Questions about GMO, Corn Genetics and some Corn Pictures

[Carol Deppe]

Reed, yes, you've nailed it. The floury part is white. The flint part may be yellow or white, with some yellows being more intensely colored and more like orange. Where the aleurone is black there can be a bleeding over of the pigment into the flint. This variety is not quite a flour corn, but it is leaning that way.

As for telling what color of flint you have when you have aleurone or pericarp colors on top that hide it, I use a nail file and file off a tiny spot on a dozen or so kernels near the base of the ear. I file just deep enough to hit the flint. There will be a ring representing the aleurone, so you can see both aleurone and flint color under the pericarp.Filing the kernels like that doesn't interfere with their being planted as seed. If you have loose kernels you can file them anywhere other than near the germ and still plant them.

[Carol Deppe]

Here are some photos of our 'Magic Manna' corn harvest this year. Bear with me, this is my first attempt to post photos. Don't know if the sizes are going to work. There are more photos over at Flickr. 


Corn Ears-Magic Manna-14T3428 by caroldeppe, on Flickr


Corn Ears-Magic Manna-14T3482 by caroldeppe, on Flickr


Corn Ears-Magic Manna Display-14T3470c6 by caroldeppe, on Flickr

[Carol Deppe]

Those were a bit too bit. Let me try that again a little smaller.



Corn Ears-Magic Manna-14T3428 by caroldeppe, on Flickr



Corn Ears-Magic Manna-14T3482 by caroldeppe, on Flickr



Corn Ears-Magic Manna Display-14T3470c6 by caroldeppe, on Flickr

[blueadzuki]

Carol, one point I wanted to bring up. In your messages you regularly refer to "black" aleurone. I don't think I've ever SEEN black. Really, really dark purple yes; dark enough that light will not pass through it as is. But in every case I have seen (even such things as "black" Aztec) in a thin enough slice, it becomes purple (or occasionally blue) Is this just one of those semantic things ("if it's a dark enough purple you can't see through it, it's visually black") or is there actually corn out there that is truly black, and I have just never seen it? (given what you say about most of the other colors being modifications of black, that seems unlikely, unless the unmodified form is extremely rare.)

[jondear]

That's some handsome corn Carol.


Who wants to explain why some corn cobs are multicolored and some such as those are single colored cobs.

[Carol Deppe]

blueadzuki--I call the aleurone color "black" because it looks black in the varieties that have "black" in the name. But as you say, this "black" is just the result of there being lots of purple or blue pigment. The aleurone pigments are anthocyanins. There a number of chemical variants of the anthocyanins that can give you kernel colors from brown/red/pink/lavender through purple to blue depending upon exactly which anthocyanin or mix of anthocyanins you end up with after all the genes have had their say. There are various genes that cause more or less anthocyanin to be made and yet other genes that produce proteins that cause reactions that change the chemistry of the anthocyanin from one variant to another.

Then there are also ears that look black but actually have very deep red pericarp. I call those "deep red" though many people would probably call them black. With the pericarp, it's easy to peel off a little and see it is actually red, not black. Also, black caused by red pericarp tastes so different from black caused by aleurone genes that I am loath to call them both black.

[blueadzuki]

Got it. Sort of like how I don't like calling the aleurone color "red" because it isn't the same thing as pericarp red. Or I suppose our family's "Black Death Paella" which is also technically just really really, purple also from anthocyanins (it's basically what you get when you make paella using so called "forbidden" rice.)

Though now a part of me is really really sorry I don't still have that grey kernel I mentioned that I found some years ago. how THAT came to be would be interesting to work out. Cursed be that grain weevil and his (or, I guess, her) progeny!

[Carol Deppe]

jondear--The outermost skin of the kernel, the pericarp, is synthesized by the mother plant, so it's her genes that determine what the color will be, and it will be one color for all the kernels in a ear. So if the mother is into red pericarp, every kernel on every ear will have a red pericarp. (I'll mention some fudge factors later.) The aleurone layer is determined by the genetics of the seed, and different seeds on an ear can have different genes for aleurone color.

So if a corn planting has genetic variability for the aleurone pigment genes but uniform for pericarp genes, you will have different colors of kernels on each ear. If a corn planting has variability for pericarp colors but is uniform for aleurone colors, you will get different solid-colored ears from the planting. If the corn planting is variable for both aleurone and pericarp colors, you'll see both patterns. You might see a solid pericarp-pink ear but be able to see the various different kernel colors underneath, for example. If the pericarp is dark red it might hide all the underlying kernel variability giving an ear that looks solid red. And so on.

There are two fudge factors. First, the pericarp colors have, in genetics-speak, variable penetrance and variable expressivity. That is, even when the gene is present it doesn't express uniformly. So an ear may be deeper pink/red at one end than the other for example. And when the gene is present it may express so little you just get a light pink tinge or maybe the ear even looks white. The second fudge factor is jumping genes. Controlling elements can jump from one spot to another in the genome, and if they land in or vacate a region that controls how much pigment is made you can have sections of an ear where all the kernels have much more or much less pigment than their neighbors.



'Magic Manna' flour corn has solid colored ears because it is uniform for aleurone color (clear) and endosperm (white) but varies for pericarp color which is red/pink, orange-brown/tan, or clear.

Abenaki flint (aka Roy's Calais) is uniform for yellow flint and clear aleurone, but varies for pericarp color, which is red or clear.

Cascade Ruby-Gold flint is uniform for yellow-orange flint and clear aleurone, but varies for pericarp color, which is red, orange-brown, or clear.

So all three of those varieties give solid-colored ears of different colors that can be sorted to produce cornbread with different flavors.

[jondear]

Maybe I should keep it simple and just order some cascade ruby gold... When do you start taking orders for 2015 Carol?

The more I read about grain corn, the more I like the idea of single colored cobs so it's easier to work with in the kitchen.

[Carol Deppe]

jondear, I hope to have the Fertile Valley Seeds catalog out by early December, but won't start shipping seed until Feb 1. I'll also be at the (Eugene Oregon) Good Earth Home and Garden Show all day Saturday, giving talks, answering questions, and selling seeds and signing books.

I've got lots of Magic Manna this year, so will be able to sell pounds as well as little packets. I'll also be introducing 'Pancake White Manna' and 'Brown Gravy Manna', sister lines to Magic that are half to 2/3 of the indicated color, and the rest all the rest of the colors of 'Magic'. 'Pancake White' is for people who best like the white ears for making pancakes, sweet breads, cakes, cookies, and biscuits. 'Brown Gravy' is for people who especially like using MM for gravy, savory (nonsweet) cornbread, and a different flavor of biscuit. (Of course I'm also working on a 'Parching Red Manna', but that is taking longer.) I plant the different lines all in one field in adjacent blocks, and just eat one row from the edge of each block. The idea is to deliberately allow a certain amount of gene flow between the lines to help keep numbers and genetic heterogeneity up, but not so much that the ear color frequencies merge back into those of 'Magic'. I'll also be introducing 'White Candle Gaucho', a sister line to 'Gaucho' I developed from a mutant that showed up in 'Gaucho'. It's white with a candle pattern on the hilem. So you can plant 'Gaucho' and 'White Candle' in the same row or field, just eat the area where the varieties come together, and save seed from the rest.

The idea behind sister varieties is that they are basically identical in genetic background except for just a gene or two, but that gene totally changes the flavor or use pattern so gives you a different food. But occasional crosses between the sister varieties is just no big deal. My idea is to build ease of seed saving right into the genetics of the varieties.

[reed]

I'v had a wonderful idea. The latest in a long line since I got hooked on this corn breeding thing, but this one has survived longer than most. I thought about it all day as I worked on building a new equipment shed.  I got up this morning and still haven't thought of a reason to discard it like its predecessors. It isn't really my idea but rather Carol's. I couldn't stop thinking about her "sister lines" and it occurred to me I might be able to do that with a sweet and a cornbread variety both based on a lot of the same parentage. In a way it accomplishes my original goal of having sweet corn that is also good for meal except it would be two lines instead of one. 

I could plant and grow them right beside each other and just eat the immediate neighbors for corn on the cob, flour crossing on the sweet wouldn't hurt anything at all. The dry sweet kernels should be easy to see on the meal corn and just pick them out before grinding. Likewise the flour kernels would be easy to see on the sweet ears and just pick them out before planting. 

It's foundation will be Painted Mountain or more likely Carol's Magic Manna since she has already eliminated all color except for pericarp and already divided it into the colors I know I like. I also like the sound of that as it should help provide a visual alert to any GMO contamination in future generations, assuming I can eliminate all yellow in all the other varieties also.  All the (se) sweet varieties I have collected are white except for Ruby Queen, (su) sweets are red, blue or black except Orchard Baby and Yukon Supreme which are yellow. I'll dissect some Ruby Queen to see what other colors it has and just drop it if I find yellow. On the other two I'll detassel them and keep careful track of their descendants for the first few years. I like them though for their extreme earliness. 

I shouldn't have to add many more flour types as I suspect even though Carol developed Magic Manna  in Oregon it is plenty diverse enough to adapt to my dried up Indiana ridge top.  Any I do add will be white.  I'll will be tossing in a little Indiana part flint just so I can say I added something local and because it tastes so good and it should add a little texture to my cornbread. 

Selection will be begin the second the seeds get covered by virtue of the fact that my new corn patch hasn't grown anything except grass and weeds for 50 years and will have no amendments except some radishes that the deer are currently keeping mowed down. A fence for it is next on my list after finishing the new shed. Coon traps are staying out all winter to try to preempt their influence. I also have no way to get water over there. Being able to survive such conditions is a high priority but I hope next summer is kind regarding rain so I can get things mixed up good before losing a good quality along with a bad one.  

That's the plan as of now, any and all comments and suggestions are greatly appreciated. 

[jondear]

We know sh2 and sy corn needs isolation from other corn so there isn't starchy kernels but if it was done on purpose and the starchy kernels grown out would they stay starchy and possibly be useful as a dry corn crop or would some sweet segregate out?

I guess I should also ask the inverse, if a synergistic corn was used as a pollen donor, some starchy kernels are apparent. If those were discarded would starchy kernels keep showing up in the offspring?

[Carol Deppe]

Reed--It doesn't matter whether your sweet corn and field corn have the similar genetic background since you are not trying to combine the sweet and field into sister lines. (And that combination would defeat the concept of sister lines, because crosses between them screw up the other.) You aren't creating sister lines, you're just using rigging the genetics to allow you to grow two varieties and keep them pure even if they have the same or overlapping pollination windows. I do that sort of thing all the time. My grower who grew Cascade Creamcap Flint for me also grew 'True Gold' Sweet corn. The latter is much later. Even so, there was pollination overlap, but the grower had eaten sweet corn and take flint for his home use from where the blocks came together. But in addition, the crosses between the varieties were 100% easy to identify and screen out.

For it to work, you need each variety to have some recessive that will be overridden and be an indicator of crosses to the other variety. So any white field corn and any yellow sweet corn will work. Crosses of either are obvious on the other. so the pairs you mentioned involving a white field corn and a yellow sweet (or red pericarp over a yellow sweet) would work. But not black sweet, unless it was over yellow endosperm. (heterozgous black isn't always apparent).

The white sweet corns wouldn't work, because a cross of white onto a white field ear isn't necessarily apparent. Red pericarp isn't a useful indicator, since it is maternal tissue and doesn't reflect the genetics of the seed, thus doesn't indicate crossing.

I bred Magic Manna (and Pancake White Manna) from Painted Mountain by gentle mass selection, keeping the numbers high so as to maintain all the heterogeneity, resilience, and agronomic virtues Dave Christiansen put into that variety, but simply eliminated the variability for aleurone color. So it should grow anywhere Painted Mountain grows. The Pancake White will have up to about a third ears of other (solid) colors, however, you can just eat those too.

But actually, any white field corn would do and would allow you to recognize the crosses in both directions when grown next to a yellow-endosperm sweet. You say you would like a bit more crunch that flour corn has. So you might prefer a dent. You could make a helluva white dent, I'll betcha, by crossing Pancake White Manna and Cascade Creamcap. You could plant both in alternating rows, detassel one of them, then grow out and stabilize the hybrid by mass selection and create your own very early white dent. Furthermore, you can do that with the "white side" of your field while growing the yellow sweet corn too.

It's often easier to keep varieties pure by rigging things so you recognize hybrids rather than have to avoid them. For example, if one bean has purple plants and one green, the hybrid will usually have pink plants. This means you can eliminate any crosses before they start to flower. If you are selling the seed it doesn't work, because some is crossed. But if it's for your own purposes, it works just fine because you know to watch for and cull the hybrids.

[Carol Deppe]

Jondear--If you have a cross of sh2 and su sweet corns, you'll get field corn. Then both segregate out. And if you keep the wrinkled kernels and grow those you keep getting a mix of field and sweet. I've run into this situation when trying to breed sweet corn from sweet contamination in field varieties. Too often, there is more than one kind of gene for "sweet" involved.

[reed]

Carol, Well back to the drawing board again, had a feeling that might happen.  I got a good view of my new corn spot finishing the roof of the shed I'm building so that's  where I'll spend the day in contemplation. One thing for now, the red pericarp isn't a good indicator. Is that because while pericarp color is maternal and all the kernels on a particular cob are the same, it doesn't mean that plants grown from that one cob will all have the same color pericarp? Each one will still have a single color but it won't necessarily be the same as the ear it came from. 

A brown ear of Magic Manna for example could produce any combination of the other colors? Kernels from my dark red ear might or might not grow out with the same dark red pericarp?