Chestnut chromosomal differences affecting blight resistance

By 1950, the American chestnut, once the "King of the Appalachian Forest," was extirpated. Organizations like the American Chestnut Foundation are working to restore the species by introducing blight resistance from Chinese chestnut through advanced backcross breeding techniques. Backcross breeding can only succeed when the chromosomes of both species are compatible. Because Chinese-American chestnut hybrids are viable, people have assumed that the two species are highly compatible. 

Photo Credit

Nurul Faridi, USDA Forest Service

These images show the major differences in the Ribosomal DNA (major 35 gene) regions and Satellites between American chestnut (AC) and Chinese chestnut (CC).  This heterochromatic DNA of Chinese chestnut may have some hidden properties that influence the blight resistance.

However, genetics research from SRS has uncovered significant chromosomal differences between American and Chinese chestnuts, particularly in the satellite regions around the nucleolus organizing region. This region involves the major protein synthesis genes, which are vital for growth and development. 

This innovative research could revolutionize understanding of DNA functions across species and support the development of a blight-resistant American chestnut.