Corn breeding

[alan]

Tom,

Glad to see and read this post and see you working with the "Asronomy Domine" genepool. The seed you recieved this past season was about 150 crossed up cultivars selected gently in a general direction (lol, hope that makes sense). Thus far most of the Astronomy Domine project has been a "let the pollen fly" and then select for what we like project. Even without heavy selection criteria (other than cold wet soil germination, taste, lodging resistance, and disease tolerance) we are still heading towards certain averages; mid season, prolific (two ears), non tillering, and multi colored, as well as about 20% SE kernels. To maintain color, it's important to plant way less yellow corn than of the individual colors.

Anyhow, the crop this year has come along nicely, and I must thank Johno for taking such good care at selecting and developing the original 40 plus variety line and returning some of it to me in order to backcross it into the newer genepool. This year we added about five SE hybrids into the mix and several old OP varieties. The diversity is astounding and the pedigree now includes about 170 plus varieties.

Let me know how the crop does for you Tom and if you would like/need some more seed of the newest genepool for continued experimentation let me know as this year I've harvested about a bushel of selected seed.

At this point in time I will move towards heavier selection of traits which I favor here in Indiana as opposed to the wide variety of maturities and traits I have been working on. The corn will always remain very diverse with options available to nearly all growers in all regions and locations much like painted mountain, but being on the ground floor will offer the most "wiggle" room with the quickest returns to those in favor of making uniqe selections for their regions.

Also, I have continued, despite the fact that my climate does not require it, to make selections for cold and wet soil germination, I am able to plant this corn here in the Ohio Valley a full two weeks prior to even field corn entering the ground at this location. Those who want to grow this corn should not find themselves afraid to plant it even in the most marginal of climates, produce seed, even if it is a small amount in the first year (trust me, there is more than enough heterosis in any one of these ears to start and maintain a population) due to pollination, climate, or other factors, and then grow on a second year and watch the vast improvement which is made.

This years seed crops were put through the ringer, planted 4 days earlier than normal, hit with frost 3 times, grown on heavy red clay unamended and taken through the hottest and one of the driest summers on record sans irrigation, what has survived and thrived is what goes in the bags/packs this year.

[Tom Wagner]

I meant to 'talk' about the corn project here in Washington, but didn't because I was not sure if the corn would 'make'.

I picked just a few ears for drying down purposes to get viable seed for next year. If you read my first topic starter...I had quite a few varieties planted for making crosses, meaning to detassel everything but the Astronomy Domine. Well....that did not get done but the crossing between the rows happened anyway.

I made quite a few selections of the Painted Mountain...without a doubt the earlierst of the lot. The Roy Calais corn (Corn without a summer) from the yellow ear selection had colored kernels indicating crosses as well as the Sunshine showing other colors.

The Sunshine was from five year old seed. It did remarkably well...Thanks to Victory Seeds...it followed their blurb nicely:

'

Sunshine' was developed at the North Dakota Agricultural Experimental Station (AES) by A. F. Yeager to thrive in areas with shorter growing seasons. ‘Sunshine’ is the stabilized cross of ‘Golden Bantam’ [1902, W. Atlee Burpee] and ‘Gill’s Early Market’ [Gill Bros. Seed Co., Portland, Oregon]. Originally released in 1927, it remained very popular, under several name variations, until seed companies began favoring the sale of unstable, F1 hybrids and last sold commercially in 1992.

The stalks grow to about 5½ feet in height with ears setting about one foot from the ground. It retains the good, old-time corn flavor of its ‘Golden Bantam’ parent but reaches roasting ear stage three to ten days earlier. The ears are six to eight inches long averaging twelve rows of golden yellow kernels. It did great in our Oregon and Tennessee 2003 trial, as well as in our seed production grow outs in 2004 and 2005. We look forward to hearing how it does in your garden.

I will have to 'salvage' many ears to dry down inside...the field was planted around July 1 and is partly flooded now. The earliest tasseling Astronomy Domine in every other row are likely male parents, the late ones not at all. I will likely harvest the quickest maturing ears of each accession and the selection rate will be 20% of each population if that.

Imagine that many of the many lines of corn have ears still in the sweet corn eating stage...therefore any ears mature enough to have hard colored seeds are a rarity. Sweet corn for eating in Washington is an October thing going into November. I think I will be successful in getting some good good germplasm going for mixing early types and fast drying down corns.

[kctomato]

www.sciencedaily.com/releases/2010/11/101123121117.htm

Scientists Re-Sequence 6 Corn Varieties, Find Some Genes Missing


ScienceDaily (Nov. 23, 2010) — Most living plant and animal species have a certain, relatively small, amount of variation in their genetic make-up.

Differences in height, skin and eye color of humans, for example, are very noticeable, but are actually the consequences of very small variations in genetic makeup.

Researchers at Iowa State University, China Agricultural University and the Beijing Genomics Institute in China recently re-sequenced and compared six elite inbred corn (maize) lines, including the parents of the most productive commercial hybrids in China.

When comparing the different inbred corn lines, researchers expected to see more variations in the genes than in humans.

Surprisingly, researchers found entire genes that were missing from one line to another.

"That was a real eye opener," said Patrick Schnable, director of the Center for Plant Genomics and professor of agronomy at ISU.

The research uncovered more than 100 genes that are present in some corn lines but missing in others.

This variation is called the presence/absence variation, and Schnable thinks it could be very important.

Schnable's research is the cover article for the current edition of the journal Nature Genetics, and has been highlighted by the association Faculty 1000, which identifies the top 2 percent of important research from peer-reviewed journals worldwide.

"One of the goals of the research is to try to identify how heterosis (hybrid vigor) works," said Schnable. Heterosis is the phenomenon in which the offspring of two different lines of corn grow better than either of the two parents. This is the attribute that has enabled corn breeders to produce better and better hybrids of corn.

For instance, two lines of corn can be bred to produce a hybrid that increases yield or resists drought or pests better than either of the parents.

With the current discovery that certain genes are missing from inbred corn lines, Schnable thinks science is a step closer to identifying which genes are responsible for which traits.

Knowing which genes are important would provide a shortcut for breeders to produce hybrids with specific traits.

For example, if one inbred line is missing a gene and is drought susceptible, crossing that line with a line that includes the missing gene and is drought tolerant, might lead to a better hybrid, according to Schnable.

"If we can understand how heterosis works, we might be able to make predictions about which inbreds to cross together," said Schnable. "I don't think we'll be able to tell plant breeders which hybrids will be the absolute winners. But we might be able to say 'These combinations are probably not worth testing.'"

Schnable sees combining genes from two lines as a chance to introduce the best from both plants.

"These are complementing somehow," he said. "It's like a really good marriage. She's good at this, and he's good at that, and together, they form a good team."

The potential for improvement is great, but Schnable cautions that much work needs to be done.

"We are at the point where we think this is going to be important, but we don't know which genes specifically are going to be important," he said. "Now we need to figure out which genetic combinations will be predictive of hybrid success."

materials provided by Iowa State University

.

Journal Reference:

1. Jinsheng Lai, Ruiqiang Li, Xun Xu, Weiwei Jin, Mingliang Xu, Hainan Zhao, Zhongkai Xiang, Weibin Song, Kai Ying, Mei Zhang, Yinping Jiao, Peixiang Ni, Jianguo Zhang, Dong Li, Xiaosen Guo, Kaixiong Ye, Min Jian, Bo Wang, Huisong Zheng, Huiqing Liang, Xiuqing Zhang, Shoucai Wang, Shaojiang Chen, Jiansheng Li, Yan Fu, Nathan M Springer, Huanming Yang, Jian Wang, Jingrui Dai, Patrick S Schnable, Jun Wang. Genome-wide patterns of genetic variation among elite maize inbred lines. Nature Genetics, 2010; 42 (11): 1027 DOI: 10.1038/ng.684

[spacecase0]

that sure is interesting about the DNA,
I wonder when they will publish results

[kctomato]

they already have published

the reference is the last thing in that post

[thefuture]

so if we get 2 tasty heirlooms and grow them together we can get hybrid vigor AND good taste in the next generation?

[DarJones]

so if we get 2 tasty heirlooms and grow them together we can get hybrid vigor AND good taste in the next generation?

Not necessarily. If the '2 tasty heirlooms' happen to be very closely related to start with, there is likely to be little or no benefit. If the '2 tasty heirlooms' happen to be very distantly related, crossing could combine deleterious genes to produce a useless hybrid. The advantage comes from finding '2 tasty heirlooms' that combine well to produce a hybrid that is outstanding. All it means is that you may have to hunt around to find really good combining ability, but the odds are more in your favor with distantly related than with closely related varieties.

To use a classic example, southern dent corns commonly grown in the Southeastern U.S. do not normally produce outstanding hybrids when crossed with other southern dents. The same can be said when you cross northern flint corns among themselves. But when you cross a southern dent with a northern flint, there is a much higher probability of high combining ability resulting in a very productive hybrid. This particular cross is the basis of most hybrid corn in use today.

DarJones

[thefuture]

thanks. i am just about giving up on corn anyway...tried it for several years and have never had more than a dozen ears. too finicky and susceptible. sticking with potatoes, sweet potatoes and squash for calories. plus fruit.

[joseph]

I'm wondering how much of the so called "hybrid vigor" is due only to erasing the effects of "inbreeding depression"?

[DarJones]

In the case of corn, 'hybrid vigor' exceeds the production potential of any extant open pollinated lines. Understanding why this disparity exists gets down to some serious chromosomal anomalies in corn.

Most commercial agricultural crops are a result of hybridization of two related species. Examples include wheat, rutabaga, potato, etc. This type of hybridization could result in conservation of all the chromosomes of both parent species such as in the rutabaga which has the full set of chromosomes from turnip and cabbage. It could also involve chromosome reduction such as happens when teosinte is crossed with tripsacum. In a few generations, only the teosinte chromosomes are retained but they incorporate several snippets of dna that crossed over from the tripsacum. In this type hybrid species the chromosomes have often been knocked for a loop with bits missing here and there in the genome. This is exactly the set of traits that corn exhibits where the chromosomes behave as would be expected in a composite species formed from two related but separate species. The problem is that we can't positively prove that any such species combination event occurred in corn. The single most significant feature of such a composite species is that it is VERY INTOLERANT OF INBREEDING. Guess what? Corn is extremely intolerant of inbreeding. But this does not prove that corn is a composite species.

So to partially answer your speculation, a corn line made by crossing several different selected breeds will be highly heterozygous and therefore likely to be much more productive than the lightly to highly inbred lines from which is is derived.

If you want to see something interesting try crossing pencil cob corn with Hickory King. I found out several years ago that this cross is significantly more productive than either parent. You can get similar results by crossing Mandan Bride with Cherokee Squaw.

DarJones

[spacecase0]

Dec 4, 2010 18:21:35 GMT -8 joseph said:

I'm wondering how much of the so called "hybrid vigor" is due only to erasing the effects of "inbreeding depression"?

I think you are right, and that should be easy to test,
but everything I have seen shows that you are right,
o I am not sure that I need to test it

[Ray]

Just a few words of thought.
With all the Astronomy Domine corn sent out to others, how can it be assured that such corn won't return polluted by GMOs and go on to pollute the entire Astronomy Domine experiment?

Are there safeguards which ensure Painted Mountain has not been GMO-polluted?

As much as I like Double Red, I read it came from a cross with a Burpee hybrid (Ruby Queen). With that in mind, is there any chance it can be known to be certainly either free from GMO's or possibly contaminated by GMOs?

These are just some thoughts, not accusations, okay? I am saying we all must be VERY careful now that Monsanto's GMO corn has made accidental GMO-pollution a big threat. We could easily spread it while thinking we are preventing it.

[Tom Wagner]

Are there safeguards which ensure Painted Mountain has not been GMO-polluted?

Ray,

Thanks for posting as a guest and not even as a member. I understand and do not believe that guests should be treated with less approval than members.

Your question is a good one. But allow me to turn the question around.

HOW CAN WE ENSURE PAINTED MOUNTAIN HAS BEEN GMO-CROSSED?

How can we prove a negative until we prove a positive?

Last year...2011...I had some Painted Mountain near some ROUNDUP READY silage corn. I collected the seed carefully and labeled it so. It was planted out 2012 and was observed for traits.

The PM x RR GMO was at least a foot taller than PM.
The ear placement was a foot or more higher.
The silk was red
The kernels all had a red dot on the silk attachment.
The kernel color was majority yellow with a few darker kernels.
The cob was reddish pink
The row number...instead of 8, 10 or 12..was 14 to 16
The lodging was nil
The corn expressed the STAYGREEN traits.

Expectation of the F-2 crop:
Wide range of row number
Dented kernels
Wide range of short to tall corn stalks
High expression of dark green leaves and stalks perhaps >than 20%
Many with narrow and/or upright leaves
Many with no tillering
Etc.
29% less yield than hybrid
Many runty ears as would approach the inbred type

Segregation for tolerance to ROUNDUP? I don't know the rates.
Most of the corn will still be yellow with maybe 1/4 colors..red, blue, etc.

If one is going to take safeguards against admixture...one better know what to expect.

I don't suppose anyone would want the F-2 seed of Painted Mountain (PM) x ROUNDUP READY silage corn. I have a small quantity available. I was thinking it could be planted in a commercial field at the same time as the RR corn next year and see what percent of the seedlings are killed by ROUNDUP.

The red dot coming from the presence of the RR corn may only be a marker and may or may not be connected to the RR gene (s).

I could take a picture of an ear of PM x RR to illustrate if anybody wants to see the effect of a purposeful admixture. Since I am quite adverse to the idea of GMO corn encroachment into OP corn...I am somewhat nervous to even having this sample in my possession. But knowing what to look for is part of the protection game.

Bt toxin is widely used in genetically modified crops but I don't think the corn locally is thus modified...I could be wrong. The way to find it admixed into Painted Mountain would be interesting if anyone knew.

I am not privy to all the traits in corn that have been modified...the only one I know about is the ROUNDUP READY kinds.

I am for the most part ignorant of the long range effects of GMO contamination...hoping someone else..(professionals) would chime in.

WHERE, OH WHERE, ARE OUR INVESTIGATIVE REPORTERS? I am not one but I'll bet this post is as close as many are going to be able to find and read.

[DarJones]

Do a bit of due diligence and you will find that the primary genes in corn are:
Roundup Ready gmo herbicide tolerant with multiple variants over the years
Liberty Link gmo herbicide tolerant
BT gmo corn borer and rootworm tolerant
There are several other genes that are included such as a wireworm specific tolerance gene, the newly developed 2,4,D tolerant gene, and a couple of others that have been used but are not as prevalent.

You can read quite a bit on the wiki articles below.

en.wikipedia.org/wiki/Genetically_modified_maize

en.wikipedia.org/wiki/Genetically_modified_tomato
DarJones

[joseph]

Dec 8, 2012 11:54:02 GMT -8 @Ray said:

With all the Astronomy Domine corn sent out to others, how can it be assured that such corn won't return polluted by GMOs and go on to pollute the entire Astronomy Domine experiment?

I am saying we all must be VERY careful now that Monsanto's GMO corn has made accidental GMO-pollution a big threat. We could easily spread it while thinking we are preventing it.

I personally don't care about GMO contamination. It is not something that I can pragmatically measure in my crops. The closest commercial corn field to my garden is miles away.

But if someone did care, it would be possible to screen for GMO in one's own garden without being dependent on a plant breeder to maintain GMO-free crops.

For example with corn: If seed was only saved from plants that had a healthy corn worm living in them, then you would be safeguarding against the BT GMO modification. I hate to suggest that people aught to grow wormy corn, because breeders have been working for decades, by natural selection, to develop corn that has tighter husks so that less worms get in, but it's a great method to test for one type of GMO. Eventually the worms will develop a tolerance for BT, but until that happens...

And to eliminate the GMO for glyphosate tolerance, you could save the seed from each mother separately, and plant them ear-to-row, and spray the field with glyphosate, and then plant the same mother seed the next year, but eliminating from the planting any of the sibling groups that showed resistance to glyphosate. I guess you could do the screening indoors during the winter. Or you could do a general screening of the whole population. Plant a bulk sample of seed, and spray it with glyphosate, and see if anything survives. I don't know what an acceptable level of contamination would be 5%? 1:10,000? I guess each grower gets to make that determination for themselves.

Or there might be phenotype characteristics that are linked to the GMO that could be utilized by clever growers to keep their seed free of contamination. For example one fellow I know has a garden that is surrounded by GMO corn, but he is able to grow GMO free sweet corn, because his strain of sweet corn has only white kernels, so when he is saving seed, he sorts the seed and throws away anything with a yellow kernel, because commercial GMO corn has dominant yellow kernels, and pollen from them causes the seed to be yellow. This method depends on the gardener doing perfect sorting every year, but it's well within the capabilities of most gardeners. There might be other traits more closely linked to the GMO alleles that could be used on F2 or later generations of seed. I think that of more use than writing to congress, would be growing out some GMOs, or studying some gene-maps, and figuring out, and publishing which traits are visible in F1 crosses and which traits are closely linked in later generations. That way home growers could be better informed about how to deal with GMOs on an individual basis.

Toms list is a good start. Painted Mountain has a natural percentage of red silks, and red cobs, so that's not definitive, but some of the other traits might be.

In my carrots, I eliminate Cytoplasmic Male Sterility, (another gift from The Company), by closely examining each flower, and chopping out any plant that doesn't have normal looking anthers.

We eat lots of mildly poisonous foods: Wheat, beans, potatoes, wine, lettuce, peanuts, etc...
We have, as a people, chosen to tolerate the low level of toxicity in return for high food value. Perhaps we will choose to do the same thing with low levels of GMO contamination.

To address the two varieties specifically mentioned: Astronomy Domine has expanded to include thousands of growers. Even if a strain here or there gets heavily contaminated, there will always be closely related strains which are not. Painted Mountain is still maintained principally by one grower who lives in a harsh climate in which GMO corn does not thrive, so it is not planted by the neighbors.