This article appears in the January 2018 issue of Potato Grower.
A genetically improved potato designed to have resistance to a devastating global plant disease has successfully come through the first year of field trials.
The field trial conducted by The Sainsbury Laboratory (TSL) in the United Kingdom involves incorporating late blight-resistant genes from a wild potato relative into a cultivated Maris Piper potato (a popular variety in Europe).
“The first year of the Maris Piper field trial has worked brilliantly,” says TSL’s Jonathan Jones. “We’ve observed resistance to late blight in all the lines.”
Late blight in potatoes is a global challenge, a devastating crop disease that can wipe out whole fields of potato plants. At present, crops all over the world must have multiple treatments with fungicide to combat the pathogen and ensure a good harvest.
Plants have powerful defense mechanisms against diseases, but to work they must be activated, and this requires the plant to detect the disease-causing organism. The potato modification involved the addition of three genes that enable late blight detection. After the first year of the field trial, scientists observed a marked improvement in late blight resistance. The image below shows the differences between the resistant plants, which look healthy, and the heavily blight-affected, non-resistant plants. The plants have been scored for resistance, and the results of the trial will be published following further field trials in future years.
Because the resistant lines carry three different added detection genes, it will be more difficult for the pathogen to evade detection and infect the crop. In effect, the potatoes will have more lines of defense against the disease.
Maris Piper is a highly popular main crop variety in the UK, selected for these experiments with the objective of retaining its desirable characteristics while adding late blight resistance.
“We have the technology to solve the problems that affect many people’s livelihoods,” says Jones, highlighting the trial’s success and the important of this research. “Crop diseases reduce yields and require application of agrochemicals, and this field trial shows that a more sustainable agriculture is possible.”
Alongside resistance to blight, in field trials next year the modified Maris Piper will also carry traits that improve tuber quality. Two genes will be switched off in the plant, a process known as silencing. This means the new crop will be less prone to bruise damage, making it easier to ensure the potatoes meet customer quality specifications. The second trait, brought about by silencing an invertase gene, leads to lower levels of reducing sugars in low-temperature storage, which will reduce blackening and formation of acrylamide when potatoes are cooked at high temperatures—for instance, when cooking chips of fries.
This work is being carried out on a Biotechnology and Biological Sciences Research Council-funded Horticulture and Potato Initiative grant, in partnership with Simplot Plant Sciences in the U.S. and BioPotatoes Ltd. in the UK.