[throwawaygal7]

Two points:

1) resistance genes are already in the genome, they don't need to be added. This means the entire endeavor is unnecessary

2) this is an internationally recognized definition of genetic pollution, it's controversial only with a few hardliners.

[SECProto]

1. Resistance genes are already in the genome, but they have so far proven inadequate. Experiments in interbreeding and crossbreeding have been going on for 60 years from the USDA, the American Chestnut Foundation, the American Chestnut Cooperators Foundation, etc - and none of them have declared "victory" yet. There's no reason to assume there'll be blight-resistant chestnut seedlings available anytime soon. Or anytime late, to be honest.

2. If you read the wikipedia article [1], it has an entire section on why it's controversial. It also has links to an article on genetic rescue[2], which I think is more relevant.

[1] https://en.wikipedia.org/wiki/Genetic_pollution#Controversy

[2] https://en.wikipedia.org/wiki/Genetic_rescue