Written by Steve Savage
Rogue wheat is growing in wheat fields in 127 countries around the world! Should consumers be concerned?
Ok, I’m indulging in a poor imitation of the emotive language common in sensational writings about food issues. What I said in the paragraph above is all true, it’s just misleading because of a lack of context. After the “crisis” of glyphosate tolerant wheat being found in an Oregon field, I thought it would be useful to put that event into perspective. So…
Wheat 1.0
Wheat is largely a “saved seed crop,” meaning that farmers set aside some of the grain from each harvest to use as seed the next year. This is a practical thing for these growers to do because planting rates of wheat seed are very high (e.g. 80 or more lbs/acre) so it would be very expensive to haul bags or bins of seed very far. Also, except for a little bit in Europe, wheat is not a hybrid crop, like corn, so it is not necessary to buy new seed each year to get the highest yielding types. If a farmer plants the wheat from last year’s crop, he/she will get the same kind of wheat in the new harvest… well, mostly. Wheat is not pollinated by insects, but rather by wind, so pollen can blow in from another field where the variety might be different. This is something like a 1% issue. The wheat can get mixed over time because of little amounts left in combines or grain wagons. Also, weed seeds can build up over time – that is definitely rogue genetics! Over time, if only saved seed is used, the field will represent a mix of genetics.
The Genes My Friend Are Blowin’ In The Wind
Mixing different genetics in a field is problematic for wheat producers, because unlike some other major crops, there are extremely important quality differences between types of wheat. These differences are related to genetics, and the price a farmer can get for the crop often depends on being able to achieve certain standards. There are specialists within the field of food science called “Cereal Chemists” who measure all sorts of properties of wheat to characterize lots of wheat/flour so that bakers and others can get the results they desire. (When I first heard the term cereal chemist I thought they were saying “serial chemist:” e.g. someone who keeps committing chemistry!)
Wheat is Not Just Wheat
Wheat is definitely not just one commodity. There are very different wheats that have been bred over the centuries for very different purposes. The major categories of wheat are “Hard” or “Soft,” “Red” or “White,” “Winter” or “Summer,” and “Normal” vs “Durum.” So for baking an artisan bread or making pizza crust where “dough strength” is important you want a “Hard Red Spring Wheat.” If you want to make Asian soft noodles you want a “Soft White Spring Wheat.” If you want to make pasta, you want “Spring Durum Wheat.”
The various types of wheat achieve their best quality in different geographic/climatic regions, but even within a region and a type of wheat, there are differences in quality based on the variety and the weather in a given growing season. If you are a wheat farmer growing for any of those (or many other) specific markets, you have to be concerned about the purity of the genetics of the wheat in your field. If you plant a high quality variety for a specific use, you can only replant with saved seed for a few years before genetic/variety drift – “rogue genetics” if you will – renders your crop of too poor quality for your market.
How The Wheat Industry Manages This Issue
This issue of genetics has been a very long-term challenge for wheat growers. Long ago, the industry set up a system to deal with it. Crop Improvement Associations were established in each state to oversee the careful production of specific varieties with enough isolation from other fields of wheat and with inspection to insure that the resulting “certified seed” is genetically pure enough. In fact, there is a specialized verb, roguing, which refers to eliminating the genetic off-types in a seed field. This is just part of how real seed production is done.
Certain farmers in every geography specialize in growing this seed, and they then sell it to their neighbors with a small premium above commodity grain prices to pay for the effort and the testing. Because of this system, wheat growers can deliver wheat with specific quality requirements in spite of the unavoidable genetic drift in their fields. If the quality requirements are super exacting (e.g. those who grow the varieties for Wheaties and other branded, specialty wheat products), it is often grown under a contract which requires that new certified seed is used for every planting. Unlike corn and soy where the harvest is typically commingled in one big, efficient “river” of grain, for wheat, lot-by-lot “identity preservation” is common. Reliably delivering specific types of wheat to different customers is completely feasible.
The 2002 Intimidation of the North American Wheat Industry Didn’t Have To Go Down Like That
As I’ve described in a previous post, GMO wheat was on the verge of commercialization around 2002 when European and Japanese buyers threatened to boycott all North American wheat if any commercial GMO wheat was planted. Threatened with the loss of lucrative markets, the US and Canadian growers reluctantly asked Syngenta and Monsanto to halt their commercialization plans. What is sad is that standard certified seed and identity preservation mechanisms could have been employed to allow North American wheat growers to both enjoy the benefits of plant biotechnology and still meet the non-GMO demands of some of their customers. All that would have been needed was a rational threshold for “adventitious presence” of tiny amounts of other genetics – something that is already commonplace for “rogue” genetics of other types. When European millers buy Hard Red Spring Wheat from Canada or North Dakota, there are defined standards for how much of something else could be present because of carry-over from bins or harvesting equipment, etc. In the grain industry it is not normal to have a zero tolerance – that just isn’t practical. The same should have been the case for non-GMO wheat.
The current “rogue GMO wheat” debacle in the Pacific North West never needed to happen. All the regulatory approvals were on track to be granted and sizable field trials had been conducted. Efforts were certainly made to prevent any gene flow from the tests to other wheat, but it would not have been some disaster if it had happened. Again, the system was in place to manage that genetic issue just like every other one in this complex crop. Instead, the entire process was derailed setting things up for this “crisis” in Oregon today. It will only be a crisis if the Asian customers respond irrationally. Unfortunately, this is what they seem to be doing.
So yes, there is “rogue wheat” in fields in 127 countries. Using time-tested protocols we can still have wheat that is genetically pure enough to make all the delicious foods we make from different kinds of wheat. What happened in Oregon need not disrupt that if the customers will allow the industry to deal with it the way they deal with all genetic drift issues.
You are welcome to comment here and/or to email me at savage.sd@gmail.com #GMOReason #wheat @grapedoc
I can’t resist putting some data in a post, so here is a graph of world wheat planting based on FAOSTATS
Written by Guest Expert
Steve Savage has worked with various aspects of agricultural technology for more than 35 years. He has a PhD in plant pathology and his varied career included Colorado State University, DuPont, and the bio-control start-up, Mycogen. He is an independent consultant working with a wide variety of clients on topics including biological control, biotechnology, crop protection chemicals, and more. Steve writes and speaks on food and agriculture topics (Applied Mythology blog) and does a bi-weekly podcast called POPAgriculture for the CropLife Foundation.
I also posted this on Steve’s site:
Just some technicalities, but wheat is primarily self-pollinated, with most pollination occurring before the anthers extrude and the flowers (florets) open, which then allows for pollen to be carried by wind. So cross pollination by wind is usually less than 5%, unless some male sterility from environmental factors like freeze damage or drought stress cause the florets to remain open longer.
Even though a wheat variety is highly inbred, and very uniform, it is not necessarily made up of identical clone plants. For most varieties there will be some variation for minor traits that remain in the population, but overall, the plant types are very uniform in performance and appearance. Over time, genetic drift (unrelated to out-crossing, which is what you refer to as drift) occurs as a result of environmental factors exerting natural selection pressure on the population, acting on those small differences between individual genotypes. Eventually, the variety may deviate from the original variety, without any out-crossing or contamination. This is why breeders and parent seed producers have to maintain breeder’s seed of the variety, by planting it in isolation and roguing any off-types to maintain the parental source.
In addition to any genetic drift, out-crossing, or variety contamination, farmers buy new seed to avoid seed transmitted diseases or the replanting of weed seed that is difficult for the farmer to get cleaned out of his saved seed.
Also, the great majority of wheat IS co-mingled like corn and soy, but only within the individual market classes. Individual market classes for the most part are separated in the US by geographic region, although there is some overlap.
I thought i read that there is a plan that if any GM wheat strains are to be approved for commmercial use, they would be approved simultaneously on both Americas, Australia and, possibly, Asia. Is that plan actually in place?
Benjamin,
Thanks for the perspective on both sites. Yes, that is the plan.
Here is a post from 2009 about this
http://uk.reuters.com/article/2009/05/14/wheat-biotech-idUKN1450449920090514
I think we’ve discussed this before but it seemed appropriate to bring it up here – why not use a leaf color trait or something to make the GM plants obvious? Especially for something like wheat where unwanted plants are rogued out, it makes sense to me that you could have the GM trait adjacent to a trait to turn on an anthocyanin or something with a leaf specific promoter. The seeds wouldn’t be affected, but it’d be easy to spot the lone purple plant in the sea of green (or vice versa if you wanted all GM traited plants). Now, I can think of reasons why you wouldn’t want it to be obvious, such as sabotage, etc but let’s put that aside for a moment. If GM wheat had been so colored, it would be easier to segregate and rogue, so may have been more palatable to the industry as a whole, allowing farmers that grow for domestic purposes to choose traited seed if they wanted.
Thanks for that link Steve. That sounds like a good strategy if it can be coordinated to have the trait available in adapted varieties at the same time.
Anastasia, that also makes sense. There is quite a bit of anthocyanin present in some wheat varieties. I don’t know if it would be problematic to get them to produce more. Some lines have a trait known as purple straw that only shows up at drydown. Another problem is that many varieties appear purple if stressed when they are young, such as when they are waterlogged or suffering from cool weather or phosphorus deficiency. I know you were just giving a suggestion. I’m kind of at a loss for other alternatives that would work better. It is not quite as simple as the purple stalk marker used in corn. There are a lot of traits in wheat that might be used, but many of them tend to have variable expression depending on environment. The other big problem is due to its hexaploid nature, getting anything to be expressed in the first place. If you could get it linked to the gene for awns, at least you could know that if you rogued out all the awnless plants, it would breed true, as the awned allele is recessive.
I’ve got a couple of wheat fields in Oregon this year but not near the fields of concern. A lot of what is grown around me is soft white so I did look up the varieties in question and was glad to see they weren’t what I planted.
Something that may be of interest…if one is producing wheat to sell as planting seed there is going to be more care in keeping fields clean of other varieties. In fact I (and some other farmers I know) will plant mixtures of varieties of the same type. For example I have fields with two varieties of soft white and (on another field) two varieties of hard red spring. The market is fine with that sort of blending.
What the producer is trying to do in this situation is hedge against a problem with one particular variety by adding genetic diversity to a field.
Anastasia – there are some very good reasons one would not add such a trait.
First, any trait requires regulatory approval. What covers the cost of said? (Can one even justify the inevitable sacrifice of rats/pigs/chickens etc that would occur testing the trait)
Second – jacking up something like anthocyanin production will inevitably have effects on yield, which is an instant killer of any commercial product – “hey, use our new trait, which for no particularly good reason will give you a 5-10% yield hit”
Linking to a native trait would also be rather difficult – ploidy aside, genetic linkage requires close proximity – if there is one thing you probably don’t want in a transgenic it is close proximity to any actual genes – it gets regulatory jumpy, it upsets folk who may want to do trait introgression (the preference is for this to be as tight as possible, if you can avoid carryover of any other parts of the genome this is ideal, but if you’re carrying over a load of non-coding intergenic space it probably doesn’t matter so much.
During the testing phase one could, probably, fire in a stacked vector with your trait of interest + visible marker. One could not however use native traits this way – transformation is too random, and it is far too costly to eitgher hope you land in the right place, or breed the gene into the right place for testing
If it was a standard color trait, the reg process would only have to happen once, and if it was a non-novel trait then it wouldn’t be to onerous. Perhaps ARS or someone could do that work. I’m just trying to think of creative ways to make it easier for coexistence and segregation. I mean, it’s unnecessary if people are using AOSCA guidelines for seed production, etc but it might make people stop freaking out… maybe?
Even occuring once the reg process is intensely painful. Seems rather a waste of time and effort. It’s also going to take a lot of time and effort to do trait integration work (you’d have to link tightly to your GOI through breeding as deregulation is on an event level not a gene/protein level) – this costs an arm and a leg anyway, and gets mroe expensive the more genes one adds to the mix (for a stack of 8 genes smattered around the genome how does one track those (for instance)?
It is an idea that may work in theory, I don’t however see it either being commercially viable, or indeed somethign that’d stop anyone freaking out – if you’re freaking out about GM crops jsut now then no sensible measure is likely to stop this.
Why not use Transcription Activator-Like Effector Nucleases (TALENs)to do a site specific mutation in the plant of interest? It was developed by Voytas et. al. at the University of Minnesota. Wouldn’t this work for site directed mutagenesis?
http://www.nature.com/nmeth/journal/v9/n1/full/nmeth.1852.html
https://www.cbs.umn.edu/lab/voytas
Michael,
In theory various directed mutagenesis approaches could work, but the trick with glyphosate tolerance is that it seems to take two distinct amino acid changes – one to make the EPSPS tolerant and one to make it still functional enough in the plant. That is what Luca Comai found when he found the CP4 sequence long ago while working for Calgene. Of course there are many more models for glyphosate tolerance to be explored among resistant weeds, so maybe there is something that could be done in a non-transgenic fashion.
Steve, I asked you this before in some other post but I don’t think I got a reply(?). Would it be possible to use bacterial C-P lyase as a glyphosate resistance gene (enzyme that cuts glyphosate into phosphate and sarcosine)? No-one would be able to complain about herbicide residues…