Episode three of the second season of Free the Seed! the Open Source Seed Initiative podcast
This podcast is for anyone interested in the plants we eat – farmers, gardeners and food curious folks who want to dig deeper into where their food comes from. It’s about how new crop varieties make it into your seed catalogues and onto your tables. In each episode, we hear the story of a variety that has been pledged as open-source from the plant breeder that developed it.
In this episode, host Rachel Hultengren spoke with Bill Whitson about ‘Rozette’, a new potato variety that Bill developed and pledged as open-source.
Be sure to check out Bill’s blog post about selecting ‘Rozette’, which includes more photos of the candidate lines that he considered during the project: https://www.cultivariable.com/potato-the-story-of-rozette/
‘Ozette’ potato tubers; ‘Ozette’ flower; minitubers from true seed of ‘Ozette’; first generation of ‘Rozette’ (Photo credit: Bill Whitson)
– Visit the Cultivariable website to purchase true potato seeds and tubers. (Please note that Cultivariable is taking a break from selling tubers this year in order to focus on growing clonal crops from tissue culture, so ‘Rozette’ will likely be available next in 2020).
– Kenosha Potato Project http://kenoshapotato.com/
– Slow Food Ark of Taste https://www.fondazioneslowfood.com/en/slow-food-presidia/makah-ozette-potato/
– Carol Deppe’s Breed Your Own Vegetable Varieties
Let us know what you think of the show!
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Free the Seed! Transcript for S2E3: Rozette Potato
Rachel Hultengren: Welcome to episode three of the second season of Free the Seed!, the Open Source Seed Initiative podcast that tells the stories of new crop varieties and the plant breeders that develop them. I’m your host, Rachel Hultengren. Every episode we invite a plant breeder to tell us about a crop variety that they’ve pledged to be open-source.
My guest today is Bill Whitson. Bill is the owner of Cultivariable, an experimental nursery on the central coast of Washington state. He breeds a large number of minor crop species, but focuses on the Andean root and tuber crops mashua, oca, ulluco, yacon, and potato. In the past ten years, he has released 37 new varieties belonging to nine species and all varieties released since 2013 have been OSSI pledged.
Rachel Hultengren: Hi Bill – welcome to the show!
Bill Whitson: Hi Rachel, thanks for having me!
Rachel Hultengren: Yeah, we’re really excited to get to chat today! So we’ll be talking about your potato breeding, and specifically about a variety you’ve just released, ‘Rozette’, but first maybe we could take a broad view to start, and then focus in. So let’s talk about the natural history of potatoes. Where in the world are potatoes from, and how long have they been cultivated there?
Bill Whitson: So we don’t really know how long potatoes have been cultivated, but they originated in the highlands of the central Andes, so think southern Peru and Bolivia. And they were probably first domesticated something like 10,000 years ago. And those landraces and lines of potatoes are now a distinctive group known as ‘Andean potatoes’, or Solanum tuberosum andigenum, which are varieties that are primarily adapted to grow in short-day photoperiods.
So what that means is that they don’t produce tubers until the daylength falls to 12 hours or less. And that’s because they evolved near the equator, where the day length changes very little. And this is a common feature you see in tropical plants. That’s kind of an inconvenient feature if you’re growing away from the equator, where the daylength changes a lot.
Because, for example, in North America we don’t have a 12 hour day length until fall. So about September 22nd is when we get to that point. So if you’re waiting on potatoes to produce tubers until September 22nd, there are very few climates where that’s going to work out well for you. The plants are going to be killed by frost, or they’re going to be drowned in the field by rains, so there are a lot of problems to that.
But there was a branch of potatoes that was established later – we’re not sure exactly when, probably several thousand years after they were domesticated in the Andes – in coastal Chile. And those became the [Tuberosum] group of potatoes, that over time adapted to the differing daylengths in coastal Chile and became capable of tuberizing under any length of day, so we call those day-neutral potatoes. And those, then, became the basis of the modern potato. So we don’t exactly know all the contributions, but most of what went into the European potatoes were contributions from Chilean landraces of potatoes, and then various diverse contributions that have been added through modern breeding. For example, there are about one hundred species of wild potato that are now sometimes used in modern breeding to further add genetic diversity.
So it’s a fairly complex picture, but the homeland of the potato is the central Andes, and then the homeland of really the potato of commerce in North America and Europe is Chile.
Rachel Hultengren: So the Chilean potato is the basis for the potatoes that we have here in North America at a large scale, and the potatoes that went to Europe initially. So what was the path of travel like for potatoes from the coast of South America to get to where we are now?
Bill Whitson: So, yeah. The potatoes were first carried to Europe in the 1500’s. The Spanish discovered the crop as they moved their way through the Andes, and eventually they began to ship potatoes probably from both sides of South America on their trading routes. So it’s not completely clear what exactly ended up in Europe. It’s likely that potatoes from the Andes were initially taken there, and then somewhat later potatoes from Chile. And eventually, as everyone knows, they had terrible problems with late blight in Europe, which became the Irish potato famine. And that probably wiped out a lot of the original Andean potatoes that had been carried to Europe. It gets very unclear after that point, exactly what happened. There were probably contributions from both Andean and Chilean potatoes, and at this point it’s likely that more of the potatoes that survived were potatoes from Chile.
One of the major progenitors of modern potatoes is a – or was, it no longer exists – was a potato cultivar known as ‘Rough Purple Chili’, which was taken from Chile to somewhere on the East Coast of the U.S., and that became the foundation of breeding for late blight resistant potatoes. And that particular landrace is in the background of something like 80% of modern commercial potato varieties.
Rachel Hultengren: Wow. Apart from that ‘Rough Purple Chili’, did most potato varieties stop in Europe on their journey between South and North America?’
Bill Whitson: Right, so at first, most of them went to Europe, where some amount of work and selection was done, and then were brought to the U.S. But that ‘Rough Purple Chili’ represented a break where suddenly the United States became a center of new potato development. And then varieties that developed from that were being sent to Europe to help with the problem of producing potatoes that were resistant to Late Blight. So from that point on, it was kind of a transatlantic trade in potatoes that has just continued ever since. And of course, with the advent of modern plant breeding around the time of World War II, things have really opened up a lot. From that point forward, people started making large collections of germplasm in South America and introducing genetics from wild potatoes and broadening the genetic base of the potatoes of commerce quite a bit. But the early potatoes that we had in the United States came almost completely from European lines.
Rachel Hultengren: Scientists have recently used genetic analysis to determine that there was likely another path of dissemination for potatoes in the U.S., which was up the West coast as the Spanish came. And one of these varieties is one that you’ve worked with, which is ‘Ozette’. Can you tell me the story of that variety?
Bill Whitson: Yeah, so ‘Ozette’ really represents a bit of a break from the standard story of the potato, and that wasn’t recognized until fairly recently. So ‘Ozette’ is a potato that has been maintained by the Makah people of the Olympic Peninsula [of Washington State] for about 200 years. And it’s a kind of unusual-looking potato. It’s a fingerling type, so it’s longer than it is wide, and it has deep eyes, which is a feature that you commonly find in what are commonly termed ‘primitive potatoes’. So you would see that a lot in Andean potatoes and Chilean landraces, but it was usually bred out very quickly from European potatoes for reasons I’m not completely clear on.
So it was a bit of a mystery, where this potato came from. It doesn’t look much like other potatoes we have in the United States, and it wasn’t… nobody was really aware that it was there until the late 1980’s, when the USDA National Plant Germplasm Repository did a collection there. And not long after, it was commercialized by Ronniger’s Potato Farm and became available pretty widely.
But it wasn’t until 2010 that they did some research and looked into the genetics of this potato and discovered that it pretty clearly traces its origin back directly to Chilean potatoes instead of to those lines that were introduced from Europe or were introduced to the East Coast of the U.S. So from there, they puzzled out that it probably represents a unique introduction.
The Spanish in the 1700’s had trade routes up and down the West Coast of North and South America with stops in Chile and Mexico. So the thought is that ‘Ozette’ was probably either brought directly from Chile, or originated in Chile and made a stop in Mexico on the way up the coast before it was ultimately planted in a garden at a fort (near Lake Ozette on the Olympic Peninsula) that only lasted for about a year. So you can imagine the crazy investment it took to get this potato to the Olympic Peninsula; they had to sail ships all the way up the coast from Chile, they had to establish a fort, they had to build a garden, and then they went away a year later. And the only thing that was really left a hundred years later was this potato that was kept by the Makah. So it’s a pretty cool story.
Rachel Hultengren: That seems like quite a journey for that potato to make.
Bill Whitson: Yeah, and it’s not the only one. There are a couple of other varieties that have been stewarded by tribes in the Pacific Northwest that probably came here the same way. But ‘Ozette’ is by far the most commonly available and popular of those varieties. I believe it’s been inducted into the [Slow Food] Ark of Taste, and so that gave it a lot of press, and it’s become a fairly popular variety, particularly in the Pacific Northwest.
Rachel Hultengren: So ‘Ozette’ is the starting point that you used for developing this new variety, called ‘Rozette’. Maybe you can tell us why you chose… I mean, it sounds like there were a lot of great qualities to ‘Ozette’, but what particularly stood out to you to make that one of the parent lines that you wanted to use?
Bill Whitson: Sheer ignorance, really, is my excuse for trying to breed with ‘Ozette’. It’s a great potato for this climate, but it’s a terrible potato to breed with. Potatoes have a lot of hurdles that you have to overcome to be able to breed with them, and it varies a lot from one variety to another. But ‘Ozette’ has kind of the full set of problems that we deal with in potatoes. And the worst of those is that it very rarely flowers. This is a problem we see with a lot of potatoes, most likely because they’ve been clonally propagated for long periods of time. In many cases that means that they’ve accumulated genetic load and lost the ability to reproduce sexually very effectively.
Rachel Hultengren: Can you say a little bit more about that genetic load? What does it mean for a plant or a variety to have a genetic load that would keep it from flowering?
Bill Whitson: Sure. So when we say ‘genetic load’, we’re just talking about the accumulation of mutations over time. And the problem with mutations is that they’re very rarely beneficial. Most mutations result in a loss of fitness, rather than an increase of fitness. If you reproduce a plant sexually, then it has the opportunity to recombine and go through various types of error corrections to try to eliminate those deleterious mutations. But if you propagate a crop clonally, then you just accumulate them over time. And if they’re bad enough, you may get to the point where the plant simply can’t survive anymore.
But assuming that there’s someone there to keep selecting tubers that grow well for them, then you may only lose features that aren’t of importance to you. So if you’re a farmer and you’re trying to select a potato that continues to grow well for you, you keep choosing to replant the tubers of plants that have yielded well for you. But you might not care whether or not that plant flowers or makes berries or sets seeds well anymore. And so if you extend that over hundreds or potentially even thousands of years, you may lose the ability for the plant to reproduce itself through seed, and it may then require a farmer to be there to keep replanting it from tubers. So that is one of the key problems with potatoes.
Some of them flower very well, but many of them, particularly those that have been highly selected, have lost that ability to some degree. And ‘Ozette’ is probably one of the worst. It flowers here on average every three years, and I might only see a flower or two when that happens. So you have to be paying attention if you want to breed with it, and you have to catch those flowers and make sure you get them pollinated if you’re to have any hope of getting seed.
Rachel Hultengren: So you didn’t know, before you chose it as a variety you wanted to breed with, that it flowered so poorly?
Bill Whitson: Right. You never really know… There’s relatively few people doing potato breeding, and most of them are working with improved lines that are well-established, that are well-documented, a lot of papers have been written about them, and their characteristics are widely known. But with some of these lesser-known varieties, you’re really on your own. And so not many people had done any, or had attempted any breeding with ‘Ozette’. As far as I’m aware, no one else has actually accomplished breeding with ‘Ozette’ before now – it’s just so difficult to work with.
So you have to grow the plant to discover whether or not breeding is going to be possible with it. And ‘Ozette’ had enough problems that it turned out to be a terrible choice. But I liked it well enough that I kept growing it, and every few years I would get flowers and I would pollinate them. And finally, a few years ago, in 2016, we got a flush of flowers, and I pollinated them with pollen from different varieties, and managed to get three of those flowers to form berries. And ultimately got 170 seeds from those berries. Each of those was an opportunity to see progeny from ‘Ozette’ for the first time.
Rachel Hultengren: I expect that few people probably know what potato flowers look like – could you describe them for our listeners?
Bill Whitson: Yeah, potato flowers can be really beautiful. I often think that there’s potential for also breeding potatoes as an ornamental. The flowers can come in all the colors that potato tubers can come in; so you have white flowers, you have blue flowers, you have red flowers, and all the variations on those. So you have anything from pink to dark blood red, and kind of light powdery blues to very very dark purples. There are nectar guides on the corollas of the flowers that can be a different color or a darker shade than the petals, so you often get a darker star shape within the corolla of the flower. And yeah, I probably can’t really do them justice.
But particularly, varieties that flower well, the short-day varieties that I deal with from the Andes, produce very very big plants that produce a lot of flowers. And so they can be surprisingly beautiful ornamental plants. If not for the fact that they would eventually accumulate diseases that you would introduce to your food crop, they’d be a much more appealing kind of ornamental, because they’re grown from tubers you could plant them in a flower bed and have them come back year after year.
Rachel Hultengren: Yeah, that would be interesting to have them as a cut flower, like a dahlia or something, but growing them has the potential of them then acting as a reservoir for viral diseases for anybody who’s actually growing potatoes.
Bill Whitson: Right.
Rachel Hultengren: And the flowers look sort of like tomato flowers?
Bill Whitson: They are, but they’re larger than tomato flowers. I’d say anything from probably 2 to 2.5 inches in diameter, something like that. On a large potato plant, you could have two to three hundred flowers that open over a period of a month or so.
Rachel Hultengren: What were you looking to change about ‘Ozette’, and what were you hoping to keep the same in its progeny?
Bill Whitson: Yeah, it’s hard to have any expectations before you’ve seen some progeny from a potato, because potatoes are so genetically diverse. A lot of the crop plants that we work with are heavily inbred, so they’re homozygous for most of the traits that we care about – there’s not a lot of genetic diversity in there. So you can look at the parents and have a pretty good idea, if you make a cross, what kind of traits you’re likely to see.
Rachel Hultengren: What does it mean for a plant to be homozygous?
Bill Whitson: So for many crops… Many crops are diploid, which means they have two complementary sets of chromosomes.
Rachel Hultengren: Like humans?
Bill Whitson: Like humans. And if you’re homozygous, then each of the two alleles that you have for any given gene are the same. So there’s no chance, for example, if a homozygous plant pollinates itself, that you will get a different result, because no matter how you recombine two alleles that are the same, they’re still the same.
If you take two plants that are homozygous, but have different versions of that gene, then you get a very predictable mixing of the two. That’s how you, for example, get an F1 hybrid; you take two highly inbred plants and cross them, and you know you’re going to get a uniform result from that cross, because those two alleles are going to be intermixed evenly. So with an inbred plant you can get reasonably predictable results.
But potatoes have never been inbred; biologically, they’re an outbreeding species, so they have all kinds of obstacles to self-pollination, and as a result they are highly genetically diverse. And there’s an additional layer of complexity, in that most potatoes are polyploids. They’re specifically tetraploids, which means that instead of having two sets of chromosomes like a diploid, they have four sets of chromosomes. So you have twice the possible genetic complexity in there. And none of that has ever been inbred to achieve stabilization.
So the first time you grow a potato from true seeds, you really have very little idea of what to expect. So I didn’t know what I was going to get from ‘Ozette’. And beyond the unknown of what kind of genetic diversity was in ‘Ozette alone’, it was pollinated with just incredibly diverse pollen. So really anything could have come out of these seeds. But my hope was that I would get something similar in flavor and form to ‘Ozette’, but with some color, which is why I pollinated with pollen from red and blue varieties.
Rachel Hultengren: So when you grew out all of the seeds that you were able to get – those 170 something – what did those seedlings look like?
Bill Whitson: About half of them were white to light yellow potatoes that were either round or oval with shallow eyes, and I would expect that is largely a contribution from more modern potatoes among the pollinators that I used. We also got a lot of potatoes that were… probably the next largest group were white to yellow potatoes that had blue patches around their eyes. What I didn’t see a lot of, unfortunately, was the shape of ‘Ozette’ that I wanted. So there were a few fingerlings among the batch, and there were a few that picked up the kind of color that I was hoping to see.
But really there was only one that stood out in the batch for being a potential keeper. And that was one that more-or-less kept the shape of ‘Ozette’, and kept its deep eyes, and also came out with red skin and a little bit of red flesh. So that was very close to what I was hoping for. But the problem was that in that first generation, the tubers were mostly very small. So I had hopes, but I wasn’t terribly optimistic. Sometimes in the first generation you grow a potato from seed, you only get small tubers, and then they perform much better when you replant those tubers and grow them again. But I usually have pretty good results in the seedling year. When I grow here, the seedling year tends to look very similar to what I’ll get when I grow from tubers. So I was afraid that I was going to get a variety that was close, that looked good, but that only produced marble-sized tubers for the most part. So I replanted that the next year, and was happily surprised that the tubers came out of the ground actually a little bit larger on average than ‘Ozette’, so we’re talking about the larger ones being in the range of about 5-7 inches long, and the yields were good and the taste was great! So I got really lucky; the odds of getting a keeper in the first generation out of a cross are not that great. Usually it takes me on the order of going through four to five hundred seedlings to find one that I think is worth keeping, and with ‘Ozette’ I had less than two hundred seeds, so I beat the odds there, and I got lucky in one generation of selection, which is great.
Rachel Hultengren: In one of your emails, you compared it to pulling a winning lottery ticket on the first try –
Bill Whitson: Right.
Rachel Hultengren: – which seems like a great metaphor.
Bill Whitson: Yeah, you can do that with clonally propagated plants. You know, it’s not necessarily the expectation that you would have, but with plants that are seed-propagated, where they’re inbred, you typically have to go through the period of stabilization, and that may take up to seven years before you get that plant to the point where, when you grow it from seed, you get uniform results. So the wonder of cloning is that if you have a tuber, you can make more tubers, and those will all produce the same phenotype over time. So there’s no stabilization required, there’s just the period of bulking up your seed tubers to the point where you can plant the amount that you want.
Rachel Hultengren: So you said that it tastes really good – I was wondering: how do you taste the candidate lines that you’re looking at when you’re breeding a new variety?
Bill Whitson: Well the first thing I do is kind of a rough pass, looking for anything that has traits that I don’t think will be acceptable. So I tend to just throw out round white potatoes without even a taste test, because I’m just not very interested in them. I tend to throw out any potatoes that have just unacceptable form or yield. But past that point, I’m usually left with about half the crop, and I taste all of those. Every potato goes in the microwave and I taste a bite or two to get a sense for it. At certain times of the year I may not even need to eat any other meals that day (laughs) because I’m just taste-testing potatoes all day. But it was fairly straightforward with ‘Rozette’, because I didn’t have that many progeny from that plant. I probably taste tested about 60 of them.
Rachel Hultengren: That still seems like quite a lot – that’s a lot of potatoes.
Bill Whitson: I don’t necessarily eat the whole tuber, though. In many cases, it only takes a bite to determine that I’m not interested in growing that one anymore. And maybe 5% or less of the crop will either have a flavor that I immediately recognize as good, or at least good enough that I want to give it a bigger try.
Rachel Hultengren: Putting potatoes in the microwave and taking a bite – that sounds like it is similar to the way that maybe the average consumer would eat a potato. But there are so many different ways to eat a potato – do you do any more advanced testing to see if a line would do well as a potato chip or a French fry, for example?
Bill Whitson: I generally don’t do any of that. I will cook a potato in more ways once I’ve decided that it’s worth keeping around, but the microwave taste-test serves as a pretty good proxy, in general. I’m able to tell, more or less, what the texture of the potato is like and what the flavor of the potato is like, and generally I don’t have any surprises when I go on to prepare the potato in other ways. But I never consider things like chipping or fry color or any of those… Those are all characteristics that are very important to commercial commodity potato growers, but they don’t really hold much interest for me.
I’m probably never going to breed a variety that is going to be grown as a commodity crop, so I don’t even consider those kinds of traits.
Rachel Hultengren: Who is your target market for a new variety? Who do you keep in mind when you’re making selections?
Bill Whitson: Well, first me. Really I’m ultimately breeding potatoes that I like, and if other people like them too, that’s great. I don’t really have a set of criteria in mind for other people. So the people, in general, who are most interested in what I breed are home growers and small market gardeners. And that’s because the varieties that I select tend to be varieties that are going to require hand harvesting. I tend to select smaller potatoes; I tend to select potatoes that don’t senesce uniformly, and so they’re not ideal for harvesting with a tractor. So the people that grow what I produce are generally going to be working by hand or they’re going to have smaller two-wheeled tractors, things like that. And that’s a pretty big limitation.
The average tuber size that I select is about 3 inches; that’s about half the size that they typically shoot for in commodity potatoes. And that makes a big difference in mechanical harvesting. A lot of the potato equipment that’s available for tractors is going to pass through a lot of the tubers at a 3 inch tuber size and just make a mess instead of picking them all up and packing them up neatly for the farmer. So I’m really targeting small scale production.
Rachel Hultengren: How would you describe the overarching goal of your potato breeding program?
Bill Whitson: It’s pretty much the same as my goal with all the crops I work with, which is to introduce new flavors, forms, and colors that are not common in the existing commercial crop. And so with potatoes, that’s pretty easy. Potatoes are vastly more diverse in South America than they are in North America. In the Andes alone, they have about 5,000 landraces (or cultivars depending on how you look at it). And those range incredibly widely. They tend to be a bit smaller than the potatoes that we’ve selected for growing in North America and Europe, but they have a wide variety of skin and flesh colors in different combinations, they have all kinds of different forms and shapes. They can have very very deep eyes. There are all kinds of different forms, and the colors are nothing like what you’ll find in commercial potatoes. So they’ll very often have, for example, a mix of vivid yellow and red or blue flesh in the same variety. Many of the skin patterns involve two different colors, so you could have a variety, for example, that’s deep blue with bright yellow eyes, or deep red with yellow eyes. Red and white or blue and white – there are just a lot of combinations.
So my goal is to introduce, as much as possible, that kind of diversity in a package that people can grow at the very least in the Pacific Northwest. As I mentioned earlier, one of the problems with Andean potatoes is that they don’t form tubers until later in the year – they have a short-day photoperiod. And so that rules out their cultivation in most of North America, but in the maritime Pacific Northwest, we have mild falls, it’s possible to grow those varieties. And one of the things I’m able to do through breeding is to select potatoes those that have those kinds of really interesting appearances and fantastic flavors of the Andean potatoes but that also form tubers at least a little bit earlier in the year. So it’s a slow process, but I’m selecting for varieties that will set tubers at 13 or 14 hours instead of 12. That can get you as much as a month earlier, and make it really much more practical to grow these kinds of varieties, again at least here in the Pacific Northwest.
Rachel Hultengren: Yeah, a month makes a huge difference, in terms of, at least here in the Pacific Northwest, how much rain you’re getting and the chance of frost. So if you can move that tuber harvest up into the early fall, that would make a big difference.
Bill Whitson: Yeah, absolutely. And I know that difference very well (laughs), because we get something between 110 and 120 inches of rain here, but most of that comes between October and May. So (laughs) if I can get a variety that I can harvest in September, that’s a huge difference for me. Because otherwise I’m standing out in the field while we get 2 or 3 inches of rain a day, harvesting potatoes. So I’m highly motivated to find varieties that I can harvest while the weather is still at least a little bit dryer.
Rachel Hultengren: Yeah, that sounds like it would be a tough harvest day, or several, depending on how many potatoes you have in the field.
Bill Whitson: Right.
Rachel Hultengren: I’m curious when you got into potato breeding. When did this start for you?
Bill Whitson: I guess around 2007. I started breeding plants around 2005, mostly on a lark. I read a copy of Carol Deppe’s Breed Your Own Vegetable Varieties, and I thought, “Well that would be a good hobby.” And yeah, I don’t have a farming background or gardening or anything, really. I had never really grown any vegetables before I decided I would take a crack at breeding them.
Rachel Hultengren: That was quite an inspiring book.
Bill Whitson: Yeah, I guess I was looking for something at the time, and it sounded interesting. So I thought the thing to do would be to pick a crop that really nobody works on, because at least then you’d have a chance of discovering something new and interesting. So I put my early efforts into working with the Jerusalem artichoke, which is a crop that, although it has seen some breeding work, it has been mostly toward using it for biofuels. There hasn’t really been much work done on it in terms of making it a better edible.
But the Jerusalem artichoke is a terrible plant to breed with (laughs), and a really terrible choice for a new vegetable breeder, because it turns out to be horribly complicated.
Rachel Hultengren: So you shifted your focus to potato – is potato that much easier of a crop for a new vegetable breeder?
Bill Whitson: Right, so one led me to the other. The thing about the potato was that there was just a mountain of research on the potato. You know, lots of people breed potatoes, and there were hundreds of papers about breeding potatoes for every paper that existed on the Jerusalem artichoke. So it really became the plant that taught me plant breeding. For several years, I just read four or five different papers every day to try to get a handle on potato breeding. So now I tend to think of all plants kind of like potatoes because it was what I started with. I guess you could say it’s my root metaphor for plant breeding.
Rachel Hultengren: You’ve written that “failure is a good teacher” on one of your blogs posts that I read, in reference to starting out in potato breeding. What were some of the lessons you learned early on?
Bill Whitson: Oh, well I mean, maybe the most valuable lesson is that it’s almost impossible to compete with commercial potato breeders in the commodity potato field. And honestly, I wasn’t that interested in it anyway. But it doesn’t take much potato breeding to realize how… what kind of numbers you have to deal with to select the next great ‘Russet Burbank’-style potatoes. Those guys will plant a hundred thousand seedlings, and from those hundred thousand seedlings maybe introduce one new variety. If you want to make the next ‘Russet Burbank’, and you want a variety that has good disease resistance, excellent yield, uniform coverage in the field, perfect chipping ability, the right fry color that they want, you’re probably not going to achieve that on a small scale. The numbers involved are just crazy.
So if you grow a thousand Russet potatoes, you might think, “Well, odds are I’m gonna find a good one in there” and you will. You’ll find a good one. But it won’t be the equal of a commercial commodity potato on even half of the criteria that they consider important. It’s just such a crazy numbers game. Again, you would have to win the lottery, but you’re gonna have to buy a lot of tickets to compete in that world.
Rachel Hultengren: So you’ve pledged this variety and 36 other new varieties to the Open Source Seed Initiative, and I wanted to talk a little bit about intellectual property as it relates to potatoes. What sort of intellectual property can be applied in potatoes?
Bill Whitson: Well, you can… I mean, there are really only two methods that are common. The most common by far is to get Plant Variety Protection in the U.S. or what in other countries is called “Plant Breeder’s Rights”; that’s a monopoly enforced by the government for 20 years, where you can prevent any other parties from propagating the variety, but it is fair game to use for breeding. You can also potentially seek patents. Patents are a thornier matter with plants. You can potentially get a utility patent for certain kinds of traits. There’s some debate about whether or not that’s in the spirit of the patent code, but people have certainly done it. It’s more common for people to seek patents when they’re doing genetic engineering than when they’re doing conventional breeding, but it is definitely possible to get patents for conventional breeding. And patents also, I think, last for 20 years. But they give you a lock on propagation but also breeding. So the main distinction between the two is that with Plant Variety Protection people can at least use the variety for breeding.
Rachel Hultengren: Well, so to be clear – there are Utility Patents, which only since the 1980’s have people been able to apply to plants, and then there are Plant Patents, which came about back in the 1930’s for asexually propagated species. But even though potatoes are an asexually propagated species, potatoes and other tuber-producing food crops were excluded from that legislation.
Bill Whitson: Yeah, it’s weird isn’t it? So you can get PVP or you can get a utility patent, but for some reason you can’t get a plant patent for a tuber. (Laughs) It’s weird.
Rachel Hultengren: Yeah, the intellectual property landscape is not particularly straightforward in most cases. Is there a story that encapsulates for you the need for the Open Source Seed Initiative?
Bill Whitson: Well, my previous career was in the software development world. So I’ve been involved in patents for various software features. And in the time that I worked in software development, I went from a general feeling that patents were probably a good thing that increased innovation – which is kind of the standard party line – to being a lot more skeptical about them. And those were through encounters with patent law through software. So one example would be just the small amount of work that it actually takes to get a patent that can really ruin someone else’s company. And that doesn’t feel like it enhances innovation to me. So that made me pretty skeptical about intellectual property. I mean, I’m not completely opposed to it. I don’t necessarily have a better idea, in some cases. I’m not even necessarily opposed to using things like Plant Variety Protection. I think it’s overall a fairly balanced system that I don’t object to. But I think it’s good to have a greater diversity of options. So the OSSI really provides people a kind of option that didn’t exist before. And I think open-source has been really good for the software industry in a lot of ways. So I don’t know where open-source seeds are going, but I think it’s good to have that option, and I’m happy to encourage it as much as possible.
Rachel Hultengren: That’s a unique perspective, to come from the tech industry where you have experience both in patents and in open source for code, and then apply that thinking in plants.
Bill Whitson: Yeah. I don’t have the experience, though, in the plant breeding field to see what all the effects of intellectual property have been in plant breeding. I mean I see some of that from kind of a more distant perspective. I think that’s where OSSI is a really good idea, because although it’s not likely that there’re going to be a bunch of big companies or university breeders that are going to want to use my germplasm as a starting point, it at least gets some varieties out there that can act as a monkey-wrench and slow that system down and maybe make people think about it a little more. I think one of the great things about the OSSI is you get a packet of seeds that has the pledge on it, and so now, maybe you’ve never thought before about the intersection of intellectual property and plant breeding. And you’ve just got that little snippet that makes you, maybe for the first time, think about that and take a position on it.
Rachel Hultengren: Going back to ‘Rozette’ – I assume that you named it that because it came from ‘Ozette’ and has rose colored skin.
Bill Whitson: Pretty much!
Rachel Hultengren: I was wondering – did you consider any other names for it?
Bill Whitson: I hate naming varieties. (Laughs) It’s my least favorite part of the process.
Rachel Hultengren: Why’s that?
Bill Whitson: I don’t know. I don’t find it easy. I spend far too much time thinking about it; I never really get to anything that I find particularly satisfying. So normally I just name varieties using a pattern. So for the past few years it’s been place names in the Pacific Northwest, particularly the Olympic Peninsula. So I have a book of old place names for western Washington, and I just open it to a random page and pick something, for the most part.
But for ‘Rozette’, it just seemed kind of obvious. It’s somewhat descriptive, it’s a little bit cute, but I only picked the name because it was easy. Normally that’s the part that I just – yeah, I really don’t like.
Rachel Hultengren: Have you ever considered partnering with a small child, and just giving them that role entirely for your company? Being like, “Your only job is to give me interesting plant names”?
Bill Whitson: Well, I have a couple of nieces that are just about to that age, where they’ll probably be good at that. So I think that’s a good idea. I would be happy to outsource that to elementary school kids at any time.
Rachel Hultengren: You could probably pay them with ice cream.
Bill Whitson: Absolutely. (Laughs)
Rachel Hultengren: Would you have any advice for somebody who’s interested in getting into plant breeding, possibly into potato breeding?
Bill Whitson: So for plant breeding in general, I would say, “Just do it.” Don’t overthink it. Buy some varieties, grow them in close proximity to one another, let the insects cross them up, save the seed, plant it out and see if you get anything new and interesting. People tend to think that it’s harder than it is. I mean, there are certainly elements to it that are hard, and where you’ll benefit from doing your research and learning more. But as Joseph Lofthouse likes to point out, plant breeding for most of human history was done by illiterate farmers. So you don’t need to spend a whole lot of time reading and researching to get started. You just need to start growing and breeding plants.
As for potatoes – if you want to breed potatoes, find someone who you can get true potato seeds from. Because starting from potato tubers, particularly of existing commercial varieties, is just hard, and it’s unnecessarily hard. I went through that phase of trying to grow from all the commercial potatoes that are available, and so many of them are just poor flowerers, have male sterility, and other problems that it’s really hard to get off the ground in many places.
So I can sell you potato seeds – it’s a large part of what I sell. You can get them through something like the Kenosha Potato Project, or you can find someone else you know who’s growing potatoes. You can potentially get them from the USDA. There are lots of sources. It’s just going to be a lot easier and your progress is going to be a lot faster if you start from seed.
Rachel Hultengren: Is there anything else you would like to tell us about the story of breeding ‘Rozette’?
Bill Whitson: If you’re interested in breeding potatoes and you haven’t done it before, that could be an encouraging story for you. Because although it took a while to get to the point where I could actually get a berry from that variety and get seed, from that point it really only took one generation of selection. I grew out something like 150 seedlings and whittled that down to one variety that offered something new and unique. The space required to do that is probably only about two to three hundred square feet. So it’s something that someone could easily do in their backyard.
You’re not necessarily going to discover the next big commodity potato, but it’s pretty easy to discover a new variety that you’ll certainly be very happy with and want to grow for yourself and your family for many years.
Rachel Hultengren: Well, Bill, thank you so much for joining us today. It’s been a real pleasure to get to hear the story of ‘Rozette’, and about your potato breeding.
Bill Whitson: Absolutely – thanks so much!
Rachel Hultengren: We’ve been speaking today with Bill Whitson of Cultivariable about his potato variety ‘Rozette’. If you’d like to grow ‘Rozette’, tubers should be available from the Cultivariable website in 2020.
To see some stunning photos of potato flowers and ‘Rozette’ itself, check out our show-notes on the Open Source Seed Initiative’s website at osseeds.org. Bill has also written a blog post about the process of selecting ‘Rozette’, which we’ll link to in our show-notes. If you’d like to find true potato seed for your own potato breeding project, you’ll also find links in the show-notes to the various sources that Bill mentioned during our conversation.
Let us know what you thought of this episode by tweeting @OSSeeds. You can find us and like the Open Source Seed Initiative on Facebook. If you’d like, you can give us a review on iTunes, which will help other potential listeners find us there, or you can just tell a friend! Our theme music is by Lee Rosevere.
Thanks for listening! Until next time, I’m your host, Rachel Hultengren and this has been Free the Seed!