If we were to poll readers about the most loathed insect pest, I suspect the winner might be the Colorado potato beetle. You can repel the beetles using heavy mulches and companion planting, and you can delay your planting time to reduce pest pressure. This helps to a certain degree. Farmers and gardeners have vacuumed them up, squashed them and cursed them. Now there may be a better solution, or at least another tool to add to the other tactics — growing potato plants with resistance to the beetles.
Dr. Yvan Pelletier has looked to the wild relatives of potatoes for answers. Dr. Pelletier is a retired scientist with Agriculture and Agri-Food Canada (AAFC) in Fredericton, NB. He found that potato beetles prefer not to eat the leaves of Solanum oplocense, a wild relative of cultivated potatoes (Solanum tuberosum).
Since the Irish Potato Famine of 1845-46, plant breeders have developed new potato strains by crossing conventional potatoes with their wild relatives from South America. Breeding initially focused on blight resistance.
Recently, Dr. Helen Tai, an AAFC potato genomics scientist, analyzed the leaves of the wild plant and identified the chemicals linked with resistance to the beetles. AAFC plant breeders cross-pollinated the wild plant with cultivated potatoes. The cross was done in the greenhouse using traditional plant breeding, not genetic engineering. In Canada, cross-pollination for potato breeding is done in a heated greenhouse. The flowers of the cross-pollinated plants produce actual seeds (not seed potatoes). These seeds are stored and planted in the greenhouse to grow plants that produce small mini tubers (small seed potatoes). The mini seed potatoes are collected and will be planted at the AAFC breeding farm in New Brunswick the following spring.
At the breeding farm, AAFC potato breeding scientist Dr. Benoit Bizimungu, selects plants that produce tubers that meet the needs of Canadian farmers and consumers. He then further screens for Colorado potato beetle resistance as well as resistance to other diseases. The resulting potato selections are now being grown out in research fields and on a few farms. If all goes well, a potato with resistance to the Colorado potato beetle will be available soon.
- Janet Wallace