Tetrazolium Chloride Seed Viability

Question 1

Describe seed viability as a collective term.

Answer 1

The proportion of seeds within a sample that have the ability to successfully germinate.

Question 2

State two reasons that seed viability testing is useful.

Answer 2

Labelling for faster distribution than waiting to complete germination tests.
Estimating seed viability and determining reasons for poor germination.

Question 3

Describe a tetrazolium test.

Answer 3

A biochemical test that differentiates living and dead tissues in seed embryos based on the activity of dehydrogenase enzymes.

Question 4

How does a tetrazolium test work (4 points)?

Answer 4

Upon imbibition, respiration will increase in viable seeds, increasing the activity of the dehydrogenase enzyme which release hydrogen ions.
Hydrogen ions reduce the colourless tetrazolium salt solution into a red chemical compound called formazan.
The formazan stains living cells red, dead cells remain colourless.
The intensity and pattern of the staining on the embryo indicate viability.