Nonviable Seeds May Contain Research-Quality DNA

The research was conducted by plant physiologist Christina Walters, plant physiologist Gayle M. Volk and plant geneticist Christopher M. Richards at the ARS National Center for Genetic Resources Preservation (NCGRP) in Fort Collins, Colo.

Like all genebanks, the NCGRP stores genetic materials that researchers can use to study the nature, function and evolution of genes. All seeds lose viability in storage, however, and samples that can no longer germinate are often discarded. But new research shows that even low-viability seeds can contain research-quality DNA.

The ARS scientists examined three sets of seeds, ranging in age from one year to 135 years. They were able to extract usable DNA from all of the seeds—even the oldest set, which had been stored in a Georgia attic since the Civil War.

This is significant because donated collections, such as the Civil War seeds used in this study, are sometimes infested with microbes that contain enzymes capable of degrading the seeds' DNA. Fortunately, genetic materials at the NCGRP are stored under optimal conditions, and are at lower risk for degradation.

Because the oldest seeds in this study are no longer capable of germinating, the scientists have no means of measuring their phenotypes, or observable genetic traits. However, stable DNA enables researchers to study the parent plants' genetic material and uncover information about their genetic diversity.