By
Sandra L. Anagnostakis,
The Connecticut Agricultural Experiment Station, Box 1106,
New Haven, CT 06504, phone 203-974-8498, fax 203-974-8502
American
chestnut trees were once a major part of our North-Eastern
forests. In the 1880's a fungus came into the U.S. on imported
Japanese chestnut trees. It infected through wounds and quickly
spread, killing our native chestnuts and chinquapins.
Even though this chestnut blight fungus kills stems, the trees
usually sprout from the base forming a clump of sprouts which
become wounded, infected, die, and sprout again.
The Connecticut Agricultural Experiment Station has been working
on this problem since the beginning of the epidemic, planting
resistant Asian chestnut species and crossing them with susceptible
American trees. We now have the finest collection of species
and hybrids of chestnut trees in the world.
In 1972 we imported from Italy a biological control, which
is a virus that keeps the blight fungus from killing chestnut
trees. The virus-infected strains have less pigment when grown
in the lab, and produce swollen cankers on the bark instead
of the lethal, sunken cankers. These swollen cankers have
healthy tissue underneath them.
This biological control works well in orchards, keeping even
very susceptible, American chestnut trees alive, and allowing
the breeding work to continue. It works less well in the forest,
where many other trees are competing for the light, nutrients,
and moisture.
We have some new virus-infected strains of the fungus which
have been improved using molecular biology, and these are
being tested in the Housatonic State Forest in Sharon, CT.
We are proceeding with the double approach of improving the
biological control of chestnut blight disease and breeding
better, more disease resistant trees for forests and for orchards.
-
Chestnuts
-
An Historical Reference for Chestnut Introductions Into
North America
-
Chestnuts And The Introduction Of Chestnut Blight
-
Oriental Chestnut Gall Wasp Found On American Chestnut
Trees
-
Valuable Chestnut Germplasm In Connecticut
-
Chestnut Breeding In The United States
-
Sources Of Chestnut Trees 1998
