TACF discontinues development of Darling 58 transgenic chestnut tree

General Fruit Growing
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Some information on its performance:

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Have to respect their integrity. That is a tough call.

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“we have newer and better-performing trees ready to test.” One of the objectives from the 2018 meeting in Huntsville was to move the Oxalic Acid Oxidase gene into position behind a wound initiator, in other words, so it will only be expressed when a tree is wounded. Inside information says they succeeded and are evaluating the result. I asked about this while harvesting chestnuts in the Florence location a few months ago and was told they have advanced work being done.

  1. Somebody misidentified and shipped the wrong tree for evaluation, it was not Darling 58.
  2. Darling 58 is still not good enough to do the job, over-expressing OAO has serious negative consequences.
  3. Some newer modified trees with targeted changes in the genome don’t have the negatives of the first generation trees such as Darling 58. Negatives include reduced growth, significantly higher mortality in the field, and general failure to thrive.
  4. Current approach is a combination of known resistance genes from Chinese chestnut combined with OAO behind a wound initiator. It looks like this will meet objectives for general forest use.
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Sounds like that was a well-reasoned decision but they learned from the failure (OAO transgenic cannot be constitutively “always on” but inducible (“when needed”) and they are still identifying resistance genes from Chinese chestnuts that would be additive to OAO (and probably will be).

“Success consists of going from failure to failure without loss of enthusiasm”
Churchill

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