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Page 4076. Saturday, September 16, 2000. 1:07 AM
Doug Palaschak's #4076 homozygous conversion theory and other theories.
Copyright. September 2000. Douglas Palaschak.
Click here to see Essay #5493 - the miracle of hybrid corn - how it was developed.
Click here to see Essay # 3916 - Seed and Greed - the Terminator Gene.
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I ramble at first: the basic mechanism is at the end.
Background: When farmers grew their own seed corn:
Joe Lowery is one of my heroes. He passed away a few years ago. He knew how to farm well and prosper. He assembled and improved the 80's (an "80" is an 80 acre field - ¼ mile wide x ½ mile long) that constitute the Lowery farm that my brothers began farming in about 1975. Joe Lowery taught my brothers many secrets of managing light, water, and soil to grow corn and soybeans. My Brother Jerry tells me that Joe Lowery was one of the folks who grew his own seed corn using stock from the university of Illinois. From what I hear from farmers, the current generation of farmers are about 2 generations removed from the days when folks grew their own seed corn. Sadly, to my Brother Greg who now farms the Lowery Farm and has fired me and Jerry, Joe Lowery's seed separator is just an antique. The hand corn sheller is now just a toy. Joe used them both to produce his own seed - - and he urged Jerry and Greg to do it - but that was the boom days when the Russians bought our expensive corn. Maybe we should reconsider Joe's advice today.
Untested theory: I theorize as follows:
High yield and high oil are not Shades of Grey
Some traits are not controlled by the elementary Mendelian model. These traits may be shades of grey, so to speak. Example: human skin color. If a dark skinned person mates with a light skinned person, their child may be an average skin color - neither dark nor light.
However, my subconscious tells me that high oil and high yield are each completely dominant as used in TopCross corn - and therefore I theorize that the simple Mendelian model could be used to produce homozygous high oil corn as follows.
Corollary: Using a proxy to deselect double recessive invisible traits
You can't see the high oil trait when you are walking out in the field deselecting the double recessives. Therefore we may elect to live with possibility that 25% of our corn will be double recessive for low oil. That means that our percentage of oil at the grain elevator might only be increased 75% of the distance between the normal level and the optimal high oil level. In the alternative we can devise a method to select for double recessive - such as linking a visible trait to the genetic material the controls embryo size which is the proxy for oil content. I theorize that high oil is a proxy for season length - and season length is a visible trait. We might make a pass through the field on the 100th day after planting and see if we can observe 25% of the plants that are noticeably ahead of the other plants - and then eliminate them from seed stock.
Non genetic corollary:
Much of what the seed companies know as expertise is obtained from the Universities. We can discover methods of achieving our agronomic goals.
My theory: It came to me in the shower in September 2000.
Hybrid corn such as high oil corn can be converted to a 93% homozygous heirloom seed in just one generation. I do not claim that nobody else has this theory. It is simply a corollary of the basic model of genetics established by the Monk Gregor Mendel.
Gedanken - German word meaning "a thought experiment"
We begin with 1/ 3 bushel of seeds harvested in a TopCross field. That is enough seed for an acre of corn - which in turn will produce 120 bushels of corn, of which 75% will be suitable for seed. This 90 bushels will provide seed for 270 acres of corn - or enough for a farmer who farms 540 acres - which is about an average size Illinois corn and soybean farm.
This is the F1 generation.
The F1 generation that concerns us hangs on the 90% of the plants that were produced by the pink seeds(1).
The phenotype is uniform (in other words, all the stalks from the pink seeds produce uniform corn) because both the parents were homozygous. Therefore we know that the embryo carries a genetic code of HhYy for the following reason. It received one H gene from the unwound single helix of DNA from the nubbins from the blue pollinator seeds from the University of Illinois progeny which has 7.5% oil content symbolized by the capital H.
Similarly it received one h gene from unwound single helix from ovule in the cob of plants grown from the pink seeds which is the standard corn bred for high yield and normal oil content of 6% symbolized by small h.
Similarly it received one Y gene from the unwound single helix from the standard high yield corn produce by the pink seeds.
Similarly it received one y gene from the unwound single helix from the pollen of the blue seeds which have low yield.
Then the 2 single helixes joined, there was only one possible combination. The ovule produced by the pink seed produced a Y and received a y. The ovule produced an h and received an H from the pollinator from the blue seed.
Conclusion: look at the field
Obviously high yield and high oil are dominant genes. Were it not so, we would have a field of nubbins with low oil. We don't.
Now: fast forward
Imagine that we planted TopCross pink and blue seeds in spring 2000. We harvest the F1 generation in fall 2000. (This example is unrealistic for farmers in Allen township because Cargill employed illegal monopolistic forces to distort the market for the progeny of the seeds of its competitors who produce high oil corn. Cargill seed sells no high oil seeds. I complained to the FTC.)
(Look on the ground at harvest in fall 2000. Aha!!! Why are the cobs white? Maybe that is the visible link to the gene
that produces male sterility which is maybe recessive?)
We must harvest the corn by hand. We will set aside some nubbins in case we can find a way to do the TopCross process(2). We will only use the seeds from the pink seeds (which produce the full size ears) which means that we will harvest our 1/ 3 bushel of seed stock by hand.
Fast Forward to spring 2001
Okay, we have our 1/ 3 bushel of seeds harvested from the plants from the spring 2000 pink seeds. The corn from the plants from the blue seeds has been separated from our seeds when we picked them by hand. We selected only the big ears - not the nubbins. Now from what I have written about DNA spirals, we know that this F1 generation is uniform - - but not homozygous. It is heterozygous. Remember, our seeds for spring 2001 contain this genetic code: HhYy = high yield and high oil. They all contain this same coding. They are heterozygous - which means that the H contains a capital and a small H. Not uniform. By comparison, our smaller pile of corn from the fall 2000 nubbins is homozygous as follows: HHyy= high oil and low yield - but we won't be using that in today's though experiment. Homozygous means that the H's are homo - alike - in this case, both capital. Also, the Y's are both capital. Hetero means capital and small.
Gedanken. Thought Experiment.
Because every seed is the same in this F1 generation, we can simply use one seed to figure out the possibilities and then extrapolate. This one seed will produce pollen and self-pollinate. The male gametes in the pollen will have the same genetic code as the ovules (in the cob): namely HhYy. Now when the double helix unwinds, there are 4 combinations: HY, hy, Hy, hY - - - but I have limited our experiment to one trait, namely, yield, the Y trait - and so we have 2 possibilities: Y and y - big yield and small yield. We can live with 7.5% oil (as compare to 8% - which is a 25% downward reduction on the path from 8 to the standard 6% corn oil content) but we cannot stand a 25% drop in yield - - therefore we will focus on creating corn that is homozygous for high yield - - at least for this thought experiment.
The ovule similarly unwinds a helix having Y and y - - and therefore each ovule has an equal statistical probability of having either Y or y. Then occurs the germination with the male gamete from the pollen. There are the following possibilities:
Possibility #1: Y from ovule Y from pollen = homozygous kernel manifesting in high yield.
Possibility #2: Y from ovule y from pollen manifesting high yield because high yield is dominant.
Possibility #3: y from ovule Y from pollen manifesting high yield because high yield is dominant.
Possibility #4: y from ovule y from pollen manifesting low yield because this is double recessive.
Plan: We simply harvest the yy ears because they will be small. We feed them to the pigs. Now lets consider the genetic content of the remaining seed stock. Lets add up the genes. We have YY from possiblity #1, Yy from #2, yY from #3. Number 4 has been eliminated. Add up he genes from 1,2 and 3 = YY, Yy, + yY = 4 Y's and 2y's. We have decreased the likelihood of receiving y in the next generation. Thus the percentage of high yield genes is now 4 out of 6 = 66% whereas we started with 50%.
Conclusion: Harvest of 2001 will yield 75% high yield. We would need to plant 33% more seed in spring 2001. That is unacceptable; we will have to do another generation.
Now if we do this same process in the spring of 2002 lets see the possibilities. The odds are 2 to one in
favor of getting a high yield gene. Here are the combinations.
Y from ovule; Y from pollen - manifesting in high yield because high yield is dominant.
Y from ovule; Y from pollen - - - - same here - and all the way down until you get to double recessive.
Y from ovule; y from pollen
Y Y
Y Y
Y y
yY
yY
yy but this double recessive will be visible and eliminated.
Lets add them up YY, YY, Yy,
YY YY Yy
yY yY
Total Y's = 5 + 5 + 2 = 12 out of 16 = 3/4. Now we have improve the odds of getting a high yield gene to 3/4.
Hmm. Can we extrapolate the next generation. Let's look at the patterns: 1/2, 2/ 3, 3/ 4; 3/4, 8/ 9 , 15/ 16. See the table below.
Thus the phenotype in harvest of 2002 is 8/9 high yield - which means that we would need to plant 11% more seed in the spring of 2002 - which is what we do now with high oil corn - so that is acceptable. But can we predict 2003 without doing the tedious adding.
Table Showing Improvement each year and diminishing marginal returns.
In Spring 2001 the F1 generation: 1/ 2 of its genes are high yield and the fall 3/ 4 of its kernels are high yield
In Spring 2002 the F2(?) generation: 2/ 3 of its genes are high yield and in the fall 8/ 9 of its kernels are high yield
In spring 2003 the F3 generation: 3/ 4 of its genes are high yield and in the fall 2003, 15/16 of its kernels high yield
The mathematical progression in the improvement in genetic content is obvious after a while. The numerator and denominator increase by one each year. Similarly the progression in the phenotype percentage is obvious also. The numerator is the square of a number that increases b one each year. The numerator is that squared number minus one. Conversely, the number of double recessives is simply 1 divided by the square of a number that increases by one with each generation of progress.
If we are right, then the seeds from spring 2003 will produce only 1/16 nubbin = 93% high yield. We would have to plant 7% more seed but our seed cost would be $3 per bushel instead of $100 which means that we would save $33 per acre = the equivalent of 11 bushels of corn.
Important fundamental theory: Once you do the selecting process and produce seed that is 2/ 3, 3/ 4 or whatever percentage homozygous, it doe not regress. The selection process produces lasting results.
Aha! Now I understand why the sheller has the attachment for removing the fat kernels from the ends. These kernels are fat due to their location on the ear. If we are selecting for fat kernels then we should select at the place on the ear with the kernels would otherwise be uniform in size. Therefor the process would be to shell off the fat end kernels, dispose of them, and then do the selection with the grader from kernels on the mid section of the ear. And then maybe do a separate process to select the fattest of the fat end kernels. Surely there is some writing about how this was done historically.
Whoops. Problem. My theory was predicated on F2 ears with uniform kernels - but the ear will contain a
distribution of kernels in Mendelian distribution - because of stray pollen. Which mean that we can't send out the high school kids to pick the nubbin ears. Hmm. (Wow. I am glad that I thought this through a bit before acting. ) Now it seems that it would be easier to spot a high oil kernel (bigger embryo) than a high yield kernel. Hmm. Or, in general, seed selection must be done by the individual kernel? Well, that is why they had seed separators. Okay, well I'm ready to buy that expensive corn seed now. Aha!! If each stalk were to be self pollinating - by putting a bag over its own pollen over the ear, for example, then the double recessive would indeed be completely on one ear! Aha!!! I am the king of all bootstrapped geneticists!!! (Remember, we only care about eliminating double recessives which means that the ears that we seek are homozygous!!!) (Okay, I realize that somebody named Pfyster, or Funk probably figured this out a century ago.)
Wow, I think I know how Gregor Mendel felt. I wish that I had some Enigma to listen to know - with the Gregorian chants in the background.
But seriously, there are obviously techniques for selecting high yield traits by the kernel? Obviously if you could link some color or other visible trait to the trait to be selected then selection would be easier - - but if you can do genetic surgery, then maybe there are more direct routes to high yield.
Idea: Buy a book about it!
1. The generation of nubbins on the pollinator stalks would seem to theoretically be homozygous high oil low yield corn. Hmm. If we could discover how to produce male sterile corn then we could do the TopCross thing ourselves - but I digress - or rather I demonstrate the seamless web of possibilities.
2. "Aha!", you are saying. "You are telling me to breach my contract." I am saying that the contract should be void as violating public policy!! Would you permit the sale of houses that would be destroyed by contract after one use? Would you eat at a restaurant that made you sign a contract to eat at no other restaurant? Their plea about the cost of producing this seed is pathetic in its dishonesty. Corporate ficta are designed to destroy the human farmers! Your Dad should have told you: "Watch out for folks who don't want you to grow your own seeds." Of course, had he said that you would have thought him crazy. Who knew that corporate thieves would become so bold.