TACF cites "significant performance limitations"

In a December 8 press release, the American Chestnut Foundation (TACF) announced that it was withdrawing support for the "Darling 58" genetically engineered American chestnut tree "for several pending regulatory petitions that would authorise distribution of transgenic Darling trees outside permitted research plots".

TACF cited "significant performance limitations that, from TACF’s perspective, make it unsuitable as a restoration tree".

TACF said: "Throughout 2023, TACF and its partners observed disappointing performance results from broad scale field and greenhouse tests of advanced-generation Darling trees across several different geographic locations at external testing facilities. As discussed in the September 15, 2023 episode of the Foundation’s webinar series, Chestnut Chat, analysis indicated striking variability in Darling trees’ blight tolerance, significant losses in growth competitiveness, and increased mortality."

William Pitt, TACF’s President and CEO, said, “Within the past few weeks, academic colleagues brought to our attention their newest findings suggesting a significant identity error in the propagation materials supplied to TACF. Independent confirmation now shows all pollen and trees used for this research was derived not from Darling 58, but from a different prototype, one which contains a deletion in a known gene. That deletion, along with the discouraging field performance collectively renders these trees, in TACF’s opinion, unsuitable as the basis for species restoration. Fortunately, we have newer and better-performing trees ready to test.”

Sara Fern Fitzsimmons, TACF’s Chief Conservation Officer said, "It is our assessment that these trees would impair future deployment of disease-resistant American chestnut populations. Premature distribution of this or other inferior varieties also may unfairly skew public perception against biotechnology solutions to save threatened forest tree species.”

This announcement follows closely on the heels of calls by a coalition of organisations for the US Department of Agriculture to reject deregulation of the Darling 58 GM chestnut tree based on the revelation by researchers of significant problems with the tree.

In a statement on December 7, Global Justice Ecology Project Executive Director Anne Petermann said, "The only ethical move by the D58 researchers, knowing these GE [GM] trees have problems that they don’t understand, is to withdraw their petition to the USDA for deregulation of the D58. Now that the TACF has withdrawn support for this failed project, we again call on the USDA to deny the petition for deregulation."