![]() In Pennsylvania, more than 25 percent of the hardwoods were American chestnut trees. The tree was very densely populated with a range from Maine to Georgia. It would be hard to exaggerate the importance of the American chestnut in eastern United States forests. "I look at disease resistance as a puzzle, and hopefully the material from China will be just another piece." "The blight fungus is remarkably diverse in China, much more so than here, but that's because it evolved there over millions of years and is fairly new to North America," Fitzsimmons explained. While in China, the American contingent conferred with a Chinese forest pathologist who has studied the blight. "What better place to get disease-resistant material than the place where resistance comes from?" "The chestnut blight is common in China - it just doesn't kill the trees," said Fitzsimmons. Researchers believe a broad diversity of resistance genes will provide a lasting defense against the deadly blight. "Even if this plant material doesn't pan out, we have so much material coming through the pipeline that it will do the trick," she said.įitzsimmons and four other scientists - including Kim Steiner, professor of forest biology and director of the Arboretum at Penn State - journeyed to China in September to research getting even more blight-resistant plant material to breed with American chestnut trees. That's exciting."Įven if the sixth-generation trees now being grown don't produce satisfactory blight-resistant seed, Fitzsimmons is confident that blight-resistant American chestnut trees will be developed soon. "But it might not be much more than 10 or 15 years until folks can go to local garden stores or nurseries and buy blight-resistant chestnut trees. ![]() "It may take 100 or 150 years to see these trees restored to Eastern forests on any sort of large scale," Fitzsimmons conceded. Because most of the organization's hybrid trees are being grown in the South, blight-resistant candidate trees first will be planted in Jefferson National Forest in Virginia, Cherokee National Forest in North Carolina and Daniel Boone National Forest in Kentucky. Forest Service will get 50 percent of the chestnut foundation's sixth-generation tree seedlings to plant in federal forests where blight resistance can be monitored, Fitzsimmons noted. ![]() "But we will be testing it in the next 10 years to be sure the blight resistance is there." "Does this process work? Honestly, we don't know," she said. But it will be years until researchers know for sure. Those potted plants could be - indeed should be – blight-resistant, according to Fitzsimmons. We collected seed from those trees last year and we actually have sixth-generation plants growing in pots right now at Penn State." "The fifth generation trees are currently planted at the Penn State Arboretum and at our Meadowview facility in southwestern Virginia. "We have a six-generation breeding program - we think that will be adequate for both full American character and blight-resistance," said Sara Fitzsimmons, Northern Appalachian regional science coordinator for the American Chestnut Foundation and a research support technologist in Penn State's School of Forest Resources. ![]() Through the first-half of the 20th century, the species (Castanea dentata) - which was by far the dominant forest tree species in Pennsylvania and the East - was virtually eliminated from the landscape by an Asiatic blight fungus (Cryphonectria parasitica) carried on exotic plant materials imported by plant explorers in the late 1800s.Ī decades-long process of introducing blight resistance by cross-breeding Chinese chestnut trees with American chestnuts, and then back-crossing the hybrids with American chestnuts to select for desirable American chestnut form and traits, seems to be close to bearing fruit.
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