Dogwoods fight fungus: fungus wins.Dogwoods fight fungus; fungus wins A deadly fungus is attacking flowering dogwoods, and new research indicates the trees have little chance of resisting it. "Dogwoods have more problems than this disease, but none is quite as deadly as anthracnose anthracnose Plant disease of warm humid areas, caused by a fungus (usually Colletotrichum or Gloeosporium). It infects various plants, from trees to grasses. Symptoms include sunken spots of various colours in leaves, stems, fruits, or flowers, often leading to wilting and ," says plant geneticist Frank S. Santamour of the Department of Agriculture's National Arboretum arboretum: see botanical garden. arboretum Place where trees, shrubs, and sometimes herbaceous plants are cultivated for scientific and educational purposes. An arboretum may be a collection in its own right or a part of a botanical garden. in Washington, D.C. Dogwood dogwood or cornel (kôr`nəl), shrub or tree of the genus Cornus, chiefly of north temperate and tropical mountain regions, characteristically having an inconspicuous flower surrounded by large, showy bracts which anthracnose was first noted in the late 1970s in New York New York, state, United States New York, Middle Atlantic state of the United States. It is bordered by Vermont, Massachusetts, Connecticut, and the Atlantic Ocean (E), New Jersey and Pennsylvania (S), Lakes Erie and Ontario and the Canadian province of , Pennsylvania, New Jersey and the Pacific Northwest. Since then, the disease has spread the length of the Appalachian Mountains, but its full extent is unknown. To test whether dogwoods from any region could resist the disease, Santamour grew seedlings from trees from 17 states and then planted them in Maryland's Catoctin Mountains, where they would be naturally infected. After 2-1/2 years, all the trees "were completely gone," he says. "So the disease is not going to be confined to be in childbed. See also: Confine by any [genetic] resistance and is just going to spread. And it will depend on weather and about 10,000 other things how fast and how much it spreads." The origin of the disease remains obscure. "Whether it's a native American fungus that remained dormant for years or [was imported] from abroad, we don't know," Santamour says. Pathologists have not even identified the species of the fungus, he adds, and no fungicidal fun·gi·cide n. A chemical substance that destroys or inhibits the growth of fungi. fun  gi·cid treatment has yet been found. The disease seems confined to the native U.S. dogwoods. When Santamour tested the Asian dogwood species, Cornus kousa, it showed some leaf spotting but resisted the full-blown disease. |
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