principles and development of test guidelines. introduction test guidelines represent an agreed and...

PRINCIPLES AND PRINCIPLES AND DEVELOPMENT OF TEST DEVELOPMENT OF TEST

GUIDELINES GUIDELINES

PRINCIPLES AND PRINCIPLES AND DEVELOPMENT OF TEST DEVELOPMENT OF TEST

GUIDELINES GUIDELINES

IntroductionTest Guidelines represent an agreed and harmonized approach for the examination of new varieties and should be the basis of the DUS test.

The Plant Variety Protection Board shall issue species-specific test guidelines for use in examining the distinctness, uniformity and stability of the plant samples subject of the application.

Why Test Guidelines necessary?• Prescribe the propagating material requirements

• Procedures for the conduct of tests

• Methods and observation

• Set of descriptors or table of characteristics

Composition of a Test Guidelines• Chapter I – Subject of these Guidelines• Chapter II – Material Required• Chapter III – Conduct of Tests• Chapter IV – Methods and Observations• Chapter V – Grouping of Varieties• Chapter VI – Characteristics and Symbols• Chapter VII – Table of Characteristics• Chapter VIII – Explanations on the Table of

Characteristics• Chapter IX – Literature• Chapter X – Technical Questionnaire

I. Subject of these Guidelines• Indicates what particular variety applies

these guidelines

II. Material Required• Quantity and quality of the seed required

for testing the variety.

III. Conduct of Tests

• Duration of Tests

• Testing place

• Conditions for conducting the

examination

• Test design

• Number of plants / Part of plants to

be examined

• Additional test

IV. Methods and Observation• Distinctness

Consistent DifferencesClear Differences

• Uniformity

• Stability

Sample Size Number of off-types allowed

1-5 0

6-35 1

36-82 2

83-137 3

138-198 4

199-262 5

V. Grouping of Varieties

• Select varieties of common knowledge

• Organize the growing trial so that similar varieties are grouped together

• CharacteristicsThe Table of characteristics should be used for assessing DUS

• NotesNumerical notes are given opposite the states of the different characteristics for electronic data processing.

VI. Characteristics and Symbols

• Legend:Asterisked characteristics (*)

Important characteristics and should always be examined for DUS.

Plus sign (+)See explanations of the Table

of Characteristics in Chapter VIII.

VI. Characteristics and Symbols

VII. Table of Characteristics

Results from a given genotype or combination of genotypesBe sufficiently consistent and repeatable in a particular environmentExhibit sufficient variation between varieties to be able to establish distinctnessBe capable of precise definition and recognitionAllow uniformity requirements to be fulfilledAllow stability requirements to be fulfilled

Selection of Characteristics

State of Expression of Characteristics

Qualitative characteristics – (QL)

Expressed in discontinuous statesAll states necessary to describe the full range of characteristicsSelf explanatory states

Not influenced by environment

Example: Sex of plant: female (1)male (2)

Quantitative characteristics – (QN)

Expression can be recorded on a one-dimensional scaleContinuous variation from one extreme to the otherThe range of expression can be divided into number of states of expression

Example: Length of stem: short (3) – medium (5) –

long (7)

Quantitative to Qualitative characteristics(QN)

Quantitative- ColorYellow (1); Green (2); pink (3)

Quantitative- Only yellow and pink varieties: Intensity of color

weak (3); medium (5); strong (7)

Pseudo Qualitative characteristics – (PQ)

Range of expression to be at least partly continuous but in more than one dimensionCannot be adequately described by defining two ends of a linear rangeEach individual state of expression needs to be identified to adequately describe the range of the characteristics

Example: Shape: ovate (1) – elliptic (2) – circular (3) - obovate

(4)

DIVISION OF RANGE OF EXPRESSION INTO STATES AND NOTES (1)

• The usual range or note is “1-9”

• As a general rule, states are formed in such a way that for the weak and strong expressions, a reasonable word pair is chosen. For example:

•Weak/strong

•Short/long

•Small/large

•Narrow/?

DIVISION OF RANGE OF EXPRESSION INTO STATES AND NOTES (2)

Note State

1 very weak or absent or very weak

2 very weak to weak

3 weak

4 weak to medium

5 medium

6 medium to strong

7 strong

8 strong to very strong

9 very strong

Note State

1 very small or absent or very small

2 very small to small

3 small

4 small to medium

5 medium

6 medium to large

7 large

8 large to very large

9 very large

DIVISION OF RANGE OF EXPRESSION INTO STATES AND NOTES (3)

Standard Range Version 1

State

1 very weak or absent or very weak

3 weak

5 medium

7 strong

9 very strong

Standard Range Version 2

State

1 very weak or absent or very weak

3 weak

5 medium

7 strong

- -

DIVISION OF RANGE OF EXPRESSION INTO STATES AND NOTES (4)

Standard Range Version 3

State

- -

3 weak

5 medium

7 strong

9 very strong

Standard Range Version 4

State

- -

3 weak

5 medium

7 strong

- -

•Botanical Order

Seeds (submitted)SeedlingsWhole plantRootStemLeafInflorescenceFlower (calyx, sepal, corolla, petal, stamen, pistil)Fruit or grain (harvested material)

Order of Characteristics

From weak to strong

From light to dark

From low to high

From narrow to broad

Order of states of expression

Criteria for Example Varieties

• Availability

• Provide a clear example of the state and range

of expression

• Used many characteristics as possible and

should not be used only for one or very few

characteristics

• Should be proposed and agreed by the

examiners.

VIII. Explanation on the Table of Characteristics

•Explanations covering several and individual characteristics in the Table of Characteristics

IX. Literature

X. Technical Questionnaire

•To be completed by the applicant

•To be submitted to the PVP office together with the application form

•Provide relevant information for conducting the DUS trial

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TOMATO NATIONAL

TEST GUIDELINE