Question

Write notes on Central seed testing laboratory.

Answer 1

Seed testing is performed for a number of reasons, including research purposes or to determine if seed storage techniques are functioning. There are four tests most commonly done. The first two listed below are common for scientific research.

For commercially sold seed, all four of these tests are done in dedicated laboratories by trained and usually certified analysts. The tests are designed to evaluate the quality of the seed lot being sold.[1]

Germination test : Reports the percentage of seed that germinated. In commercial settings, tests are usually made in either 200 or 400 seed samples.

Viability test (TZ test): A test for viability that involves three steps:

1. preconditioning (imbibition)

2. preparation and staining (sometimes cutting the seed and then soaking the seed in a 2,3,5 triphenyl tetrazolium chloride solution)

Tetrazolim chloride seed testing: The Tetrazolium Chloride (TZ) test is often called the quick germination test. It’s a chemical test used to determine seed viability, and results are usually available within 24 to 48 hours.

How is the TZ Test Different From a Germination Test? The TZ test can give you an early and quick snapshot of seed viability but is not a replacement for the more comprehensive seed germination test. In Canada, the TZ test is not officially recognized by the CFIA (except for western wheatgrass where the TZ result may be added to the germination for a final germination total). In the United States, the TZ test can be used as a replacement for a germination test, although a follow-up germination test is usually recommended.

Why do a TZ Test?

Advantages of the TZ test are:

A rapid evaluation of seed viability.

Detect seed weaknesses before they become evident in germination tests.

Timely guidance in quality control programs.

Disadvantages of the TZ test are:

Requires specialized training and experience.

Test is usually more laborious and tedious to perform than a germination test.

Test results do not reflect fungal infection or chemical damage.

Test results do not reflect dormancy.