Home grown US chestnuts, a GM poster boy?

By 20. June 2014Blog, Quality, Taste

Reported in the science magazine New Scientist last week, scientists from The American Chestnut Research and Restoration Project have created an American chestnut  that is resistant to the blight has all but wiped it out in most of the US.

American chestnut (Castanea dentata) was widespread in the US until a devastating fungus was accidentally imported from Asia at the beginning of the last century. The scientists have managed to insert a gene from wheat that produces an enzyme that breaks down an acid made by the fungus preventing it from causing lesions.

The culitvar, named Darling4 have so far performed well when infected with the fungus and the trait seems to be heritable. This is good news as the scientists say that means they can plant seedlings which are a lot faster to produce than cuttings. Newer cultivars in production are even starting to perform better than the Chinese Chestnut which has a natural resistance to the fungus.

So is this a success story for genetic modification? As they like to say here in Germany, Jeine (a mix of yes and no). The trees do have resistance to the fungus but so do the Asian chestnuts (Castanea crenata and Castanea mollissima). Seeing as hybrids can be made of the trees some might say it makes more sense to identify the resistance genes in these trees and breed it into the American chestnut. This is actually what they are doing in a parallel project started in the 1970’s. They now have a tree that is 94% American Chestnut with resistance similar to that of Chinese Chestnut.

On the other hand trees take a long time to reach maturity even with forced grafting so it could be argued that GM provides a quicker fix to the problem, the gene inserted comes from a food plant so that should at least alleviate the fears of some and the GM varieties are starting to be more resistant than the Chinese chestnut.  

Either way you look at it, the American Chestnut, in one form or another, is coming back from the brink.

Read the full story on the New Scientist website.