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‘‘blight resistance” and “straight stem.” It appears that, genetically, these traits are very closely linked in a manner that is mutually exclusive...a peculiar and unfortunate quirk of nature.
Radiation Breeding
Evolution is a slow process. Given adequate geologic time, the American chestnut would possibly evolve into a form that would be able to survive and compete in the woods. We can "speed up” evolution, and (hopefully) channel the process in a desired direction, by inducing genetic mutations. These mutations—changes in the organism’s genetic structure—provide the driving force for evolution.
Mutations can be induced by subjecting the seeds to radiation. ‘‘Radiation breeding” has produced many desirable agricultural crops.
The radiation treatment alters the genetic information within the seeds. This alteration is a haphazard process, and the chance of producing a desirable mutation is very, very small. It probably will never happen.
Breeding Surviving
Chestnut*
Occasionally, a wild American chestnut will survive to be very large. Although these surviving trees have the blight, they have so far been able to withstand its effects. There might be a genetic basis for this natural resistance. Therefore, we might logically expect to be able to breed these known surviving trees, and establish their offspring in the forest.
The trick is to obtain viable seeds or cuttings from these trees. No one has been able to perfect a method of rooting the cuttings made from old chestnut trees. Seeds produced by the surviving chestnuts aren’t usually viable, because of the
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