Question

TZ test is used for testing _________

• A. Seed germibility
• B. Seed viability
• C. Seed moisture content
• D. Seed physical purity

Hint:

Remember the biochemistry of the TZ test:
- Colorless Tetrazolium \( \rightarrow \) Reduced by Dehydrogeses in living tissues \( \rightarrow \) Red Formazan stain.
This is the standard biochemical method for rapid seed viability determition.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
In nursery technology, seed testing is essential to evaluate seed quality before sowing.
Evaluating seed viability is crucial for estimating the germition capacity of a seed lot.

Step 2: Detailed Explation:
The Tetrazolium (TZ) test is a rapid biochemical test used to determine seed viability.
The test involves soaking seeds in a colorless solution of 2,3,5-triphenyl tetrazolium chloride.
This chemical interacts directly with active dehydrogese enzymes involved in cellular respiration in the living tissues of the seed embryo.
The dehydrogese enzymes reduce the colorless tetrazolium salt into an insoluble, stable red compound called formazan.
As a result, living, respiring tissues in the embryo stain a bright red color, while dead or non-viable tissues remain uncolored.
This test allows foresters to determine seed viability within 24 to 48 hours, which is particularly useful for dormant forest seeds that would otherwise take weeks or months to germite in standard germition tests.

Step 3: Fil Answer
Therefore, the TZ test is used to evaluate seed viability.