A new method for inducing breeding materials of rubber tree based on budding

Abstract

The application provides a new rubber tree breeding material induction method based on budding, comprising the following steps: S1, selection of rootstock varieties and scion varieties; S2, juvenile of the rootstock varieties and the scion varieties; S3, preparation of the rootstock and the scion; S4, budding; S5, screening of the budding mutation material: phenotype identification screening, stress resistance identification screening or molecular identification screening; the application selects rubber tree varieties with complementary traits as the rootstock and the scion, effectively improves overall traits, gradually induces target traits of the scion through multiple budding of the juvenile bud strip, effectively optimizes the target traits, and improves trait stability; the target budding mutation plant is quickly and accurately screened through molecular identification screening, stress screening and phenotype identification screening, the new variety breeding process is accelerated, the breeding period is shortened, and the thought for creating and widening new rubber tree breeding materials is widened.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of crop cultivation, in particular to a new rubber tree breeding material induction method based on budding. BACKGROUND

[0002] Budding technology is an important asexual propagation method in rubber tree seedling breeding, which combines the excellent traits of scion and stock, can accelerate the propagation of excellent varieties and maintain the stability of varieties. By selecting appropriate scion and stock, budding technology can not only improve the growth rate of rubber tree, but also is beneficial to the stability of traits and maintain excellent economic traits. In production, the first puffy leaf of the budding seedling will show the phenotypic traits of the scion and the stock, indicating that the stock has a significant effect on the traits of the scion. In theory, the stock and the scion will transmit genetic information in the form of miRNA, transport protein, etc. In addition, during the fusion development of the cambium at the joint between the stock and the scion, some stock cells may be embedded in the scion tissue to form chimeras. The above phenomena and theories provide a basis for inducing variation of the scion through budding technology. Through budding, breeders can improve part of the traits of the scion variety in a short period of time, shorten the breeding cycle, and ensure that the excellent traits of the scion variety are inherited.

[0003] However, at present, how to select appropriate scion and stock combination for rubber tree breeding, improve budding technology, and purposefully induce variation of the traits of the scion variety, improve the comprehensive traits of the scion, and shorten the breeding cycle of new varieties is a technical problem that needs to be solved. SUMMARY

[0004] Therefore, the present application provides a new rubber tree breeding material induction method based on budding, which improves the comprehensive traits of existing varieties, shortens the breeding cycle of new varieties, and broadens the ideas for rubber tree breeding new materials.

[0005] The technical scheme of the present application is implemented as follows:

[0006] A new rubber tree breeding material induction method based on budding, the specific steps comprising:

[0007] S1, selection of stock variety and scion variety: selecting rubber tree varieties with complementary traits as stock variety and scion variety;

[0008] The "trait complementation" of the present application refers to that a rubber tree variety with excellent main traits (such as fast growth, high yield, etc.) but obvious defects in one or a few traits (such as cold tolerance) can be used as a scion variety, and a variety with excellent complementary traits (such as cold tolerance) of the scion variety is used as a stock variety. For example, the variety Reyan 879 has excellent yield traits but poor cold tolerance, and the variety 93114 has excellent cold tolerance but low yield. In this case, Reyan 879 can be used as a scion variety, and 93114 can be used as a stock variety.

[0009] S2, juvenile of the stock variety and the scion variety: when the stock variety or the scion variety is a non-juvenile bud cutting, juvenile is performed, specifically as follows:

[0010] (1) seedlings are cultivated from rubber tree seeds, 1-2 year old seedlings are used as stocks, and bud pieces on branches of the rubber tree variety to be juvenile are used as scions;

[0011] (2) bud grafting is performed, the main stem of the stock is sawed off after the bud pieces survive, the bud pieces germinate and grow into bud cuttings, the third and subsequent bud pieces on the bud cuttings are used as scions, 1-2 year old seedlings are used as stocks to perform bud grafting again, the above process is repeated for 3-4 times, and juvenile bud cuttings of the stock variety or the scion variety are obtained;

[0012] S3, preparation of the stock and the scion: specifically as follows:

[0013] (1) seedlings are cultivated from rubber tree seeds, 1-2 year old seedlings are used as stocks, and the third and subsequent bud pieces on the juvenile bud cuttings of the stock variety in step S2 are used as scions;

[0014] (2) bud grafting is performed, the main stem of the stock is sawed off, the bud pieces germinate and grow into bud cuttings, and the fourth and subsequent leaves on the bud cuttings are used as intermediate stocks for bud grafting mutagenesis;

[0015] (3) the third and subsequent bud pieces on the juvenile bud cuttings of the scion variety in step S2 are used as scions for bud grafting mutagenesis;

[0016] S4, bud grafting: the scions for bud grafting mutagenesis in step S3(3) are grafted on the main stem of the intermediate stocks for bud grafting mutagenesis in step S3(2), the main stem of the intermediate stock is sawed off after the bud pieces survive, the bud pieces germinate and grow into the first leaf, the bud pieces of the first leaf are grafted on the main stem of the intermediate stock for bud grafting mutagenesis in step S3(2), and the above process is repeated for 3-5 times, and candidate bud grafting mutagenesis plants are obtained;

[0017] S5, screening of the bud grafting mutagenic material: the candidate bud grafting mutagenic plant obtained in step S4 is subjected to phenotype identification screening, stress identification screening or molecular identification screening, and when the bud grafting mutagenic plant meeting the phenotype identification screening, stress identification screening or molecular identification screening is used as the bud grafting mutagenic breeding material for breeding new rubber tree varieties.

[0018] Further, in steps S2(2) and S3(2), the position for bud grafting is the main stem of the intermediate stock at 5-10 cm from the ground.

[0019] Further, in steps S2(2), S3(2) and S4, the position for sawing off the main stem of the stock is 5-10 cm above the bud piece.

[0020] Further, in step S4, the position for the bud grafting mutagenic scion to be bud grafted on the main stem of the intermediate stock in step S3(2) is the main stem above the third leaf; and the position for the bud piece of the first leaf to be bud grafted on the main stem of the intermediate stock in step S3(2) is the main stem above the third leaf.

[0021] Further, in step S5, the specific steps for the phenotype identification screening are as follows:

[0022] (1) The candidate bud grafting mutagenic plant is planted in a field, and the scion variety plant and the stock variety plant are used as the control plants;

[0023] (2) After the fifth leaf of the candidate bud grafting mutagenic plant and the control plants grows, the phenotype trait test is performed according to the Appendix A1 Basic Traits of Rubber Tree (including 31 traits such as leaf shape, leaf greenness, leaf glossiness, etc.) and the Appendix A2 Selected Traits of Rubber Tree (including 3 traits such as latex water dry rubber content, powdery mildew resistance, anthracnose resistance, etc.) of NY / T 2749-2015 Guide for Testing Specificity, Uniformity and Stability of New Plant Varieties Rubber Tree;

[0024] (2) After the fifth leaf of the candidate bud grafting mutagenic plant and the control plants grows, the phenotype trait test is performed according to the Appendix A1 Basic Traits of Rubber Tree (including 31 traits such as leaf shape, leaf greenness, leaf glossiness, etc.) and the Appendix A2 Selected Traits of Rubber Tree (including 3 traits such as latex water dry rubber content, powdery mildew resistance, anthracnose resistance, etc.) of NY / T 2749-2015 Guide for Testing Specificity, Uniformity and Stability of New Plant Varieties Rubber Tree;

[0025] (3) If the phenotype trait of the candidate bud grafting mutagenic plant meets any one of (a)-(c), it is the target bud grafting mutagenic plant;

[0026] (a) simultaneously having the specific traits of the scion variety plant and the stock variety plant;

[0027] (b) having the traits between the specific traits of the scion variety plant and the stock variety plant;

[0028] (c) having obvious change in the traits relative to the scion variety plant.

[0029] Further, in step S5, the specific steps of the stress resistance identification screening are:

[0030] (1) The candidate bud grafting mutagenesis plant is propagated by bud grafting, and the scion variety plant and the rootstock variety plant are used as control plants;

[0031] (2) Any one or simultaneous stress treatment such as simulated low temperature, drought or wind blowing is carried out in an artificial climate chamber, and the phenotypic changes of the candidate bud grafting mutagenesis plant and the control plants are observed;

[0032] (3) If the candidate bud grafting mutagenesis plant and the control plants show obvious difference after stress treatment, it is the target bud grafting mutagenesis plant.

[0033] Further, in step S5, the specific steps of the molecular identification screening are: the leaves of the candidate bud grafting mutagenesis plant, the scion variety and the rootstock variety are selected, DNA is extracted, the molecular marker primers with obvious polymorphism of the scion variety and the rootstock variety are selected, PCR amplification is carried out, and the polymorphism of the product is detected, when the PCR product of the candidate bud grafting mutagenesis plant has the molecular marker polymorphism of the scion variety and the rootstock variety at the same time, it is the target bud grafting mutagenesis plant.

[0034] Further, the molecular marker primers include SSR, SNP and MNP, but are not limited thereto.

[0035] Further, in step S5, the rubber tree new variety breeding is carried out according to the NY / T 607-2018 Rubber Tree Breeding Technical Regulations.

[0036] Compared with the prior art, the beneficial effects of the present application are:

[0037] The rubber tree breeding new material induction method based on bud grafting of the present application effectively improves the overall scion variety traits by selecting rubber tree varieties with complementary traits as rootstock and scion, effectively optimizes the scion traits and improves the trait stability by juvenile bud strip and multiple bud grafting, and quickly and accurately selects the target bud grafting mutagenesis plant by molecular identification screening, stress resistance identification screening and phenotypic identification screening, accelerates the new variety breeding process and shortens the breeding cycle. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 It is a bud grafting juvenileization diagram of the juvenile rootstock of the present application.

[0039] Figure 2 It is a bud grafting diagram of the scion variety and the rootstock variety of the present application.

[0040] Figure 3 It is a scion growth diagram after bud grafting of the scion variety and the rootstock variety of the present application. DETAILED DESCRIPTION

[0041] In order to better understand the technical content of the present application, the following specific examples are provided to further illustrate the present application.

[0042] The experimental methods used in the embodiments of the present application are all conventional methods unless otherwise specified.

[0043] The materials, reagents, etc. used in the embodiments of the present application can be obtained from commercial channels unless otherwise specified.

[0044] The "complementary traits" of the present application refers to that the rubber tree variety with excellent main traits (such as fast growth, high yield, etc.) but obvious defects in one or a few traits (such as cold tolerance) can be used as a scion variety, and the variety with excellent complementary traits (such as cold tolerance) of the scion variety is used as a rootstock variety, for example, the variety Reyan 879 has excellent yield traits but poor cold tolerance, and the variety 93114 has excellent cold tolerance but low yield, at this time, Reyan 879 can be used as a scion variety and 93114 can be used as a rootstock variety.

[0045] Example 1

[0046] A new material induction method for rubber tree breeding based on budding, the specific steps comprising:

[0047] S1, selection of rootstock variety and scion variety: selecting rubber tree varieties with complementary traits as rootstock varieties and scion varieties;

[0048] S2, juvenile of rootstock variety and scion variety: when the rootstock variety or the scion variety is a non-juvenile bud, juvenile is performed, specifically:

[0049] (1) cultivating seedlings from rubber tree seeds, using 1-year-old seedlings as rootstocks, and using bud pieces on the branches of the rubber tree variety to be juvenile as scions;

[0050] (2) budding on the main stem of the rootstock 8 cm from the ground, after the bud piece survives, sawing off the main stem of the rootstock from 5 cm above the bud piece to make the bud piece sprout and grow into a bud, and after the third leaf of the bud sprouts, using the third leaf and the bud pieces above it as scions, and using 1-year-old seedlings as rootstocks to perform budding again;

[0051] (3) repeating the process of step (2) for 3 times to obtain juvenile buds of the rootstock variety or the scion variety;

[0052] S3, preparation of rootstock and scion: specifically:

[0053] (1) cultivating seedlings from rubber tree seeds, using 1-year-old seedlings as rootstocks, and using the third leaf and the bud pieces above it on the juvenile bud of the rootstock variety in step S2 as scions;

[0054] (2) cutting the main stem of the stock plant 10 cm above the bud piece, allowing the bud piece to sprout and grow into a bud shoot;

[0055] (3) when the bud shoot grows to the fourth leaf and above, taking the bud piece of the third leaf and above of the bud shoot of the step S2 as the scion for bud grafting mutagenesis;

[0056] S4, bud grafting: bud grafting the scion of step S3(3) on the main stem of the intermediate stock plant of step S3(3) above the third leaf, after the bud piece survives, cutting the main stem of the intermediate stock plant 10 cm above the bud piece, allowing the bud piece to sprout and grow into a first leaf, and bud grafting the bud piece of the first leaf on the main stem of the intermediate stock plant of step S3(3) above the third leaf, repeating the above process 4 times to obtain a candidate bud grafting mutagenesis plant;

[0057] S5, phenotype identification and screening of the bud grafting mutagenesis material:

[0058] (1) planting the candidate bud grafting mutagenesis plant in a field, taking the scion variety plant and the stock variety plant as control plants;

[0059] (2) when the candidate bud grafting mutagenesis plant and the control plants grow to the fifth leaf, performing phenotype trait testing according to the NY / T2749-2015 Plant New Variety Specificity, Consistency and Stability Test Guide Rubber Tree;

[0060] (3) if the phenotype traits of the candidate bud grafting mutagenesis plant meet any one of (a)-(c), it is the target bud grafting mutagenesis plant;

[0061] (a) having the specific traits of both the scion variety plant and the stock variety plant;

[0062] (b) having traits between the specific traits of the scion variety plant and the stock variety plant;

[0063] (c) having obvious changes in traits relative to the scion variety plant.

[0064] S6, stress identification and screening of the bud grafting mutagenesis material:

[0065] (1) bud grafting propagation of the candidate bud grafting mutagenesis plant, taking the scion variety plant and the stock variety plant as control plants;

[0066] (2) performing any one or simultaneous stress treatment of simulated low temperature, drought or wind blowing in an artificial climate chamber, and observing the phenotype changes of the candidate bud grafting mutagenesis plant and the control plants;

[0067] (3) If the candidate bud grafting mutagenesis plant and the control plant show obvious difference after stress treatment, it is the target bud grafting mutagenesis plant.

[0068] S7, molecular identification screening of bud grafting mutagenesis material: selecting the leaves of the candidate bud grafting mutagenesis plant, the scion variety and the rootstock variety, extracting DNA, selecting molecular marker primers (including but not limited to SSR, SNP, MNP, etc.) with obvious polymorphism of the scion variety and the rootstock variety, performing PCR amplification, and detecting the polymorphism of the product, when the PCR product of the candidate bud grafting mutagenesis plant has the molecular marker polymorphism of the scion variety and the rootstock variety at the same time, it is the target bud grafting mutagenesis plant;

[0069] When the bud grafting mutagenesis plant meets any one of S5, S6 or S7, it can be used as a bud grafting mutagenesis breeding material, and the breeding of a new rubber tree variety is carried out according to the "NY / T 607-2018 Rubber Tree Breeding Technical Regulations".

[0070] Example 2

[0071] A new material induction method for rubber tree breeding based on bud grafting, the specific steps comprising:

[0072] S1, selection of rootstock variety and scion variety: selecting rubber tree varieties with complementary traits as rootstock varieties and scion varieties;

[0073] S2, juvenile of rootstock variety and scion variety: when the rootstock variety or the scion variety is a non-juvenile bud, juvenile is performed, specifically:

[0074] (1) Rubber tree seed cultivation seedling, 2-year-old seedlings are used as rootstocks, and bud pieces on the branches of the rubber tree variety to be juvenile are used as scions;

[0075] (2) Bud grafting is performed on the main stem of the rootstock 5 cm from the ground, after the bud piece survives, the main stem of the rootstock is sawn off 8 cm above the bud piece, so that the bud piece germinates and grows into a bud, and after the third leaf of the bud grows out, the bud piece above the third leaf is used as a scion, and the 2-year-old seedling is used as a rootstock for bud grafting again;

[0076] (3) The process of step (2) is repeated 4 times to obtain the juvenile bud of the rootstock variety or the scion variety;

[0077] S3, preparation of rootstock and scion: specifically:

[0078] (1) Rubber tree seed cultivation seedling, 2-year-old seedlings are used as rootstocks, and bud pieces on the branches of the rubber tree variety to be juvenile are used as scions;

[0079] (2) The main stem of the stock plant 10 cm from the ground is grafted, the main stem of the stock plant is sawn off 10 cm above the bud piece, the bud piece is made to germinate and grow into a bud shoot, and the bud piece of the first leaf is grafted onto the main stem above the third leaf of the intermediate stock plant in the bud grafting mutagenesis in step S3(3) to repeat the above process three times to obtain a candidate bud grafting mutagenesis plant;

[0080] (3) When the bud shoot grows to the fourth leaf and above, the bud piece of the third leaf and above of the bud grafting mutagenesis plant is used as the scion for bud grafting mutagenesis;

[0081] S4, bud grafting: the scion for bud grafting mutagenesis in step S3(3) is grafted onto the main stem above the third leaf of the intermediate stock plant in the bud grafting mutagenesis in step S3(3), the bud piece is made to germinate and grow into a bud shoot, and the bud piece of the first leaf is grafted onto the main stem above the third leaf of the intermediate stock plant in the bud grafting mutagenesis in step S3(3) to repeat the above process three times to obtain a candidate bud grafting mutagenesis plant;

[0082] S5, phenotype identification screening of bud grafting mutagenesis material:

[0083] (1) The candidate bud grafting mutagenesis plant is planted in the field, and the scion variety plant and the stock variety plant are used as control plants;

[0084] (2) When the fifth leaf of the candidate bud grafting mutagenesis plant and the control plants grows, the phenotype trait test is carried out according to NY / T2749-2015 Plant New Variety Specificity, Consistency and Stability Test Guide Rubber Tree;

[0085] (3) If the phenotype trait of the candidate bud grafting mutagenesis plant meets any one of (a)-(c), it is the target bud grafting mutagenesis plant;

[0086] (a) has the specific traits of the scion variety plant and the stock variety plant;

[0087] (b) has traits between the specific traits of the scion variety plant and the stock variety plant;

[0088] (c) has obvious changes in the traits relative to the scion variety plant.

[0089] S6, stress identification screening of bud grafting mutagenesis material:

[0090] (1) The candidate bud grafting mutagenesis plant is grafted and propagated, and the scion variety plant and the stock variety plant are used as control plants;

[0091] (2) Any or simultaneous stress treatment such as simulated low temperature, drought or wind blowing is carried out in an artificial climate chamber, and the phenotypic changes of the candidate bud grafting mutagenesis plant and the control plants are observed;

[0092] (3) If the candidate bud grafting mutagenesis plant and the control plant show obvious difference after stress treatment, it is the target bud grafting mutagenesis plant.

[0093] S7, molecular identification screening of bud grafting mutagenesis material: selecting the leaves of the candidate bud grafting mutagenesis plant, the scion variety and the rootstock variety, extracting DNA, selecting molecular marker primers (including but not limited to SSR, SNP, MNP, etc.) with obvious polymorphism of the scion variety and the rootstock variety, performing PCR amplification, and detecting the polymorphism of the product, when the PCR product of the candidate bud grafting mutagenesis plant has the molecular marker polymorphism of the scion variety and the rootstock variety at the same time, it is the target bud grafting mutagenesis plant;

[0094] When the bud grafting mutagenesis plant meets any one of S5, S6 or S7, it can be used as a bud grafting mutagenesis breeding material, and the breeding of a new rubber tree variety is carried out according to the "NY / T 607-2018 Rubber Tree Breeding Technical Regulations".

[0095] Example 3

[0096] A new material induction method for rubber tree breeding based on bud grafting, the specific steps comprising:

[0097] S1, selection of rootstock variety and scion variety: selecting rubber tree varieties with complementary traits as rootstock varieties and scion varieties;

[0098] S2, juvenile of rootstock variety and scion variety: when the rootstock variety or the scion variety is a non-juvenile bud, juvenile is performed, specifically:

[0099] (1) cultivating seedlings from rubber tree seeds, taking 1-year-old seedlings as rootstocks, and taking bud pieces on the branches of the rubber tree variety to be juvenile as scions;

[0100] (2) bud grafting is performed on the main stem of the rootstock 5 cm from the ground, after the bud piece survives, the main stem of the rootstock is sawn off 8 cm above the bud piece, so that the bud piece germinates and grows into a bud, and after the third leaf of the bud grows out, the bud piece above the third leaf is used as a scion, and the 1-year-old seedling is used as a rootstock for bud grafting again;

[0101] (3) repeating the process of step (2) 3 times to obtain juvenile buds of the rootstock variety or the scion variety;

[0102] S3, preparation of rootstock and scion: specifically:

[0103] (1) cultivating seedlings from rubber tree seeds, taking 1-year-old seedlings as rootstocks, and taking bud pieces on the branches of the rubber tree variety to be juvenile as scions;

[0104] (2) cutting the main stem of the stock plant 8 cm above the bud piece, allowing the bud piece to sprout and grow into a bud shoot;

[0105] (3) when the bud shoot grows to the fourth leaf and above, taking the bud piece of the third leaf and above of the bud shoot of the step S2 as the scion for bud grafting mutagenesis;

[0106] S4, bud grafting: bud grafting the scion of step S3(3) on the main stem of the intermediate stock plant of step S3(3) above the third leaf, after the bud piece survives, cutting the main stem of the intermediate stock plant 8 cm above the bud piece, allowing the bud piece to sprout and grow into a first leaf, and bud grafting the bud piece of the first leaf on the main stem of the intermediate stock plant of step S3(3) above the third leaf, repeating the above process 5 times to obtain a candidate bud grafting mutagenesis plant;

[0107] S5, phenotype identification and screening of the bud grafting mutagenesis material:

[0108] (1) planting the candidate bud grafting mutagenesis plant in a field, taking the scion variety plant and the stock variety plant as control plants;

[0109] (2) when the candidate bud grafting mutagenesis plant and the control plants grow to the fifth leaf, performing phenotype trait testing according to the NY / T2749-2015 Plant New Variety Specificity, Consistency and Stability Test Guide Rubber Tree;

[0110] (3) if the phenotype traits of the candidate bud grafting mutagenesis plant meet any one of (a)-(c), it is the target bud grafting mutagenesis plant;

[0111] (a) having the specific traits of both the scion variety plant and the stock variety plant;

[0112] (b) having traits between the specific traits of the scion variety plant and the stock variety plant;

[0113] (c) having obvious changes in traits relative to the scion variety plant.

[0114] S6, stress identification and screening of the bud grafting mutagenesis material:

[0115] (1) bud grafting propagation of the candidate bud grafting mutagenesis plant, taking the scion variety plant and the stock variety plant as control plants;

[0116] (2) performing any one or simultaneous stress treatment of simulated low temperature, drought or wind blowing in an artificial climate chamber, and observing the phenotype changes of the candidate bud grafting mutagenesis plant and the control plants;

[0117] (3) if the candidate bud graft mutagenesis plant and the control plant show obvious difference after stress treatment, the target bud graft mutagenesis plant is obtained.

[0118] S7, molecular identification screening of bud graft mutagenesis material: selecting the leaves of the candidate bud graft mutagenesis plant, scion variety and rootstock variety, extracting DNA, selecting molecular marker primers (including but not limited to SSR, SNP, MNP, etc.) with obvious polymorphism of scion variety and rootstock variety, performing PCR amplification, and detecting the polymorphism of the product, when the PCR product of the candidate bud graft mutagenesis plant has the molecular marker polymorphism of the scion variety and the rootstock variety at the same time, the target bud graft mutagenesis plant is obtained;

[0119] When the bud graft mutagenesis plant meets any one of S5, S6 or S7, it can be used as a bud graft mutagenesis breeding material, and the new rubber tree variety is selected according to the “NY / T 607-2018 Rubber Tree Breeding Technical Regulations”.

[0120] Test example

[0121] The new rubber tree variety is selected by the bud graft-based rubber tree breeding new material induction method of embodiments 1-3, the time used for completing the selection of the new rubber tree variety is counted, and the bud graft mutagenesis rate is calculated.

[0122] The results are shown in Table 1.

[0123] Table 1

[0124]

[0125] As can be seen from Table 1, the rubber tree breeding new material induction method of the present application can significantly shorten the breeding cycle of new varieties, has a good bud graft induction rate, and can effectively improve the economic benefits of rubber trees.

[0126] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for inducing new breeding material of rubber tree based on bud grafting, characterized in that, The specific steps include: S1, selection of rootstock varieties and scion varieties: selecting rubber tree varieties with complementary traits as rootstock varieties and scion varieties; S2, juvenile of rootstock varieties and scion varieties: when the rootstock variety or the scion variety is a non-juvenile bud, juvenile is performed, specifically: (1) rubber tree seed cultivation seedlings, 1-2 year old seedlings are used as rootstocks, and bud pieces on the branches of rubber tree varieties to be juvenile are used as scions; (2) bud grafting is performed, after the bud pieces survive, the main stem of the rootstock is sawn off, the bud pieces germinate and grow into bud shoots, after the bud shoots grow into the third leaf, the bud pieces above the third leaf are used as scions, 1-2 year old seedlings are used as rootstocks to perform bud grafting again, the above process is repeated 3-4 times, and juvenile bud shoots of the rootstock variety or the scion variety are obtained; S3, preparation of rootstocks and scions: specifically: (1) rubber tree seed cultivation seedlings, 1-2 year old seedlings are used as rootstocks, and the bud pieces above the third leaf on the juvenile bud shoots of the rootstock variety in step S2 are used as scions; (2) bud grafting is performed, the main stem of the rootstock is sawn off, the bud pieces germinate and grow into bud shoots, and when the bud shoots grow into the fourth leaf and above, the intermediate rootstock for bud grafting mutagenesis is obtained; (3) the bud pieces above the third leaf on the juvenile bud shoots of the scion variety in step S2 are used as the scions for bud grafting mutagenesis; S4, bud grafting: the scions for bud grafting mutagenesis in step S3(3) are grafted on the main stem of the intermediate rootstock for bud grafting mutagenesis in step S3(2), after the bud pieces survive, the main stem of the intermediate rootstock is sawn off, the bud pieces germinate and grow into the first leaf, the bud pieces of the first leaf are grafted on the main stem of the intermediate rootstock for bud grafting mutagenesis in step S3(2) as scions, the above process is repeated 3-5 times, and candidate bud grafting mutagenesis plants are obtained; S5, screening of bud grafting mutagenesis materials: the candidate bud grafting mutagenesis plants obtained in step S4 are subjected to phenotype identification screening, stress resistance identification screening or molecular identification screening, when the bud grafting mutagenesis plants meet the phenotype identification screening, stress resistance identification screening or molecular identification screening, the bud grafting mutagenesis plants can be used as bud grafting mutagenesis breeding materials, and new rubber tree varieties are bred.

2. A method for inducing new breeding material of rubber tree based on bud grafting according to claim 1, characterized in that, In steps S2(2) and S3(2), the position for performing bud grafting is on the main stem of the rootstock 5-10 cm from the ground.

3. The method for inducing new breeding material of rubber tree based on bud grafting according to claim 1, characterized in that, In steps S2(2), S3(2) and S4, the position for sawing off the main stem of the rootstock is 5-10 cm above the bud pieces.

4. The method for inducing new breeding material of rubber tree based on bud grafting according to claim 1, characterized in that, In step S4, the position for grafting the scions for bud grafting mutagenesis in step S3(3) on the main stem of the intermediate rootstock for bud grafting mutagenesis in step S3(2) is on the main stem above the third leaf; and the position for grafting the bud pieces of the first leaf on the main stem of the intermediate rootstock for bud grafting mutagenesis in step S3(2) as scions is on the main stem above the third leaf.

5. The method for inducing new breeding material of rubber tree based on bud grafting according to claim 1, wherein, In step S5, the specific steps for phenotype identification screening are: (1) the candidate bud grafting mutagenesis plants are planted in a field, and the scion variety plants and the rootstock variety plants are used as control plants; (2) when the fifth leaf grows on the candidate bud grafting mutagenesis plants and the control plants, phenotype trait testing is performed according to NY / T 2749-2015 Plant New Variety Specificity, Consistency and Stability Test Guide Rubber Tree. (3) If the phenotypic traits of the candidate bud grafting mutagenesis plant meet any one of (a)-(c), it is the target bud grafting mutagenesis plant; (a) It has specific traits of both scion variety plants and rootstock variety plants; (b) It has traits between the specific traits of scion variety plants and rootstock variety plants; (c) It has obvious changes in traits relative to scion variety plants.

6. The method for inducing new breeding material of rubber tree based on bud grafting according to claim 1, wherein, In step S5, the specific steps of the stress resistance identification screening are: (1) Bud grafting propagation of the candidate bud grafting mutagenesis plant, with scion variety plants and rootstock variety plants as control plants; (2) Simulating low temperature, drought or wind blowing stress treatment in a phytotron, and observing the phenotypic changes of the candidate bud grafting mutagenesis plant and the control plants; (3) If the candidate bud grafting mutagenesis plant and the control plants show obvious differences after stress treatment, it is the target bud grafting mutagenesis plant.

7. A method for inducing new breeding material of rubber tree based on bud grafting according to claim 1, characterized in that, In step S5, the specific steps of the molecular identification screening are: selecting leaves of the candidate bud grafting mutagenesis plant, scion variety and rootstock variety, extracting DNA, selecting molecular marker primers with obvious polymorphism between the scion variety and the rootstock variety, performing PCR amplification, and detecting the polymorphism of the products. When the PCR products of the candidate bud grafting mutagenesis plant have both the molecular marker polymorphisms of the scion variety and the rootstock variety, it is the target bud grafting mutagenesis plant.

8. A method for inducing new breeding material of rubber tree based on bud grafting according to claim 7, characterized in that, The molecular marker primers include SSR, SNP and MNP.

9. The method for inducing new breeding material of rubber tree based on bud grafting according to claim 1, wherein, In step S5, the breeding of new rubber tree varieties is carried out according to the "NY / T 607-2018 Rubber Tree Breeding Technical Regulations".

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