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
..\Test Guidelines\TG-Tomato as of 15Nov05.DOC
TOMATO NATIONAL
TEST GUIDELINE