Esther van der Knaap
Assistant Professor
Department of Horticulture and Crop Science

Williams Hall 1680 Madison Ave. Wooster, OH 44691 Phone: 330-263-3822 Fax: 330-263-3887

Email: vanderknaap.1@osu.edu

WEBSITE at oardc.osu.edu/vanderknaap/
at OSU since 2001

Laboratory website:  www.oardc.ohio-state.edu/vanderknaap/

Area of interest: Molecular, developmental and genetic basis of tomato fruit morphology and development

Education:

Michigan State University, East Lansing MI                                    Ph.D            1998            Genetics           

Wageningen University, Wageningen, the Netherlands                        BS/MS            1990            Plant Pathology

Positions held:

2006-present            Assistant Professor, Department of Horticulture and Crop Science, OARDC/The Ohio State University, Wooster OH 44691

2001-2006            Research Scientist and Adjunct Assistant Professor, Department of Horticulture and Crop Science, OARDC/The Ohio State University, Wooster OH 44691.

• Post-doctoral Associate, Department of Plant Breeding, Cornell University, Ithaca NY 14853.

1993-1998            Graduate Assistant, MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing MI 48824.

1990-1992             Visiting Scholar, Department Nematology, University of California, Riverside.

Research projects:

Tomato fruit development: 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. 

Tomato SNP discovery: This project aims to identify, utilize and publicize Single Nucleotide Polymorphism (SNP) within cultivated tomato using Conserved Orthologous Sequences (COS). 

Cherry fruit size and marker development: This project focuses on characterizing fruit size and quality traits in cherry breeding populations. 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 molecular marker development, a standard QTL strategy focused on fruit size and quality traits followed by QTL validation and allele mining. 

Interspecies barriers within the tomato clade:  This project centers on identifying loci and genes that control 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.

Role of auxin in fruit development: 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.

Courses taught:

HCS830 Genome rearrangements and phenotypic change

HCS830 Role of domestication genes in plant development

Refereed publications last 5 years:

Olmstead, J.W., A.M. Sebolt, A. Cabrera, S.S. Sooriyapathirana, S. Hammar, G. Iriarte, D. Wang, C.Y. Chen, E. van der Knaap and A.F. Iezzoni. 2008. Construction of an intra-specific sweet cherry (Prunus avium L.) genetic linkage map and synteny analysis with the Prunus reference map. Submitted

Darrigues, A., J. Hall, N. Dujmovic, S. Gray, E. van der Knaap, D.M. Francis. 2008. Tomato Analyzer – Color Test:  a new tool for efficient digital phenotyping. Accepted in J Am Soc of Hort Sci.

Xiao, H., N. Jiang, E. Schaffner, E.J. Stockinger, and E. van der Knaap. 2008. A retrotransposon-mediated gene duplication underlies morphological variation in tomato fruit. Science 319: 1527-1530. Featured on the cover of the journal

Gonzalo, M.J. and E. van der Knaap 2008 A comparative analysis into the genetic bases of tomato varieties exhibiting elongated fruit shape. Theor Appl Genet 116: 647-656

Paran, I. and E. van der Knaap. 2007 Genetic and molecular regulation of fruit and plant domestication traits in tomato and pepper. J Exp Bot 58: 3841-3852

Van Deynze, A., K. Stoffel, C.R. Buell, A. Kozik, J. Liu, E. van der Knaap and D.M. Francis. 2007 Diversity in conserved genes in tomato. BMC Genomics 8:465.

Brewer, M.T., J.B. Moyseenko, A.J. Monforte,and E. van der Knaap 2007. Morphological Variation in Tomato: A Comprehensive Study of Quantitative Trait Loci Controlling Fruit Shape and Development. J Exp Bot 58: 1339-1349

Welty, N., C. Radovich, T. Meulia, and E. van der Knaap 2007. Inflorescence development in two tomato species. Can J Bot 85: 111-118

Labate J.A., M.J. Gonzalo, D.M. Francis, W.Yang, E. van der Knaap et al 2007. Tomato. In: Kole C (ed) Genome Mapping and Molecular Breeding in Plants. Springer, Berlin, Heidelberg, New York.

Tian, M., J. Win, J. Song, R. van der Hoorn, E. van der Knaap and S. Kamoun 2007. A Phytophthora infestans cystatin-like protein targets a novel tomato papain-like apoplastic protease. Plant Physiol 143: 364-377.

Eduardo, I., J. Obando, J.A. Martínez, A. Alarcón, P. Arús, J.M. Álvarez, E. van der Knaap, J.P Fernández-Trujillo, and A.J. Monforte 2007.Estimating the Genetic Architecture of Fruit Quality Traits in Melon Using a Genomic Library of Near Isogenic Lines. J Am Soc of Hort Sci 132: 80-89.

Brewer, M.T., L. Lang,K. Fujimura, N. Dujmovic, S. Gray and E. van der Knaap 2006. Development of a controlled vocabulary and software application to analyze fruit shape variation in tomato and other plant species. Plant Physiol 141: 15-25. Featured on the cover of the journal.

Dujmovic, N., R. Drushal, B. Strecker, E. van der Knaap, M. Brewer and S. Gray 2005. Tomato Analyzer: an application for phenotypic analysis of tomato fruit. Proc Midstates Conf Undergrad Res Comp Sci Math 3:20-29

Van der Knaap, E., A. Sanyal, S.A. Jackson, and S.D. Tanksley 2004. High-Resolution Fine-Mapping and FISH analysis of sun, a Locus Controlling Tomato Fruit Shape, Reveals a Region of the Tomato Genome Prone to DNA Rearrangements. Genetics 168:2127-2140. Faculty of 1000: evaluations for van der Knaap E et al Genetics 2004 Dec 168 (4): 2127-40 http://www.f1000biology.com/article/15611181/evaluation

Yang, W., X. Bai, E. Kabelka, C. Eaton, S. Kamoun, E. van der Knaap and D. Francis 2004. Discovery of single nucleotide polymorphisms in Lycopersicon esculentum by computer aided analysis of expressed sequence tags. Mol Breeding 14:21-34.

Van der Knaap, E. and S.D. Tanksley 2003. The making of a bell pepper-shaped tomato fruit: identification of loci controlling fruit morphology in Yellow Stuffer tomato. Theor and Appl Genet 107:139-147.

Grants past 5 years:

2008            Washington Tree Fruit Research Commission. PI. Identifying sweet cherry fruit size genes and molecular markers

2007-2010            USDA Plant Biology: Growth and development. CoPI. Auxin-regulated fruit development in Arabidopsis and tomato.

2006-2010            NSF-Plant Genome Research Program. Funded collaborator. Using Genomic Tools to Identify Interspecific Reproductive Barriers in the Tomato Clade.

2005-2008            USDA Plant Genome, bioinformatics and genetic resources. CoPI. Genomic Resources to Improve Fruit Size and Quality in Sweet Cherry.

2004-2007            USDA Plant Genome, bioinformatics and genetic resources. CoPI. Development and application of an informative set of anchored markers for tomato breeding.

2004-2006            NSF multi-user equipment award. PI. Instrumentation for high-throughput genotyping and sequencing projects.

2003-2008            NSF Young Investigator Award in Plant Genome Research. PI. Genetic, Molecular and Developmental Analysis of Variation in Tomato Fruit Morphology.

2002-2003            OARDC Research Enhancement Competitive Grants Program, Seed grant. PI. Map-based cloning of SUN, a gene controlling variation in tomato fruit shape.

Other accomplishments last 5 years:

• Undergraduate laboratory internships offered to Mark Hanke (CoW), Patrick McKenzie (CoW), Jason Dickey (ATI), Amy Barrett (ATI), Cody Weisz (ATI), Sarah McNulty (ATI), Erin Schaffner (CoW), Maria Stillitano (Mount U), Nic Welty (Carnegie Mellon), Caitlin Cardina (Oberlin), Katie Gerber (Butler), Elizabeth Wojtowicz (CoW), Claire Anderson (Kenyon), Lucas Tomko (Hiram), Lauren Rackoff (CoW), Stephanie Edmisson (CoW).
• Development of Tomato Analyzer software application (available from our website). Initial development by Lixin Lang and Dr. Kikuo Fujimura (OSU). Upgrades were conducted as part of the College of Wooster AMRE research projects with Dr. Simon Gray and undergraduate students Nancy Dujmovic, Ben Strecker, Rick Drushal, Ellen Wagner and David Sullivan.
• Database construction: http://www.tomatoshapes.net with undergraduate students Dustin Welty, Traian Andrei, Jason Berry, and Dr. Denise Byrnes (College of Wooster).

Last modified: 5/7/2008