GM crops

[Arete]

Yes, Arete, I am not dumb.

 

You stated two reasons joined by the conjuction and.

 

I agreed with the second reason and asked for an explanation of the first.

 

Repeating the explanation of the second does not constitute an explanation of the first.

 

There are two distinct mechanisms by which transgenes could escape from a GM crop into the environment, which I have tried to describe for you.

1) through introgression of genes into wild plants, via hybridization with wild relatives.

2) or the direct recruitment of transgenic individuals into the enviroment - i.e. transgenic individuals becoming pests.

 

You stated you understood the second mechanism, but asked for further clarification of the first. I tried to provide you with a more extensive explanation. There's no need to get testy, I was actually trying to fulfill your request.

[studiot]

There are two distinct mechanisms by which transgenes could escape from a GM crop into the environment, which I have tried to describe for you.

 

Statement 1

 

One of the fundamental reasons for GM crop sterility is to prevent horizontal gene transfer with non-GM crops and wild plants,

 

How is this a mechanism?

 

I asked for a reason why you made this statement or an explanation of it.

 

Statement 2

 

and to prevent them from spreading and becoming pests themselves.

 

and I stated that I understood this one - I understand it to be a reason for not wanting the cross tranfer, not a mechanicsm for it.

 

So I am still awaiting an explanation of the first statement.

Edited July 15, 2012 by studiot

[too-open-minded]

If you guys will just stop trying to prove eachother wrong you will learn a lot more about this subject.

 

Whats the problem with patented pollen pollinating wild plants? I'm not saying their isn't one, I'm saying I lack a degree in botany and dont understand.

[Moontanman]

If you guys will just stop trying to prove eachother wrong you will learn a lot more about this subject.

 

Whats the problem with patented pollen pollinating wild plants? I'm not saying their isn't one, I'm saying I lack a degree in botany and dont understand.

 

 

I think that's a legitimate question, if the GM plants are sterile then how can they pollinate wild relatives? there are no wild maze plants btw... and the idea that GM corn or potatoes or any other GM plant might take over the wild is a bit of fear mongering isn't it?

[too-open-minded]

If 30 years ago people were told that air-sol cans leak CFC's into the atmosphere which break down its chemical composition. They probably wouldn't believe you.

 

I'm always open to hear a new argument.

[Arete]

I asked for a reason why you made this statement or an explanation of it.

 

I'm not sure what you are not understanding...

 

The thing particular to GM crops is not wanting the transgenes to get into the enviroment. The reasons are numerous and not limited to - conferring herbivore resistance on native populations and subsequent ecosystem imbalance, the advent of herbicide resistant domestic escapees becoming pests, the inability of companies to sell costly to produce GM crops once they are widespread, etc.

 

One of the mechanisms by which transgenes could get into the environment is if a population of native plants was pollinated by a GM crop, resulting in hybrid offspring into which the transgenes had introgressed. In order to prevent this scenario, the companies which sell GM seeds have engineered them to be sterile. The pollen of these sterile GM crops is nonviable, and as a result there is no risk of the transgenes escaping into the enviroment via the mechanism of introgression with wild relatives of the GM crop.

 

The second mechanism is migration and subsequent recruitment. Rather than hybridizing with the wild variants, the GM crop produces fertile seeds within itself, these spread into the enviroment via vectors and a population of plants with transgenes in it arises this way. If the GM crop is sterile, this obviously cannot happen as it will be incapable of producing viable seeds.

 

there are no wild maze plants btw

 

Yes there are - maize is a domesticated variant of Teosinte' date=' with which it readily hybridizes - in fact numerous backcrosses between domestic maize and various teosinte species has been used to generate new commercial varieties.

 

http://www.nytimes.c...?pagewanted=all

http://en.wikipedia.org/wiki/Teosinte

http://www.springerl...01x775455x6666/

 

Here's a picture comparing a wild teosinte seed head, a domestic maize seed head with a hybrid in the middle

Edited July 16, 2012 by Arete

[too-open-minded]

Thankyou for clearing that up a bit^

 

but why does it matter if wild plants crossbreed with GM genes? Is their a problem that will arise or is it just an argument lol?

[Arete]

Thankyou for clearing that up a bit^

 

but why does it matter if wild plants crossbreed with GM genes? Is their a problem that will arise or is it just an argument lol?

 

Say your transgene is BT toxicity - this means when insects eat the plant, they die. If this gene gets introgressed into native populations, plants which form the basis of the food chain could become toxic to the animals which eat them and could upset the balance of the entire ecosystem.

 

Or say an invasive GM crop gets into an ecosystem, and you've engineered it to be resistant to herbicides so farmers can spray their fields for weeds without killing the crop. Once it's a pest, it will be extremely hard to control.

Edited July 16, 2012 by Arete

[Moontanman]

I'm not sure what you are not understanding...

 

The thing particular to GM crops is not wanting the transgenes to get into the enviroment. The reasons are numerous and not limited to - conferring herbivore resistance on native populations and subsequent ecosystem imbalance, the advent of herbicide resistant domestic escapees becoming pests, the inability of companies to sell costly to produce GM crops once they are widespread, etc.

 

One of the mechanisms by which transgenes could get into the environment is if a population of native plants was pollinated by a GM crop, resulting in hybrid offspring into which the transgenes had introgressed. In order to prevent this scenario, the companies which sell GM seeds have engineered them to be sterile. The pollen of these sterile GM crops is nonviable, and as a result there is no risk of the transgenes escaping into the enviroment via the mechanism of introgression with wild relatives of the GM crop.

 

The second mechanism is migration and subsequent recruitment. Rather than hybridizing with the wild variants, the GM crop produces fertile seeds within itself, these spread into the enviroment via vectors and a population of plants with transgenes in it arises this way. If the GM crop is sterile, this obviously cannot happen as it will be incapable of producing viable seeds.

 

 

 

Yes there are - maize is a domesticated variant of Teosinte, with which it readily hybridizes - in fact numerous backcrosses between domestic maize and various teosinte species has been used to generate new commercial varieties.

 

http://www.nytimes.c...?pagewanted=all

http://en.wikipedia.org/wiki/Teosinte

http://www.springerl...01x775455x6666/

 

Here's a picture comparing a wild teosinte seed head, a domestic maize seed head with a hybrid in the middle

 

 

Thanks for the information on that, I was unaware of the link between corn and Teosinte.

 

Thanks for clearing the up the sterility thing, for some reason i was reading it that one of the dangers of current GM plants was hybridization. The sterile thing seemed to be separate somehow...

 

I still think they idea of food crops escaping into the wild is less than supported, you jump from food crops to domestic plants but I see a slight difference being that while all food crops are domesticated not all domesticated plants are food crops.

 

Some domesticated plants escape into the wild with out help, transferring something like herbicide resistance to elephant ear would be a bad thing... I don't think it needs it... even where it's grown for food...

 

http://en.wikipedia.org/wiki/Taro

 

This stuff is going wild where I live, we used to be too far north...

[zapatos]

Say your transgene is BT toxicity - this means when insects eat the plant, they die. If this gene gets introgressed into native populations, plants which form the basis of the food chain could become toxic to the animals which eat them and could upset the balance of the entire ecosystem.

 

Or say an invasive GM crop gets into an ecosystem, and you've engineered it to be resistant to herbicides so farmers can spray their fields for weeds without killing the crop. Once it's a pest, it will be extremely hard to control.

You are also not allowed to sell GM corn if you did not pay for GM corn. If someone growing non-GM corn has their crop pollinated by the GM corn growing next door, they could be subject to litigation if they sold their crop.

 

Organic crops sell for a higher price than GM crops. If the organic crop is pollinated by GM crops the value of the (used to be) organic crop goes down.

[jeskill]

I still think they idea of food crops escaping into the wild is less than supported, you jump from food crops to domestic plants but I see a slight difference being that while all food crops are domesticated not all domesticated plants are food crops.

 

 

GM canola has been found at fairly high levels in the wild: http://www.nature.com/news/2010/100806/full/news.2010.393.html

[Arete]

GM canola has been found at fairly high levels in the wild: http://www.nature.co...s.2010.393.html

 

"Sagers agrees that feral populations could have become established after trucks carrying cultivated GM seeds spilled some of their load during transportation. She notes that the frequency and population density of GM canola that they found may be biased as they only sampled along roadsides."

 

Sounds like a biased sampling regime probably accounts for the extremely high prevalence in this case. It is of concern when supposedly sterile crops manage to escape however.

[studiot]

Once again too-open minded posted where I was heading before I arrived.

 

Whats the problem with patented pollen pollinating wild plants

 

We are discussing the reasons behind genetic manipulation.

 

First the pros stated that it was to provide enhanced yield, quality and disease/pest resistance as the only reasons and the only manipulations.

 

When pushed they admited that another manipulation has been sterility to prevent transfer to existing species.

 

Now I have consistently discussed potatoes and several hers have stated that potatoes are not grown from seed.

 

So why does sterility matter if some manipulated genes spread beyond their field?

 

The result if not sterile would not result in a new generation of potatoes anyway.

 

My underlying question is since getting all the reasons out in the open is like drawing sharks teeth, what else are they hiding?

 

A further observation is that the deliberate sterility demanded nowadays is the exact opposite of the reuqirement of traditional selective breeding where the product is of little use if it cannot breed true.

 

What I am seeking is an open and honest debate leading to the best deployment of the technology.

[Moontanman]

Then there is the idea that food crops are as they are because we modified them in ways that cause them to, at the very least, be much more inviting to wildlife as a food source than the original wild plant was. A domesticated plant in the wild is immediately targeted and eaten, their food value is much higher than wild plants and they stick out like sore thumbs because of this... only our intervention prevents them from being eaten.

 

Possibly there are a few domesticated plants that could survive in the wild but I have my doubts on this idea...

 

An abandoned garden, dozens of different food plants, allowed to go to seed with out being harvested, the next spring do any of the food crop plants come back up? Without our care would any of them even survive, I've seen this happen, the only things that reappear are some perennials like asparagus, it can come back over and over but I've never seen them spread...

 

I'll Stop, this is so strange to me, after growing up on what just a dirt farm, no equipment other than horses and mules and human power, it's difficult to imagine the food crops we grew having any chance what so ever, even with near constant attention they often failed to grow...

[JMJones0424]

Now I have consistently discussed potatoes and several hers have stated that potatoes are not grown from seed.

 

So why does sterility matter if some manipulated genes spread beyond their field?

 

The result if not sterile would not result in a new generation of potatoes anyway.

Perhaps I wasn't clear last time, potatoes are typically grown from tubers rather than seed as a matter of convenience. Potatoes can and do p[roduce viable seed, that ends up being new potatoes. Volunteer potatoes are an issue, specifically because most commercial potato varieties are hybrids that don't breed true, and when they do self-seed a field, they end up contaminating next year's harvest with potatoes that have unwanted characteristics if the volunteers are not dealt with.

 

My underlying question is since getting all the reasons out in the open is like drawing sharks teeth, what else are they hiding?

 

Nothing. It has already been explained succinctly. Many agricultural crops are simply cultivars of species found in the wild. Besides the political concerns, even if there is no concern about some kind of run-away contamination of modified genes in the wild, you don't necessarily want some genes, like those that enable pest or disease resistance, to spread to wild populations. If they do, then pests and diseases resistant to that gene are more likely to arise, and your IPM strategies are now defeated. This is the same reason that pesticides are best used when they are targeted for a particular problem rather than used broadly.

 

A further observation is that the deliberate sterility demanded nowadays is the exact opposite of the reuqirement of traditional selective breeding where the product is of little use if it cannot breed true.

Your observation is ludicrous. Try and make a list of commercial varieties that are not hybrids and you'll find how far off the mark you are.

 

What I am seeking is an open and honest debate leading to the best deployment of the technology.

 

That's great. So few of the population has any connection to the origin of their food that debates like this seem to devolve into people shouting past each other. Let's see if we can correct more of your unfounded assumptions.

[Arete]

Possibly there are a few domesticated plants that could survive in the wild but I have my doubts on this idea...

 

Here's a US federal list of invasive plants - note most of them are escapees of gardens or cultivation: I think, rice, sugar cane and backberries get a mention in there at a cursory glance. http://plants.usda.gov/java/noxious?rptType=Federal

 

State lists also linked.

[studiot]

Your observation is ludicrous. Try and make a list of commercial varieties that are not hybrids and you'll find how far off the mark you are.

 

 

Ludicrous huh?

 

Then why have others here taken great pains to describe the creation of non poisonous potatato tubers by selective breeding?

 

Are you trying to tell me that these potatoes we deliberately bred for sterility?

Edited July 16, 2012 by studiot

[Arete]

Are you trying to tell me that these potatoes we deliberately bred for sterility?

 

Generally speaking, potatoes are not sterile, and can grow from both seeds and vegetative propagation. JMJones explained that pretty thoroughly I thought, here:

 

potatoes are typically grown from tubers rather than seed as a matter of convenience. Potatoes can and do produce viable seed' date=' that ends up being new potatoes.[/quote']

[JMJones0424]

Ludicrous huh?

 

Then why have others here taken great pains to describe the creation of non poisonous potatato tubers by selective breeding?

 

Are you trying to tell me that these potatoes we deliberately bred for sterility?

 

No. First of all, you've yet to give an example of sterile potato line. I'm not convinced that you understand what a true breeding line is.

 

A true breeding line is a cultivar of a plant that when it is crossed with another of the same cultivar produces seed that contains the same characteristics as the parents.

 

A hybrid is a cross between two different cultivars. Hybrids marketed by seed companies typically contain desirable traits from both parent lines, but hybrids will not produce seed that are true to type. In order to maintain a hybrid cultivar, you must purchase seed that is the cross of the original parents from a seed company, make the seed yourself, or vegetatively propagate the plant.

 

Because potatoes propagate so readily from last year's seed potatoes, it is more common to use vegetative propagation to grow a particular hybrid cultivar. This does not mean the seeds from that hybrid are sterile. They just don't reliably produce plants with the desired traits. This also does not mean that no one grows potato from seed. In order to breed potatoes and come up with new lines, you have to maintain breeding stock to cross.

 

I think you are confusing different topics in this thread. Please, continue asking questions, but I can't read your mind. If I don't immediately address your concerns, it isn't because I'm trying to pull the wool over your eyes, it's because I don't know what you know.

[too-open-minded]

Regardless of whether or not this is a possible problem, it wouldn't hurt to devise a emergency plan incase this problem arose.

 

Why don't you guys stop trying to prove eachother wrong and devise some methods we could use to stop this problem if it hypothetically happened?

[Arete]

It has happened:

http://www.nature.com/news/2010/100806/full/news.2010.393.html

http://independentsciencenews.org/environment/transgene-escape/

 

Controlling it is something termed transgenic mitigation, which basically tries to limit gene flow between the source and recipient populations, in either one or both directions - there's a bunch of ways of doing this as outlined in a number of papers:

 

http://www.ncbi.nlm.nih.gov/pubmed/14871372

http://www.isb.vt.edu/articles/feb0603.htm

 

"Most molecular approaches with potential for controlling gene flow among crops and weeds have thus far focused on maternal inheritance, male sterility, and seed sterility. Several other containment strategies may also prove useful in restricting gene flow, including apomixis (vegetative propagation and asexual seed formation), cleistogamy (self-fertilization without opening of the flower), genome incompatibility, chemical induction/deletion of transgenes, fruit-specific excision of transgenes, and transgenic mitigation (transgenes that compromise fitness in the hybrid). As yet, however, no strategy has proved broadly applicable to all crop species, and a combination of approaches may prove most effective for engineering the next generation of GM crops."

 

http://www.nature.com/nbt/journal/v20/n6/abs/nbt0602-581.html

[JMJones0424]

Regardless of whether or not this is a possible problem, it wouldn't hurt to devise a emergency plan incase this problem arose.

 

Why don't you guys stop trying to prove eachother wrong and devise some methods we could use to stop this problem if it hypothetically happened?

 

Numerous non-profit and for profit organizations maintain seed banks and "heritage" varietals. The one I use most is Southern Exposure Seed Exchange. These groups serve two purposes, they maintain older varieties that are not currently commercially viable but still have appeal or may prove useful for breeding projects in the future, and they also serve as a reserve of genetics should the homogenization of commercial lines lead to a catastrophic problem in the industry such as a particular disease or pest susceptibility.

 

On another note, this is the second time I've seen you interject into this thread that we need to "stop trying to prove each other wrong." I am not, nor do I believe anyone else in this thread is dogmatically trying to assert my position. I am trying to clear up a specific confusion that I have noticed. Asking us to do otherwise is unproductive.

[too-open-minded]

Don't get so defensive their scooter.

[imatfaal]

o/t

 

Too-open-minded: Science doesn't work by everyone agreeing to differ and accepting every opinion has equal merit; some ideas are incorrect and can be shown to be incorrect, other theories survive and are built upon. Whilst we don't want anyone to fall out over a scientific disagreement - we also must keep the discussion and the argument going. It is only through testing ideas that we progress, and that often means showing that someone is wrong; their logic may be askew, they might be ignorant of certain facts, or interpreting data incorrectly - but at the end of the day some people will be wrong and that needs to be shown.

[studiot]

Science doesn't work by everyone agreeing to differ and accepting every opinion has equal merit; some ideas are incorrect and can be shown to be incorrect, other theories survive and are built upon. Whilst we don't want anyone to fall out over a scientific disagreement - we also must keep the discussion and the argument going.

 

Thank you imatfaal.

 

Now all we need is for respondents to address the points made by others rather than going off on a frolic of their own in discussion

 

studiot, on 16 July 2012 - 09:29 PM, said:

 

Ludicrous huh?

 

Then why have others here taken great pains to describe the creation of non poisonous potatato tubers by selective breeding?

 

 

Are you trying to tell me that these potatoes we deliberately bred for sterility?

 

JM Jones:

 

No. First of all, you've yet to give an example of sterile potato line. I'm not convinced that you understand what a true breeding line is.

 

 

Let me try this again in the face of substantial nasturtiums being cast against my person rather than proper discussion of my logic.

 

Earlier in this thread it was stated (not by me) that the progenitor of modern potato crops were poisonous.

It was also stated (again not by me) that this poisonous characteristic was removed or reduced to tolerable levels by selective breeding by native americans up to a thousand years ago.

 

So, quite naturally, I questioned whether they also wanted their improved potato to be unable to be planted to yield a crop on a year by year or generation by generation basis.

 

I think those early practitioners of GM did not want to prevent a % of each year's harvest being saved as 'seed' to plant for the next year - in fac that is what the wanted and they wanted the subsequent harvest to grow at least as well as the previous.

 

So I am making the point that the idea of actively preventing this by further and more sophisticated exploitation of GM techniques, not originally employed. I don't see how you can breed infertility into a strain by selection.

I am further questioning whether the motives for these later developments are as purely virtuous as the original ones.

 

As such I do not appreciate being mocked for my views.