Paises bajos: How Crop Science Is Transforming the Humble Potato

n a field near the Dutch village of Angeren, a biotechnology company named Solynta grows potatoes in square plots, about 16 by 13 feet each. One afternoon last summer, Hein Kruyt, then the company’s CEO, paced around the field, pointing at the leafy spuds. The plants looked vigorous but not particularly special. And yet their genetic make-up, potato breeders say, is something extraordinary.

Solynta’s potatoes are at the vanguard of a breeding project, launched almost two decades ago, that has shaken up the world of potato research. They are products of hybrid breeding, a technology that has improved many crops beyond breeders’ wildest dreams — but not most commercially grown potatoes, due to a quirk in their biology. As a result, potato breeding is so slow that people today are still eating many of the same cultivars their great-grandparents did a century ago.

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Experts say Solynta has cracked that problem, which helped lay the groundwork for a revolution in potato breeding.

Hybrid breeding will enable breeders to create new varieties faster and more systematically, said Shelley Jansky, a retired plant breeder at the U.S. Department of Agriculture and a professor emeritus at the University of Wisconsin-Madison. New potato cultivars could better withstand diseases, heat, drought, or salt. Yields could increase. Boutique varieties could have more interesting tastes, shapes, or colors. And there’s no genetic engineering required, a huge advantage given regulatory hurdles and public opinion, said Kruyt, who’s now the company’s chief financial officer.

Major advances in agriculture usually debut in wealthy countries, and only make it to the Global South years later, if they get there at all. But the potato revolution, if indeed it materializes, may start in Africa. Solynta started selling its potato seeds in 2023 but the spuds — and those from other companies that have jumped on the bandwagon — aren’t quite competitive yet in Western countries; their yield is still below the roughly 39,500 pounds per acre that Western European and U.S. farmers harvest every year, on average. However, their yields are already substantially higher than the average in the highlands of East Africa, where most African potato farming occurs.

Kenya may go first: The Kenya Plant Health Inspectorate Service officially approved three of Solynta’s first hybrid potato variants in April. And in late June, Solynta announced a deal with pharmaceutical and agricultural giant Bayer to distribute its potato seeds in that country and in India.

A field near Angeren, Netherlands, where Solynta tests various new varieties of hybrid potatoes. Visual: © Solynta

The timing is auspicious. Potato production in Africa has doubled over the past two decades, and policymakers increasingly think the nutritious tubers could play an important role in feeding the continent’s burgeoning population, said Elly Atieno of the International Potato Center in Nairobi, Kenya. “In Kenya, I think it’s now the second crop, and the government is really giving it a lot of attention,” Atieno said. “I see the same trend in countries like Rwanda, Uganda, Tanzania.”

“I’ve been following this technology for 15 years. As a potato expert, I was always interested. And now I think the time has come where it can begin to make an impact,” said Peter Gildemacher, a tropical agronomist who co-founded and leads the Sepia Foundation, which hopes to help introduce hybrid potatoes in sub-Saharan Africa. (The foundation has received funding from Solynta but operates independently from the company.) “I think it would be cool if, for once, Africa was a frontrunner.”

It’s hard to overstate the importance of hybrid breeding, which has been used in many crops throughout the last century. The basic idea is simple. Through rounds of self-fertilization, breeders create inbred plant lines that have the same version of a gene on both of their chromosomes. Inbreeding tends to lead to feeble, lackluster plants, but when two inbred parental lines are crossed, their progeny is often healthy and vigorous.

A key advantage of hybrid breeding is that it’s easy to introduce new traits. If, for example, breeders find a wild maize variant that is resistant to a pest, they can cross it with one of their inbred lines and then, using a method called backcrossing, eliminate virtually all the wild plant’s genes except the ones conferring resistance. This process, which takes a couple of generations, lets breeders add desirable traits one by one.

Another advantage of hybrid breeding is uniformity. All the seeds from a cross of two inbred parental lines have the exact same genetic make-up, providing a high degree of predictability that farmers value.

“I think it would be cool if, for once, Africa was a frontrunner.”

To create inbred lines, however, breeders typically self-fertilize plants over and over. That’s long been impossible with potato plants, which have a natural protection system against inbreeding. To complicate matters further, most commercially grown potato varieties are tetraploid instead of diploid, meaning they have four sets of chromosomes in each cell instead of two. That makes breeding like “throwing the dice to see what the offspring are like,” Jansky said, which isn’t a very efficient way of developing new varieties.

About two decades ago, Dutch plant geneticist Pim Lindhout decided to sink his teeth into this problem. Lindhout had worked at Wageningen University & Research for almost two decades, specializing in tomato breeding, and in 2006 he joined De Ruiter Seeds, a major leader in vegetable seeds whose CEO wanted to branch out into potatoes. Lindhout accepted the challenge, but “I said, guys, that research is so primitive,” he says he told colleagues at the time. “There has to be a different way.” But others had tried to improve potato breeding, in vain, for a century, he said. “People always give me this pitying look. ‘Pim, you’re thinking like a tomato,’ they said. ‘Potatoes are different. You need to think like a potato.’”

U.S. seed giant Monsanto bought De Ruiter in 2008 but was not particularly interested in the potato research, Lindhout said. A special carve-out in the acquisition deal, he said, allowed him and three colleagues to acquire the potato work, which they pursued in their own time.

The stakes, they knew, were high. Hybrid breeding would allow them to combine the best characteristics of existing cultivars. Or they could introduce desirable traits from the staggering biodiversity of locally grown potatoes in South America — for instance, to create varieties better able to withstand the effects of climate change, or that are resistant to the many fungal, bacterial, and viral diseases that plague potatoes.

The female flowers on a potato plant in a Solynta greenhouse are treated to avoid self-pollination. To breed a new potato variety, carefully selected male plant pollen is used to fertilize female plants. Visual: © Solynta

Propagation of a hybrid potato plant in Solynta’s lab. Visual: © Solynta

One other benefit: hybrid potatoes could be grown directly from seeds, rather than from the expensive egg-sized tubers, called seed potatoes, that are currently required to plant each season’s potato crop. Seed potatoes are bulky, costly to ship, and perishable; “true potato seeds,” as breeders call them, are tiny, weigh almost nothing, and will last for years. They make it much easier to introduce any newly bred cultivar anywhere in the world.

In 2010, Lindhout left Monsanto, along with Kruyt and two other colleagues, to work fulltime for Solynta, which they had founded in 2007. In a 2011 paper in the journal Potato Research, they announced the creation of their first stable, inbred potato lines. Solynta’s team had produced them using a gene named Sli, discovered in 1998, that allows a wild potato species to self-fertilize. Breeding the gene into other varieties allows them to inbreed as well. And, because Lindhout and his team had started with diploid plants, they didn’t have to deal with the messiness of tetraploid varieties. Though the first inbred lines produced puny tubers, hybrid breeding opened up a new world.

Solynta’s work has caused a great deal of excitement in the traditionally staid world of potato breeding. HZPC, a Dutch company that has bred potatoes the traditional way for more than a century, has accelerated its hybrid potato breeding program, launched in 2010. The J.R. Simplot Company, a giant U.S. producer of potatoes and frozen French fries, has teamed up with German seed producer KWS to develop hybrid potatoes specifically aimed at the potato chip and French fry industries. Their joint venture, named Aardevo, is also based in the Netherlands. U.S. scientists funded by the USDA have launched the Potato 2.0 Project. And Sanwen Huang, one of Lindhout’s former Ph.D. students, is developing hybrid potatoes at an institute of the Chinese Academy of Agricultural Sciences in Shenzhen.

With the explosion of interest has come a classic intellectual property fight. Solynta has obtained patents on the creation of hybrid diploid potatoes in the European Union, the United States, and several other countries, and is open to making deals to license the technology, Kruyt said. “I don’t know how you would make hybrid potatoes without using my claims,” he said.

Solynta potato seeds that have been harvested from potato berries. In a 2011 paper, Solynta’s team announced the creation of their first stable, inbred potato lines. Shown here are “naked” seeds; later a special clay coating is added to make it easier for growers to sow the seeds. Visual: © Solynta

But a law office in London has challenged the European patent — on whose behalf is unclear — claiming, among other things, that Solynta’s method is not really new and does not contain an “inventive step.” And Solynta believes Aardevo is infringing on its patent. In July 2023, authorities visited Aardevo’s office for an unusual evidence seizure at the request of Solynta. Aardevo declined to answer questions about the case, but a statement on its website says the company’s work “does not infringe a valid patent,” and calls Solynta’s case “unfounded.”

Regardless of how such conflicts are resolved, Solynta’s potato seeds will likely take at least four years before widespread introduction, Kruyt said, because yields must improve further. Aardevo’s former managing director Paul van den Wijngaard, said its products won’t be ready until after 2030. “Eventually, in 15 to 20 years, I think the whole tetraploid system will be replaced,” said Huang.

In the meantime, Solynta and HZPC have turned their attention to East Africa, where the current average potato yield is just 9,000 pounds per acre, one fifth of the United States. Part of the reason is that African farmers typically reserve part of their harvest to plant the next season, which causes fungal, bacterial, and viral diseases to accumulate over generations, reducing yields. (Although a few seed potato companies exist in Sub-Saharan Africa, the region lacks the extensive, tightly regulated potato seed sector that rich countries have developed, in part because tubers are so costly and difficult to transport.)

“Eventually, in 15 to 20 years, I think the whole tetraploid system will be replaced.”

True seeds are a much cleaner starting material, because very few diseases spread through seeds. Solynta’s varieties, which are resistant to late blight, the fungus that caused the great Irish potato famine, have the potential to double yields “immediately,” according to Kruyt.

Wachira Kaguongo, chief executive of the National Potato Council of Kenya, predicts farmers will embrace the hybrid potato. The technology is “very suitable and very good for farmers,” he said, “because it tries to address all of the challenges, to a large extent, in terms of storability, in terms of transportation, in terms of reduced disease.”

Beans at the CIAT gene bank in Colombia, which has just sent its latest consignments of seeds for conservation at the Global Seed Vault in Svalbard, Norway.

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Kaguongo likened the arrival of hybrid potatoes to the introduction of mobile phones, which took Africa by storm in part because there were so few land lines. “It happened very fast because there was gaps in telecommunication,” he said. Because a seed potato system is lacking, “the same thing could happen here.”

Exactly how hybrid potatoes will find their way to African fields is still unclear, however, according to Kaguongo. Farmers could buy and sow their own seeds and grow them all the way into mature plants, he said, as most vegetable farmers now do. But in many places on Earth, the season is too short to grow a mature plant from seed. Besides, starting with true seeds takes dedication and care that potato farmers aren’t always used to investing. Tubers, which have their own nutrients and water, are much easier to grow. That’s why some experts believe specialized farmers could produce seed potatoes, or even seedlings, from seeds and sell them to farmers nearby, who would still get the benefit of disease-free starting material and access to breeding innovations.

Kaguongo said several models will have to be tried. Gildemacher said he believed the way to go is to foster a specialized business that grows seed potatoes from seeds. The Sepia Foundation, which he co-founded, hopes to partner with local organizations to facilitate this transition across Africa.