Roger T. Chetelat

Roger Chetelat

Position Title
Director, C.M. Rick Tomato Genetics Resource Center

Department of Plant Sciences, College of Agricultural and Environmental Sciences

104 Asmundson Hall

Profile Introduction

Molecular and classical genetics of tomato; wide hybridization and interspecific incompatibility; use of molecular markers in breeding; germplasm conservation.

Research Interests

Interspecific Reproductive Barriers

We study prezygotic interspecific reproductive barriers using cultivated tomato and related Solanum species as a model. Our focus is on the pollen factors that regulate unilateral interspecific incompatibility and their role in self-incompatibility. Two of these factors, a Cullin1 and an S-locus F-box protein, are involved in overcoming S-RNase based pollen rejection in both intra- and interspecific incompatibility.  Another factor, FPS2, participates in an S-RNase independent pollen rejection mechanism.   We're interested in understanding not only the mechanisms of pollen rejection but also how the underlying genes contribute to mating system changes and reproductive isolation between populations and species.

Genetic Resources

Using marker assisted selectxion, we are transferring the genome of Solanum sitiens, a species endemic to the Atacama Desert of Chile, into the genetic background of cultivated tomato. The goal is to synthesize a comprehensive library of introgression lines, each containing single recombinant chromosome segments that together represent an entire donor genome. These lines are being used to map QTLs for pollen-pistil incompatibility traits.  In the future we would like to use them to identify QTLs or genes for increased abiotic stress tolerance.


Grad Group Affiliations

  • Horticulture and Agronomy
  • Integrative Genetics and Genomics

Specialties / Focus

  • Plant Breeding


  • 151 Asmundson Hall
    • Kaoru Tonosaki
    • Xiaoqiong Qin
    • Scott Peacock
    • Oliver Betz
  • C.M. Rick Tomato Genetics Resource Center/ Annex 9, Asmundson Hall
    • Scott Peacock
    • Tom Starbuck
    • Magdalena Mendoza
    • Anastasia Mathews
    • Kyle Johnson
    • Emily Shoenborn

Field Sites

  • Vegetable Crops Fieldhouse / greenhouse facilities

Honors and Awards

  • Fellow of AAAS

    Professional Societies

    • American Association for the Advancement of Science
    • Botanical Society of America


    • 1979 BS Biology Santa Clara University
    • 1983 MS Plant Physiology University of California, Davis
    • 1994 PhD Genetics University of California, Davis


    Markova, D. N., J. J. Petersen, S. E. Yam, A. Corral, M. J. Valle, W. Li, and R. T. Chetelat (2017). Evolutionary history of two pollen self-incompatibility factors reveals alternate routes to self-compatibility within SolanumAmerican Journal of Botany (in press).

    Baek, Y. S., S. M. Royer, A. K. Broz, P. A. Covey, G. López-Casado, R. Nuñez, P. J. Kear, M. Bonierbale, M. Orillo, E. van der Knaap, S. M. Stack, B. McClure, R. T. Chetelat and P. A. Bedinger (2016). Interspecific reproductive barriers between sympatric populations of wild tomato species (Solanum section Lycopersicon). American Journal of Botany 103:1964-1978.

    Markova, D. N., J. J. Petersen, X. Qin, D. R. Short, M. J. Valle, A. Tovar-Méndez, B. A. Mcclure and R. T. Chetelat (2016). Mutations in two pollen self-incompatibility factors in geographically marginal populations of Solanum habrochaites impact mating system transitions and reproductive isolation. American Journal of Botany 103: 1847-1861.

    Toal, T. W., D. Burkart-Waco, T. Howell, M. Ron, S. Kuppu, A. Britt, R. Chetelat and S. M. Brady (2016) Indel Group in Genomes (IGG) Molecular Genetic Markers. Plant Physiology, vol. 172: 38-61.

    Chetelat, R. T. (2016) Overcoming sterility and unilateral incompatibility of Solanum lycopersicum × S. sitiens hybrids. Euphytica 207:  319-330.

    Li, W and RT Chetelat (2014) The role of a pollen-expressed Cullin1 protein in gametophytic self-incompatibility in Solanum. Genetics 196:439-442.

    Powell, ALT, C Nguyen, et al. (2012) Uniform ripening encodes a Golden 2-like transcription factor regulating tomato fruit chloroplast development. Science 336: 1711-1715.

    Li, W, and RT Chetelat (2010) A pollen factor linking Inter- and Intraspecific Pollen Rejection in Tomato. Science 330: 1827-1830.

    Tam, SM, JB Hays, and RT Chetelat (2011) Effects of suppressing the DNA mismtach repair system on homeologous recombination in tomato. Theor. Appl. Genetics 123: 1445-1458.

    Li, W, S Royer, and RT Chetelat (2010) Fine mapping of ui6.1, a gametophytic factor controlling pollen-side unilateral incompatibility in interspecific Solanum hybrids. Genetics 185: 1069-1080.

    Bedinger, PA, R Chetelat, B McClure, LC Moyle, JKC Rose, S Stack, E van der Knaap, Y Baek, G Lopez Casado, PA Covey, A Kumar, W Li, R Nunez, F Cruz-Garcia, and S Royer (2010) Interspecific reproductive barriers in the tomato clade: opportunities to decipher mechanisms of reproductive isolation. Sex. Plant Reprod. (online DOI 10.1007/s00497-010-0155-7).

    Albrecht, E, M Escobar, and RT Chetelat (2010) Genetic diversity and population structure in the tomato-like nightshades Solanum lycopersicoides and Solanum sitiens. Ann. Bot. 105: 535-554.

    Tam, SM, S Samipak, A Britt, and RT Chetelat (2009) Characterization and comparative sequence analysis of the DNA mismatch repair MSH2 and MSH7 genes from tomato. Genetica 137: 341-354.

    Chetelat, RT, RA Pertuze, L Faundez, EB Graham, and CM Jones (2009) Distribution, ecology and reproductive biology of wild tomatoes and related nightshades from the Atacama Desert region of northern Chile. Euphytica 167: 77-93.

    Albrecht, E, and RT Chetelat (2009) Comparative genetic linkage map of Solanum sect. Juglandifolia: evidence of chromosomal rearrangements and overall synteny with the tomatoes and related nightshades. Theor. Appl. Genet. 118: 831-847.

    Jones, CM, CM Rick, D Adams, J Jernstedt, and RT Chetelat (2007) Genealogy and fine mapping of obscuravenosa, a gene affecting the distribution of chloroplasts in leaf veins, and evidence of selection during breeding of tomatoes (Lycopersicon esculentum; Solanaceae). Amer. J. Bot. 94: 935-947.

    Canady, MA, Y Ji, and RT Chetelat (2006) Homeologous recombination in Solanum lycopersicodes introgression lines of cultivated tomato. Genetics 174: 1775-1778.

    Canady, MA, V Meglic, RT Chetelat (2005) A library of Solanum lycopersicoides introgression lines in cultivated tomato. Genome 48: 685-697.

    Pertuze, RA, Y Ji, and RT Chetelat (2003) Transmission and recombination of homeologous S. sitiens chromosomes in tomato. Theor. Appl. Genet. 107: 1391-1401.