Growing Prehistoric Corn (Teosinte)

Zea mexicana plant grown 2011 in Loveland, Colorado
Zea mexicana plant grown in N. Colorado (October 2011)

I grew some Teosinte again this year. I was able to plant several different varieties, so i could evaluate them and observe their differences. There seemed to be more differences than similarities, and there were a few traits that were common with some of my Indian Corn that i like to grow. One interesting trait that i occasionally see in my indian corn is where there are some male parts that grow on the very tops of the cobs that in theory could produce pollen to self pollinate. The problem with this trait in corn is that it usually doesn’t seem to function anymore when it does show up, and in most cases never appears at all.

Zea mexicana silking and setting seed in Colorado
Zea mexicana silking and setting seed in N. Colorado (October 2011)

Here is a “cob” of Zea mexicana teosinte that has made it to the silking stage and is ready to accept pollen. I’m delighted to have found a variety that has the potential of setting mature seeds here in my garden. Teosinte is native to Mexico, so there are quite a few differences in the length of the growing season between Mexico and Colorado. So far only Zea mexicana and a variety of teosinte called “Northern Tepehuan Maizillo” are the only types to reach the pollen stage here in Colorado; and Zea Mexicana is the only one so far to reach the silking/seed stage. I look forward to trying to grow (and maybe cross) both these varieties next year. This Zea mexicana plant is really close to producing mature seeds, but the plant is dying due to a frost the other night. If i can start some Zea mexicana earlier in the season, then i might have a better chance of getting some mature seeds before winter.

I grew a very nice specimen of Zea diploperennis last year, and i hoped it would be able to survive the winter, but it did not reappear this year. I planted some more, but they were in a nutrient deficient spot, and had stunted growth this year.

teosinte_distribution_map
Distribution map for teosinte growing areas

A theory of mine that I’d like to explore sometime in the future has to do with the origin of Corn (Maize). Teosinte is obviously the origin, but there are significant differences in seed shape and cob formation. My current theory is that cobs are an emergent trait that appeared after two distinct teosinte lines crossed. The most likely cross in my mind is one between Zea mexicana and Zea parviglumis. Their ranges come very close to overlapping in several areas. After growing several varieties in my garden this year, i can tell you that strangely Zea mexicana and Zea parviglumis are eerily similar to corn. Zea parviglumis is a tillered teosinte, but it has only has about 6 tillers, but other varieties like Zea diploperennis or Zea huehuetenangensis have like 10 tillers each. Zea mexicana has no tillers. Zea parviglumis is a little short, and Zea mexicana is fairly tall. Theoretically if they were crossed then the resulting hybrid should be the same height as the corn that grows in my garden, and the intermediate growth pattern should also be closer to corn than either parent.

Teosinte hybrid showing an emergent but primitive 4 rowed cob

Part of my idea of an emergent cob from a teosinte hybridized with another teosinte species is based on the work done by Mary Eubanks. Mary Eubanks has published a few articles about a theory that Gamma Grass (Tripsacum) is one parent of modern corn that hybridized with teosinte a long time ago in Mexico. It’s an interesting theory, but it seems that most geneticists don’t believe Tripsacum is a parent that led to corn. I also have my doubts about it, but the the work done by Mary Eubanks is still important. She has created Tripsacum-Teosinte hybrids at Duke University.  Her work shows that when teosinte is hybridized with a similar grass species (Tripsacum) that in F2 generation a primitive 4 rowed cob starts to form and is an emergent trait.

Diagram showing postulated evolution of modern maize

Surprisingly there don’t seem to be a lot of pictures of teosinte on the internet. If your interested in seeing a few more pictures of the ones i grew this year in 2011, then by all means visit my photobucket page here. The pictures of teosinte are not individually labeled as to which species is which, but i can tell them apart after growing them.

Zea mexicana grown in N. Colorado (2011)

EDIT (October 24, 2011): I was able to hand pollinate the Zea mexicana plantin my yard today with the pollen from the Zea mexicana. They only have about a day and a half before a big snow storm, so i hope it’s enough time to actually fertilize the seeds. I will try and cut the plants down and bring them inside to dry. Here’s hoping! 😀

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