The American Chestnut and the Zambi Fungus

In the eighties, a plant breeder at the university of minnesota of charles burnham thought about back cross breeding specifically. The american chestnut foundation was to basically work on this hypothesis that six generations of hyberdization and back crossing and then intercrossing would create a blight resistant one. It's been a tougher nut to crack than they'd initially hoped. After decades and decades of work, organization has been able to breed American chestnuts that are moderately resistant to the fungus.