The van der Knaap lab

Members of the van der Knaap lab From Left: Marin Brewer, Amy Barrett, Maria Stillitano, Nic Welty, Erin Schaffner, Jenny Moyseenko; Esther van der Knaap, Jason Dickey, and Han Xiao

rectangle fruit Breeding and mutation analysis in tomato have resulted in a diverse germplasm collection, providing a rich resource for studies on fruit morphology. Fruit morphological changes often occur during ovary development prior to pollination or during maturation of the fruit after pollination and fertilization. Therefore, tomato varieties displaying altered fruit shape provide unique insights into developmental processes controlling ovary and fruit growth and maturation. Understanding the molecular genetic basis of diversity in fruit form will allow insights into evolutionary processes in tomato as well as other fruit-bearing crops, and modification of developmental processes regulating ovary and fruit formation.

In our laboratory, the basis of variation in tomato fruit shape is studied by taking on a multi-tiered approach. Firstly, we are performing a genetic analysis to identify loci that control variation in fruit shape (van der Knaap et al., 2002; van der Knaap and Tanksley 2003). Selected loci will be fine-mapped to allow identification of the genes underlying the trait (van der Knaap and Tanksley, 2001; van der Knaap et al, manuscript in preparation). Secondly, we are conducting developmental analyses to describe when changes in fruit shape occur during ovary and/or fruit growth. In addition, we want to know which tissues(s) in the ovary or fruit display altered growth characteristics to allow changes in final fruit shape. Thirdly, we are taking a molecular approach to identify genes with altered expression levels during ovary and fruit growth. Also, we are identifying genes with different levels of 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 how fruit morphology is regulated. Lastly, we are taking a bioinformatic approach by developing software to semi-automatically quantify fruit morphological characteristics and integrating analysis of these shape characteristics with gene expression and genotype information.

circle fruit

Contact Information

Esther van der Knaap
Department of Horticulture and Crop Science
204A Williams Hall, The Ohio State University/OARDC
Wooster OH 44691
Tel:330-263-3822; FAX:330-263-3887; email: vanderknaap.1@osu.edu
http://www.oardc.ohio-state.edu/vanderknaap