The stacking of genes is necessary for a strong and lasting resistance to Phytophthora blight. These are the scientific results of the potato field trials in Flanders and the Netherlands.
Researchers from Ghent University, ILVO and VIB -who were involved in the Wetterese GM potato field trial in 2011-2012- together with Dutch colleagues from Wageningen University & Research Centre (Netherlands) published the research results of their field trials in Flanders and the Netherlands in the journal Crop Protection. The clear conclusion is that only a stack of several genes provides good resistance. According to the researchers, potato plant breeders should develop new varieties using a wide combination of previously unapplied natural resistance genes.
As a reminder, the field trial with genetically modified potatoes in Wetteren caused quite a stir at the time. The potatoes in the trial had one up to three natural resistance genes to 'blight,' caused by the fungus Phytophthora infestans. Blight is worldwide and in our country the greatest threat to potato. It is estimated that the disease in Belgium alone, every year causes 55 million euros in economic damage. Potato growers treat the plants on average 15 times per season to keep the disease under control.
The field trials in the Netherlands and Flanders have shown that the tested genes each make a different contribution to resistance. But it is ultimately only the stack of several genes that provides good resistance. More in detail: the resistance coming from Solanum venturii yields the highest individual protection, but eventually, plants that carry a combination of resistance genes coming from Solanum venturii, Solanum stoloniferum and Solanum bulbocastanum performed best.
Haesaert, G., Vossen, J.H,. Custers, R. et al. (2015) “Transformation of the potato variety Desiree with single or multiple resistance genes increases resistance to late blight under field conditions” Crop Protection (77), 163-175.