What are hybrid plants?

It turns out the wheat I ordered is hybridized. I’ve read all about this now, and it appears that for the greater good my little plot will have to be burned and buried under concrete.

I learn from the internet that hybrid plants are beastly Frankensteinian creations, invented by Monsanto to keep humans from saving seeds and control the food supply. “Hybrid foods will not grow in nature” and “they are not as good as non-hybrid and organic foods”.

As you may or may not know, this is all nonsense. The parts about how hybrids are “unnatural” are hilariously wrong.

The truth is this:

Hybrids are what happens if you don’t apply enormous pressure to inbreed.

That is, when you buy an organic, non-hybrid variety that “breeds true” to its type, what you are buying is a plant that has been heavily inbred for many generations in order to remove genetic variety. Inbred seed will produce a crop where each plant has almost the exact same genes, meaning all things equal they grow into uniformly shaped vegetables.

For a gardener or an aspiring farmer, uniformity is important - it helps to harvest wheat that blooms at the exact same height, or to pick tomatoes that all fit in the same plastic containers.

But there are problems with inbreeding. For instance, parasites will have a much easier time attacking plants in field of near clones. Figure out how to “break into” one plant, and you’ve cracked them all!

This, of course, is why most life on earth does not inbreed. Using sexual reproduction means each individual will have a unique combination of genes - a jumbled combination of the parents genes - making it trickier for parasites to spread from one individual to another.

Alas, the evil geniuses at Ramona Organic Farms, along with thousands of years of evil genius farmers before them, have found a way to eat their wheat and plant it to. For as you will find out, there’s a way to create hybrid seeds that grow into uniform crops.

Detour into a simpletons understanding of genes

I’m assuming at this point that you know we have genes and that you will accept my somewhat spotty but sure-of-myself knowledge of them. If you know about gene things and you want to watch me embarrass myself, keep reading. If you don’t know about gene things, here is a totally accurate primer on gene things.

Genes are like “slots”, spaces where actual genetic material can fit, like this:

So, lets say we have a gene for eye color (which, we don’t, we have lots, I’m simplifying here), a dedicated empty space in our genome where the information about eye color goes. The genome is made up of lots of these “slots”, genes linked one after another:

The actual DNA that goes into the gene slot, like the DNA for “brown eyes”, is called an “allele”. Here’s a lush brown allele plugged into the eye color gene:

If you’re familiar with software, you might think of the gene as an interface and an allele as one of many implementations of that interface.

If you follow so far, you now know more about genetics than most people in the world, congratulations!

There’s one more concept to include before I can get back to the problem with my devil wheat. When we have children, we say that you get some of your DNA from your mom, and some from your dad. What does that actually mean?

Well, it turns out that every gene actually has two slots for DNA, so for every gene in our cells, we have two alleles! When we humans reproduce, the child will need two alleles to fit into the two eye-color gene slots; you get one from your mom, and one from your dad.

This is where simplifications like “dominant” and “recessive” genes comes from. It’s easy to imagine what would happen if both slots for the eye color gene was set to “brown” - but what happens if you have mixed alleles for the same gene?

The answer is “it depends”. Importantly, it is not as simple as one getting “used” and the other somehow disabled - both alleles will be “used”, or expressed. In the case of eye color, the brown allele might “overpower” the green - but the green allele will still be actively in use.

How hybrid devil plants are made

Lets, for the sake of argument, say I’m God. I’m not saying I’m not, or that I am, but that independent of whether I am God or not that we assume I am for the duration of the next paragraph.

I summon into being a cucumber-like plant species named Andy and I decree that Andy contains two genes; one to control Andys color, and the other to control Andys resistance to bugs. Just like a human, for each gene, Andy has two slots for alleles. All in all, something along these lines:

There are two colors of Andy - yellow and green. Green is “dominant”, so if an Andy has both green and yellow alleles, it comes out looking green. And there are two alleles for bug resistence; one for spiders and the other for bees, for whatever reason.

Now, I like both yellow and green Andy, so I’ve inbred two varieties. “Early Bird Yellow Andy” and “Honest Jakes Green Andy”. Here they are now:

Since they are inbred, as long as I keep inbreeding, Honest Jake will give me green Andys, and Early Bird will be yellow. But you might spot a problem. Because I’ve inbred them, the bug resistence genes are also inbred - Honest Jake is resistant to spiders, and Early Bird is resistant to Bees. This is another problem with inbred plants - they have less useful genetic material than hybrids.

Now, what happens if these two inbred varieties where to breed with each other? Well, for each gene, the offspring would get one allele from its mom and one from its dad. For the color gene, it would get one color allele from Early Bird, and one color allele from Honest Jake.

Since both of Early Birds color alleles are yellow, the offspring will always get a yellow allele from Early Bird. Likewise, it will always get a green allele from Honest Jake. This means that all the immediate offspring will always have one green and one yellow allele, one from each parent. Likewise, they will always have one allele for spider resistance and one for bee resistance.

Here’s one way it could play out, with four new plants in the offspring. Notice that, while they all have slightly different DNA, they all have the same general combination; one green and one yellow allele, one bee allele and one spider allele:

You might realize what’s happened here already - since I said green would be dominant over yellow, our hybrid Andy generation will all be lush green.

So all the offspring will all look like Honest Jake green Andys - but they will also all be resistant against both bees and spiders.

Imagine what happens if there are other alleles that work together to make bigger fruits, handle droughts and so on - a hybrid will potentially have a much more broad set of alleles at its “disposal”. This effect, where a hybrid is stronger than an inbred line is called “hybrid vigor”, and is the reason most plants we grow today are hybrids.

But lets keep playing the tape - because what happens next is interesting. The seeds from our hybrid generation are supposed to be sterile, right? Engineered by Monsanto lawyers to convert your soul to intellectual property? Not so, but something interesting happens:

Again, each child gets one allele from its mom and one from its dad. But this time, it’s a 50/50 shot if it will get green or yellow. Some children may get a yellow from the mom and a green allele from the dad. Some might get green from both, or vice versa. In the figure above, three out of the four children have at least one green allele. One has only yellow alleles, so it will turn out yellow.

If you think about this, what’s just happened is that you had a field of Andys that were all green. And then you took seeds from that field and planted it - and now, suddenly, 25% of the plants are yellow!

The fascinating net effect is that when two inbred lines breed, their children will be uniform - but their grand-children will be massively genetically diverse. This is the reason we usually do not save seeds from first-generation hybrids - the second generation is not going to be uniform and and thus they are no good for commercial purposes where we want uniformity.

How you like them wheat berries, then?

On the one hand, my wheat crop is useless for flour. Much of the wheat came out with tiny ears, much too small to make wheat from. But some of it came out with huge ears, and that means this could be a cool opportunity I’ve stumbled upon; I could try inbreeding this wheat back to a stable variety.

The beauty of saving seed from my hybrid wheat would be if I succeed the result would be bred specifically to grow in my climate here in Missouri.

There’s a caveat though - some plants don’t take well to inbreeding. If they become too inbred, they grow useless and sterile, like the Swedish Royal Family. For those plants, you need to keep a large enough crop to keep genetic variety going. I’m not sure if this wheat is one of those plants, but I guess I’ll find out.