This report, cross-posted from Science Daily, celebrates the “return” of the American Chestnut to New York City, 100 years after the Chestnut was wiped out by a pathogenic fungus. But let’s not mistake this event for anything resembling ecological restoration. The new trees are genetically modified, making this much-lauded event not so much the return of a native as the implantation of an exotic. Perhaps, if no relatives of the Chestnut exist nearby, we can expect the standard dangers from the release of GE pollen to minimal. But if this GE Chestnut, planted in a field trial at the New York Botanical Garden, sets a precedent for field trials of other GE species, such as the pines and poplars that are under research and the quarter of a million GE eucalyptus trees that Arborgen is planning to plant in field trials across the southern US — than what it bodes is a new form of blight altogether. – the GJEP team
“We’ve been working on this for a long time and are looking at many genes. One particular gene has become my favorite,” said Dr. William Powell, a plant biotechnology expert at ESF. “And over the years it has convinced me that this gene is going to do the trick.”
Powell and his colleague, Dr. Charles Maynard, a tree improvement specialist, are enthusiastic about a gene derived from wheat that they have shown to increase resistance to a fungal pathogen in hybrid poplar. Powell and Maynard believe this gene will also be effective in the American chestnut because it detoxifies the oxalic acid produced by the blight pathogen. Oxalic acid kills the trees by attacking the cambium, the part of the tree that allows it to continue reproducing cells. A canker forms and everything above the canker dies. The roots can remain healthy and continue to send up shoots but the trees die back to ground level within a few years.
“If we can eliminate the oxalic acid, we probably will get a resistant tree,” Powell said.
The American chestnut was once a dominant species in the forests of the eastern United States; it accounted for 25 percent of the trees in the forest. A healthy one can grow more than 100 feet tall and measure 10 feet in diameter.
“This was a key species in the eastern forest. It was super at producing nuts for wildlife; very important for agriculture for human consumption of the nuts; very important for the lumber industry, making a rot-resistant, fast-growing wood product; and it was an important part of our history,” Powell said. “We really want to bring it back. The only way it can come back is to make a resistant tree because no one has been able to control the blight any other way.”
The location of the planting is significant.
“We’re very excited to be going back to The New York Botanical Garden because that’s a stone’s throw, literally across the street, from where the blight was discovered in 1904,” Maynard said.
Author Eric W. Sanderson, in his 2009 book, “Mannahatta: A Natural History of New York City,” wrote that when Henry Hudson first saw the island now called Manhattan in 1609, the American chestnut was “king of kings,” making up more than half the trees in the forest.
Powell and Maynard, who describe themselves as the third generation of scientists searching for a solution, have conducted their research through the American Chestnut Research and Restoration Program at ESF, with support from the New York chapter of The American Chestnut Foundation, the Forest Health Initiative, ArborGen and many others. They were the first research team to run field trials of transgenic varieties.
The trees being planted at the Botanical Garden are among more than 100 varieties of transgenic American chestnuts that are being tested in field trials or waiting to be tested for blight resistance. The planting is one of several events April 18 that will celebrate the progress made during the 25 years that Maynard and Powell have devoted to the effort.
Before the planting, the two scientists will present a 3 p.m. lecture on the economic and ecological importance of the American chestnut tree, their research progress and the trees that are about to be planted. After the trees are planted, the events will conclude with an ESF Alumni reception and dinner in the Lillian and Amy Goldman Stone Mill on the Bronx River and adjacent to the native Forest in the heart of the Garden.