuned for news on this exciting gene, how the mutation arose, and its role in fruit development.
Collaborative
projects: This project revolves around Single Nucleotide Polymorphism (SNP) discovery and application in tomato. This project is in collaboration with Drs. Allen van Deynze (UC-Davis) and David Francis (Ohio State) and is intended to improve DNA-based marker availability for breeding populations of tomato. More information can be found at http://www.oardc.ohio-state.edu/tomato/translational_genomics.htm. and project summary. Another collaborative project centers on interspecies barriers in the tomato clade. The specific aims are to identify genes responsible for the recognition and rejection of pollen from closely related species. PI of this project is Pat Bedinger (Colorado State) and coPIs/collaborators are Bruce McClure (U of Missouri), Roger Chetelat (UC Davis), Joss Rose (Cornell), Steve Stack (Colorado State). More information can be found at http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=0605200
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