Walter De Jong

My research centers around the genetic improvement of potato, both by conventional and molecular genetic means. The breeding program aims to develop new chipping and tablestock varieties that are adapted to the Northeast and meet ever-changing needs of the regional potato industry. The highest priority is to develop agronomically-acceptable varieties that are resistant to the golden nematode, a soil-borne pathogen present in NY but no other state. Resistant varieties provide the single best means to prevent nematode spread. The discovery of a second race, Ro2, in Long Island and now in upstate NY presents a new and serious challenge: how quickly can we develop varieties resistant to both races? To facilitate this we are working to map the gene(s) responsible for Ro2 resistance to permit marker-accelerated selection. The breeding program also seeks to develop potatoes with trichome-mediated broad-spectrum resistance to insects, as well as late-blight resistant varieties. Potatoes with novel coloration, e.g., red or purple or yellow pigmented flesh, are garnering increasing consumer interest. To support breeding of such varieties, and to develop tools useful for understanding many fundamental aspects of gene regulation in tubers, we are working to isolate the genes responsible for most of the natural variation in tuber coloration. To date we have identified genes that correspond to four key color loci – R, required for red tuber color, P, required for purple tuber color, D, required for expression of red or purple in tuber skin, and Y, required for yellow tuber flesh, respectively. Most recently, we have begun work aimed at isolating a gene required for round versus long tuber shape (Ro).

Selected journal articles:

• Hamilton, J. P., Hansey, C. N., Whitty, B. R., Stoffel, K., Massa, A. N., van Deynze, A., De Jong, W. S., Douches, D. S., & Buell, C. R. (2011). Single Nucleotide Polymorphism Discovery in Elite North American Potato Germplasm. BMC Genomics. 12:302.

Book Sections

• De Jong, H., Sieczka, J. B., & De Jong, W. S. (2011). The Complete Book of Potatoes: What Every Grower and Gardener Needs to Know. p. 260 Timber Press, Portland, Oregon, USA.

• PLBRG 6100: Practicum in Plant Breeding
• PLBRG 6500: Special Problems in Research & Teachng