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Evidence Guide: AHCSDT409 - Perform a tetrazolium test

Student: __________________________________________________

Signature: _________________________________________________

Tips for gathering evidence to demonstrate your skills

The important thing to remember when gathering evidence is that the more evidence the better - that is, the more evidence you gather to demonstrate your skills, the more confident an assessor can be that you have learned the skills not just at one point in time, but are continuing to apply and develop those skills (as opposed to just learning for the test!). Furthermore, one piece of evidence that you collect will not usualy demonstrate all the required criteria for a unit of competency, whereas multiple overlapping pieces of evidence will usually do the trick!

From the Wiki University

 

AHCSDT409 - Perform a tetrazolium test

What evidence can you provide to prove your understanding of each of the following citeria?

Prepare replicates for testing

  1. Draw seeds from the pure seed fraction for the number of replicates to be tested ensuring there is no selection of seed which may cause biased results
  2. Use safe work practices and personal protective equipment
Draw seeds from the pure seed fraction for the number of replicates to be tested ensuring there is no selection of seed which may cause biased results

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Use safe work practices and personal protective equipment

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Prepare seed and tetrazolium solution

  1. Pre-moisten seed under prescribed temperature and light conditions to reduce possibility of injury to seeds when puncturing or cutting and to enable penetration of the tetrazolium solution
  2. Remove sticky mucilage from seeds as necessary
  3. Expose seed tissue before staining as appropriate for the species being tested
  4. Keep seeds moist before testing
  5. Prepare tetrazolium solution using distilled water and add trace amounts of fungicide or antibiotics to solution if necessary for the species being tested
Pre-moisten seed under prescribed temperature and light conditions to reduce possibility of injury to seeds when puncturing or cutting and to enable penetration of the tetrazolium solution

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Remove sticky mucilage from seeds as necessary

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Expose seed tissue before staining as appropriate for the species being tested

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Keep seeds moist before testing

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Prepare tetrazolium solution using distilled water and add trace amounts of fungicide or antibiotics to solution if necessary for the species being tested

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Stain with tetrazolium solution

  1. Immerse seeds in tetrazolium solution
  2. Maintain test at a temperature within the range 20 to 40°C, and maintain low light levels to facilitate staining
  3. Increase duration of staining if temperatures below 30°C are used or decrease if higher temperatures are used
  4. Decant the solution at end of staining period, rinse seeds with water and keep damp
Immerse seeds in tetrazolium solution

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Maintain test at a temperature within the range 20 to 40°C, and maintain low light levels to facilitate staining

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Increase duration of staining if temperatures below 30°C are used or decrease if higher temperatures are used

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Decant the solution at end of staining period, rinse seeds with water and keep damp

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Evaluate test results

  1. Examine and evaluate each seed as viable or non-viable based on staining patterns applicable to the species being tested
  2. Count the number of seeds considered viable in each replicate
  3. Calculate the percentage of viable seed in each replicate and determine average percentage of viable seed across all replicates
Examine and evaluate each seed as viable or non-viable based on staining patterns applicable to the species being tested

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Count the number of seeds considered viable in each replicate

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Calculate the percentage of viable seed in each replicate and determine average percentage of viable seed across all replicates

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Finalise reporting and clean up

  1. Record and report results of test
  2. Collect and dispose of laboratory and hazardous waste
  3. Clean apparatus and equipment used in tetrazolium test and dispose of used chemicals and solutions safely
Record and report results of test

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Collect and dispose of laboratory and hazardous waste

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Clean apparatus and equipment used in tetrazolium test and dispose of used chemicals and solutions safely

Completed
Date:

Teacher:		 Evidence:

 

 

 

 

 

 

 

Assessed

Teacher: ___________________________________ Date: _________

Signature: ________________________________________________

Comments:

 

 

 

 

 

 

 

 

Instructions to Assessors

Evidence Guide

Element

Performance criteria

Elements describe the essential outcomes.

Performance criteria describe the performance needed to demonstrate achievement of the element.

1. Prepare replicates for testing

1.1 Draw seeds from the pure seed fraction for the number of replicates to be tested ensuring there is no selection of seed which may cause biased results

1.2 Use safe work practices and personal protective equipment

2. Prepare seed and tetrazolium solution

2.1 Pre-moisten seed under prescribed temperature and light conditions to reduce possibility of injury to seeds when puncturing or cutting and to enable penetration of the tetrazolium solution

2.2 Remove sticky mucilage from seeds as necessary

2.3 Expose seed tissue before staining as appropriate for the species being tested

2.4 Keep seeds moist before testing

2.5 Prepare tetrazolium solution using distilled water and add trace amounts of fungicide or antibiotics to solution if necessary for the species being tested

3. Stain with tetrazolium solution

3.1 Immerse seeds in tetrazolium solution

3.2 Maintain test at a temperature within the range 20 to 40°C, and maintain low light levels to facilitate staining

3.3 Increase duration of staining if temperatures below 30°C are used or decrease if higher temperatures are used

3.4 Decant the solution at end of staining period, rinse seeds with water and keep damp

4. Evaluate test results

4.1 Examine and evaluate each seed as viable or non-viable based on staining patterns applicable to the species being tested

4.2 Count the number of seeds considered viable in each replicate

4.3 Calculate the percentage of viable seed in each replicate and determine average percentage of viable seed across all replicates

5. Finalise reporting and clean up

5.1 Record and report results of test

5.2 Collect and dispose of laboratory and hazardous waste

5.3 Clean apparatus and equipment used in tetrazolium test and dispose of used chemicals and solutions safely

Required Skills and Knowledge

Element

Performance criteria

Elements describe the essential outcomes.

Performance criteria describe the performance needed to demonstrate achievement of the element.

1. Prepare replicates for testing

1.1 Draw seeds from the pure seed fraction for the number of replicates to be tested ensuring there is no selection of seed which may cause biased results

1.2 Use safe work practices and personal protective equipment

2. Prepare seed and tetrazolium solution

2.1 Pre-moisten seed under prescribed temperature and light conditions to reduce possibility of injury to seeds when puncturing or cutting and to enable penetration of the tetrazolium solution

2.2 Remove sticky mucilage from seeds as necessary

2.3 Expose seed tissue before staining as appropriate for the species being tested

2.4 Keep seeds moist before testing

2.5 Prepare tetrazolium solution using distilled water and add trace amounts of fungicide or antibiotics to solution if necessary for the species being tested

3. Stain with tetrazolium solution

3.1 Immerse seeds in tetrazolium solution

3.2 Maintain test at a temperature within the range 20 to 40°C, and maintain low light levels to facilitate staining

3.3 Increase duration of staining if temperatures below 30°C are used or decrease if higher temperatures are used

3.4 Decant the solution at end of staining period, rinse seeds with water and keep damp

4. Evaluate test results

4.1 Examine and evaluate each seed as viable or non-viable based on staining patterns applicable to the species being tested

4.2 Count the number of seeds considered viable in each replicate

4.3 Calculate the percentage of viable seed in each replicate and determine average percentage of viable seed across all replicates

5. Finalise reporting and clean up

5.1 Record and report results of test

5.2 Collect and dispose of laboratory and hazardous waste

5.3 Clean apparatus and equipment used in tetrazolium test and dispose of used chemicals and solutions safely

The candidate must be assessed on their ability to integrate and apply the performance requirements of this unit in a workplace setting. Performance must be demonstrated consistently over time and in a suitable range of contexts.

The candidate must provide evidence that they can:

prepare replicates for testing

prepare seed and tetrazolium solution

stain seeds with a tetrazolium solution

evaluate and report test results

record and report test results

clean apparatus and equipment used in test and dispose safely of used products

The candidate must demonstrate knowledge of:

calculations, tolerances and rounding results

enterprise and/or legal traceability requirements

enterprise standard operating procedures (SOPs)

interpretation and recording of test result, including simple calculations

relevant health, safety and environment requirements

seed biology

tetrazolium testing procedures

the role of the International Seed Testing Association (ISTA) and the ISTA Rules for Seed Testing

Range Statement