// This is a machine generated transcript. Please report any transcription errors to will-help@illinois.edu.

[00:00:00]
Brian Mackey: From Illinois Public Media, this is the 21st Show. I'm Brian Mackey. According to the U.S. Department of Agriculture, corn is Illinois's top crop. This will come as no surprise to anyone who's driven the endless miles of our interstate highways. And when you think about what happens with modern corn, how could it not be number one? It's, of course, eaten as a delicious vegetable. You can find other uses for it. It's eaten secondhand through the livestock that it feeds. There's also the many products sweetened with high fructose corn syrup, and it's used in ethanol, the fuel additive. One reason that corn has been so successful here in the 21st state is the science behind hybridization, which allows farmers to ensure a high yield that can survive the harsh realities of extreme weather, pests, viruses, and other threats. But new research from the University of Illinois Urbana-Champaign suggests that the way we've been using these hybrids could be setting up problems in the future.

Joining us now to talk more about their work, we're joined by three researchers from the UI's Department of Crop Sciences. Camila [Godoy] dos Santos is a postdoctoral researcher. Alex Lipka is a professor of biometry, and Martin [Bohn] is a professor of maize breeding and genetics. Camila, Alex, Martin, welcome to the 21st Show. [They're] joined me in studio today. Thanks for being here.

[00:01:27]
Alex Lipka: Very glad to be here. Yeah, it's

[00:01:29]
Brian Mackey: awesome. And listeners, you can join us as well at 800-222-9455. That's 800-222-9455. Martin, I'm gonna start with you and maybe we can begin by talking about the corn that we do grow in Illinois. What is the typical breed we use here in modern agriculture?

[00:01:49]
Martin [Bohn]: So the corn that we are using here is the corn [be dent] and, you know, this is a corn variety or family of corn that — is that is — was developed by, you know, several other families of corn that moved in from the east. And from the east and, so the canonical story tells us that there was the southern [dents] in the southeast of the U.S. and then the northern [dents] in the northeast of the U.S. and with settlers these corn families and populations moved into the Midwest and here they started to hybridize and sometimes farmers recognize that by crossing some families of these different groups — the southern [dent reed] was one of these important populations within that group — and from the north, from Pennsylvania, the Lancasters, for example, when they cross these and they recognize that there is hybrid vigor, they can create something that produces more than the parents that were crossed with each other. But then I think the modern concept of [heterotic] groups is developed in, you know, after the Second World War when people wanted to, you know, put this — wanted to utilize that concept in hybrid breeding. They developed inbred lines and then they recognize that crossing inbred lines from these different families, you know, created hybrids that were highly productive and some of these modern heterotic groups that are used — these genetic families that are genetically different — are the stiff [stalks].

[00:04:08]
Brian Mackey: I'm gonna ask you to pause on the [stiff stalk versus non-stiff stalk]. We'll come back to that in a little bit. And Alex, let me bring you into the conversation. Talk a little bit more — and sometimes I say, you know, this is not a college class. Talk to me like I'm, you know, a smart 13-year-old — and help me understand why this specific method. It sounds like maybe there were some accidents that, you know, farmers sort of intuiting and understanding this stuff, and now there's science behind it. Why are these methods what we're using to, you know, create corn in 2026?

[00:04:36]
Alex Lipka: OK, so, yeah, so everything Martin was describing, you can think of developing two different boxes of Legos, OK. So one of these heterotic groups is a bunch of mom plants, and then another box of Legos is a bunch of dad plants, right? So then you pick — you know, breeders can pick your favorite mom plants, your favorite dad plant, cross them — you have an F1 offspring. And then they produce, you know, they yield much better than what you would expect from, from like the original — from the contributions of each Lego alone.

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Brian Mackey: OK, so that that makes sense, and I think that would work with my son. Camila, let me bring you into the conversation. So the corn — you know, we've talked a little bit about the corn we're using today, how it developed. With that in mind, can you say more in detail about what your research found about some of the potential problems here? And again, keeping in mind like you're talking to a smart teenager.

[00:05:38]
Camila [Godoy] dos Santos: Yeah, so the idea of our work was to see — was to check if this population, this population of lines that we have, if this [has] a genetic variation — and for this we develop a different type of models.

[00:06:04]
Brian Mackey: You can have a glass of water if you need. Yeah, take a drink of water. So you're saying that for, you know, you develop these different types of models to see if there's genetic variation. You're good to go, yeah.

[00:06:16]
Camila [Godoy] dos Santos: Yeah, so we, with this model we thought that we don't have genetic variation across the stiff stalk lines across this population, and this is a critical result because [the] stiff stalk population is the most important [heterotic] group in the current [Corn] Belt. And we of course perform a different type of traits and the genetic variation was gone for the grain yield, the most important trait. So for the most important trait and the most important line population, we found that we don't have genetic variation anymore.

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Brian Mackey: OK, so you're lacking some of this genetic variation. And I guess Martin, let me come back to you then. What are some of the consequences? I guess maybe a more basic question — is there a new corn sort of breed every year? I mean, is this something that's constantly evolving — not evolving in the sense of evolution, but constantly changing to keep up with, you know, insects and new pesticides and things like that?

[00:07:23]
Martin [Bohn]: Yeah, I think this is the business model of the breeding industry, isn't it? I think they are developing new inbred lines within these heterotic groups every year and they try to combine the positive traits within each of these inbred lines that they then, you know, transfer into the hybrids by crossing these inbred lines with each other. And I have to come back to this Lego model that Alex talked about — you know, if you have a lack of genetic diversity. If you have only red Legos within of a certain size in your toolbox,

[00:08:05]
Brian Mackey: the classic 4-by-2

[00:08:07]
Martin [Bohn]: and it's red, then you are lacking the variance, you are lacking the combination in your toolbox that allows you to adapt to future environments. And I think we need to recognize that we have to make decisions now with regard to the development of our inbred lines and germplasm and heterotic groups, if we want to develop inbred lines for future environments for the next 20 or 30 years. We are making decisions now and if we — and we recognize with our study that for most of the corn, specifically for the non-stiff stalks, we have all the genetic diversity that we need in order to improve that heterotic group and to bring that side into our hybrids. However, for the stiff stalks, as Camila said, particularly for the stiff stalks that we utilize here in the Midwest, we are lacking the diversity. We are not able in the future to adapt to things that will change. We already experience, isn't it, that the weather is changing, it's getting more extreme, more flooding, it's getting hotter — with this, more insects are coming in, more diseases are coming in. We have to futureproof our hybrids by adding or keeping up the genetic diversity that we have.

[00:09:43]
Brian Mackey: [I want to] kind of interrupt. A little earlier when we were talking about stiff stalk versus non-stiff stalk. So maybe Alex, I'll come to you — and if you can just say a little more about that. So I think stiff stalk, it's sort of intuitive. You're driving down the highway, you see all that corn lined up, perfectly aligned. I remember I was actually talking with the state's Department of Agriculture director this week about some of the storm damage, and he said, you know, sometimes that corn, it just kind of pops right back up, the stiff stalk stuff. What is the difference? What are we eating? What are we feeding to our animals? What are we putting in our gas tanks — you know, what is that? Yeah, talk more about this stiff stalk versus — I don't know if it's limp stalk or non-stiff stalk — what term we should use.

[00:10:23]
Alex Lipka: Right? So stiff stalk versus non-stiff stalk. So I'll say off the bat that my colleague Martin is definitely the expert on this kind of stuff. But, so, yeah, you know, the way corn breeding has happened, right? You kind of select your corn, like your Legos, into these different bins of like stiff stalk versus non-stiff stalk. So these are two different boxes — stiff stalk, non-stiff stalk — and then they just bred for, you know, favorable traits. So I guess the appearance. And I remember Martin you saying the other day that stiff stalk, they were selecting for this phenomenon you're describing where if it's windy, the plant will fall down, so they were selecting for making literally the stiff stalk so it can be resistant to the wind. And non-stiff stalk, I am guessing that they were selecting on something else.

[00:11:21]
Martin [Bohn]: Yeah, absolutely. I think you're absolutely right. So the stiff stalk — actually most of these or most important inbred lines out of the stiff stalk group were developed from the Iowa Stiff Stalk Synthetic. And my colleague [Sprague] — [George] Sprague — in the ['30s], I think, he had the idea to develop this population. We call this a synthetic that is particularly bred for stiff stalks and he combined 16 inbred lines. He selected these for their stalk traits and root traits, and then out of these, you know, mix them together to form this population and improve this over time. And out of these different cycles of improvement of this synthetic, important — you know, really, really important — inbred lines were developed that are reused constantly, and their offspring are reused constantly. And this is the problem — you know, this is a genetically narrow base, and from this base we are selecting inbred lines and often these well performing inbred lines out of the stiff stalk heterotic group are all related. And so

[00:12:44]
Brian Mackey: that is year after year.

[00:12:45]
Martin [Bohn]: Yeah, exactly, and you're absolutely right, we know that they are good, so therefore we are reusing them. But using then also modern technology like genomic selection — and Alex and Camila, they are the experts in genomic selection — this is making our breeding program so effective and predictable that we are draining the genetic diversity very quickly.

[00:13:11]
Brian Mackey: So Camila, how do you determine this? I mean, are you getting dirt under your fingernails? Do you have to do this season by season? Is it computer modeling? Are you peering into a microscope? What is this actual work of doing this research look like?

[00:13:23]
Camila [Godoy] dos Santos: Oh yeah, actually we already have the field data and the genetic data. So what I did was use this data and try to develop a model to transform the data in a biological meaning, so using, for example, the information — the genetic information of the parents — I was able to predict the hybrids, and I construct — use that information to get accurate models to answer all this question that we have because, OK, we need to understand if that population has a genetic variation, but for that we need to develop good models to have this answer in a great way. So I try to put together all this information into the model and collect all this information and this answer, yeah. And actually this work — the genetic variation was the first and the second part was genomic selection because we use the same to predict hybrids.

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Brian Mackey: Let me — we're gonna need to take a break here in a second, but I guess just briefly — and maybe Alex you can just outline — what are some of the potential challenges. I mentioned climate change is one. What are some of the other things that we might be worried about, you know, in just like maybe 30 seconds. Give us a quick list of some of the problems that, you know, could come up. Yeah,

[00:15:02]
Alex Lipka: so yeah, climate change, absolutely. Also, you know, this loss of genetic diversity — like how can you increase more Legos into that box of parents.

[00:15:14]
Brian Mackey: Why do we need to though? What do we — what would — what do the Legos solve for?

[00:15:18]
Alex Lipka: So imagine that you have hybrids and they all essentially have the same mom, right? So if a disease comes in and all of these hybrids are susceptible to the disease, you'll have one less tool in your tool set to combat that. And worst case scenario, maybe you won't be able to eat anymore. So,

[00:15:36]
Brian Mackey: OK, well, that is a great setup. We're going to take a break and we will talk maybe — is there a possible future where we don't have corn? Oh my goodness. All right. We are talking about this with three researchers from the University of Illinois who've been looking into this idea of a lack of genetic diversity in our corn, which could make it harder to develop corn that can withstand some future threats. Martin [Bohn] and Alex Lipka are professors at the UI. Camila [Godoy] dos Santos is a postdoc researcher there. If you want to join us, 800-222-9455 is the number. We're gonna continue after a short break. 800-222-9455. This is the 21st Show. Stay with us.

It's the 21st Show. I'm Brian Mackey. I'm joined in studio today by three experts from the University of Illinois Urbana-Champaign's Department of Crop Sciences, and we're talking about corn genetics and potential issues they've been studying with the future development of new corn hybrids. This has to do with the lack of genetic diversity, which could make it harder to develop corn that can withstand potential future threats such as climate change, viruses, pests. We're talking about this with Camila [Godoy] dos Santos, a postdoc researcher at the UI, Alex Lipka, professor of biometry, and Martin [Bohn], professor of maize breeding and genetics. You can join us at 800-222-9455. That's 800-222-9455.

So, Alex, what are some of the ways farmers can balance, you know, the predictability they want — there's so many uncertainties in farming. If they can find something that they know works, a lot of farmers are going to stick with that, you know, while also ensuring this potential genetic diversity in the corn that they're, you know, breeding and growing.

[00:17:46]
Alex Lipka: Yeah, so there are multiple ways to approach this. I think the simplest thing is, so Camila's research has shown that it's the training material for these genomic prediction models that really matter. You have to have your training corn have the same, you know, genes, alleles, allele frequency, all that stuff as your predicted hybrids. So her results showed compellingly that if you include the parents, you're going to get more accuracy. So that's one route. Another thing is, when you're doing this genomic selection, you're selecting on the genetic potential of a hybrid, OK? So, yeah, so breeders, if they use genomic selection, they'll they might select for the best [maize] hybrids. Well, you can also select on the variability of the hybrids. So you can make sure you're intrinsically including some genetic variation in your decisions. And Martin is on several projects that [are] looking into increasing genetic diversity into the heterotic groups themselves — that is adding some more exotic Legos into your box of Legos.

[00:19:04]
Brian Mackey: OK. How do you actually do that? And I don't know who wants to take this — Camila — like what, what is that actually, like, what is the process by which this happens?

[00:19:14]
Martin [Bohn]: So I think the process is a lengthy process, and this is the reason why industry is often reluctant to do this because they reduce the eliteness of their germplasm by adding foreign materials, exotic materials, so they then have to build it up again. So here at the university, we are able to do this, we can do this in the long run.

[00:19:39]
Brian Mackey: And it's not economical to test in the fields

[00:19:43]
Martin [Bohn]: and then also to make these crosses and it takes time to develop these materials. And perhaps a little example — so we are developing — so we recognize that our modern corn hybrids lack the ability to interact with their soil microbiome, so they are not recognizing what microbes are there and then manage these according to their needs. And we've shown that early hybrids from the '60s, '70s and '80s are able to do this. So we lost that trait, we lost that Lego piece out of our box and we need to bring it back. And we recognize that we have to go back to [teosinte], the domesticated form of corn from Mexico, to bring back that trait, and this is what we are doing. And together with colleagues we created crosses between modern corn and domesticated corn and over time developed these new varieties that again contain that little Lego piece that we lost, and we brought it back through that route.

[00:20:54]
Brian Mackey: I gotta say reading your research was the first time I'd ever been introduced to the concept of wild corn. I didn't even know that was something you could find in the world. I don't know if you can talk about that or — and I understand that maybe, you know, going back in generations and, you know, bringing grandparent corn or great-grandparent corn — Camila, you can talk about some of that work as well. Yeah,

[00:21:14]
Camila [Godoy] dos Santos: you can go back in this because we have [lines] that can contain genes for — I don't know — resistance for disease and pest, and we cross with the modern lines to try to get this resistance again. So yeah, of course, because we have today elite lines in a real breeding program, in a modern breeding program, we have elite lines — and for example the stiff stalk populations, they are elite lines — and you can go back in [these] lines and make [these] crosses, yeah.

[00:22:00]
Brian Mackey: We got a question from a listener, Sonia in Decatur, who emailed [and] said, when did this idea for adding Roundup to the corn come up? And why must we do this? And I'm gonna tease — we actually have coming up tomorrow on the show a conversation about pesticide drift and some people who have, you know, some significant property next to commodity crop fields, and they're concerned. They've seen damage to their trees. They wonder about what it's doing. There's a school that was next to one of these fields, and the kids were told to shower after a cloud drifted into their playground one day. That's tomorrow's show. But Martin, maybe you can address some of — you know, what is — is there value — I presume since it's so wide — you know, what is the good in Roundup? What are some of the downsides? Talk us through that.

[00:22:44]
Martin [Bohn]: So corn is transgenic, so it carries genes that protect it against the herbicide, so we can spray and, you know, manage all the weeds out of the corn field without killing our corn hybrids, and this is a very effective way of managing, you know, these weeds. I have a breeding program for maize hybrids, particularly developed for organic farming systems. And when I talk to organic farmers, then managing weeds is on top of their list. You know, they want hybrids that can, you know, tolerate high weed pressure. And so in conventional agriculture, we don't have that problem because we are using Roundup. And whether, you know, it's very effective — I think some of my colleagues are working on Roundup glyphosate-tolerant weed populations — and so there are issues around this. But, you know, in terms of managing weeds, this is a very important tool for conventional agriculture. However, you know, there's a lot of discussion going on. You mentioned with other pesticides and herbicides, there are environmental issues. People say there might not be environmental issues using Roundup, but there's definitely a large group of consumers that thinks otherwise and there's some research that is not really conclusive. So I think it's a great question to ask and a great question to ask [of] the industry whether there are alternatives.

[00:24:46]
Brian Mackey: This is probably the last question we may have time for. You sort of tease this idea that, you know, we could have a future without corn, right? I think I was thinking of that movie "Interstellar." I don't know if you saw this about 10 years ago, science fiction film. Set aside the part where they go to space. The reason they're doing that is there's some unnamed blight on Earth. Corn is the only crop left in that version of our potential near future. Could there be a future — and Alex, I'll send this to you — like where we don't have corn, because of, you know, some of these problems that you all are studying?

[00:25:18]
Alex Lipka: I think potentially, but unlike "Interstellar," I don't think it's the end of the world. I think honestly, my philosophical thoughts on this is we need diversity of foods to eat. So for example, I'm really interested in so-called orphan crops in Africa, and I think that if you put resources to such crops that maybe do not have as much, you know, advanced genotyping and phenotyping, we can get more food available and it's more resilient to any stresses that the next future decades will throw at the fields.

[00:25:58]
Brian Mackey: Alex Lipka is a professor of biometry. Martin [Bohn] is professor of maize breeding and genetics, and Camila [Godoy] dos Santos is a postdoc researcher, all in the Department of Crop Sciences at the University of Illinois Urbana-Champaign. Thank you so much for being with us, sharing your work with us today on the 21st Show.

[00:26:15]
Alex Lipka: Thank you for having us on.

[00:26:16]
Martin [Bohn]: Thank you. This was awesome.

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**Flagged for Human Review:**

- **[00:00:00]** "Camila Godo dos Santos" — Spelled as "Godo" in the original transcript. Verify correct spelling of speaker's last name. The NPR transcription uses "Godoy dos Santos"; bracketed as [Godoy] throughout.
- **[00:00:00] / [00:25:58]** "Martin Bone" — Spelled as "Bone" in the original transcript. Verify correct spelling. Bracketed as [Bohn] throughout based on contextual inference (common German-origin surname in academic maize breeding).
- **[00:01:49]** "corn be dent" — Unclear phrase in original. Likely "corn [be dent]" refers to "dent corn" (*Zea mays* var. *indentata*). Verify intended term.
- **[00:01:49]** "southern dance reed" — Unclear phrase in original; may refer to a specific corn population name. Bracketed as [dent reed] pending human verification.
- **[00:01:49]** "the Lancasters" — Possible reference to "Lancaster Sure Crop," a historic corn variety. Verify intended reference.
- **[00:04:08]** "the sus the nonst" — Unintelligible in original. Inferred as [stiff stalk versus non-stiff stalk] based on context; verify.
- **[00:11:21]** "my colleague Sprague, John Sprague" — The Iowa Stiff Stalk Synthetic is historically attributed to **George F. Sprague**, not "John Sprague." Bracketed first name as [George] pending human verification.
- **[00:19:43]** "tiocente" / "omesticated" — Original transcript unclear. Inferred as [teosinte] (wild ancestor of corn) and "domesticated" based on context; verify.
- **[00:26:15]** Speaker label for "Thank you for having us on" assigned to Alex Lipka based on spk_1 designation; verify against audio.