Pumplin: Public and industry response to purple tomatoes are questions

So, GMO transgene purple flesh tomatoes are coming with the transgene coming from snap dragons.

Have been discussing this for awhile here:

I love the idea of blue fleshed tomatoes just as I love the blue skinned tomatoes but the source is undesirable. Transgene technology is on the verge of being obsolete. As a genetics nerd I dislike it because it randomly inserts genes from other species without much control over where it lands. Which has the potential to mess up the history of plant evolution.

Since this is not an acceptable way to breed tomatoes for organic standards and since I have been working on tomatoes for organic growing this then just becomes a potential source of genetic contamination for breeders like me. It also would be very easy to contaminate the exserted stigma tomatoes with. In the article I linked they lean on tomatoes being selfers but this isn’t always the case! I figure as soon as these are out and popular, I won’t be able to trade tomato seeds any more as anyone who freely grows this might accidentally introduce contamination. It basically puts tomatoes in the same category as corn which has had GMO transgene contamination risk for years.

It probably does, which is unfortunate.

On the other hand, I think I’ve heard before that you’re allowed to save your own seeds from those particular GMO tomatoes? So the legalities of it might be less concerning than other GMO crops. It might be worth checking to see if cross-contamination isn’t something we need to be legally concerned about in our landraces.

Concerns about the technology itself are of course a personal philosophical choice.

As for me personally, I see it as risky, not inherently bad. I see it as a tool that might be useful, while also being something you don’t want to toss into your gene pool by accident. Similar to letting your landrace cross with poisonous relatives. There may be a good reason for doing that, but it’s something you want to think twice, thrice, probably ten times about before doing it.

I want to caution everyone who replies to this thread to stay calm, and to respond only in productive ways that are valuable to the discussion. No heated rants about the evils of big ag.

Can you expand on what the second sentence means?

Hi Christopher,

So with transgenes what the scientists do is take a gene which can come from any source and use something like a modified virus to insert it into the organism they want to modify. That modification does not have a lot of control and anywhere with the right start sequence will do.

By contrast the more modern CRISPR technology makes an edit in a much more precise location. For example, for this same result, you could use CRISPR technology to edit in the genes from the closely related tomatillo that code for purple flesh in tomatillo.

So one of my objections here is simply that it uses the older technology inserts a bit of snapdragon gene into a location that can’t be that carefully controlled in the genome, when the technology is already here to make the modification in a more elegant and controlled way from a closer relative.

Though as I understand it neither way of modifying the tomato genome would be acceptable under organic standards as they currently exist. Which means that to remain an organic breeder I couldn’t work with or accept contamination from either.


I don’t want to throw the baby out with the bath water but gmos bother me. I don’t think we know enough to go tinkering. There is always a risk that a hitherto unknown protein may be created. It makes me nervous.

I’m very pleased that, at least to date, very few gmo crops have been approved for general growing here in Australia. In fact, I only know of two: one food crop (papaya) and one utility crop (cotton). GMO canola is in trial but given that our biggest canola customer, Japan, has already said it will not buy gmo canola I can’t see many farmers being all that keen to grow it.


I saw an article today about GMO American chestnut. I started reading it and it was so geared towards getting people to comment in favor of it that I stopped reading. I am not totally against GMO solutions for wild plants like American chestnut that are devastated by introduced pathogens. However, I also think there is a viable path to use more natural plant breeding with chestnut species from other continents and am not convinced the GMO chestnut is necessary. If I remember the particulars, it is also an older technology transgene plant.

Might be worth doing, might not, though not ready to comment in favor of it. Not sure I can say much against it either- though If I did comment I might say that I prefer this work be redone with a gene edited version with genes from other chestnuts.

The trouble is that the resistance in other species of chestnut turned out to hinge on a number of different genes. Multi-generational efforts to backcross the resistance using conventional breeding wound up determining that it would not be possible to “unlink” blight resistance from other traits that make the American chestnut resistant.

The GMO germplasm that is pending uses a single gene insertion from wheat which will be passed on to 50% of offspring. If approved for release, the plan is to cross it with as much genetic variety of pure American chestnut as possible through a participatory breeding project. Our farm is involved in a minor way in this project as a potential site to cross the GMO darling with pure American stock.

I’m not very sympathetic to genetically modified organisms, but my optimism for non-GMO techniques has waned as I’ve watched the backcrossing efforts not pan out over my lifetime. There are still folks looking for spontaneous resistance in surviving pure American chestnuts, and I imagine in time it would be easier to use GMO technology to add those multiple genes from other chestnuts rather than a trait from wheat.

That would be best in my mind. But on the other hand, there is reason to believe the existing reservoirs of pure American chestnut diversity are in danger of no longer producing pollen if we wait much too much longer.


You make a better argument than the article I saw which seemed to be arguing that people who have reservations about genetic engineering are being very unreasonable.

Yeah, arguments about “reasonability” tend to be silly when you don’t start first with defining why one particular viewpoint is more reasonable than another. And usually the only way to really do that is to show that there’s internal inconsistency in one viewpoint, and internal consistency in another.

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Sounds like the right takeaway to me.