
Science Friday Into the Woods, From Chestnut Genetics To Tiny Forests
Feb 27, 2026
Hanna Lewis, author and urban rewilding advocate who champions the Miyawaki mini-forest method. Dr. Jared Westbrook, chestnut restoration scientist using breeding and genomic tools to rebuild American chestnuts. They discuss rapid miniforest planting for tiny urban sites. They explore decades-long chestnut breeding, genomic selection to speed resistance, and how small dense forests establish quickly.
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Complex Genetics Behind Chestnut Resistance
- American chestnut restoration uses decades of backcross breeding to combine Chinese blight resistance with American form.
- Hundreds of orchards supply diverse crosses and recent genome sequencing revealed many genomic regions contribute to resistance.
Speed Breeding With Genomic Selection
- Use genomic testing to speed selection by genotyping seedlings and planting top performers rather than waiting for long field inoculation trials.
- This lets breeders select the ~10% best offspring and accelerate multi-generation improvement in a decade instead of many decades.
GM Approach Fell Short In Field Trials
- Genetic engineering alone proved insufficient because complex, multi-gene resistance and field performance differ from seedling assays.
- A transgene from wheat gave seedling resistance but failed long-term in field trials and slowed growth.


