The viability of seeds is tested by:

Viability of seeds can be known by two methods: (i) ability to germinate, (ii) testing their ability to respire. All viable seeds respire. This can be tested by immersing a section of seed containing the embryo in $0.1 \%$ solution of triphenyl tetrazolium chloride. The viable embryo will turn pink due to conversion of colourless triphenyl tetrazolium chloride into insoluble coloured dye called triphenyl formazone due to reduction. Tetrazolium Chloride (TZ) test is also called as quick germination test. Related Theory Seed or plant viability is the measure of how many seeds or how much plant material in a lot are alive and could develop into plants that will reproduce under appropriate field conditions. It is very important that seeds or plant material stored in the gene bank are capable of producing plants when sown in the field. They must have high viability at the start of storage and maintain it during storage, as it will stored for a longer period of time.