Examples of Biotech Trees

Below are a few places where biotech trees are badly needed, promising work is underway, or have already had significant impacts.

Restoration of American Chestnut
The American chestnut (Castanea dentata) was a large, deciduous tree of the beech family native to eastern North America (Figure). However, the species was devastated by a fungal disease, the chestnut blight (Cryphonectria parasitica). After years of intense research, blight resistant trees have been produced, and are planted in multiple field trials. Efforts are underway to obtain regulatory approval for their use in forest restoration. More here.



Emerald Ash Borer-Resistance
An aggressive, exotic pest from Asia, the Emerald Ash Borer (EAB) (Agrilus planipennis Fairmaire), first identified in Michigan in 2002 is killing all species of Ash in the U.S. and Canada at a rapid pace. Once infected, stands typically have 100% mortality. The cost of treating, removing, and replacing the 38 million ash trees in U.S. communities is $25 billion, which doesn’t include natural forest tree loss. All ashes (Fraxinus spp.) native to North America appear to be susceptible. Conventional breeding is difficult and slow; thus, there are efforts underway to develop a biotech ash tree that resists the EAB. More here



Insect Resistant Poplar
Insect pests are major sources of damage and mortality, but are very costly to control, difficult to breed against, and pesticide use can have harmful environmental consequences. Researchers in the USA, France, and China have produced hybrid poplars that are fully resistant to targeted beetle and caterpillar pests, and can show much enhanced growth rate as a result. More here.



Papaya Ringspot Disease Resistance
Biotech papaya trees that are resistant to the ringspot virus have been available since 1997. The disease was threatening to wipe out the entire papaya industry in Hawaii prior to the introduction of resistance genes, which act like vaccinations that boost natural immunity processes. More here.



Citrus Greening Resistance
Citrus greening is considered one of the most serious plant diseases in the world, and has infected most of the citrus fruit trees in Florida. Once infected, there is no cure, and the trees produce fruit that is small, bitter, and under-ripe. This disease threatens every acre of citrus in the world. Genetic engineering of trees or biocontrols appear to be potent solutions. More here



Slow-Browning Apple
The Canadian biotech company, Okanagan Specialty Fruits, has received commercial approval in Canada and the U.S. for an apple tree that browns extremely slow when they are cut. Okanagan’s “Arctic” apples achieve the non-browning effect by silencing a natural gene that encodes the polyphenol oxidase enzyme. This should result in more consumption of healthy apples and less food waste. More here.



Trees that are Efficient for Bioenergy and Pulp
Scientists have modified the lignin content and structure in wood to make it yield more ethanol when fermented, or require less energy and chemicals to produce pulp. Though not commercial, field trials have been successfully carried out in the USA, Canada, and Europe. More here.



Trees with Modified Flowering Control
The slow onset of flowering impedes the speed of conventional tree breeding, and the release of pollen and seeds from exotic or genetically engineered trees can impede or prevent their regulatory approval. There have been very promising developments in flowering control both demonstrating effective containment and rapid flowering to speed breeding. More here and here.