| Potato virus Y (PVY) and Potato leafroll virus (PLRV) are the most important aphid-transmitted viruses in potato. Historically, control of virus spread has been through the use of pesticides to control vectors. However, insecticides are of inconsistent benefit in preventing virus spread, especially for non-persistently transmitted viruses like PVY. A goal of the Minnesota Potato Breeding Program has been to discover resistance to green peach aphid, Myzus persicae (Sulzer) and potato aphid, Macrosiphum euphorbiae (Thomas), and to use marker assisted selection to advance cultivar breeding. I subjected 174 advanced potato lines to intensive selection for resistance to these pests. Potato lines that consistently expressed resistance to both aphids were crossed with current cultivars to produce F1 populations. Aphids were tested for survivorship, development, reproduction and adult longevity. Life tables were constructed and intrinsic rates of increase were calculated. I screened resistant and susceptible plants using a bulked segregant analysis approach with SCAR and SSR markers and mapped green peach aphid resistance in two distinct potato populations. Markers will be used to guide aphid resistance integration into current potato cultivars in the future. Crosses were evaluated for aphid and virus resistance and continued until an acceptable cultivar was produced, containing aphid and virus resistance. In addition, I used electrical penetration graphs to record feeding behavior on resistant and susceptible plants. With these techniques, I ascertained that resistance(s) expressed in our potato lines are due to antibiosis and not antixenosis. |
