Saw this really amazing video[0] the other day about American Chestnut Foundation's breeding program in Virginia to revive the American chestnut
Basically they hybridized it with Chinese/Japanese chestnuts (which are blight resistant). Then they take the offspring, test for blight resistance and rebreed those back with purebred American chestnuts. Then they repeat the process. Take those offspring, select for blight resistance, rebreed with American species, etc
After a few generations they created an American chestnut tree that looks almost exactly like the purebred versions but retains the blight resistance of the Japanese and Chinese species
For anyone wanting to learn more about this breeding technique, it's called backcrossing[1]. It's also used for agricultural crops, but requires many generations.
Saw that video recently as well. What's remarkable about this find is the size of the specimen, and that it's confirmed to be 100% American Chestnut. Hopefully with the hybrid approach, this find, and further breeding/propagation work, we can see a large scale return of this incredible species.
Why don't they use agrobacterium transfection, gene guns, or molecular techniques to directly transfer the resistance genes over? Do we not know what the genes themselves are?
I'm not criticizing their technique! Nor do I think I know better. This is amazing and valuable work, and I'd love to know more.
The genetic modification the ACF is doing is actually very controversial among the community of people commuted to restoring fruit and nut biodiversity.
I just saw Eliza Greenman speak on this subject, never expected that to circle back to HN.
Cool to see this here and people talking about it. I volunteered with the American Chestnut Foundation during my summers in high school. Usually spent a few weeks on the Meadowview research farm collecting catkins off trees, “processing” the catkins to bottle the pollen, bagging trees to prevent uncontrolled cross pollination, and pollinating trees by hand.
My uncle and I also usually took hikes in NC to try and find remaining trees with pollen in the wild. From what I understand, the pollen from these few remaining living trees is used to help re-introduce regional biodiversity into the backcrossed American/Chinese hybrids.
Highly recommend going and helping out on the farm if you can spare a week or two, or joining your state chapter if you’ve got one - or sending your kids!
It's too late this year but would they want me to mail catkins from a chestnut producing survivor up in NJ? I also have chestnuts collected from prior years and 2 seedlings growing from some of the prior collected ones that were planted.
The survivor has 2 branches coming out of trunk each roughly 42" in circumference, it is not as tall as the one in the article but it's probably got similar girth. The tree is at least 70 years old, I'll confirm with the landlord whether he planted it or if it survived from before his time (he's been here approx 90 years, and I know one red oak and an eastern red cedar is older than he is). We do have Chinese/Japanese chestnuts on the grounds here that are more prolific and it's likely the seedlings I have are hybrids, but who knows?
One interesting thing I noted from the American vs. Chinese/Japanese chestnuts is the chestnut weevil does not appear to infect the nuts.
I grew up on a farm near Media, Pennsylvania. We had quite a few American Chestnut trees. One of my first childhood memories is picking up the nuts off the grass. I doubt those trees are still there. I should go back sometime and see.
> There used to be about 4 million American chestnut trees in eastern U.S. forests, until chestnut blight (Cryphonectria parasitica) arrived […]
The number is closer to 4 billion with a B[1]
Their range was across
eastern North America and I’ve read estimates that they may have been a quarter to a third of the trees in those forests before the blight arrived.
It also makes me wonder. There was an estimated 30-60 million buffalo before colonialism in the Americas. However, those numbers were probably only possible to reach because of human activity driving out other apex predators and becoming themselves the apex predator. Similar story with paw-paws. Though they're not necessarily being threatened by anything currently, their range is decreasing. It turns out humans were essential for its distribution (likely due to other megafauna going extinct). Another example that comes to mind is the "prairie turnip" which as a staple food of many peoples that lived in the grasslands. Despite harvesting being a destructive process, the action actually ended up helping to spread their seeds. Without human harvest we've again seen a decrease in their range. I can also go on about how essential California cultural burns are for most of the "native" ecology, but I'm sure you get the point
Anyways I guess what I'm getting at is: I wonder how much humans played a role in it achieving such a widespread distribution.
There was a recent book called Dark Emu about aboriginal Australian's role in the native landscapes. Early colonists often remarked that the place looked like a giant, well-managed park. Well it turns out they actually did play a huge role in purposeful management of it. They even grew grains in massive monocultural fields that were often even larger than modern agricultural plots. Similarly there's been a ton of recent research into Amazonia and looking at it as a "manufactured landscape" because of how important the purposeful management of it by native peoples was to the ecosystem as a whole
Interestingly, I just walked out to a large chestnut tree on Spring Street by my place in Nevada City, CA and measured it's circumference - I got 127 inches, roughly - getting the tape measure around it was a bit challenging. It might be 40-50 feet tall but there is another much taller with less diameter down the hill from it (tree mentioned in article is 50 ft tree, 35 inch diameter, pretty average for here).
There are many chestnut trees in the town, planted in the gold rush days, I believe. last fall, I gathered enough nuts walk around town to supplement my diet for a few months. The nuts haven't started falling this year.
Of course, these tree survived the blight because they're well outside the range of the Eastern Chestnut. But still, if someone wants to see chestnut trees, they're here and probably in a lot of places where they were planted outside their range.
Episode of the podcast "Atlas Obscura" which provides some background on the destruction of the American Chestnut and ongoing efforts to revive the species:
Reading the first chapters about the American Chestnut made me cry, and I’m not prone to crying. I had to put the book down for a week, and re-examine some of my beliefs about nature and mankind.
Yup, same recommendation. That was my first time even hearing about this massive, landscape shifting chestnut blight; I have no idea how it isn't now commonly known.
And it was just a really great story in general. Definitely recommend.
> There used to be about 4 million American chestnut trees in eastern U.S. forests, until chestnut blight (Cryphonectria parasitica) arrived in New York via infected plants and spread rapidly, nearly wiping out the majestic trees
Yes! This is a remarkable typo that gives a very different impression of the history of the tree. 4 million trees in the whole eastern US would make them uncommon even at their peak, when the truth is that they were everywhere.
There was a crime pays and botany doesnt podcast 2 weeks ago with an interesting interview with someone from this project. http://www.esf.edu/chestnut/
The group is mentioned in the first comment of the first link you posted from 2017, so people might be interested in a more recent update.
If this tree had a secret to cultivating a resistant strain that would be very awesome.
Is there a good app which lets you input your zip code, maybe also sun exposure and soil conditions, how many feet of width and height you have available, and then where it will spit out a list of well-suited tree specimens with some nice pictures of each?
Why stop at trees? I imagine you could do an alternate reality app for landscaping that shows you what your landscape "could look like". Including flower beds, ground cover alternatives to grass, etc.
Has anyone heard anything about the Darling 58 genetically modified American Chestnut that is resistant to the blight? Last I heard the USDA was reviewing it for approval to sell.
Still being reviewed… They have thousands of trees planted, and have had at least three generations of trees in the “wild” (in very controlled plots). There has been a lot of fort going in to introducing more diversity into the Darling 58 variety, with pollen from a wide range of American Chestnut populations being used to make the next generation.
I have an F1 hybrid American/Chinese hazelnut in its 9th year on my little hobby farm (southern Ontario). It's done ok, no blight ... yet. It's too far from my other chestnuts (Chinese) to get pollinated to produce nuts tho. I keep meaning to get more trees. It's a nice looking tree.
I used to live in a historic property in rural MI built in the 1800s. There was a huge chestnut tree growing on it that was at least 50ft tall and looked like it could've been as old as the house.
I don't live near there anymore but I always wondered if it might have been an American chestnut.
Every year around this time we seem to get somebody posting Chestnut tree articles that imply that it's impossible to grow an American chestnut tree or that somehow American chestnuts are rare. My Dunstan Chestnut tree is doing tremendously well after 5 years, and it has a circumference of more than a foot. They even sell them in Walmart now. What am I missing?
Here is the link if you need one:https://chestnuthilloutdoors.com/learning-center/dunstan-che... They are very easy to grow.
Not certain, but that Dunstan is likely a hybrid species of American with Chinese chestnut for blight resistance.
The genetically pure American Chestnut tree was nearly eliminated by this blight. So backcrossed hybrids and genetically modified varieties of the American Chestnut are exciting, because there's a hope they could return to their former glory in the ecosystem.
This particular tree is a large specimen of genetically pure American Chestnut, growing in the east coast region as well, so a great find for conservation.
In all, hybrids may be great for individuals, but this movement intends to be more selective for restoration purposes.
This article makes it sound as if there's no large American Chestnuts, but that's not completely accurate. The largest trees in the US are a pair of trees in Thurston County, WA, that are 80-90' tall with ~10' circumferences: https://d3f9k0n15ckvhe.cloudfront.net/wp-content/uploads/202...
IIRC, they do grow, blight free in the West. However, anything in the Appalachian range, (this species' native habitat?) dies from blight pretty consistently. Lost 4 billion trees in 40 years.
I often wonder how different the Blue Ridge mountains looked 100 years ago, with the American Chestnut and various other trees that different forms of blight have since killed. It’s kind of sad visiting Clingman’s Dome or Mt. Mitchell, where you can see the skeletons of all the dead trees.
I was walking through a local bird sanctuary this morning. The various species of woodpeckers are doing very well, because of all the dead and dying ash trees (Emerald Ash Borer.)
Is there a theory where this tree came from? Is it presumed blight resistant or just really lucky for its location? The old trees live on in the roots but the young shoots die off, presuming blight resistance, did it evolve asexually?
does anyone know if there are any american chestnuts with natural immunity (via mutations?) with 4 billion trees it would seem that there would be some. There are HIV immune individuals after all.
How can they all die so fast and sudden? Wouldn't we expect a certain % to have some immunity, and then those genes pass on and the population eventually recovers?
I read in the book "American Chestnut, The Life, Death, and Rebirth of a Perfect Tree" by Susan Freinkel that when the blight was first discovered in the early 1900's scientists thought that cutting down chestnut trees in the east would stop the blight from spreading. Many trees were cut down that might have had some level of resistance to the blight.
Maybe that might have happened, but panic due to the blight massively increased logging of healthy Chestnuts trees. It wasn't just the blight that caused the ecological disaster; greed and shortsightedness probably played an equal part as well.
Plant immune systems aren't as adaptive as ours, and the American chestnut had no reason to evolve any immunity to the blight because it wasn't present on the continent until the early 1900s.
culi|3 years ago
Basically they hybridized it with Chinese/Japanese chestnuts (which are blight resistant). Then they take the offspring, test for blight resistance and rebreed those back with purebred American chestnuts. Then they repeat the process. Take those offspring, select for blight resistance, rebreed with American species, etc
After a few generations they created an American chestnut tree that looks almost exactly like the purebred versions but retains the blight resistance of the Japanese and Chinese species
Really amazing work
[0] https://www.youtube.com/watch?v=DbrY-J0bpto
nebul|3 years ago
[1] https://en.wikipedia.org/wiki/Backcrossing
greenonions|3 years ago
echelon|3 years ago
I'm not criticizing their technique! Nor do I think I know better. This is amazing and valuable work, and I'd love to know more.
lettergram|3 years ago
dfc|3 years ago
subpixel|3 years ago
I just saw Eliza Greenman speak on this subject, never expected that to circle back to HN.
lettergram|3 years ago
Though, they are still going through the FDA, EPA, and USDA process...
https://www.federalregister.gov/documents/2021/08/06/2021-16...
audiodude|3 years ago
bergenty|3 years ago
mattegan|3 years ago
My uncle and I also usually took hikes in NC to try and find remaining trees with pollen in the wild. From what I understand, the pollen from these few remaining living trees is used to help re-introduce regional biodiversity into the backcrossed American/Chinese hybrids.
Highly recommend going and helping out on the farm if you can spare a week or two, or joining your state chapter if you’ve got one - or sending your kids!
joecool1029|3 years ago
The survivor has 2 branches coming out of trunk each roughly 42" in circumference, it is not as tall as the one in the article but it's probably got similar girth. The tree is at least 70 years old, I'll confirm with the landlord whether he planted it or if it survived from before his time (he's been here approx 90 years, and I know one red oak and an eastern red cedar is older than he is). We do have Chinese/Japanese chestnuts on the grounds here that are more prolific and it's likely the seedlings I have are hybrids, but who knows?
One interesting thing I noted from the American vs. Chinese/Japanese chestnuts is the chestnut weevil does not appear to infect the nuts.
wyclif|3 years ago
helen___keller|3 years ago
> There used to be about 4 million American chestnut trees in eastern U.S. forests, until chestnut blight (Cryphonectria parasitica) arrived […]
The number is closer to 4 billion with a B[1]
Their range was across eastern North America and I’ve read estimates that they may have been a quarter to a third of the trees in those forests before the blight arrived.
1 https://en.m.wikipedia.org/wiki/American_chestnut
culi|3 years ago
It also makes me wonder. There was an estimated 30-60 million buffalo before colonialism in the Americas. However, those numbers were probably only possible to reach because of human activity driving out other apex predators and becoming themselves the apex predator. Similar story with paw-paws. Though they're not necessarily being threatened by anything currently, their range is decreasing. It turns out humans were essential for its distribution (likely due to other megafauna going extinct). Another example that comes to mind is the "prairie turnip" which as a staple food of many peoples that lived in the grasslands. Despite harvesting being a destructive process, the action actually ended up helping to spread their seeds. Without human harvest we've again seen a decrease in their range. I can also go on about how essential California cultural burns are for most of the "native" ecology, but I'm sure you get the point
Anyways I guess what I'm getting at is: I wonder how much humans played a role in it achieving such a widespread distribution.
There was a recent book called Dark Emu about aboriginal Australian's role in the native landscapes. Early colonists often remarked that the place looked like a giant, well-managed park. Well it turns out they actually did play a huge role in purposeful management of it. They even grew grains in massive monocultural fields that were often even larger than modern agricultural plots. Similarly there's been a ton of recent research into Amazonia and looking at it as a "manufactured landscape" because of how important the purposeful management of it by native peoples was to the ecosystem as a whole
wrycoder|3 years ago
Thousands of eyes!
joe_the_user|3 years ago
There are many chestnut trees in the town, planted in the gold rush days, I believe. last fall, I gathered enough nuts walk around town to supplement my diet for a few months. The nuts haven't started falling this year.
Of course, these tree survived the blight because they're well outside the range of the Eastern Chestnut. But still, if someone wants to see chestnut trees, they're here and probably in a lot of places where they were planted outside their range.
quixoticelixer-|3 years ago
pseudolus|3 years ago
https://www.atlasobscura.com/articles/podcast-american-chest...
altairprime|3 years ago
goldenkey|3 years ago
[deleted]
2bitencryption|3 years ago
It's a fictional collection of stories, all linked by trees (it makes sense if you've read it).
Beautifully written, and gave me a huge appreciation for trees.
timst4|3 years ago
mastersummoner|3 years ago
And it was just a really great story in general. Definitely recommend.
bpodgursky|3 years ago
Fwiw this is wrong -- it used to be 4 billion.
tylerrobinson|3 years ago
jseliger|3 years ago
https://news.ycombinator.com/item?id=26441593
https://news.ycombinator.com/item?id=30333498
dendrite9|3 years ago
The interviewer is not for everyone but I thought it was pretty good discussion. https://www.spreaker.com/user/16676611/restoring-the-america...
zaroth|3 years ago
Is there a good app which lets you input your zip code, maybe also sun exposure and soil conditions, how many feet of width and height you have available, and then where it will spit out a list of well-suited tree specimens with some nice pictures of each?
greenonions|3 years ago
mod|3 years ago
I was thinking for gardens and fruit trees.
I'm particularly interested in well-suited plants because I will inevitably ignore them, and I'm hoping they can thrive without me.
I'm planting figs this fall.
lostlogin|3 years ago
euroderf|3 years ago
sarchertech|3 years ago
JshWright|3 years ago
Here’s the 2021 update for the program: https://www.esf.edu/chestnut/progress-report/2021.htm
dang|3 years ago
https://www.imdb.com/title/tt11741708/
cmrdporcupine|3 years ago
I have an F1 hybrid American/Chinese hazelnut in its 9th year on my little hobby farm (southern Ontario). It's done ok, no blight ... yet. It's too far from my other chestnuts (Chinese) to get pollinated to produce nuts tho. I keep meaning to get more trees. It's a nice looking tree.
nathancahill|3 years ago
sg47|3 years ago
BooneJS|3 years ago
bentcorner|3 years ago
nickspacek|3 years ago
nybsop|3 years ago
jppope|3 years ago
billfor|3 years ago
greenonions|3 years ago
The genetically pure American Chestnut tree was nearly eliminated by this blight. So backcrossed hybrids and genetically modified varieties of the American Chestnut are exciting, because there's a hope they could return to their former glory in the ecosystem.
This particular tree is a large specimen of genetically pure American Chestnut, growing in the east coast region as well, so a great find for conservation.
In all, hybrids may be great for individuals, but this movement intends to be more selective for restoration purposes.
leetrout|3 years ago
https://youtu.be/zcLQz-oR6sw
bcbrown|3 years ago
tunap|3 years ago
Edit:
https://en.wikipedia.org/wiki/Chestnut#North_America
tootie|3 years ago
pivo|3 years ago
Xcelerate|3 years ago
pfdietz|3 years ago
heartbreak|3 years ago
peteradio|3 years ago
trelane|3 years ago
jppope|3 years ago
quixoticelixer-|3 years ago
paulpauper|3 years ago
mvidal01|3 years ago
Maursault|3 years ago
pjscott|3 years ago
phkahler|3 years ago
cnees|3 years ago
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roflyear|3 years ago
bardworx|3 years ago
tylerrobinson|3 years ago
mod|3 years ago
redtriumph|3 years ago