North American Fruit Explorers mailing list at ibiblio

[Road's End Farm <organic87@frontiernet.net>]

On Nov 6, 2014, at 9:08 PM, Elizabeth Hilborn wrote:

> They are apparently transgenic with a wheat oxalate oxidase gene which 
> renders the trees resistant to fungal-associated pathology. They make the 
> point that these new trees have more American Chestnut genetic material 
> than the complex hybrids such as Dunstan.

From the article:

> This gene doesn't hurt the fungus, but instead detoxifies the acid used by 
> the fungus to attack the tree, essentially changing the fungus from a 
> pathogen to a saprophyte that lives on the bark of the tree without causing 
> significant harm.

So these trees will continue to host the fungus, thereby remaining a 
permanent locus for infection. In many parts of the country, the fungus seems 
to be persistent in any case; but I'm not sure that it's not an issue 
everywhere. 

I wonder why they didn't take the resistance genes from the Chinese chestnut, 
instead of from a plant as distantly related as wheat? I don't know whether 
the Chinese chestnut genes allow the tree to continue hosting the fungus or 
not -- does anyone else?


-- Rivka; Finger Lakes NY, Zone 6A now I think
Fresh-market organic produce, small scale