Hybrid potato can help feed

Published: 14-01-2014, | Member: Solynta

In the early days, Lindhout’s garage doubled as a storage room for his research potatoes. In cold and wet weather, he had to move them to his bathroom. This typifies Lindhout, a man with vision, a goal, and the drive to get his ideas off the ground. Even if that meant his family sometimes had to put up with potatoes in their bathroom. That was back in 2008, when Lindhout had just launched Solynta, a biotech company that breeds new potato varieties using modern techniques. “But I actually started out breeding tomatoes, first as a researcher at Wageningen UR and later for De Ruiter Seeds. There I came across potato breeders and saw that developing new potatoes was a completely different matter from tomatoes. The portfolio of available tomato varieties is overhauled every five years. They keep getting juicier, sweeter and more disease-resistant. But producing a new potato variety takes at least 15 years. Genetically, potatoes haven’t changed in decades! No wonder we’re still growing Bintje, a variety that’s almost a century old,” says Lindhout.

Tetraploid versus haploid
But why is it so much more time-consuming to develop a new potato variety? Lindhout: “Market potato varieties are tetraploid. This means their DNA has four copies of each chromosome. Many other plants are diploid, so there are only two copies of each chromosome in the DNA. When crossing tetraploid plants, many undesirable genes are passed on as well, so it takes years to develop a new variety in which the negative genes are offset by other, positive genes and you end up with a variety that has the traits you’re looking for.” “The selection process is empirical and takes an incredibly long time,” Lindhout explains. Therefore, tomato breeding tends to use diploid varieties, which are inbred to effectively eliminate negative genes. Genetically speaking, this is very profitable and results in better hybrid varieties. However, applying this principle to potatoes is not as straightforward as it seems because of a strong inbreeding depression, a prevalence of weak and dead plants. Potato breeders had tried many times to circumvent inbreeding depression but the results were disappointing. It was assumed that the hybrid breeding technique simply was not applicable to potatoes. “This was exactly what triggered me,” says Lindhout. “The challenge was to produce hybrid potatoes which had been strongly inbred yet contained the desired traits. With my knowledge of genetics and breeding I was sure it could be done. So I started experimenting.”

Wild potato gene
Lindhout’s experience as a researcher and the freedom of being self-employed paid off. In 2009, after years of experiments, he achieved a breakthrough. Lindhout’s company Solynta had started to work with diploid potatoes from Wageningen University’s breeding program and crossed these with a semi-wild potato species from Japan containing the Sli-gene. Introducing this gene made it possible to successfully inbreed diploid potatoes and to obtain homozygous diploid lines. This made it possible to identify and eliminate unwanted properties. Subsequent crossing of these lines created a hybrid potato that resulted in bigger tubers or a higher yield. This technology has been successfully used in corn breeding, producing hybrid varieties that yield up to five times as much as the original species. Lindhout: “I presented my breakthrough with the potato at a conference in Finland in 2011. The audience was skeptical. I think they felt threatened because this technology could truly revolutionize potato breeding. We were not taken seriously. In early 2012, we published our findings in a scientific journal and distributed this throughout our network. Again, we encountered resistance, but over the course of that year we saw that there was a growing interest in our technology.”


Ambitious goals
Despite the skepticism of other potato breeders, or perhaps thanks to it, Solynta is determined to prove that hybrid breeding technology works. The company aims to introduce a new variety by 2015 and sa ys it is 60 to 70% of the way towards reaching that goal. Their next objective is set for 2018: to introduce a Phytophtora-resistant potato with a higher yield than current varieties. This would be a huge achievement, since half of all chemicals currently used in Dutch agriculture are deployed to combat this plant disease. Lindhout: “In twenty years or so, our technology will be commonplace in the world of potato breeding. New hybrid varieties will be sold as seed rather than seed potatoes. Seeds are also much cleaner than seed potatoes, making it easier to export the new varieties.” However, introducing new varieties is costly. “In that respect, winning the 2012 Food Valley Award has been a great help. It raised the interest of potential investors. We’re also exploring our options to do business in China. After all, the Chinese consume more potatoes than any other nation in the world, so there must be plenty of opportunities there,” says Lindhout.

Apart from the financial challenge, Solynta also has to jump through some regulatory hoops. “Certification of seeds and phytosanitary rules and regulations urgently need harmonization at the European level,” says Lindhout. All in all, these are exciting and challenging times for Solynta, the biotech company that has come a long way, from storing its propagation material in a bathtub to revolutionizing the field of potato breeding. “We are going to change the way the world breeds potatoes forever. Because hybrid varieties can help feed the growing world population. What better goal to strive for?”