Late in 2023 The American Chestnut Foundation (TACF) abruptly withdrew its support for the State University of New York’s College of Environmental Science & Forestry (SUNY-ESF) petition for deregulation of the Darling line of genetically modified (transgenic) American Chestnut. Many of you have interest in it, have done work with it in the field, or have even committed financial resources to TACF and/or TACF’s Maine Chapter in furtherance of it. Many of you wrote or called me. In summary, the question you all asked was, “Wait, what?” I didn’t have answers. Since then, TACF has shared some of the reasoning for discontinuing its support of Darling, and SUNY-ESF has acknowledged a critical labeling error. The United States Department of Agriculture (USDA) final determination on the petition is still outstanding.
Initially I wasn’t even sure how to respond, because it came as quite a surprise. So, I’ve waited to comment on behalf of the chapter, have read what’s available, asked questions, attended Chapters Committee meetings and Chestnut Chats, and have tried to understand where we go from here. At the risk of being redundant, because some of this has been published elsewhere, this presents what we know. And in summary, where I think we stand with Darling as a chapter, at least in the near term.
What we Know
The USDA issued a preliminary ruling that is stated in the following link:
https://www.aphis.usda.gov/brs/aphisdocs/19-30901p-dpra.pdf
It suggested that the Darling 58 transgenic variety of American Chestnut developed by SUNY-ESF was close to final action. The VT-NH Chapter optimistically looked forward to a final deregulation decision. We expected it to clarify the extent to which we could participate in Darling pollinations and plantings beyond the only site permitted within our two states.
Last summer chapter members pollinated flowers on trees with what we believed to be Darling 58 pollen. It was obtained through TACF from the University of New England (UNE) in Biddeford, Maine. But later genetic testing revealed the trees from which the pollen was harvested by UNE were Darling 54, not Darling 58. Both varieties are part of the deregulation petition, but Darling 54 is inferior to Darling 58, based on location of the Oxalic Oxidase gene on chromosomal structures. Both varieties rely on the same “constitutive promoter” which turns oxidase production in the trees on continuously.
SUNY-ESF recently acknowledged a labeling error going back to 2016, which led to errant research result reporting between the varieties, and to the mistaken pollen variety from UNE. From what I can determine, the mistake was so early in Darling’s development that most, if not all observations of the trees represented as Darling 58, are almost entirely of Darling 54. And, that little Darling 58 even exists. Here is a link to SUNY-ESF’s current position regarding its work with Darling.
https://www.esf.edu/chestnut/progress-report/2023.php
TACF looked forward to a final deregulation decision too, until it withdrew support for it. So, the withdrawal did come as a surprise. TACF has stated that the withdrawal is based on performance issues observed with Darling varieties and has shared some of those performance concerns. Having supported SUNY-ESF financially and directly in other ways, TACF is unhappy and disappointed about what has happened. The following link includes Chestnut Chats discussing the TACF position and its concerns about the Darling tree performance.
The VT-NH chapter supports an “all possible” approach to restoration be it with a blight resistant or blight tolerant American Chestnut. Our Chapter’s goal, stated in the December 2021 Strategic Plan, remains:
Self-sustaining stands of blight tolerant American Chestnut trees growing in Vermont and New Hampshire woodlands.
The term blight tolerant was used in the Strategic plan because when it was written emphasis was given to transgenic tree success. The term blight resistance is more general term and applies to a wider range of restoration approaches. Even if the Darling varieties fail in part or completely, we support the pursuit of a transgenic variety, or other tree, which could replace it, consistent with the 3-BUR strategy (Breeding, Biocontrol and Biotechnology) for successful reintroduction.
In 2022 our chapter funded transgenic research both at TACF and through TACF’s Maine Chapter working with UNE, by granting $2,000 to each. We have never funded SUNY-ESF directly. There are other programs we could consider funding in the future.
Summary
Notwithstanding the critical labeling error, it’s possible that SUNY-ESF is well along in biotechnology research seeking a blight tolerant transgenic variety. We hope that SUNY’s wound-inducible DarWin variety, which is now being speed-bred at UNE, will outperform Darling. But with no direct support going to SUNY-ESF, and as a licensee of TACF, we can only wish SUNY-ESF the best right now and follow their efforts. We can do nothing with or for Darling. Our chapter will follow other biotechnology research efforts which TACF sponsors and/or supports being done elsewhere. Such efforts are underway at the University of Georgia. For now, the biotechnology prong of “3-Bur” has taken a big step back from where we thought it was. There don’t appear to be any actionable efforts we can take this year with transgenics, much less Darling.
The good news is that the VT-NH Chapter has focused on location of wild type trees, and preservation of genetic diversity of known American Chestnut trees. Our recent work includes plantings in Germplasm Conservation Orchards (GCO’s), maintenance of breeding and seed orchard trees with unique American ancestors, and distribution of free, pure American seeds to members each year. We’ll continue all these efforts. This positions us well for restoration trial plantings when blight resistant or blight tolerant pollen becomes available – wherever it may come from and whenever it becomes available. The female flower of American and hybrid-American trees remains key, and our efforts have prepared us for that eventuality.
Part of the reality of scientific research is that there are unanticipated bumps in the road. We are navigating one such bump. But an “all possible” strategy, within the constraints of our chapter’s financial and human volunteer resources, remains the best long-term way to attain our goal until another promising development materializes.
I hope this has answered some of your many questions, given you some idea of where we can, and cannot go this year as a chapter. We are planning a science meeting to guide our field efforts, and an annual meeting on May 11th, which will clarify our financial resources and will focus on both the things we are doing and might do. Thanks to all of you, we are all volunteers.
Evan Fox
VT/NH Chapter President
Below is a link to a related news story by David Brooks that ran in the Concord Monitor. It presents an overview of recent developments in chestnut restoration efforts and how they may be evolving. David has followed chestnut restoration for roughly 10 years and has coordinated with the VT/NH Chapter to write numerous informative stories about the process.
https://www.concordmonitor.com/chestnut-tree-genertic-modification-53798056
