The aphid transmitted potyviruses (potato viruses Y, A and V) can spread readily during the growing season since application of insecticides to control vector aphids does not effectively control spread of these viruses (which are acquired and transmitted in seconds).

The most effective potyvirus control can only be achieved by the deployment of resistant cultivars. Genes that confer extreme resistance to PVY or hypersensitive resistance to PVY, PVA and PVV have been identified. Of the two, extreme resistance is most effective but such genes have not been mapped for PVA or PVV and many commercial cultivars lack adequate levels of potyvirus resistance.

In this project, we are investigating extreme resistance to potyviruses found in the Institute long-day-adapted population of diploid Solanum tuberosum Group Phureja (the Phureja core collection). In a collaborative project with geneticists, we have mapped the gene (or genes) responsible for the resistance to chromosome 9 (Lesley Torrance, Graham H. Cowan, Karen McLean, Stuart MacFarlane, Aqeel N. Al-Abedy, Miles Armstrong, Tze-Yin, Lim, Ingo Hein, Glenn J. Bryan. 2020. Natural resistance to Potato virus Y in Solanum tuberosum Group Phureja. 133, 967-980) and are now doing work to clone the gene and investigate its mode of action.

Host resistance can be affected adversely by abiotic stresses such as high temperatures. The resistance we have identified is known to lose function at temperatures of 28°C and research is ongoing to study the underlying mechanisms of R gene temperature sensitivity and to identify alleles that function at higher temperatures. This work is allied to the overall Cell and Molecular Sciences department effort on research into biotic/abiotic stress in potato.