LY/T 3207-2020Guidelines for the conduct of tests for distinctness, uniformity and stability (DUS) - Sweetgum(Liquidambar Linn.) (English PDF)

4.1 Test materials

4.1.1 The applicant for variety rights shall submit test materials that meet the specified quantity and quality at the specified time and place. From non-testing country or place for materials submitted by the district, the applicant must provide relevant documents such as customs and plant quarantine in accordance with relevant regulations on entry, exit and transportation.

4.1.2 The test materials submitted should be plants of more than 2 years old that are propagated by grafting, cutting or tissue culture.

The name of the rootstock used.

4.1.3 The number of test materials provided shall not be less than 10 plants.

4.1.4 The test materials provided must be plants that are free of pests and diseases and grow normally.

4.1.5 Except for the processing of materials permitted or required by the examination and approval authority, the submitted test materials shall not be subjected to any processing that affects the expression of traits.

Rationale. If it has been processed, details of the processing must be provided.

4.2 Test method

4.2.1 Test cycle

If the test conditions are met, at least one growth cycle should be tested.

4.2.2 Test location

The test should be carried out in the test base and laboratory designated by the approval agency.

4.2.3 Test conditions

The test should be carried out under the condition that the relevant characteristics of the test material can be fully expressed, and the selected test material should at least be determined at the test site Planted for more than 2 years.

4.2.4 Test design

4.2.4.1 Each test must be based on 10 plants, and the test materials should be planted in the same place as the standard varieties and similar varieties and environmental conditions.

4.2.4.2 If certain parts of the plant need to be extracted as samples for the test, the sample collection shall not affect the observation of the entire growth cycle of the test plant.

4.2.4.3 Unless otherwise stated, all observations must be made on 10 plants or materials taken from the same parts of 10 plants.

4.2.5 Test methods for similar traits

4.2.5.1 Plants (character numbers 1~6 in Table A.1 in Appendix A)

Select the normal growth test plants to visually observe the relevant traits from different angles. The surface morphology of the bark of the young tree and whether the wing is selected less than 10 years the plants are observed.

4.2.5.2 Branches in the current year (character numbers 7 to 8 in Table A.1 in Appendix A)

At the end of spring and early summer, the middle section of the mature branches of the test plant was selected as the test material.

4.2.5.3 Leaves (the serial numbers of traits in Table A.1 in Appendix A are 10-15, 18, 21-31)

Unless otherwise specified, the mature leaves of the middle section of the upper branch of the test plant are selected as the test material for leaf and petiole traits during the growing season.

4.2.5.4 Fruit sequence. (Character sequence number 32~34 in Table A.1 in Appendix A)

Only adult plants (above 10a) are tested, and the globular fruit sequence that grows normally on the upper part of the crown is selected as the test material during the fruit ripening period.

4.2.6 Test methods for individual traits

4.2.6.1 Branches of the current year. anthocyanin colored parts (character number 9 in Table A.1 in Appendix A) trait test method at the end of spring and early summer, the current year shoots at the top of the test plant were selected as the test material. Observe the anthocyanin colored parts of the branches of the year.

4.2.6.2 Leaf. main color of young leaves and main color of new leaves (character numbers 16 and 17 in Table A.1 in Appendix A) trait test method in spring, the young leaves on the top of the current year's shoots of the test plants are selected as the main color test materials for the young leaves, and the mature leaves at the bottom of the current year's shoots the main color of the new leaf. Observe the upper surface color of the leaf.

4.2.6.3 Leaf. main color in autumn (character number 19 in Table A.1 in Appendix A) Character test method when more than 70% of the leaves show a seasonal color change in autumn, the mature leaves on the top of the tree crown of the test plant are selected as the test.

Material, observe the color of the upper surface of the blade.

4.2.6.4 Leaf. secondary color (character number 20 in Table A.1 in Appendix A) trait test method

In summer, the new leaves that were completely unfolded in the middle section of the current shoots of the test plants were selected as test materials. Observe the upper surface color of the leaf.

4.2.6.5 Phenological stage. the sprouting stage (the character number 35 in Table A.1 in Appendix A) character evaluation method in early spring, select the winter buds at the top of the shoots in the middle and upper part of the tree crown of the plant for observation. When 30% of the bud scales of the winter buds begin to split, they are leaf buds Budding period.

4.2.6.6 Phenological period. the initial period of autumn leaf discoloration (the character number 36 in Table A.1 in Appendix A) character evaluation method Observation of the sun canopy of the test plants in autumn, the date when 10% of the leaves change color is the beginning of autumn leaves change color.

4.2.6.7 Phenological phase. the duration of autumn leaves (the character number 37 in Table A.1 in Appendix A) character evaluation method in the fall, when 90% of the leaves on the canopy of the test plants fall off, it is the end of leaf fall.

4.2.6.8 Phenological stage. the end of deciduous stage (character number 38 in Table A.1 in Appendix A) trait evaluation method in accordance with the test methods 4.2.6.7 and 4.2.6.8, from the beginning of autumn leaves to the end of autumn leaves, record the number of days from the beginning to the end.

4.2.7 Additional testing

For new hybrid varieties obtained through natural or artificial pollination, if the stability test is in doubt, the specificity and for consistency and stability testing, when necessary, additional testing can be performed using the traits in Table A.1 or the traits not listed in this guide.

5.1 Specificity

If the difference in traits is constant and significant, it is considered specific.

5.1.1 Constant difference

If the difference between the test material and similar species is very clear, only one growth cycle test is needed. In some cases due to environmental factors when the difference between the test material and the similar species is not clear due to the influence of, at least 2 or more growth cycles are required.

5.1.2 Significant difference

Evaluation of the specificity of quality traits. As long as there is a difference between the test material and similar varieties in one trait, it can be determined that the variety has specificity.

Specific evaluation of quantitative traits. the test material is different from similar varieties in at least 2 traits, or the 2 codes of 1 trait are different Different, it can be determined that the species has specificity.

Specific evaluation of false quality traits. the test material has at least 2 traits that are different from similar varieties, or 2 inconsistencies in 1 trait If the code is different, it can be determined that the variety has specificity.

5.2 Consistency

The consistency judgment adopts the heterogeneous plant method. According to the 1% population standard and 95% reliability probability, the maximum allowable rate of heterotypic plants among 10 observed plants the allowable value is 1.

5.3 Stability

5.3.1 The test materials of the applied variety meet the specificity and consistency requirements in the test, and the variety can be considered as stable.

5.3.2 In special circumstances or when there are doubts, it is necessary to pass the test for 1 growth cycle again, or the applicant shall provide new test materials.

Test whether it expresses the same characteristics as the previously provided test materials.

6.1 Variety group description

Determine the grouping of test materials based on the grouping characteristics, and select similar varieties to be included in the specific growth test.

6.2 Grouping traits

6.2.1 Plant. The status of the main stem or side branches of the saplings (Characteristic No. 5 in Appendix A1).

6.2.2 Leaf. the number of lobes (character feature number 21 in Appendix A1).

7.1 Types of traits

7.1.1 Asterisk traits (the traits marked with "(*)" in Table A.1 of Appendix A). refer to the unification of trait descriptions during the review of new varieties for important variety traits used, all "star traits" should be tested when testing.

7.1.2 Plus sign traits (see the traits marked with "()" in Table A.1 in Appendix A). Refer to the performance of the traits in Appendix A1 Illustrated features (see Appendix A2).

7.2 Express status and code

The character description in Table A.1 in Appendix A has clearly given the standard definition of the expression state of each character, in order to facilitate the analysis of the expression state of the character.

Line description, analysis and comparison, each expression state has a corresponding digital code.

7.3 Expression types

GB/T 19557.1 provides the expression types of traits. qualitative traits (QL), quantitative traits (QN) and pseudo-qualitative traits (PQ) Explanation of terms.

7.4 Standard varieties

A variety used to accurately and vividly demonstrate the expression state of a certain trait.

7.5 Legend