The cut test

At the end of your germination test, if all goes well, the number of viable seeds will be above the Genebank Standards’ viability threshold (85%). But what if the results do not go the way you wished? Does that mean the seeds are no longer viable, and need regeneration? That’s possible, but there could be other reasons for apparently low germination rates, which require different courses of action. Ask yourself the following questions:

This is where a cut test provides useful information. Cut tests are examinations of seed anatomy: they involve dissecting longitudinally through any seed that has not germinated, and observing what state the cotyledons and embryo are in. By carrying out a cut test, you may gain valuable insights into what actions you need to take to improve seed quality. Record the number of seeds that are:

• Immature: small cotyledons or under-developed embryo (reduced chance of germinating)
• Ungerminated: firm, usually white tissues (usually viable but may have died in storage)
• Empty (never had a chance)
• Moldy: necrotic, often brown tissues (dead)
• Infested (dead)

Cut tests are an important decision tool for upgrading seed processing processes. For instance, if you find significant numbers of seeds were immature, you might be able to make improvements to the cleaning process, so that immature seeds are eliminated before they go into storage. If seeds were ungerminated but still alive, perhaps there was something missing from the physical environment provided by the germination tests. Cut tests help you discover how to make improvements to your seed quality management.