Conventional and biotech breeding methods together could revive the American chestnut tree

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American chestnuts once dominated the Eastern woodlands. They were beautiful, tall trees with wide canopies and large white flowers.

And yet, 40 years after the fungus Cryphonectria Parasitica arrived, the trees, which once numbered in the billions, were gone. Some of their roots still survive, sending up twiglike shoots, but they die before they mature.

The foundation was started in 1983 to bring the trees back. Its thousands of volunteers maintain 680 orchards where American chestnuts are crossbred with blight-resistant Chinese chestnuts, then crossed back again. The goal is to develop a tree that is almost all American chestnut, but retains its Chinese cousin’s resistance to blight.

[The] State University of New York’s College of Environmental Science and Forestry has been using genetic engineering to try to develop a more blight-resistant American chestnut. It has had some success by inserting a wheat gene that breaks down oxalic acid. Oxalic acid produced by the fungus creates the canker in the tree’s cambium layer and eventually girdles the tree, cutting off its flow of nutrients and killing it.

[Kim Steiner, Penn State professor of forest biology] said the genetic work is also slow going, but the two approaches complement each other and eventually will lead to success.

The GLP aggregated and excerpted this article to reflect the diversity of news, opinion and analysis. Read full, original post:Science and volunteers work to restore American chestnut tree to U.S. forests (behind paywall)