For a moment, I was wondering why would American conservative movement fixate itself with a tree!!??
(I need to unplug from news cycle)
American chestnut tree in Centreville is the 'holy grail' for conservationists
51–60 of 157 posts
Re: American chestnut tree in Centreville is the 'holy grail' for conservationists
#52Saw 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…
Unfortunately, I can’t buy them yet. Driving me nuts
You can buy the backcrosses, as far as I know...it's the modified ones from SUNY ESF that you can't buy yet.
Re: American chestnut tree in Centreville is the 'holy grail' for conservationists
#53Saw 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…
Unfortunately, I can’t buy them yet. Driving me nuts
> Driving me nuts
I see what you did there.
Re: American chestnut tree in Centreville is the 'holy grail' for conservationists
#54> 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 Fwiw this is wrong -- it used to be 4 billion.
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.
Re: American chestnut tree in Centreville is the 'holy grail' for conservationists
#55Earlier quoted context omitted.
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.
Good question. I'd imagine something like blight resistance would probably not be a simple case of a few specific genes we can just switch over. It could also just be technology. This breeding program has been around for 50 years or so and CRISPR only really took off around 2011. In addition, the original CRISPR-Ca9 caused a lot of unintended changes in DNA and it's really critical that the new trees are morphologica…
It actually is pretty "simple" in this case (the tree needs to produce a single chemical, oxalate oxidase). There is a program that has done this very successfully, and it just working through the regulatory process before wider distribution can happen. They have thousands of trees in (controlled) forest plots, including three generations of offspring.
Re: American chestnut tree in Centreville is the 'holy grail' for conservationists
#56Saw 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…
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 things the gene gun can do turn out to be not the most useful things one could hope for from it. (It's a surprisingly brute-force device, though I guess that was all in the name if you actually took it at face value!) I don't see a ton of future for it as a generalist technology, though what things it does well it does very well.
CRISPR is... awful in different ways. (It seems to have a lot of trouble controlling how much material it transfers.) It's a laboratory curio or one-off stunt now, but I fully expect it will improve.
Re: American chestnut tree in Centreville is the 'holy grail' for conservationists
#57There is one in North Bergen, NJ. I won't say where. They can find it themselves!
If true, you should share it with the foundation that catalogs them.
Re: American chestnut tree in Centreville is the 'holy grail' for conservationists
#58How 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?
Re: American chestnut tree in Centreville is the 'holy grail' for conservationists
#59The article misstates
> 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.
Re: American chestnut tree in Centreville is the 'holy grail' for conservationists
#60Saw 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…
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. [1] https://en.wikipedia.org/wiki/Backcrossing
If you ever see a cannabis strain name with a Bx in it, it stands for Backcross!