The Vulnerability of Plant Genetic Resources Conserved Ex Situ

The realized dangers of genetic erosion in plant genetic resources have prompted political and scientific movements around the world to conserve plant genetic resources over the last 50 yr. More than 7 million plant germplasm accessions are currently conserved in 1750 genebanks worldwide, and about two million accessions are estimated to be unique. The International Treaty on Plant Genetic Resources for Food and Agriculture was established to conserve and utilize these plant genetic resources. However, long-term conservation of such a large volume of diverse germplasm remains a challenging mission. Many critical issues affecting genebank sustainability have emerged. Of note are the vulnerability of genebanks and the risk of within-genebank genetic erosion through genetic drift and viability selection. Here, we review the overall conservation efforts over the last 50 yr, analyze the critical issues in genebanks, and identify the elements that threaten long-term germplasm conservation. Measures are explored with the hope to mitigate variable threats for genebank sustainability and to secure a food supply for humanity for generations to come.