Question

What are the benefits of high resistance to chestnut blight?

Answer 1

Cryphonectria parasitica is a parasitic fungus of chestnut trees. This disease came to be known as chestnut blight. Naturally found in South East Asia, accidental introductions led to invasive populations of C. parasitica in North America and Europe. The fungal disease has had a devastating economic and social impact on communities in the eastern United States. In the first half of the 20th century it killed an estimated four billion trees. Less severe impacts have occurred in Europe due to widespread CHV1 hypovirulence. CHV1 is one of at least two viral pathogens that weaken the fungus through hypovirulence and helps trees survive.

Ecological Role: By attacking and killing the American chestnut, resulting in forest clearing and the removal of the forest canopy provided by large chestnut trees, the fungus indirectly benefits smaller hardwood trees, such as birch trees, replacing the American chestnut.

No species of chestnut is immune to blight, since all of them can get the disease. However, several species are resistant to the blight; they get the disease, but only mild cases. High levels of blight resistance are found in Asian species of chestnut, and the Chinese chestnut, C.