Evolution Of An Open Pollinated Corn Breeding Program

Version (First Release Feb. 2, 2009) Updated Beta 2.03 (Feb 8, 2009)

Well Adapted Traditional Varieties

We started our breeding program with a search for traditional corn varieties that were well adapted to northern conditions. In the late 70's when this project started there were not a lot of traditional corn varieties to choose from. Flint corn was known for its ability to do well at the northern limits of corn's adaptation. We were able to get some Garland Flint corn which was probably from the traditional northeast flint corns. The plants were single stemmed with one ear fairly high up on the stock. Yields for flint were listed as being somewhat less than other types. Dent corns generally have somewhat better yields. We found a source for Norstine Dent and added it to our trails in hopes of improving yield. The dent plants where singled stalked and generally resembled the flint. The first season trials of both of these corns separately were good, but we noticed that there was very little variation between plants within the varieties. In effort to broaden our genetic base we began to search for traditional northern varieties in the Midwest. We were very fortunate in coming across Mandan Bride Corn. It was a traditional variety flour corn adapted to the northern Midwest and had a really good reputation for being a variety that was adapted for cold and difficult growing conditions and the ability to germinate in cold soil. In addition, unlike the Flint and Dent varieties it had tillering (side stems forming at the base of the main stem) and this could add some diversity to the form of corn plants in our breeding program.

Loss Of Diversity In Traditional Varieties

Although these corn varieties looked like a good fairly broad spectrum of plant types to start working with on our breeding program, there was still in a need for more genetic diversity. The long journey of corn from its area of origin as a tropical plant (in what is now Mexico) to the present northern limit of corn growth was a long and involved one. It involved major changes to deal with drastically shorted growing seasons and major climate changes. Corn evolved to adapt to these changes but the process involved major losses in genetic diversity. The most recent losses were in the loss of many traditional varieties through lack of use and loss of seed stocks. The was also a loss of diversity in the few traditional varieties that did survive when many of those varieties were saved from extinction by some far sighted seed saver who rescued the seeds from attics and cellars but often only a very small quantity of viable seeds were saved. So what we have is only a small remnant of what we had even back in the 1800's.

Loss Of Diversity In Corn's Journey To The North

There was another major loss of genetic diversity in our traditional northern corns that was incurred as they migrated with man to the northern limits of corn agriculture. Let's take a quick look back in time to when corn was just beginning to spread from it core area of origin. Once corn growing began to provide a significant source of storage food for the Native Americans of that area then corn seed would certainly spread as a trade item, at least among neighboring related tribes. Corn culture spread in all directions from its center of origin. As the corn traveled north a certain percentage of the corn in any planting would not mature in the shortened season and some of the genes of those plants did not get passed on to the next generation. In addition, as all seed savers know, it can be difficult to keep and protect your seed from year to year. Mice and moisture can steal genetic diversity. Add to that in early times, the losses during wars, and seed eaten during famine and we can have some idea of the magnitude the loss of genetic diversity over time. Some varieties were quite literally passed on by a few handfuls of seeds and would be therefore highly susceptible to genetic drift.

If we look at this northward migration, northeast corns would have been some of the more distant from the area of origin and among those that had been most ruthlessly selected for short seasons. Both of these factors would tend to lessen genetic diversity. So based on these observations we could conclude that northern corns were especially deficient in genetic diversity and that we should look to find the most genetic diversity in areas surrounding the area of corn�s origins. In addition, if genetic diversity was lost through loss of seed, tribes near the area of origin could trade with other nearby tribe to replenish their seed stock. If seed stocks in these areas were reduced in number to where they could be in danger of genetic drift, the fact that they were surrounded by high diversity corn would mean that even small amounts of pollen contamination of their seed stocks from surrounding areas would work to replenish the diversity of their seed stock. In contrast, northern varieties suffering genetic loss had only other nearby seed stock to draw from and stock that was already deficient in diversity from their long journey of adaptation from the south.

New Diversity From Corn's Origins

In our effort to deal with the need for more diversity in our seed stock, we were able to get some seed from South America through the efforts of a professor at a local university. Here again we were very fortunate to get the Peruvian variety Cuzco, known for the fact that it had the largest seed of any corn. As it turned out the large seed trait did not show up in our breeding program but Cuzco proved to a valuable assets to our breeding program through its introduction of a great deal of diversity.

Cuzco Corn From Peru

Cuzco was grown in the area around Lake Titicaca in Peru and it grew in a high altitude climate. The real benefit that Cuzco provided us was that it was not only a source of genetic diversity but it turned out to be from a very early linage of corn (Manglesdrof) and was therefore a gold mine of diversity to replenish the gene pool that was depleted in the northern corns. Just as the selection of northern traits in corn came at the cost in genetic diversity, Cuzco came at a cost. It could not produce ears in our short season climate. To deal with this issue we researched the problem and found that by controlling day length we could trick Cuzco in to producing pollen just at the time we need to cross pollinate our northern corns with Cuzco pollen. Plants can be tricked into the proper day length reaction by covering them with a ventilated plastic trash can after a certain number of hours each day. Pollination day came and we had a number of miniature Cuczo corn plants in pollen. We carefully transferred this pollen to the silk of each of our northern strains that had been covered with paper lunch bags before the silks came out. After pollinating as may crosses to each variety as we had pollen (to maximize our seed numbers) then the silks were recovered with the bags and marked for later harvest.

We were able to see the full potential of the Cuzco seed that was not controlled for day length when the plants reached into the 8 to 10 foot stage by the end of the summer with still no ears forming. It gave us a good view of the character of this incredible corn. The plants were single stemmed with evidence of long shanks starting to develop for the ears. This must be some corn plant in its native land. We actually had to use an ax to cut the stalks down in the fall. They were like wood almost like bamboo and they had massive and aggressive prop roots high on the stem. But the real value of this corn to us only appeared when we planted out our crosses the next season.

The Results Of Crossing Locally Adapted Traditional Corns With An Origin Corn Like Cuzco

The only way to describe the crop we saw emerging as we grow out the crosses was awesome. The variations between plants were beyond any of our imaginings. We have some of 8 to 10 footers scattered among the 6 to 5 foot average heights in the rest of the crosses. But the real variation was in plant form. We could see the beginnings of almost every imaginable variation between all the forms we started with. From the large heavy robust stems of Cuzco to heavily tillered short Mandan types with Flint, Dent and Flour ears. There were plants with thick stems with and without tillers, all shapes of tillered plants with 1, 2, 3 or more tillers. (see pictures) Ears were forming on various leaf axils of the main shoot and on various leaf axils of the side shoots. The genetic diversity was as such a fundamental level that we even had occasional small ears the size of your thumb with tassels on top of the ear closely resembling primitive ears of corn found in the Bat Caves in Mexico thousands of years ago. [ See photo primitive like corn Right ]. As we continued growing the types out over the next few years the 8 - 10 foot giants disappeared (as they matured no ears) and the variety of other types increased. There were more 2 eared plants and 3 ears even appeared. At this point we had to decide what we were going to do with all this diversity. We saw no reason to select out this diversity in type and form because there was an abundance of corn maturing in our season and maturing in many forms. Our first harvests in late august (90 day corn) had some single ears on short plants beginning to dry down and some plants with first ears beginning to dry down with second ears on the way with many corn types for later pickings. This crop of corn was producing pretty well and all we needed to do was to continue to select for season (anything that matured an ear before the end of the growing season). We really had no need to select out anything because we had no idea what forms of corn we should select for or against. It was an abundance of diversity and it was producing corn all we needed to do was to decide how to direct this new found wealth. (pictures)

Deciding On a Breeding Plan

After seeing first hand the vitality and variability that came out of this increase in genetic diversity in form, shape and type we decided our first goal was to maintain as much of this new found diversity as possible in our breeding program. At the same time, we need to have a vision of what we wanted this corn to do for us. This was not a variety of corn instead it was an explosion of corn potential in multiple and changing forms while at the same time delivering up a good crop of corn while we worked with it each season. This called for special measures and the conventional methods of selecting for type and getting rid of the rest was not an option. We needed a new approach.

What Do We Want This Corn To Do For Us?

The first thing we needed was corn that matured in season. The corn was selecting itself for that. Plants that did not mature ears did not leave seed, and became less common as they contributed only pollen to the gene pool. The next question was, we needed a corn that was adapted to what season? As we moved along in our breeding program we realized that global warming was an issue that was here to stay. Seasons on average were already getting noticeably longer. The normal first fall frost that was expected at the end of August was more often happening in September and as time went on even into Oct or occasionally November. It seems a waste to want all our ears to mature at the end of August when we could be facing summers that went into Oct without a killing frost. One ear early was certainly a good thing to make sure we had something for the winter to eat but why stop at one when we had some plants with 2 or more ears. At the same time early frosts were still possible and late maturing might not make a crop. We began a new process, we did not select for certain types of plants (single stem, multiple stem, single ear, 2 ear, etc) instead we began to separate the harvest based on some simple criteria. FIRST PICK: (near the end of August when some of the small single early eared plants began ripening) we picked any ears on any plants if the ears were approaching maturity and could be dried down under cover. At the same time as we picked them, they were divided into 2 groups: SINGLE EARED PLANTS that had only one ear forming on the plant with no evidence of any more ears forming. AND plants that had one mature ear and at least one other ear forming, these were TWO OR MORE EARED PLANTS. The 2ND PICK: took place usually a few weeks later and as time went on this became the main crop. This could be anywhere from mid Sept on. The same SINGLE EARED PLANTS and TWO OR MORE EARED PLANTS were separated. The 3RD PICK: ended up being the pick just before the first expected hard frost. This had the same two categories and some of these ears came from plants with 3 or more ears. Anything not ready for this picking was picked, dried and was not saved for seed but instead eaten. This became the cut off point where some plants in this group left no seeds but still contributed to the gene pool through pollen given off earlier in the season.

One thing that stood out in this new way of managing the gene pool was that we were not selecting for a recognizable type. We did not select for any form over another. Any form (single stem, tillered stem, mixed stems) all contributed seed to the picking. In fact, we really had no idea what form of plant produced the ears once they were sorted.

Need To Look At The Situation Differently

We needed a way to look at this process differently. We began to see the advantages of looking at the gene pool and not individual plants or individual traits. And we needed a way to influence the gene pool without decreasing genetic diversity. With 1,500 plants in each breeding season we were well above the limits of genetic drift (500 plants) so as long as we didn't massively select out genes we should be ok there. The question was how to move the gene pool in certain general directions without losing diversity. We decided it would be a good idea to move towards more multi-eared corn in the gene pool. If you had one good ear early you had nothing to loose to go for a possible second ear or more. So we developed this plan. Since the only ears not in any of our pickings and categories were the ones after the last picking (that we ate), that meant that every other plant in the population was represented in one of the categories of the seed that we saved. (even those plants that left no mature ears were represented in the gene pool through their pollination of some in the saved categories). This meant that as long as we planted seed from each of all of our saved categories then the whole gene pool would be represented. With numbers well above the limits of genetic drift we were in a position to have almost no loss of diversity and we could be in a good position to influence the proportions of various genes in the gene pool. For example, we decided on a really simple (and easy) method of changing the proportions of genes in the gene pool by planting categories like 2ND PICK: 2 EARS OR MORE on the side of the garden that the prevailing winds came from. Planting categories of the plants you want to increase in the gene pool (like 2 EARS OR MORE) on the wind side of the garden meant they had the potential to pollinate the whole planting (since it was only about 100 feet wide). Planting the seeds of the categories you wanted to have a smaller share in the gene pool (like, for example, 3RD PICK: ONE EAR) on the side where the wind normally leaves the garden (where their pollen would only occasionally contribute to the gene pool when the wind blew from non wind prevailing directions) would lower their proportions in the gene pool.

Over time, multiple ears became more common in our pickings and genes that in any way contributed to multiple ears in various pickings became more common in the gene pool. We could see the change over time in more ears on the corn while at the same time we still had a showing of single ear super early plants. This opened up some really interesting possibilities. After playing around with this process over a few more years the question really arose do we really need to do this? What are we really trying to do here and maybe we already accomplished it. We have a gene pool with a fairly high proportion of mult-ear plants in a range of pickings. Maybe that is all we really need to do.

What Is Happening In A Highly Diverse Gene Pool Of Corn Under Changing Conditions?

First, Let�s Take A Look Inside The Gene Pool

The gene pool is the current collection of all the genes in a growing population of corn or in your seed stock (potential gene pool). When we look inside the gene pool we do not see plants or individual traits of plants. So we have to imagine relative proportions of various genes changing over time. Let�s take a very simple example, in a trait like eye color in fruit flies. If a single gene controls for a particular abnormal color of eye, then there must be other genes that control normal eye color. If there was a high diversity of gene types for eye color then there would be many types of eye color genes and there would be a wide variety of eye colors possible in the population. If there were very few types of genes present in the gene pool related to eye color then there would few options for eye color. In some cases there could be so few types of genes for some traits that only mutations could produce changes in the trait. (Mutations occur infrequently and are generally not helpful in breeding , at least initially.)

Looking Inside A High Diversity Gene Pool

If we are looking into a gene pool with a high degree of genetic diversity, we should expect to find a high diversity of genes for various traits. Let�s look at a high genetic diversity corn gene pool. If we have a number of dry seasons, then we can expect that any and all genes that have any positive effect in dealing with dry conditions (to the point that they increase seed production or even survival of the plants with those genes), then we can expect those genes to increase in proportion to other genes in the next gene pool of harvested plants. If this dryness trend continues over a period of years some interesting trends could develop. Once the genes that have any adaptive value on growth in dry conditions begin to increase in frequency in the gene pool, then the chance of a number of dryness adapted genes ending up together in an individual plant increases. Plants with multiple gene traits from new combinations of dry adapted genes could have significantly better survival and leave significantly more seed (and increase their ratios in the gene pool) even more than plants with only one dryness adapted gene. This could then accelerate the movement over a number of years towards more dryness adapted genes to the point where there would be a major increase. With more dryness adapted genes in the gene pool and more individual plants ending up with multi gene combinations there would even more dryness genes in the pool. Once gene ratios in the pool reach a certain critical mass then those gene ratios in the pool could increase, dramatically and in relatively short periods of time especially if dryness is a strongly selected trait (as in a drought).

View Of A Depleted Gene Pool

Now let�s look at a depleted gene pool, like for example, a northern flint corn. As northern variety we would expect loss of diversity from loss of seed stock and loss of diversity in corn�s long migration to the north. Under the same dry conditions, this depleted gene pool would be likely to have a smaller collection of dryness adapted genes (because it has less total diversity of its genes to begin with, many genes were actually lost to the gene pool, they are no longer present). In the first few years if enough dryness adapted genes of any kind where present then we might expect to see some increase in dryness adapted genes in the pool. But if the genes present gave only slight adaptive advantage then they might be found in the pool in increasing but very low levels. The chance of these genes combining in individual plants would also remain low and a cascade event of gene increase in plants with multiple dryness adapted genes would not occur. The result would be no significant sustained increase in dryness adapted genes in the gene pool of the corn and it would fail to make significant adjustments to the drying trend. Why? Either because needed genes were not in the gene pool to begin with or certain genes that interacted well with other dryness adapted gene were not present in sufficient amounts. A variety like this could be headed for serious problems (and so would the people growing it).

There�s More

Let�s delve into this a little further. Tillering in corn (where corn plants grow multiple stems form the base of the plant) added a great deal of diversity of form in our trials. Compared to the one stem single ears in the Flint and Dent corns we started with, our plants had a virtual explosion of tillering combinations. The first thing to note about tillering is that was a major factor in increased yield through increased number of ears on the tillers of tillered plants. In addition, if we look closely at the influence tillering can have we begin to notice some very interesting things. For example, besides increasing the number of ears on a plant, tillering is a very effective way of introducing staggered ear maturity as ears on tillers ripen at various stages. This is a very important trait in a global warming climate that allows us to get increased production in extended seasons while still getting a main crop in short seasons. Tillers add more leaf surface and more potential capturing of light for photosynthesis. This could provide real advantages when the stand of corn plants is thinned out by bird damage to sprouting seed, by damage to seed in sprouting due to corn seed maggot, or cold damage to seed. With significant spaces in between surviving plants you would normally expect production to go down. With tillering plants producing more leaf surface and spreading leaves further from the main stock then the remaining plants could fill in the spaces to some degree, grow faster and produce more ears with the increase in available sun and help to compensate for the loss of plants in the row. Here we have an entirely unexpected advantage of tillering compensating for poor initial stands. And there may be more advantages when we compare tillered plants with traditional single stalk plants.

Tillered Plants VS Single Stalked Plants

Single stalked plants, like the traditional Flint and Dents we used, showed no tendency to tiller. This limited any increase in yield to mostly larger ears as we saw no sign of more than one ear per stalk in our initial trials before we made crosses. Single stalked plants are really stuck with only one obvious way to increase yield, that is by larger ears. Given the selection process of a corn like a northern Flint named Garland, we would expect that it was selected from an Indian corn and it was strongly selected for ear size. We would therefore not expect much improvement in yield through ear size selection because it has already been done. Unlike the high diversity tillered corn (discussed above) we would expect little ability in the single stalk one ear corn to fill in for loss of production in a poor stand because it does not have the options of tillering. In addition, damage to the stem of a single stem corn by animal damage, wind or insect damage to the single stem could mean a complete loss of that plants production. In a tillered plant loss of the main stem would most likely stimulate the growth of the remaining tillers and increase tiller production. And it may be that the broad bushy form of tillered plants will lessen the likelihood of wind damage because the dense stand could serve as a windbreak for the plants, thereby reducing losses due to wind just by the form of the plants. Low dense bushy plants might create micro climates within the corn stand lessening evaporation in dry conditions. It seems clear where are on to something big here once corn plants move into the tillering mode. In fact, the single stem one eared corn plants with low genetic diversity have basically reached a dead end in their development and without more genes added to their gene pools do not face a bright future. In contrast, tillering certainly has a important role to play contributing vitality from a high diversity gene pool OP corn.

Gene Pool Selecting Itself For Yield

Let's look at an individual plant in this gene pool. Let's say, for example, that the average yield of kernels is say 250 seeds (We get a much higher numbers but have not measured it, so we will use this for an example, to keep the math simple). A gene pool that is weighted towards 2 or more eared corns or large one ear corns will tend to have higher average yields of kernels than plants with small ears that matured super early and stopped growing before the season was over. For example, let's say plant A has 150 kernels on a single ear and matures in 90 days and plant B has 2 ears one early with 100 kernels and a second later one with 100 kernels . If the season is especially short in that year then plant A with one mature ear (150 kernels) will contribute more to the next years gene pool than a 2 ear plant that did not mature its second ear (with only 100 kernels produced). If however, it was a longer season then the 2 eared plant might contribute two 100 kernel ears for a total of 200 kernels and it would contribute considerably more (about 25% more) to next years gene pool than plant A. Over time, plants that did better in leaving kernels in the gene pool will take over a larger share of the gene pool. Climate could push this difference in ratios in certain directions. Long seasons would be pushing the multiple ears, shorter seasons pushing up the one ear earlys. If this is true then the corn is selecting itself for yield and all we really need to do once we get a good mix in our gene pool is to take all the seeds that mature in all of our categories and dump them in a big barrel and mix thoroughly reach in and grab some seeds and plant them. The seeds we pick out should be (over time on average) in the general ratios of their presence in the gene pool of that season. In addition, the TOTAL yield of the corn should be increasing because plants that leave more seeds (yield higher) will take larger shares of the gene pool and be better represented in the next planting. Yield will increase even if you do nothing but mix the harvested seed and replant from that stock. (This random seed mixing may not be practical on a large scale, but it demonstrates the point that the corn gene pool is self regulating and moving towards higher yields.) The diverse gene pool is selecting itself for, among other things, maximum yield.

New Attributes Of The Gene Pool Emerge

In addition, the gene pool changes with changes in weather and climate (dry years select for dry year traits, wet for wet). This means that that gene pool is exhibiting a "memory". The gene pool changes after a few years of dry conditions toward being weighted toward more proportion of dry weather adaptive genes in the pool. The gene pool in a sense remembers what it experiences each season and weighs itself more heavily in certain directions as a result. In addition, it "anticipates" what is needed for the next season by the weight each previous season has given certain gene types (i.e.: drought adaptive genes or wet). The seed crop of this gene pool is in a very real sense the �best guess" based on past experience on what genes will be most needed in the next season. This is not to say that the gene pool is thinking or anticipating like a person but it is saying that the gene pool is acting like an "intelligent system". By that I mean a system that learns from and interacts with its environment. This means we have to rethink our whole view of what breeding OP corn with diverse gene pool really is. If we are no longer selecting for individual plant traits (i.e. single stem, one ear, medium height) then what is going on here?

Maybe what we have here is not a corn variety but a Self Adjusting Diverse Gene Pool That Gradually Morphs Over Time into Collections of Varieties that have adapted to the current conditions. And in addition, can over time morph into a collection of varieties that best deals with, at different times completely opposite conditions (drought vs. wet years and wet years vs. droughts). This is certainly more that we are used to expecting from a normal OP corn variety and way beyond the non existent potential for change in hybrids. This is like some kind of proto variety that creates varieties based on the experience of the past seasons and has the potential due to its genetic diversity to reverse selection for opposite traits (dry adapting, wet adapting) over time without eliminating genes from the gene pool.

Highly Diverse Gene Pool Of OP Corn As An "Intelligent System"

The gene pool of an OP corn with reconstituted genetic diversity is acting as an intelligent system and we need to understand how this works before we can begin to understand how to work with this new dynamic system. Certainly conventional methods of ruthless selecting for those traits would not work with this system. For example, intense selection for drought resistance by conventional methods will be not only selecting for drought resistance but actively throwing out of the gene pool many other genes that we have no idea what role they have to play. (Selecting just a few plants from a gene pool can not include the full spectrum of the gene types in that gene pool.) Such a strong selection will not be likely to survive in a dramatically changed environment like high moisture years because you may have already inadvertently excluded many genes or combinations of genes that would have played a role in tolerance to high moisture conditions. In fact, it would not be surprising to find that many genes that enhance moisture adaptation could be significantly reduced in a drought selected variety using conventional selection methods. This becomes a really important issue in light of the reality of Global Warming. Global Warming studies (ref) predict not only general warming trends but more severe changes of weather like more intense and prolonged heat waves, more intense and prolonged unseasonable cold waves, and both more droughts and floods in the same area. Breeding for types like drought resistance does not make sense in this new global warming world. Corn needs to be able to adjust to dramatically changed conditions, often dealing with extremes and cycles that need opposite traits.

Why Isn�t Open Pollinated Corn Acting Like An Intelligent System?

Traditional open pollinated corn is in fact working under the same intelligent system model as the high diversity corn but because of a depleted gene pool it does not have enough variety in gene type to even begin to move towards adaptation. The commonly available OP corns are often those that are intensely selected by early settlers from the original Indian varieties and they are often of such a focused and narrow gene base that there are few variations in genes to draw from for change. It is as if these varieties are snapshots in time and are stuck in that time warp because they have lost many of the genes they need to get back to the ability to change and adapt outside their very tight niche. They can be looked at as intelligent systems �trying� to adjust but without enough diversity to move in any new directions. Maybe what we really need to do, as corn breeders, is to get back to some critical mass of diversity using traditional locally adapted varieties for their wealth of northern adaptive traits and then reconstitute their diversity with an influx of genes from an �area of origin� corn. Our own view is that an intact original area corn (like Cuzco) may have advantages in not introducing too much diversity that could lead to having to get rid of problem traits later. We have no information about this except that creator of Painted Mountain (a highly diverse corn) did mention online that he was considering extensive inbreed of some of his lines to get rid of problem genes. We have had relatively few problems as mentioned earlier.

Modern Hybrid Corn Breeding: Selecting For And Against Traits

The whole development of all modern corn breeding since the invention of hybrid corn has been based on rigorous selection FOR certain desired traits and AGAINST all other traits. The whole process of hybrid corn breeding is to create designer plants that consistently show the traits we think we want. To do that and make the traits consistent and highly predictable we had to remove everything else that was not what we wanted. Besides the problem that we may be selecting for the wrong things (given global warming) and towards plant types that are consistently the same even in the face of a rapidly changeable environment, we are removing a whole lot of genes we know nothing about. If in our OP corn breeding programs we continue using the same methods used in hybrid development of ruthless selection for certain traits and getting rid of many other traits then we may be just creating a OP version of corn that is merely an poor imitation of the hybrids. The diversity of genes the hybrid breeding system or the conventional OP breeding programs throw away may be just want we need to create a truly adaptive OP corn. The genes that the hybrid breeding methods throw away are the ones that do not produce obvious visible traits that we normally look for in selection. We will call these the INVISIBLE genes that are being removed from the gene pool in almost all of modern hybrid and conventional OP selection. Let's take a closer look at this.

Genome Discoveries And The Alleged "Junk Genes"

With the discovery of efficient methods of mapping the genome of various plants and animals we gained a peak at what was going on with the INVISIBLE genes that were not associated with traits that we selected for. The big surprise was that major parts of genomes were filled with genes that we had no idea what they did. Since we were used to making major advances using our current breeding methods without knowing anything about these genes, the early theories of the role of these genes was that they were somehow left over remnants of things no longer needed. They must be, in fact, useless JUNK GENES. It seems strange that significant parts of whole genomes were just some left over thrash. Further research in this field lead to insights that some of these junk genes may actually have the ability to switch on an off other genes and modify important systems in an organism depending on certain conditions in the environment or in the organism itself. We now see that these important control mechanisms may be controlled and regulated by some of these formally "junk" genes. If we go back to our intelligent system model of the gene pool, these formally junk genes may be looked at as very sophisticated parts of the "intelligent system" that allows the organism to react to changes in ways that are very positive for the organism. It is probably not a good idea to mess with sophisticated control systems in intelligent systems without thought for the consequences.

Mandan Indian Corns: Traditional Varieties With Exceptional Adapability

We have been used to a very mechanical model of plant breeding. Pick the traits and the plant will grow to that trait all you need to do it create the proper soil and environmental conditions. In our early research on traditional corn varieties we came across a very interesting book Corn Among the Indians of the Upper Missouri by George F. Will and George E. Hyde. A collection of first hand reports from the late 1800's first published in 1917. In its descriptions by early travelers to Mandan country it had the following entry: "Of the corn plant, as raised by the Upper Missouri tribes, we have several good descriptions by early travelers. As has been said, the size of the plants and ears varied greatly. This variation was not a matter of latitude alone, but was sometimes due to special seasonal or soil conditions. It is this adaptability to conditions of climate and soil which accounts for the extreme hardiness of the Indian varieties of corn and for the fact that a failure of the crop was rarely absolute. In a poor year and in poor soil the Mandan varieties will seldom rise higher than two feet, the ears being not over three or four inches long with very few to a hill. In good season, and especially in the rich bottom land of the river valley, this same varieties will attain a height of five or six feet and will sucker profusely, producing many ears to a hill, some of which will be seven to eleven inches in length." p70

Adapability Transferred In Crosses

We found this to be true in our corn and we attribute it to the Mandan genes in some of the original crosses. We have small section of the garden over a shallow rock outcrop and during a drought (with no watering) we were amazed at how small the corn grew and yet still made small but mature ears while under better conditions produced much larger ears. We also found in more fertile sections of the garden the plants were more likely to tiller and have more ears per tiller and larger ears. This adaptability is a real asset.

It is precisely this ability to change in extraordinary ways to meet changing conditions that we will need in the future. To think that we can take a variety like Mandan Bride and ruthlessly select for certain limited traits like ear size and ignore all the genes that are lost in the process and not except some loss of function in the corn is short sighted. What is it worth to have a corn that can adjust to produce a crop under almost any conditions? It takes thousands of years of growing and evolving under difficult conditions to produce a corn that can still produce enough of a crop in bad years to insure the survival of the tribes who cultivated the corn. Some where this adaptability is coded in the gene pool and it is only with a healthy respect for those unknown gene interactions that we will able to move forward with OP corn development. Which bring us back to an important lesson we learned when we overstepped ourselves in corn breeding back in the 1970's.

Selection For Corn Traits And The Belief That We Could Design Varieties To Suit Any Need

Hybrid corn seed production was a very labor intense system and this was keeping the cost of hybrid corn seed production high. Hybrid seed production demanded that large numbers of corn had to be detassled by hand to control pollination. Discovery of a gene for male sterility in corn lead to a tricky method of growing hybrid corn seed that greatly reduced the cost of production and helped usher in the era of hybrid corn. This leads us back to the invisible genes, those genes behind the scenes (and out of mind) when we were focusing on selecting for traits we could see or measure. In the process, we thought nothing about what was happening with those gene we were unknowingly removing or adding to the gene pool. In the 1970's some of those invisible genes had a pronounced effect on the whole US corn crop. Leading to sudden and dramatic increase in susceptibility of most of the US corn hybrid varieties (most of the US corn crop) to a corn leaf blight that before this point was a minor corn disease. In a few years the corn losses were in the billions of dollars. A crash program was instituted to deal with the problem and it was found that the genes for male infertility that was introduced into almost ALL of the hybrid corn in the US to cut out detassling costs also brought with it some invisible genes that made the plants usually susceptible to the normally minor leaf blight. Unknowingly the hybrid breeder had introduced a gene that they had no reason to believe would have any effect, into the entire US corn hybrid corn crop. A crash program was instituted to correct this problem by replacing the genes used in the male sterility of corn. According to reports we were very close to some very serious losses in the entire US corn production. This is just an example of how our view of corn breeding was based on a very narrow and mechanistic model, where we selected ruthlessly for certain traits while selecting against or for a whole bunch of genes that we had no idea what role they had to play.

New Approach To Open Pollinated Corn Breeding
Reconstituted Diverse Gene Pool As A Self Adjusting "Intelligent Sytstem"

Now let�s get back to the corn patch and our breeding program. We are still leaning on the corn we are working with to tweak the diversity. We are now working on testing limited additions of more flint traits in the gene pool. But already the corn is doing most of the work for us as it adjusts to it new home. It is pretty clear to us that reconstituting a diverse gene pool fundamentally changes what happens to a corn grow under those conditions. We need to question even the concept that we want to breed corn "varieties" with certain traits when we are not really in a position to know what those traits should be. In a global warming world we increasingly need corn that can survive drying periods and wet periods in the same location. What we need is not varieties "designed" to meet certain conditions but diverse gene pools that can be released into various locations and they will adapt to those areas over time. Regional reconstituted diverse gene pools have properties that far surpass any conventional corn variety (hybrid or OP) in its ability to adjust itself to new conditions and have the flexibility to adjust to change and maintain its genetic diversity.

Creating Regional Reconstituted Diverse Gene Pools As A Transition To
An Alternative To Traditional and Commercial Corn Breeding
What is needed to create a Regionally Adapted Enhanced Gene Pool for Corn?

We have to start with OP corn varieties that are well adapted to the area. It has taken thousands of years of adaptation to evolve these local adapted varieties, This is especially important when we are looking at a move a tropical plant like corn to short season areas in a cold climate. This is the foundation for building a base for a regional corn gene pool. The goal here is to collect varieties that cover to full spectrum of types of OP corn that were once grown in the area. At this stage, It may be that the wider the base of regionally appropriate genes the better, if the corns come from traditional varieties. Corns developed since then may be introducing genes from distance genomes and may be introducing diversity outside the range of the region and may not be the best choices. Bringing in traditional varieties from similar season and climate areas is also helpful. This collection will supply the gene pool of northern adapted genes that will not be readily found in other corns. But having a good collection of traditional regional varieties is not enough, because, as stated before, what we have available to us now is a severely restricted gene pool compared not only to what we had in the past but to the true variability that corn is capable of that was lost in corn�s long journey to the north.

How Much Genetic Diversity Is Enough And Can You Have Too Much?

In our breeding program we used 2 locally adapted OP varieties that showed little variation and a 3rd OP variety from the mid west (Mandan Bride) that showed somewhat more variation (at least in form). We used Cuzco (from Peru) as the major supply of diversity and we crossed it with each of the regionally appropriate varieties. So the cross was fairly heavily weighted towards the local traits. This is important because we do not want to swamp out the local traits with too much diversity or we will have to spend more time in getting back to locally important traits later. In our breeding program, the actual ratio was influenced somewhat by the limited choices available at that time but as it turned out it seems to be just right. We had some loss during the first few years in plants that were not close to maturing here but this cleared up fairly rapidly and the genetic diversity did not create too many plants that caused a burden to the breeding program. We have now maybe only a few percent of plants that cause problems in the field. In our case there are a few plants each season that produce ears where the corn husks do not quite cover the end of the cob and we rouge these plants to prevent birds mostly blue jays from finding exposed kernels and initiating predation on other intact ears. As part of our management plan we eat these corn ears in the milk stage. We also have a small number of ears with tassels and some of these tassels have kernels and these are removed as we see them. These may seem like minor problems but even these minor instances of exposed corn can initiate a major predation by local birds (mostly jays) if not corrected. Local jays that are not used to corn growing actually need to learn that corn is in the husk and ANY exposed kernel will trigger predation in uninitiated birds. This experience has convinced us that the primary adaptive advantage of corn husks is as a deterrent or to at least a slow down to predation by birds. (We use scare tape and scare balloons to protect the breeding stock). As a result of our experience we think the ratio we used of local traits to Cuzco, (that we used for diversity) was pretty good. Locally important traits are high and diversity is very high and any higher level of diversity could result in an increase in wasted corn and in faults that may be difficult to remove, later. For example, the primitive ears and partial tassel ear forms, were very interesting to us as breeders to be able to see as slice of time in corn were the separation of tassel and ear were still in transition, if the prevalence was much higher than it was then it could be a nuisance. So there does seem to be a point where you can have too much diversity that could result in more waste to the crop that may not be that easy to remove. But if you had to make a choice you would probably want to see some waste or you may not be getting as broad a base of genetic diversity as you might need. One point to keep in mind in introducing genetic diversity is that having one long standing traditional variety, like Cuzco, we added a �whole� genome that was functionally �intact� into our gene pool. Adding more than one diversity corn may disrupt the gene pool system of the other traditional varieties used for diversity. Also adding pieces of diversity from a mixture of heavily selected corns may not have the same effect. Traditional varieties have been to a large degree selecting themselves for many traits (even within their limited gene pool) and they may retain to a significant degree the properties of an �intelligent system�. Highly selected corn with recombined traits may not have the same positive diversity effect. It looks like more work needs to be done to answer these questions.

Current Breeding Plans

We are now reaching a stage in the breeding program where the crop seems stable, has good diversity, good adaptation, and has yielded consistently under varied conditions. Besides cleaning up the 2 types of corn grain exposure traits we are seeking to lessen the percent of flour corn in the harvest. We have been doing this for about the last 10 years by eating the flour corn ears. (the flour trait has been difficult to remove). Next season we may begin testing a flint variety (Abenaki Calais Flint, Fedco Seeds) for possible future addition to the breeding stock. More on this later as you do not want to introduce ANY new corns to your breed stock without special precautions this late in the process. In our case we will grow out our candidate variety on the leeward side of the garden and religiously detassle that row and then plant out that rows decedents and detassle them as we study the results. This will allow us to see the results of the cross with no risk to the breeding stock and this method takes very little work.

In the model we are looking at we are approaching a stage where those who are creating High Diversity OP gene pool stocks would begin to look ahead a few years to a time to release some seed interested groups nearby to test and build up the seed stock. We envision a model of seed development were individuals will create a stock like this and release it to the public by giving some seed stock to other local growers where they only ask that local growers keep the stock pure (at least the first year) and then give seed stock to other interested growers to test and grow out to give to others. Ideally at least the first year or two the tester should try and keep the stock pure to give to others and after that point that could modify the stock as they see fit but they should keep backup seed from the original stock in case they need to return to the original. Once original seed stock is given out then those growers who might need to replenish their original seed stocks could go to the people that they gave seed stock. This way the burden of giving out seed does not fall on the original growers. In this model we see no problem with people deciding to grow seed stock to sell at a fair price to others as long as they acknowledge that this is not a plant protected variety, not owned by them, and if possible acknowledge the source (if they even know the source by then) so questions can be directed back to the original developers. Once people have handed some of the original seed stock to others then they are free to save and modify their own seed.

Distribution Of Seed Through Small Scale Growers

On a broader scale this model could provide for a rather rapid distribution of the seed stock with very little burden to the growers and help facilitate a transition away from the hybrid corn model to regional enhanced genetic diversity OP corn gene pools model where the gene pools are developed by interested individuals and distributed through a community of growers (like seed savers exchange). At this point in time the most receptive users would probably be small farmers, homesteaders, and those looking to establish an alternative local and value added agricultural economy. At some point it is hoped that larger farmers may become interested. Most homesteaders, and small farms harvest dry field corn by picking it in the field (like many Amish) so variation in height of corn should not be a problem. If larger farmers take an interest then harvesting by machine may take some adjustment but over time only the corn that gets picked up by the machine will ever see its way into their seed stock so this should be self correcting in most instances unless some selections cause jamming problems in the machines. But in general this is model is not intended to compete with the hybrid corn model but instead to pick up the slack where hybrids begin to fail to produce and open up formerly hybrid markets of corn to this new OP model and allow small growers, and small value added grinding operations, to move into a new niche and move our agriculture in a new local and more sustainable direction. This model of development is ideally suited for homesteaders and small farmers because any corn produced in the development of the breed is useable on the farm and the amount of work you need to put into corn breeding is not a lot more than you would need to do in production using the methods described here. Compared to the amount of work required in the conventional selection and crossing and selection method used even in OP breeding this method is ideally suited to the small grower. Your work in growing corn is producing food or feed for your animals in addition to developing the breed. In fact, it is probably because we developed this method as a hobby while we were growing our own food that lead us to the short cut methods we used. We needed to move this breeding program along with the minimum of extra work and still accomplish our breeding goals. Least work is a real asset if you grow your own food and have a multitude of jobs competing for your time. [ See FAQ Page For More Information On This Issue]

Local Control Of Corn Breeding And Production

This model has the potential to create a whole new alternative to the highly concentrated seed industry where fewer less aware companies controlling more of the seed sales The big players seem intent on focusing on making sure that everyone must buy their seed from them each year . This attempt to hijack the production of seed and the hording of our historic seed heritage is not in the best interest of the farmer, the consumer or the economy. What we are proposing here is a grassroots effort for the small farmers, seed savers and homesteaders to take back their role as caretakers and keepers of the seed.

Breeding And Distributing Updates To Meet New Needs: Inoculate Crops In The Field

During an early phase of our breeding program we came across an opportunity to breed for rust resistance (see website link). And this brings up another interesting opportunity with this model of seed production. Once we had a seed stock from our own lines that showed some resistance to rust then all we did was to plant it on the windward side of our breeding plots to maximize the spread through the corn. This was a very simple way to increase the resistance and if rust became a real problem then the gene pool would have moved in the direction of more rust resistance. As it turned out only once in 30 years was rust a major problem that reached the point of effecting yield so the genes for rust resistance are still in the gene pool but not being selected for because the problem of rust is not great at this time. This leads us to believe that in the new model of distribution growers could develop resistances to new diseases and then release "updates" to distribute to others growers who have the original seed stocks and all the growers would have to do is "inoculate" their gene pool with the "update" of resistance and then their gene pool would carry this resistance and it would only be expressed to the extent it was needed. Much like a software update this distribution would be vastly superior to the hybrid model of having to completely redevelop a new variety of hybrid (long process) to deal with changes in disease or climate. Given the fact that global warming predictions expect more diseases to move into areas that formerly did not have those diseases, the new updating model of "inoculating" existing highly diverse gene pools of OP corn means we could react to and distribute a "vaccine" carrier that would upgrade existing crops without severely disrupting the gains that growers have made in adapting their corn to their conditions. Once again we come back to the core difference between the hybrid (and conventional OP breeding) models of selecting for what you want and excluding all other traits vs. retaining genetic diversity and then adding to it as needed in the new model.

Next Stage: Creating A New Model For OP Corn Breeding

Once corn breeding focuses on the full potential inherent in genetic diversity, the role of breeders may be to develop through various methods the critical mass of diversity using locally adapted OP corns and enhancing genetic diversity with �area of origin� corns that will allow them to send out this new form of corn and allow it adjust to where it is grown. Given the magnitude of the task before us, the task of providing a reliable source of food to replace the hybrid corn that will increasing fall short of the need, we should be thankful that our work is not the work of trying to design varieties of corn but instead to recreate vibrant highly diverse gene pools that are fully capable of growing under a wide variety of conditions and improving themselves as they adjust in the process. We can do this with a minimum increase in work and gain an enjoyable hobby that will leave something of value to future generations. To the extent that we can learn to understand and facilitate the development of diverse corn gene pools and release them in the appropriate areas, the work of selecting for adaptation to an area will be passed to the corn itself. We need to begin to understand and learn to see a Regionally Adapting High Diversity Open Pollinated Corn Gene Pool as an "intelligent system" and work with it to reach its full potential.

We encourage readers to send the link to this page to others.
This site is in beta testing and will be revised and updated. See top page title line for version number. Send comments and suggestions to:
[email protected]

[ See Corn Photos Page ]
[ See Frequently Asked Questions FAQ Section Of This Site ]
[ Return To Top Of Evolution Of An Open Pollinated Corn Breeding Program ]
-- MAIN MENU: Breeding for Rust Resistance in Corn --