Checking seed quality

Visual checking of seeds can give us an indication that they may not germinate.

MSB xray machine

X-raying a sample of seeds can show how many are empty or damaged (Image: RBG Kew)

Whilst visual examination of a seed cannot tell us that a seed is capable of germination, it can give us an indication that the seed will not germinate. Following seed cleaning, we look for empty or incompletely-formed seeds and those that have been damaged by insects. Seeds that are empty or where insects have damaged key parts of the seed embryo are ‘incompetent’ and will not germinate.

The checks are carried out on a small sub-sample of the main collection either by X-ray analysis or by means of a cut-test. If either method reveals a high proportion of ‘incompetent’ seeds then it may be possible to reduce the proportion by re-cleaning.

If ‘incompetent’ seeds cannot be removed from the collection, the proportion that are capable of germination is recorded to help interpret the results of germination testing. For instance, if there are 50% incompetent seeds in a seed collection yet 50% germinate, then 100% of the competent seeds germinated. This makes sense when monitoring seed viability and understanding seed physiology. It would make less sense in the commercial world where germination needs to reflect the status of the entire collection purchased.

Find out more about X-ray analysis

Saving seeds

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