Improving Economic Traits in Cultivated Potato

Conventionaly bred potato varieties have weaknesses in production or storage that are minimized through management practices or chemical inputs.  Numerous genes have been identified that have potential to improve current potato varieties.  We are exploring the overexpression or silencing of genes to improve potato varieties that will improve the economics of managing pathogens in the field, improve storage management and improve market quality traits.  We have overexpressed eIF4E from Solanum habrochaites in PVY susceptible potato varieties.  We were able to acheive resistance to three PVY isolates (O, N:O and NTN) in inoculated greehouse tests and an aphid-vectored field study (N:O).  We expressed Rpi-blb1 in conventionally-bred late blight resistant lines as a strategy to enhance resistance to Phytophthora infestans.  In lab and greenhouse tests we observed resistance across four different isolates of P. infestans (US8, US22, US23 and US24) and US23 in inoculated field studies.  We reduced expression of the vacuolar acid invertase gene to reduce the conversion of sucrose to reducing sugars in potato tubers.  We were able to identify events that allowed the potato tubers to be stored at 4C and maintain industry acceptable chip-processing color.  These genes and others offer commercial opportunities to release and breed improved potato varieties that can save costs through production and management practices, hence reducing the environmental impact of growing and storing potatoes.