South American Corn: Synthetic Composite & Descendants

[Joseph Lofthouse]

Some years ago I studied a phylogenetic map of corn and determined that my varieties are heavily descended from the northern flints. I didn't like that, so I set out to add diversity by incorporating corns from other races. The first race to be integrated into my sweet corn included flour corns from Hopiland. I am making this thread to document the incorporation of genetics from South America.

In 2013 and 2014 a number of South American corns were planted together and allowed to inter-cross. I am calling them a synthetic composite. The germplasm was collected from across South American and the Caribbean. It contains:

• Tuxpeño composite from Southern Mexico - a dent corn but different than the North American dents
• Cuzco composite from Bolivia and Peru - some components from up to 11,000 feet elevation
• Piricinco/Coroíco composite from the Amazon basin
• Cateto and Coastal Tropical Flints from Argentina and Caribbean - the orange kernels contain up to 10X the carotenes of yellow corn
• Eagle Meets Condor - High elevation Andean corn crossed with Painted Mountain

Here's what a few cobs of each type looked like:


One that got me really excited was Cateto Sulino because it produces high carotenes in the endosperm. I'm always looking for higher nutrition in the plants that I grow. Besides, it looks pretty. The popped kernel that looks yellow is Cateto.

Today I laid out cobs from the main patch of South American corns and took photos. Here they are:

South American Synthetic Composite. 2014. Softest flour corns on the left. Flints on the right. Mixed types and dents towards the center.


Some of the Cateto cobs are almost red this year because they have so much carotene in them. I selected some seed for high carotene before planting.


There are lots of inter-grades between hard flints and soft flours. Many of them dented.


I began daydreaming about creating my own flour corn landrace after harvesting these cobs. The kernels are huge and super-soft. Sorry I didn't include anything for scale. It started snowing when I had the cobs only about 2/3 laid out so I rushed through the photography.


I don't quite know what to do with the trait for yellow aleurone demonstrated by these cobs.


I have been making crosses in order to incorporate the genetics from these corns into my sweet corn and popcorn. I hope to post more details about those projects later.

[oxbowfarm]

Very nice pictures Joseph.

I also have become very excited about the possibilities presented by incorporating more tropical and South American genetics into my corn. I have to specifically thank maicerochico for awakening me to the possibilities and for the generous gifts of seed.

The more I look into it, the more apparent it is to me how impoverished North American corn genetics were, even before the hybrid corn revolution post WW2. At the time of contact most corn being grown in North America belonged to the Northern Flint race. And it had only arrived in the few centuries before contact and was still adapting to the climate and daylength. So there was genetic impoverishment still ongoing due to founder effects. When you compare that to the richness of Central American and South American corn, the lack of diversity is troubling. Then factor in how much diversity was lost when all the older heirloom types of Northern Flint were abandoned first in favor of Cornbelt dents, then hybrid cornbelt dents. The genetic base of North American corn growing is pathetic.

I can't wait till next year to see the F1 offspring of the Cateto and Piricinco/Coroíco crosses I made this year.

Next year I am hoping to include Caribbean Flint, Mexican Highland, and Peruvian Highland into my flint corn project to look for cold tolerance and disease resistance.

P.S. I think I've mentioned this before, but the Piricinco/Coroíco composite demonstrated outstanding resistance to Northern Leaf Blight here in 2014. This was a very severe year for NLB in this area and the Coroíco was almost totally unaffected, just the occasional lesion, even while the rows were interplanted in my White Flour Grex that was showing much more severe symptoms and was filling the air with inoculum.

[Joseph Lofthouse]

Nov 25, 2014 21:50:03 GMT -5 oxbowfarm said:

I have to specifically thank maicerochico for awakening me to the possibilities and for the generous gifts of seed.

Me too I think. (Screen names change.)

maicerochico: I'd be interested in reading about the provenance of this seed if you know it... Was it adapted to North American growing conditions?

[DarJones]

Very little of the tropical adapted corn can be grown in temperate climates without first making a cross to a temperate adapted variety. Andean races in particular are difficult.

I agree that you will see a significant increase in diversity, but suspect ongoing selection will rapidly narrow the genetics in your composite.

Are you planning to use it for animal feed? or just to develop edible varieties?

[blueadzuki]

That heavily purpled speckled one in picture 5 is really nice (though admittedly it looks like it got most of it's traits from the northern side of the family) Looks like it will be a good grinder (oh wait, did you say something about dents in your opinion being only for animal food? I can't remember.)

[oxbowfarm]

The first five of the composites Joseph listed were developed by Cargill in the 70s. Tropical material was crossed with cornbelt dent to acquire daylength adaptation.

Obviously many of the genes will fall by the wayside but if you are properly selecting your seed from an adequate number of plants, you can find ways to keep a lot of it too. And if you maintain mother lines from all of it you will have multiple lines of maternal cytoplasm.

[Joseph Lofthouse]

Cateto:

PI 451691
Cargill North Temperate Zone Cateto

Narrative
Unimproved non-cornbelt flint population, altered from short to long day, cornbelt adaptation. Population with 94% recovery of Cateto flint germplasm. Husk coverage heavy. Cobs white. Kernels deep yellow to orange. All of the Argentine flint inbreds trace back to longtime open-pollinated varieties and are unadulterated by introduced germplasm. Four of these inbreds had previously been converted to earlier forms by a backcross approach where the early USA and Canadian inbreds served as sources of earliness. The other Argentine inbreds and the Cuarentin population have a late temperate zone maturity. The Brazilian populations are fully tropical. Temperate and tropical material were joined in a single population and this adapted to the Central Corn Belt through phenotypic recurrent selection.

Pedigree
Derived from 8 Argentina flint inbreds, 4.70% Arg-1, 4.70% Arg-2, 4.70% Arg-3, 4.70% Arg-4, 6.25% Arg-5, 6.25% Arg-6, 6.25% Arg-7, 6.25% Arg-8,; 4 Brazilian Cateto populations, 6.25% Cateto S. Sirao, 6.25% Minas Gerias II, 6.25% Cateto Composto, 6.25% Rio G. S. XIV; 1 Argentina Cuarentin population, 25% Cuarentin Rossi; 4 early USA breds, 0.8% WD, 0.8% W37A, 0.8% MS206, 0.8% A509; and 5 Canadian inbreds, 0.8% CMV3, 1.0% CMD5, 0.8% CK27, 0.8% CM37, 0.8% KD54.

The others are listed on this page.

Coastal Tropical Flints, PI 451690

Coroico, PI 451692

Cuzco, PI 451693

Tuxpeño, PI 451694

Eagle Meets Condor came to me directly from Dave Christensen. It is super early, so has pretty much kept to itself and not had much influence on the rest of the patch.

[maicerochico]

Joseph and Oxbow,

Here is what I know about the different Cargill Populations:

First, this is the official bulletin put out by Cargill, Inc. when they released their five populations into the public sector:

www.agron.missouri.edu/mnl/54/40gerrish.html

The Mexican Dent (mostly Tuxpeno), Caribbean, and Cateto populations were originally bred by E. E. Gerrish as sources of exotic traits. All three were taken to the 2nd backcross generation. At this stage, only inbred lines were used as representatives. Somewhere along the way Gerrish apparently decided to put the genetics into the public domain and crossed in a bunch of tropical OPVs for additional diversity. (The 1/2 inbred + 1/2 OPV pedigrees balanced performance and diversity.) The motivation behind the Cuzco and Coroico populations is much less clear to me, because any sensible tropical maize breeder knows to avoid Amazonian floury corns like the plague and that Central and South Andean breeds are essentially useless anywhere else.

My one gripe with Cargill's converted populations is their selection of conversion candidates. Even though the corns that went into their stocks are indeed fully exotic, the company intentionally chose to breed with inbreds and OPVs that had traits more amicable to established industrial agriculture (i.e. no colors but white, yellow, and orange; few and loose husks; standard, non-interlocked rows; small tassels; upright leaves; etc., etc.). This led to much representative genetic diversity being excluded from consideration.

For example, this year I grew some pure Piricinco floury maize from Peru, and, minus its expected daylength sensitivity, the corn had quite a few traits that are rare or absent in Cargill's Coroico stock. Specifically, the pure stocks had up to 18 extremely tight and thick husks, very large tassels with many branches, abundant bronze-orange-brown aleurones, near 100% row interlocking, and quite a few waxy kernels. It is interesting to note that the six OPVs used by Cargill were acquired directly from Brazilian Amerindian tribes and belong to the same breed as my Peruvian collections.

My one complaint aside, Mr. Gerrish's five pools should certainly be considered by folks on this site, because they quite possibly contain more genetic diversity than all the currently available USA heirlooms and because some of those genetics are nearly impossible to incorporate into temperate materials otherwise.

Starting next year I will begin crossing Cargill's stocks with additional representatives of the different Latin American complexes so that I can build upon their genetic bases. There are some truly amazing corns that are on the verge of extinction in their native regions and should be converted to daylength neutrality so that their genes can be preserved outside of the tropics.

[DarJones]

Do any of these corn variants show the shoe peg trait? The only commonly available shoe peg corn is Country Gentleman sweet corn. I am retrieving the shoe peg trait into a southern dent so I can cross it with a high oil line. The long term strategy is to combine high lysine, high methionine, high oil, and shoepeg into a single variety.

Yes, it may be just wishful thinking, but I hope it works.

[grano]

Fusionpower,

Isn't the commonly available Gourdseed a shoe peg?

[Joseph Lofthouse]

Nov 27, 2014 1:25:07 GMT -5 DarJones said:

Do any of these corn variants show the shoe peg trait?

I believe that this cob and a few others like it came out of the Coroico population. Definitely "rat selected".

[philagardener]

Happened across the pages of the International Maize and Wheat Improvement Center (in Mexico) today. Sounds like an interesting resource!

www.cimmyt.org/en/what-we-do/maize-research
www.facebook.com/pages/Banco-de-Germoplasma-CIMMYT/1494684564145592?fref=ts

[oxbowfarm]

A lot of my Coroico ears had very jumbled rows similar to what Joseph is showing in his picture. I don't know if it is caused by the same mechanism that causes shoepeg. Coroico has the row interlocking mechanism which is fairly unique to the Coroico/Piricinco complex. I assume the system that causes shoepeg/gourdseed is different? The top cob of these Coroico ears is kind of shoepeggy.

[DarJones]

The gourdseed corn I have seen is not shoepeg. The way to tell is to carefully pull a pair of kernels off a cob and see if they are facing each other. Most corn produces a pair of cupules, of which only one develops into a kernel, that result in all the kernels facing the same direction. Both cupules develop in shoepeg corn resulting in the haphazard appearance.

[Joseph Lofthouse]

Fusionpower: I checked the cob in the recent photo, and a similar one (that also happens to be one of the few "rat selected" cobs). More or less the embryos all face the tip of the cob. There doesn't seem to be pairs of embryos facing each other.