Scientific results of the potato field trials in Flanders and the Netherlands demonstrate that gene stacking is necessary for a strong and lasting resistance to late blight (Phytophthora infestans).
Flemish researchers from Ghent University, VIB and ILVO (involved in the Wetterese GMO potato field trial in 2011-2012) and their Dutch colleagues from Wageningen University & Research Centre have now published the results of their field research in the journal Crop Protection.
The clear conclusion is that only a stack of several genes provides a good resistance to Phytophtora. According to the researchers, potato plant breeders must therefore use a combination of natural resistance genes (which have not previously been applied), to develop new varieties that are less susceptible to diseases.
The field trial with GM potatoes in 2011-2012 in Wetteren caused quite a stir at the time. At least one and up to three natural resistance genes were added to the potatoes, against blight caused by the fungus Phytophthora infestans. Late blight is the greatest threat to potatoes. It is estimated that the disease annually causes 55 million euros in economic damage in Belgium. Potato growers spray on average 15 times a season to keep the disease under control.
The field trials in the Netherlands and Belgium have shown that the tested genes each have a different contribution to the resistance, but that in the end only a stack of several genes provides a good resistance. The resistance gene coming from Solanum venturii had the highest individual contribution to the resistance in field trials, but the best result came eventually from the plants carrying a combination of resistance genes from Solanum venturii, Solanum stoloniferum and Solanum bulbocastanum.
