The genetic and developmental basis of blossom-end rot (BER) in tomato
This project is led by Dr. Savithri Nambeesan at UGA and funded by USDA NIFA AFRI grant number 2020-67013-30912. Tomato and other crops are susceptible to blossom-end rot (BER), one of the most common physiological disorders. BER can result in crop losses of 30-50% in certain years. The major goal of the project is to identify the molecular genetic basis of BER using tomato as a model along with the elucidation of the developmental mechanisms associated with the disorder. Together, the research proposed herein will provide fundamental knowledge about initiation and development of BER in tomato and should be applicable to a range of horticulturally important fruit and vegetable crops that exhibit BER-like disorders, including breeding projects, and thus enhancing plant productivity. The three proposed aims include; Aim 1: BER fine mapping and candidate gene identification in a tomato F2 population. For this aim, tomato accessions differing in BER resistance have been identified and mapping populations generated. Future experiments are targeted towards fine mapping and development of Recombinant Inbred Lines (RILs) and Near Isogenic Lines (NILs) in order to identify candidate genes that underlie BER development. Simultaneously other mapping populations differing in BER resistance are being generated. Aim 2: Fruit growth, xylem development, calcium distribution and effect of hormone application in BER-resistant and BER-susceptible tomato accessions and NILs. Parental accessions differing in BER and introgression lines developed in Aim 1 will be used to investigate fruit developmental processes underlying BER development. Aim 3: Expression analyses to identify key regulatory pathways associated with BER. NILs generated would be genetically identical except for the BER loci which will provided putative candidate genes that are a direct consequence of the BER. More information can be found at the project summary.
SNP Discovery in Tomato
The 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.
The development of COS markers for comparative mapping in the Rosaceae and their application for understanding variation in fruit size
The project focuses on characterizing fruit size and quality traits in cherry. This project is in collaboration with Drs. Amy Iezzoni, Wayne Loescher, and Dechun Wang (Michigan State). The goal of this project is the development of the genomic resources needed to implement marker-assisted selection in cherry (Prunus sp.) breeding programs. We plan to accomplish this goal with a standard QTL strategy focused on fruit size and quality traits followed by QTL validation and allele mining. More information on the cherry project can be found at http://www.cherrygenetics.org/ and project summary.
Using Genomic Tools to Identify Interspecific Reproductive Barriers in the Tomato Clade
The 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.
Auxin-regulated fruit development in Arabidopsis and tomato
This project focuses on the role of auxin in fruit set. Adverse environmental conditions that reduce seed set (such as unfavorable weather or absence of insect pollinators) reduce fruit formation, resulting in lower yields for growers. To obtain more reliable production and to satisfy consumer demand, breeders often select for seedless varieties. The purpose of the project is to obtain detailed knowledge of the molecular pathways by which the hormone auxin regulates fruit initiation. This project is in collaboration with Jason Reed at the University of North Carolina. More information can be found at: http://cris.csrees.usda.gov/cgi-bin/starfinder/0?path=fastlink1.txt&id=anon&pass=&search=R=2341&format=WEBLINK.