Regarding GMO American chestnut / possible project at some point

[Garrett Schantz]

https://nativenewsonline.net/environment/a-transgenic-american-chestnut-tree-is-coming-who-is-it-for


This is something, that I personally dislike.


This isn't a GMO tomato.


But, I thought that I'd share it here.



These are American chestnuts, which contain wheat genes. Believe it's an enzyme sort of thing.

The article mentions that the gene is found in many food crops, and is likely fine.


One scientist and others, hopes that it will be deregulated, and that people will be allowed to pollinate mother trees using this pollen.

This would be growing / spreading out into nature.



I don't care much that a gene is found in many food crops.

How many chestnut relatives - even Oak trees and things have the gene or something similar?


Some diseases target genes and some pests target enzymes.



Also. A disease.

It'll likely adapt to the mentioned gene, rapidly. It's hosts gaining a single immunity gene, the disease will still try and infect whatever it can.

Most trees with resistances to diseases, like many plants - have networks of genes, not one thing, all working together. That's a general issue, even with tomato breeding.

Resistant genes don't last too long. Joseph's whole outcrossing idea, means genes and potential resistances can suddenly appear within a population from mutations or otherwise.



The article, mentions that breeding projects have largely failed, or they're taking too long.


I've actually heard great things about breeding projects, resistant seeds and the like get sent to researchers, those are then tested as seedlings to check their resistances to the blight.


Some seedlings have different reasons for being resistant.

There are also resistant populations of American x Chinese / other chestnuts. Some researchers are fine with using those in breeding.

There are different hybrids of native species of chestnuts, some species are very resistant to the blight.

Some populations just have immune specimens.


A researcher said that 100 years of breeding or whatever, is too long.


I agree that it's a long time, but those have more merit than transgenic specimens.


Multiple resistances, all sorts of stuff.




Cedrela odorata - is resistant to wood boring insects. And to termites. Plus it's very rot resistant.


Toona sinensis, is cold hardier and in the same family, and tribe. Toona ciliata, is also pretty interesting.

The edible leaves would go away, in a cross, I'd think.

My theory, is that they're both lumber trees - or some species are.

Eventually, pests may go over to Asia and meet those non pest resistant trees, they're used to pest resistant hosts.


But, moving those sorts of trees over elsewhere, would mean native insects elsewhere would probably be harmed by such hybrids.


I just want a cold hardier, pest and rot resistant set of lumber trees. I'd grow them in North America.


I could probably get away with growing Cedrela odorata in Zone 8B.


I've had ideas of possibly allowing the three different Redwood species, and Pseudocydonia sinensis, the Chinese quince, Chaenomeles japonica,  the Japanese quince and Cydonia oblonga, the Quince.

And some "living fossils", things like Katsura. Gingko bilboa. Katsura trees

Some crops and things, even trees - which need breeding work but do well in clearings or forests.


The idea would be to grow slow and fast growing trees, along with endangered or interesting trees.

Some trees prefer full sun or whatever else.


I'd like to eventually have an area with the mentioned things though.

Hybrids and things could be attempted.

Slower growing trees could have crops ready to harvest before they're halfways grown.


These would also function as plantations for making hybrids.

And with some slower growing trees, you could leave a bunch of trees intact.


This makes for a breeding area, which could have multiple researchers.

Different projects.

Plus, trees which are the sole representatives of their genus or family, could be grown near related ones, to see if they'd cross.


I'm fairly sure that many trees will eventually spread diseases or pests to each other, at some point.



This idea would likely be pretty sustainable, and I think that most groups or governments would like it.


The excuse of conserving endangered species and other things, would help a lot with funding. Which I wouldn't say it's an excuse myself.


There are formerly logged or cleared areas - which could be used as isolated testing areas for these sort of things.




Douglas Firs and other introduced trees have been problematic. Though, they probably wouldn't have been as bad if local trees weren't cleared out.





I'm bringing this up, because people may likely see GMO trees as options in the future.

Rot resistance, fast growing hardwoods. Huge acorns or pinenuts. Pest resistances.


I'd prefer the mentioned project.




Regardless, please do mention other GMO crops here - or ones which are beginning to gain motion.

I rather dislike this mentioned GMO thing here.


I believe Rice and Tomato GMOs may have been mentioned here before.


Chestnut, Ash and other trees also have the issue, that they're grown in plantations of sorts and scouted out for resistances.


Less predators, habitats and other things that are present out in nature are there. Any large plantings also become hotspots for pests and diseases.


These could be used for native species harmed by introduced diseases, breeding and things. The whole area would be watched by researchers to begin with.




I'm unsure if I presented a solution or not. But I've mentioned the plantation idea elsewhere and not gotten many responses.


I'm seeing a lot of things about GMOs recently as well.



I've been making lists of species and things. It's a far future project that I may never get to.

[Jeremy Weiss]

A GMO American chestnut seems sort of unnecessary, given there are resistant strains here and there anyway. Why can't the simply splice the genes from those into the strains they think make better nuts? They could also use Castanea pumila, the Allegheny chinkapin, for genes, since IT'S resistant to the disease as well.

As for tree things I'd like to see.

CRISPR splicing could certainly speed up that hypothetical Hinds/Manchurian Walnut plan I had, if one could get the important parts (Hind's Walnuts smooth, ridge free shell and Manchurian's super cold hardiness) together (I think that such a cross could make a nut that would actually be viable for growing nuts for people who like the Black Walnut taste (Hind's tastes almost identical) on a commercial scale (the smooth shell makes it MUCH easier to clean than the standard Black Walnut.)

Some sort of mix between the fruit producing American and Asian Persimmons and the Indian ones that produce ebony to create a tree that can either be used for both, or, at least, a kind of usable ebony type timber tree suitable for temperate plantation growing (American persimmon wood splinters much too easily to be usable in most woodcraft. You can make a decent golf club head out of it, but that's about it.)

SOMETHING to deal with the problem inherent in Mangosteens; namely, that since their parthenocarpic embryo's ALWAYS outgrow any sexually produced ones, ALL mangosteens on Earth are basically clones of each other. So if one get's some disease, they'll ALL get it and the fruit will become extinct. Not sure if GMO is the way to go here (sounds more like a job for induced mutation followed by embryo rescue.) but maybe genes could be brought in from other members of the genus (though carefully, since I think a lot of them have poisonous sap (so do mangosteens, but some of the others still have the sap in the fruit when the fruit is ripe.)

[Garrett Schantz]

Yeah.

The whole wheat gene thing here, I just looked at as annoying.


And from what I've read, they likely already have mature trees or something close to it.


But they aren't what people would want to use when trying to restart a population.


Castanea pumila can naturally hybridize with American chestnuts, so splicing and things wouldn't even be needed there.


The issue seems to be that hybrids aren't always as resistant.


Chinese hybrids usually are. Which also probably means that different things give them immunities.


The Ebony / Persimmon thing sounds interesting.


I'd like to see some Black Sapote / Persimmon hybrids as well. Or splices.

[Jeremy Weiss]

One REALLY interesting one might be a mix of Santalum album (sandalwood) with Santalum acuminatum or spicatum (Quandong). Fragrant wood AND edible fruits and nuts. Actually that's one that COULD use a little gene splicing, specifically, something that could make it no longer dependent on parasitizing the roots of some grasses/trees to live (which is, I imagine a major impairment to natural growth, since you have to have conditions right for both the sandalwood AND the host plants.)

Maybe also a basic splice of the genes in Prunus salicina that confer resistance to black knot and brown rot into Prunus domestica. They've done a bit of direct crossing to get some intermediates, but most are more Asian plum than European plum (the long Italian plum the use to make prunes and prunejack being the only mostly European one I know of they grow commercially in significant quantities.) It would be nice to be able to plant a tree that could give me something that was more or less a functional greengage and NOT do so knowing that in ten years or less it will be totally dead and I'll have to start over. Ditto a Mirabelle) Maybe actually take the genes from the American plum instead of the Asian, so the fruit stayed the right size. Would also love to find the rumored versions of Prunus mume whose fruit have enough sugars in them you CAN eat them raw (as opposed to candying them or pickling them), but that supposedly already exists (though I have never seen it.)

Going back to the walnuts, one could probably do some fun things with Juglans regina var. silligata (a subtype of the Persian walnut found in China, called the Iron Walnut). It's famous for growing super tall and straight, so, crossed the right way, you could probably get trees that could yield much bigger and longer walnut timbers that the normal ones could.     

[Garrett Schantz]

I mentioned Ylang-ylang - and Asimina triloba / Pawpaw hybrids being of interest in another thread.

Glad to see that someone else things those would be a nice mix.


I much prefer hybrids to GMOs.

Insertions of small flavor genes, or other things don't add as much as hybrids.


Some small things like chemicals from miracle berries, into other things, I wouldn't mind.


Imagine adding the trait / gene into lemons or oranges.

[Garrett Schantz]

I'd be interested in GMOs being used to bypass hybridization barriers.

Or allow for easier hybrids, at least one or two generations.

Make flowers and things mixed from both desired crosses, able to cross back and forth for a few generations.




Litsea garciae, the Engkala.

Or the Laurus nobilis, the Bay Laurel.



Those are both in the same family as Persea schiedeana, The Coyo. And Persea americana, The Avocado.


Many Persea species, have a few pest issues coming up.

There are cool North American species, found in Mississippi, some are in other states.


They're being impacted by bugs from Asia.


Avocados have recently been getting pest and disease issues from Asia as well.


A full on cross with Persea species and Engkala or Bay Laurel. Maybe both.


That could work if flowers structures and things or other small things are changed.



That's the largest thing I can see GMOs being useful for.

Making hybrids happen easier.

[Jeremy Weiss]

Some small things like chemicals from miracle berries, into other things, I wouldn't mind.


Imagine adding the trait / gene into lemons or oranges.

I'm not sure that would be a good idea. You probably haven't had them, but there are citrus fruits called the Jamaican Sweet Lemon, Palestinian Sweet lime, and Mango Orange that produce NO citric acid whatsoever. And they taste TERRIBLE, at least to me. Fruit is SUPPOSED to be a LITTLE tart in it's flavor, at least most are. Taking the mango orange as an example (since it's the one I have had the most times.) there's a faint raspberry taste*, but otherwise, it's like eating sugar water, there's no complexity. Also remember how POWERFUL miraculin is, a berry's worth doesn't just make a lemon taste sweet, it makes it taste SICKENINGLY sweet. Now scale that up to a fruit the size of a lemon. It'd be so sweet you'd get nauseous.

I'd love if more citruses were in the sweetness range of a Dekopon (sumo Mandarin) or an Ugli fruit, but that is a sweet-sour mix.

*possibly influenced visually by the fact mango oranges have pink pith and segment skins.

[Garrett Schantz]

Miracle fruit turns sweet and sour receptors in reverse.

So, they'd possibly still have some sensations that give tart feelings.


But yeah. I'd probably want the gene in something other than a lemon.


It would be interesting, in a low sugar sort of citrus, for diabetic people.

[Jeremy Weiss]

Your pawpaw thread gave me another good idea; a pawpaw (or other Annoacae) gene spliced with a keppel (Stelechocarpus burahol) to try and get its chemical your body processes into ionone (which is why it makes you smell like violets.) A tasty fruit that could also double as natural deodorant/perfume, and was easier to cultivate that straight keppel would probably be a big hit.   

[Zach E.]

TACF (The American Chestnut Foundation) has since backed away from the GMO approach. There were tons of problems with it. For one, the genes in Asian chestnuts for resistance aren't understood and likely highly complicated. Two, the OxO (oxalate oxidase), besides its insertion being a somewhat arbitrary "hunch," after CRISPR addition it was constitutive, rather than inducible, meaning the OxO is always turned ON. In real world terms this means trees growing under constant stress. They struggle to put on any biomass and do not function or grow normally. The icing on the cake is that the GMO program workers mixed names up, lost track of papers, submitted the wrong papers, etc. What was supposed to be Darling 58 was actually Darling 54 due to scientific mismanagement -- or what they call a "mislabeling" error.

Obviously this has been a huge embarrassment for not only TACF but for SUNY-ESF which was ostensibly sponsoring the research (although if you follow the money much of it was coming from private donations from ArborGen i.e. Monsanto). I believe the SUNY-ESF researchers have since had to pivot away from the academic funding and into a private company called American Castanea Inc. Their solution is to double down on the failed Darling 54 line (not even failed, but DOA) and combine with AI technology.

Anyhow, all that said, the original TACF breeding program has problems, which is why they don't have results yet. I'm informed through a friend of mine, Tim Eck, who is breeding backcrossed restoration chestnuts according to what he calls the Armstrong-Leffel program, different from the regular TACF breeding.

This approach began with Bob Leffel, York county PA native and former PA-TACF administrator, who noticed back in the '90s that TACF's program was doomed to fail. Obviously TACF didn't like hearing this.

The problem is mathematical. If you cross C. dentata with C. mollissima, you only have 50% of the Asian genes in the hybrid, which means a 50% chance the resistance genes are even present at all (assuming monogenic), or an even smaller chance if polygenic. With a BC1 backcross, you're now looking at 25% Asian genes, or a 1/4 chance or less that the genes for blight are present at all. Thus overcoming this bottleneck is order of business #1, which apparently TACF wasn't doing (by for instance, not evaluating resistance levels of each f1, or by leaving trees in the program with "good form" prior to evaluation, etc.)

I'll let Tim speak for himself about the breeding program he's using: https://drive.google.com/file/d/1pofL5vgU7aD5TMbQhzXd2c15UCEapapU/view?usp=drivesdk

From what I've seen, he's been having good success and has nominally 40% resistance on trees 3/4 American, on his second to last orchard. Keep in mind he's evaluating with EP155, the most virulent form of the blight in existence. In the wild, his trees would be fine. He's working on his final orchard, which once evaluations are done will settle on about 100 trees with 100% resistance and which are at least 3/4s American. A perfect genepool, rather than a perfect tree.

On a separate note, there are several species in the genus Cryphonectria and although Cryphonectria parasitic is presumed to come from East Asia, it's unproven. Since there are native strains of Cryphonectria spp. in North America, it's possible C. parasitica is a hybrid. My reasons why have to do with the epidemiology. Although chestnut blight was "officially" first recognized at the Bronx Zoo circa 1904, it had been around since the late 1800s. There are some early records which suggest a bark disease pathogen attacking chestnut trees back in the 1880s-1890s, but the lethality seemed not so severe then. But by the early 20th century, it had become a scourge, killing millions of trees. When diseases hybridize, or cross a species barrier, we see such leaps into lethality like this.