Presentation on theme: "PRINCIPLES AND DEVELOPMENT OF TEST GUIDELINES. Introduction Test Guidelines represent an agreed and harmonized approach for the examination of new varieties."— Presentation transcript:
Introduction Test 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 Differences Clear Differences Uniformity Stability Sample SizeNumber of off-types allowed 1-50 6-351 36-822 83-1373 138-1984 199-2625
V. Grouping of Varieties Select varieties of common knowledge Organize the growing trial so that similar varieties are grouped together
Characteristics The Table of characteristics should be used for assessing DUS Notes Numerical 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 genotypes Be sufficiently consistent and repeatable in a particular environment Exhibit sufficient variation between varieties to be able to establish distinctness Be capable of precise definition and recognition Allow uniformity requirements to be fulfilled Allow stability requirements to be fulfilled Selection of Characteristics
State of Expression of Characteristics Qualitative characteristics – (QL) Expressed in discontinuous states All states necessary to describe the full range of characteristics Self 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 scale Continuous variation from one extreme to the other The 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- Color Yellow (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 dimension Cannot be adequately described by defining two ends of a linear range Each 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) NoteState 1very weak or absent or very weak 2very weak to weak 3weak 4weak to medium 5medium 6medium to strong 7strong 8strong to very strong 9very strong NoteState 1very small or absent or very small 2very small to small 3small 4small to medium 5medium 6medium to large 7large 8large to very large 9very large
DIVISION OF RANGE OF EXPRESSION INTO STATES AND NOTES (3) Standard Range Version 1 State 1very weak or absent or very weak 3weak 5medium 7strong 9very strong Standard Range Version 2 State 1very weak or absent or very weak 3weak 5medium 7strong --
DIVISION OF RANGE OF EXPRESSION INTO STATES AND NOTES (4) Standard Range Version 3 State -- 3weak 5medium 7strong 9very strong Standard Range Version 4 State -- 3weak 5medium 7strong --
Botanical Order Seeds (submitted) Seedlings Whole plant Root Stem Leaf Inflorescence Flower (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..\Test Guidelines\TG-Tomato as of 15Nov05.DOC TOMATO NATIONAL TEST GUIDELINE