Reliability of germination testing of ex situ conserved seeds: a genebank case study on outsourced analyses

Germination tests are performed on a routine basis to determine the viability of genebank accessions. The results determine which accessions have to be rejuvenated. The reliability of the germination test results used by the Centre for Genetic Resources, the Netherlands was determined by the retesting of 641 random samples anonymously, in the same year and by the same testing agency as the original tests. Results showed alarmingly low reliabilities, with error levels much higher than expected based on sampling effects. The result of a germination test of a random sample with a germination of 80% was shown to have a 95% confidence interval from 63 to 97%. The errors differed strongly over crops and testing years, and were larger for crop wild relatives than for crop species.