Genetic variation within natural populations and restoration orchards of American chestnut (Castanea dentata) in New York State.

摘要

The American chestnut once dominated the eastern forest until the chestnut blight fungus severely reduced its numbers. It exists today in New York State forests due to stump sprouting and in restoration orchards established by the New York State chapter of the American Chestnut Foundation (ACF) and other private growers. RAPD variation was tested in samples representing the New York population for differences in orchard vs. natural populations and for differences among three geographical regions within the state. American chestnut populations in New York have a relatively high level of genetic diversity as compared to other forest trees. ACF orchards are maintaining natural levels of genetic diversity, which is important in avoiding a genetic bottleneck once orchard populations are bred to resistant trees from the backcross program or transgenic chestnut programs. Small, but arguably insignificant, genetic differences were found among the three geographic regions of New York State chestnut populations.