Question

Which of the following dyes is used for testing the viability of seeds?

• A. Safranine
• B. 2,6 dichlorophenol indophenols
• C. 2,3,5, triphenyl tetrazolium chloride
• D. Acridine

Hint:

The Tetrazolium test is often called the "quick test" or "TZ test".
A red stain indicates living, viable embryo tissues, whereas white or unstained regions represent dead, non-viable tissues.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Seed viability testing is crucial to determine if a seed batch is alive and capable of germination.
The Tetrazolium (TZ) test is a rapid biochemical method used to estimate seed viability by detecting metabolic activity.

Step 3: Detailed Explanation:
The chemical used in the Tetrazolium test is 2,3,5-triphenyl tetrazolium chloride (TTC).
When viable seeds absorb this colorless solution, active dehydrogenase enzymes involved in respiration transfer hydrogen ions to the TTC.
This reduction reaction converts the colorless TTC into an insoluble, stable red compound called triphenyl formazan.
Consequently, the living parts of the seed (the embryo) stain carmine red, while dead tissues remain unstained.
The other dyes listed, such as Safranine (histological stain) and Acridine (fluorescent dye), do not specifically test viability via respiratory pathways.

Step 4: Final Answer:
The dye used for testing seed viability is 2,3,5, triphenyl tetrazolium chloride, which corresponds to option (C).