One Corn to Rule Them All

Dark pigments. Blue, purple, red, brown, green, yellow-orange, or "black". All these are possible corn kernel pigmentations and indicate powerful levels of phytochemicals beneficial in the diet of humans and animals.

Correct me if I'm wrong, but as I understand it the pericarp and aleurone can be any of the colors listed above, plus white, clear, or any combination thereof, and the endosperm can be clear/white or yellow/orange.

So I'm thinking about a hypothetical corn variety very high in all possible pigments, everything together cranked up to 11, probably resulting in a black outer coat with dark orange endosperm.

One corn to bring them all and in the darkness bind them.

Does such a black-over-orange beast already exist? Is this color combination genetically possible?

I've researched Dave Christensen's deep, dark Montana Morado Maize flour corn that just became available for the first time (got my little bag of seeds few days ago - the 4th of all orders filled as far as I can tell) and while it is indeed extremely dark colored, the inside of the kernel is white and not a very dark yellow like I was hoping.

I also have an ear of an unknown variety of very dark red, almost black, large seeded flint corn, but the hard starch is clear/white when the seed coat is filed off not dark yellow or orange. Likewise the Kulli Maiz Morado seeds I ordered and likewise the very dark red Bloody Butcher selection I have.

Over the next few years I plan on making crosses of these very dark pigmented purple and red corns with high beta carotene varieties like Catento Sulino, Floriani, Atomic Orange, Nalo Orange, etc. in an effort to create a black kernel coated corn with dark orange endosperm.

(I have read Joseph Lofthouse give his reasons for selecting against darkly pigmented leaves and stems based on his belief that dark pigmentation can reduce photosynthetic efficiency, so these would probably not be selected for if this turns out to be valid. The patch of land available to me where I will be growing is not the sunniest location, so anything that inhibits photosynthesis would be a negative.)

We'll see how successful I can be at forging this darkest, richest, most Precious variety.

Any valuable input would be greatly appreciated.

O, I love corn breeding projects. I'll give a stab at some of your questions, but I think Joseph is probably the best resource so if I get it wrong maybe he will correct me.

john Harper wrote:
Correct me if I'm wrong, but as I understand it the pericarp and aleurone can be any of the colors listed above, plus white, clear, or any combination thereof, and the endosperm can be clear/white or yellow/orange.

I don't think that the pericarp can on its own, display in all that range of color. It can be anywhere from colorless and transparent to so dark red it looks almost black, and completely opaque. The aleurone from what I've seen can be a range of light blue to very dark purple. I think that the level of anthocyanins it contains accounts for that. Then the endosperm is yellow or white, but the yellow can vary from light to dark. I've read that it can be purple too if there is anthocyanin in the sap, but I've never seen that. Also, having grown a little bit of it I speculate that the orange is another possible exception to the rule of yellow or white endosperm. In fact, I believe it is a separate thing from the other genes for yellow.  I think it might be that white endosperm with lots of carotene might show as orange whereas yellow with lots of carotene might be dark orange.

So, you figure in the variability of color in the three, add in the variability of transparency and you get all the possibilities. And they are all inherited by different genes which complicates it even more.

john Harper wrote:
Does such a black-over-orange beast already exist? Is this color combination genetically possible?

Yes, it absolutely is genetically possible. I actually may still have some kernels form an ear of corn from several years back that has it (except for the carotene).  That ear is variable for endosperm, some white some yellow. The pericarp is so dark red, almost black and it is completely opaque. When removed it reveals a very dark purple aleurone. The aleurone itself is dark enough that it has to be scraped off to see the endosperm color. Actually, now that I'm remembering it, it may also be possible for anthocyanins to be in the pericarp as well, which I guess makes sense if can be in the sap. I'm thinking that because when I soaked some of those kernels in water it stained it purple.

Anyway, like I said, I'm convinced the black over orange is possible but goodness gracious, bringing the genetics for it all together and stabilizing it is a pretty ambitious goal. I say go for it!

OH! I forgot, when I grew a patch from that ear, two or three plants out of about fifty were red/purple from the prop roots to the tassels. I gave it up though because it was such a huge corn, 12 to 15 feet and also way too long season for my needs.

I found a picture of that red/purple ear I mentioned. Looking at it, especially the pealed kernel, bottom left, I don't know if anthocyanin is responsible for the color or not. It may be just the color of the pericarp caused by something else. From the snow-white appearance of that one kernel, I'd say it definitely does not have any carotene. Kernels from this ear had fantastic flavor when parched which I found out later might be related to that color in the pericarp.  

This ear was huge, 12 + inches long and as I recall had around 1200 large kernels. I may still have a hundred or so, they are old but have been stored well. If you would like to have them, send me a PM.

*But I don't think they have the anthocyanin and carotene genetics you're looking for. You may be able to join the very dark color with the high carotene but to have the dark color being due to anthocyanin instead of something else might be harder.

Beautiful! Thank you very much for your generous offer. PM on its way. :)

This ear and the kernels resemble very closely the large dark red ear that I mentioned in my OP. When I split open some of the kernels I originally thought the endosperm was dark red or purple, but when I removed some of the outer coat I could see that it was clear/white and the dark coat just wasn't letting any light through.



Do you know the provenance of that ear? The one I have was purchased at a local farm market shop as ornamental "Indian corn" this fall. The folks at the shop didn't know anything about it. Funny, it could be exactly the same variety, and it could be something almost totally unrelated. I just love the incredible diversity of corn.

The aleurone layer in corn is a single cell thick. A very thin membrane surrounding the endosperm.

In my experience, the pericarp can be colorless, or some tone of red/terracotta. I think that the phyto-chemicals in the pericarp are not all that bio-available.

The aleurone can be colorless, or some tone of purple/blue. There is a rare, highly recessive, south American aleurone that is pastel yellow.

The endosperm can be white, yellow, or orange. Yellow is zeaxanthin. Orange is beta-carotene. Both are carotenoids. I prefer the taste of beta-carotene to zeaxanthin. Both are useful to the body, and important in eye-health. In the corn plant, beta-carotene is normally converted to zeaxanthin, but the conversion efficiency is low in the high-carotene lines, so both forms are present simultaneously.

Dark purple sap might bleed into any other layer causing purple staining. The recently posted photos display what I think of as the purple sap trait... I have sometimes seen purple staining the entire endosperm. The purple color is due to anthocyanins, highly potent antioxidants. Plants with the purple sap trait also have dark purple cobs, and the anti-oxidants can be extracted from the cob and leaves as well as from the kernels. Homozygous purple sap trait leads to low productivity. Perhaps in a heterozygous state, it's not so detrimental. The kernels can be deep purple without the sap being deep purple. One time I isolated a sweet corn that tasted like cherries, because of the high anthocyanin content. I didn't eliminate the purple sap trait from my corn on purpose. I guess that the ecosystem did that for me. In any case, about 80% of the selection that happens on my farm has nothing to do with me. It is ecosystem driven.

I also see salmon colored sap sometimes. It's very subtle, and easy to miss amidst so many vivid colors.

Light red pericarp over white endosperm provides the gorgeous color of Pink from Hopi-land.

The misnomered Oaxacan Green, is blue aleurone over yellow endosperm.

Light red pericarp over yellow endosperm can be particularly striking.

I ordered some catento suleno online from someone selling it to be eaten, so I did a quick germination test on it and it seems like it'll be fine.

They also sell bloody butcher corn and about 5% of the yellow corn was red. I suspected some cross-pollination between the two kinds of corn and apparently that's what happened. You can see on the image below in the upper right-hand corner a kernel of bloody butcher that I'm fairly certain is representative of the variety, and then below are several split kernels of the suleno and the red kernels as well. You can see that the red kernels have yellow endosperm just like the yellow ones do and unlike one at the other upper right. So this encourages me that the yellow could be the dominant trait.

I found another photo pf the big red ear showing the color of the cob. Also, what happened to some kernels when they were parched on a hot iron skillet. Only a few did that, but all were very good that way.

Today I mixed up seed blends for my two parental corn breeding lines. The male line is made up of 17 different dark varieties of red, blue and purple flints. The female line is a blend of 7 different high beta carotene varieties.

Eventually I want to produce a landrace of dark seed coat, dark yellow endosperm flint corn.