What is Seed Viability? – Definition
It is the capability of plant structure (seed, cuttings etc.) to show living properties like germination and growth. Viability testing is one of the major aspects of seed technology.
If germination test is conducted to test viability, it requires long period, because of which seed processing and marketing is delayed. Hence the rapid method used to estimate or predict the germination behavior of seed is TZ test. It estimates seed viability usually within 24 to 48 hours.
Tetrazolium Test or TZ test
It is a bio-chemical test. In this test, the indicator ‘TZ’ (a colorless solution of tetrazolium salt is used).
TZ dyes living parts of seed with red color, while dead parts appear colorless. Sometimes partial coloration is also observed.