Method for mass production of rubber tree seed grafting seedling scions and seed grafting seedlings

Abstract

The invention relates to the technical field of hevea brasiliensis seedling breeding, and particularly discloses a method for mass production of hevea brasiliensis seed grafted seedling scions and seed grafted seedlings. The method for mass production of rubber tree seed grafted seedling scions comprises the following steps: S1, sawing a trunk of a scion plant at a position 50-60 cm above the ground to promote new branches to grow; s2, primary branches are cut off when the primary branches of the plants to be picked grow to 10-15 cm, tops are cut off from dense node buds when the primary branches grow to second canopy leaves, fertilization is carried out, large leaf buds of new branches are promoted to germinate to form secondary branches, secondary branches are cut off when the secondary branches grow to 10-15 cm, and secondary branches are cut off when the secondary branches grow to 10-15 cm; the reserved secondary branches grow to form green small branches with more than two fluffy leaves; s3, pruning petioles of leaves on the green small branches to promote the petioles to fall off, and obtaining the rubber tree seed grafting seedling scion after the petioles fall off completely. By means of the method for mass production of the rubber tree seed grafted seedling scions, the number of the scions is remarkably increased and is 1.60-2.50 times that of a conventional method.

Description

Technical Field

[0001] The invention relates to the technical field of rubber tree seedling breeding, and in particular to a method for mass-producing rubber tree seed-grafted seedlings, scions and seed-grafted seedlings. Background Art

[0002] Good quality and strong seedlings are the foundation for the healthy development of the natural rubber industry. In my country, rubber tree seedling breeding has gone through four stages: bud grafted stake seedlings → bagged seedlings → seed grafted seedlings and seedling bud grafted seedlings → tissue culture seedlings. Seed grafted seedlings have the advantages of short seedling raising cycle, large seedling raising volume per unit area, ability to retain complete root system, fast recovery after planting, small size, light weight (1.5-1.8kg), and easy transportation, and have become the most widely used rubber planting material in production. They are especially popular in the renewal of mountain rubber plantations in Yunnan, accounting for about 60% of the rubber tree seedling market. As rubber tree growers have a deeper understanding of seed grafted seedlings, the proportion of seed grafted seedlings has been increasing year by year.

[0003] Select 3-4 week old seedlings with seeds as rootstocks, and use buds cultivated in field multiplication nurseries as scions. Perform bud grafting indoors. After bud grafting, transplant to a seedling bag filled with substrate. Remove the top of the rootstock and the rootstock buds to promote the germination of the grafted buds. After a short period of time (6-8 months), the bud grafted seedlings with 2-3 awns are cultivated as seed grafted seedlings. In conventional seed grafted seedling breeding, buds with full and uniform bud points and large scale buds in scions with 3-4 awns are usually selected for bud grafting. The utilization rate of the scion is low. In order to improve the utilization rate of the bud eyes, the leaves corresponding to the large leaf buds of each awn (except the top awn) in the scion are usually cut off 1-2 months before the production of seed grafted seedlings, so as to promote the shedding of petioles and obtain as many awn buds as possible, which can increase the utilization rate of the scion to 40-50%. However, when pruning the leaves, in order to meet the normal growth of the scion plants, part of the leaves of each awn need to be retained for photosynthesis. There are a large number of petiole buds in the scions cultivated by this method, accounting for about 35-45% of the total buds. However, because the scions are thicker (16.8-20.21 cm), the petiole buds are larger, and their size is difficult to match with the seedling stock. In addition, the petiole buds have a thicker and harder pulvinus, which makes them easy to slide during budding, making the operation inconvenient, and the contact with the stock is poor, resulting in a budding survival rate as low as 15-36%. Therefore, in the large-scale production of seed-grafted seedlings, petiole buds are not used, resulting in a waste of 35-45% of buds.

[0004] In addition, the rootstocks required for seed-grafted seedling production are 3-4 week old seedlings. During the budding period, fresh seeds need to be sown in batches to cultivate seedling rootstocks. Rubber tree seeds are very easy to germinate after they mature and fall off, and are difficult to preserve. They need to be collected, transported, and sown at the same time. The maturity period of rubber tree seeds is concentrated from September to November each year, and the budding period of seed-grafted seedlings is concentrated from September to December each year. The budding time is short and concentrated. In addition, the utilization rate of conventionally cultivated buds is low, and it is impossible to mass-produce seed-grafted seedlings to meet the current demand for seedlings for the renewal and transformation of the second-generation rubber plantations. In order to increase the production of rubber tree seed-grafted seedlings, many seedling breeding bases usually expand the area of ​​the proliferation nursery to expand more buds for production use, but the expansion of the proliferation nursery needs to be 2-3 years in advance, and the varieties of seedlings required by the market that year are determined by the environment of the rubber planting plots. The varieties of the expanded proliferation nursery are difficult to be consistent with the varieties required that year, resulting in a situation where the market does not need the varieties with abundant scions, while the varieties with high market demand are scarce. Moreover, the location of the propagation nursery must have convenient transportation, sufficient water resources, and be close to the seed and seedling production base. Expanding the propagation nursery will not only significantly increase production costs, but also make it difficult for the plants to take root.

[0005] Based on this, there is an urgent need for a method for mass production of rubber tree seed grafted seedlings and scion and seed grafted seedlings, which has a simple cultivation method, does not occupy more land, has a high scion utilization rate, bud grafting survival rate, germination rate, seedling rate and seed grafted seedling reproduction efficiency, and accelerates the application of rubber tree seed grafted seedlings in the renewal and transformation of second-generation rubber plantations, which is of great significance to ensuring the production capacity of second-generation rubber plantations. Summary of the invention

[0006] The object of the present invention is to overcome the deficiencies of the prior art and provide a method for mass-producing rubber tree seed-grafted scions and seed-grafted seedlings, so as to at least achieve higher scion utilization rate, budding survival rate, germination rate, nursery rate and seed-grafted seedling propagation efficiency.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] A method for mass-producing rubber tree seed seedlings and scions, comprising the following steps:

[0009] S1: saw the main trunk of the budding plant 50 to 60 cm above the ground to promote the growth of new branches;

[0010] S2: When the primary branches of the budding plants grow to 10-15 cm, the primary branches are cut off; when the primary branches grow the second fluffy leaves, the tops are cut off from the dense node buds, and fertilizer is applied to promote the germination of large leaf buds of the new branches to form secondary branches; when the secondary branches grow to 10-15 cm, the secondary branches are cut off, and the retained secondary branches grow to form green small branches with more than 2 fluffy leaves after 3-4 months of growth;

[0011] S3: 20 to 30 days before the seed-grafted seedling production, the petioles of the leaves on the green twigs are trimmed to promote the petioles to fall off, and when the petioles are completely fallen off and the top leaves are in a stable or sprouting stage or an elongation stage, the rubber tree seed-grafted scion is obtained.

[0012] Furthermore, the ear-collecting plant is selected from one of the asexual varieties of rubber trees, such as Yunyan 73-46, Yunyan 80-1983, and Yunyan 73-477.

[0013] Furthermore, in step S1, the sawing of the rod is carried out in April to May every year;

[0014] Furthermore, in step S1, urea is applied 2 to 4 days after the sawing to promote the germination of new buds;

[0015] Furthermore, in step S2, after the primary branches are cut off, 3 to 4 primary branches are retained on each trunk;

[0016] The close-node buds are lateral buds that grow in the axils of the smaller leaves on the upper part of the leaf canopy.

[0017] Further, in step S2, the fertilization is the application of nitrogen, phosphorus and potassium fertilizers;

[0018] Furthermore, in step S2, after the secondary branches are pruned, 2 to 3 secondary branches are retained for each primary branch.

[0019] Preferably, the primary branch pruning and the secondary branch pruning are performed by selecting weak, dense or drooping branches for pruning.

[0020] Furthermore, in step S3, the petiole pruning method is to prune the petiole of the leaf corresponding to the large leaf bud on the green twig until 1 / 2 to 3 / 4 of the petiole is retained, so as to promote the petiole to fall off naturally. Such a pruning method can avoid damage to the scion during the pruning process.

[0021] Another object of the present invention is to provide a method for mass production of seed-grafted seedlings, comprising the following steps: respectively selecting petiole leaf buds, de-petiole leaf buds and scale buds of the rubber tree seed-grafted seedling scions obtained by the above method for seedling bud grafting, then transplanting them into a seedling bag filled with a substrate, placing them in a seedling bed according to the type of buds, and cultivating them after conventional management for 6 to 8 months to obtain seed-grafted seedlings.

[0022] Preferably, the rootstock variety used for the budding is GT1.

[0023] The beneficial effects of the present invention are:

[0024] 1) The method for mass production of rubber tree seed seedlings and scion grafts provided by the present invention is simple to operate, extremely easy to master, and has no requirements on the professional technical level of the operator.

[0025] 2) The method for mass-producing rubber tree seed seedling scion provided by the present invention can significantly increase the number of scions, which is 1.60 to 2.50 times the number of scions in conventional methods.

[0026] 3) The method for mass-producing rubber tree seed-grafted scions and seed-grafted seedlings provided by the present invention can increase the number of buds by 35.0-38.0%, the utilization rate of buds by more than 90%, the budding survival rate by more than 79.0%, the germination rate by more than 96%, the nursery rate by 75-80%, and the seed-grafted seedling propagation efficiency by 55.0-60%, which is 20-26% higher than that of conventional methods, and solves the problem of low survival rate of budding of seedlings with petioles and leaf buds.

[0027] 4) The mass-produced seed-grafted seedlings of the present invention have good growth potential, with an average stem diameter of 4.10 to 4.60 mm and an average seedling height of 34.0 to 36.0 cm when they are planted, and they grow evenly. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 There are green twigs (A) and three types of buds: petiolate buds, depetiolate buds, and scale buds (B);

[0029] Figure 2 It is the process of budding seedlings with petiole leaf buds;

[0030] Figure 3 It is the process of budding seedlings with petioles removed and leaf buds grafted;

[0031] Figure 4 It is the process of scale bud seed grafting. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0033] Example

[0034] Experimental materials: The excellent clone variety 'Yunyan 73-46' of rubber tree in the field multiplication nursery was selected as the bud plants.

[0035] Test method:

[0036] (1) Sawing the stems: On April 20, 2023, the main branches of the plants collected from the field proliferation nursery were sawn 50 to 60 cm above the ground to promote the growth of new branches from the main stems. Two days after sawing the stems, 50 to 100 g of urea was applied to each plant to promote the germination of new buds. Water was applied once every two days to keep the surface soil moist.

[0037] (2) Pruning of new branches: When the primary branches growing from the main trunk of the ear-collecting plant grow to 10-15 cm, they are cut off so that each main branch retains 3-4 primary branches; when the primary branches grow to the second leaf, the tops are cut off from the dense node buds, and 50-100g urea and 60-120g compound fertilizer urea (N:P:K=15:15:15) are applied to each plant to promote the germination of large leaf buds of the primary branches to form secondary branches. When the secondary branches grow to 10-15 cm, they are cut off so that each primary branch retains 2-3 secondary branches. After 3 months of growth, the retained secondary branches will form green small branches with more than 2 leaves and a thickness of 9.27-10.25mm.

[0038] (3) Pruning petioles: 20 days before seed-grafted seedling production, prune the petioles of the sparse large leaves on the green twigs (at this time, the top leaves are in the sprouting stage, elongation stage, or leaf expansion stage) cultivated in step (2), retaining 1 / 2 to 3 / 4 of the petioles to promote petiole shedding.

[0039] (4) Selection of scion: Select the green buds obtained in step (3) whose petioles have completely fallen off and whose top leaves are in the stable, sprouting or elongation stage as scions for breeding seedlings.

[0040] Seed grafted seedling breeding method: select the petiole leaf buds, depetiole leaf buds and scale buds of the scion cultivated by the above method for seedling bud grafting, then transplant them into seedling bags filled with substrate, and place them in seedling beds according to the bud types. After 6 months of routine management, seed grafted seedlings are cultivated.

[0041] Comparative Example

[0042] Experimental materials: The excellent clone variety 'Yunyan 73-46' of rubber tree in the field multiplication nursery was selected as the bud plants.

[0043] Test method:

[0044] (1) Sawing: On April 20, 2023, the main branches of the plants collected from the field proliferation nursery were sawn 50 to 60 cm above the ground to promote the growth of new branches from the main trunk. Two days after sawing, 50 to 100 g of urea was applied to each plant to promote the germination of new buds. Water was applied once every two days to keep the surface soil moist.

[0045] (2) Pruning of new branches: When the primary branches growing from the main trunk of the ear-collecting plant grow to 10-15 cm, they are pruned off so that each main branch retains 3-4 primary branches. After 3 months of growth, the retained primary branches will form green branches with more than 3 leaves and a stem thickness of 11.0-22 mm.

[0046] (3) Pruning petioles: 20 days before bud grafting, prune the petioles of the sparse large leaves on the green branches (at this time, the top leaves are stable) cultivated in step (2), retaining 1 / 2 to 3 / 4 of the petioles to promote petiole shedding.

[0047] Seed grafted seedling breeding method: select the petiole leaf buds, depetiole leaf buds and scale buds of the scion cultivated by the above method for seedling bud grafting, then transplant them into seedling bags filled with substrate, and place them in seedling beds according to the bud types. After 6 months of routine management, seed grafted seedlings are cultivated.

[0048] Experimental example

[0049] During the implementation of the above embodiments and comparative examples, various growth data were collected to compare the breeding effects of seed-grafted seedlings, as follows:

[0050] Statistical results of stem thickness and quantity of scion: 20 scion plants of the embodiment and the comparative example were randomly selected for statistics, and the number of available scions and stem thickness of scion finally obtained from each scion plant were counted, as shown in Table 1. 25 scions cultivated by the embodiment and the comparative example were randomly selected, and the number of petiole-free leaf buds, petiole-bearing leaf buds and scale buds were counted, and the proportion of each bud piece was calculated, as shown in Table 2, and then the utilization rate, bud grafting survival rate, budding rate, nursery rate and seed grafting seedling breeding efficiency (bud piece proportion × bud piece utilization rate × bud grafting survival rate × budding rate × nursery rate) of different types of bud pieces were counted, as shown in Tables 3-7. When the seed grafted seedlings cultivated by the embodiment were transplanted, the growth of seed grafted seedlings in 4 production areas was randomly selected and counted, and the statistical results are shown in Table 8.

[0051] Table 1 Statistical results of scion stem diameter and number

[0052]

[0053] As can be seen from Table 1, the stem diameter of the scion cultivated by the present invention is significantly lower than that of the conventional method, with an average of only 10.24±0.88 mm, which is 6.46 mm thinner than the scion cultivated by the conventional method, and is more compatible with the size of the seedling rootstock; the method for mass production of scion for seed grafted seedlings of the present invention can significantly increase the number of scions, and the number of scions per scion plant is significantly more than that of the conventional method, with an average of 11.31±3.77 scions per plant, which is 1.74 times that of the conventional method.

[0054] Table 2 Proportion of different types of buds Unit: %

[0055]

[0056] Table 3 Utilization rate of different types of buds Unit: %

[0057]

[0058] It can be seen from Table 2 and Table 3 that the proportions of petiole buds, de-petiole buds and scale buds in the scion cultivated by the present invention and the conventional method are not much different, and the utilization rates of de-petiole buds and scale buds of the two methods are both above 90%, while the utilization rate of petiole buds is very different between the present invention and the conventional method, which is as high as 91.0±1.41% in the present invention, while that of the conventional method is only 38.98±0.12%, a difference of 52.02%.

[0059] Table 4 Survival rate of bud grafting of different types of buds Unit: %

[0060]

[0061] As shown in Table 4, the survival rate of seedling bud grafting of the scion cultivated by the present invention is good, with an overall mean of 81.04±0.53%, and the survival rate of bud grafting of the three types of buds is higher than 79%. The survival rate of seedling bud grafting of the scion cultivated by the conventional method is average, with an overall mean of 65.44±0.95%, which is 15.60% lower than that of the present invention, which is caused by the low survival rate of bud grafting of petiole leaf buds, which is only 34.13±2.64%, which is 46.73% lower than that of the present invention.

[0062] Table 5 Germination rate of seedlings inoculated with different types of buds Unit: %

[0063]

[0064] As shown in Table 5, the buds of the mass-produced seed-grafted scions of the present invention have better budding, with an overall mean of 98.28±0.01%, 11.26% higher than that of the conventional method, and the budding rates of the three types of buds are all above 96.00%. Among the scions of the conventional method, the budding effects of the petiole-free leaf buds and scale buds are better, both above 97.0%, which is equivalent to that of the present invention, while the budding effect of the petiole-withdrawn leaf buds is poor, with an average of only 63.34±4.72%, 34.01% lower than that of the present invention.

[0065] Table 6: The emergence rate of seedlings from different types of buds Unit: %

[0066]

[0067] Table 6 shows that the seed-grafted seedlings bred by the present invention have a higher emergence rate, with an overall mean of 77.01±0.55%, 22.01% higher than the conventional method. The biggest difference is the emergence rate of petiole buds, which is 76.60±0.30% in the present invention, while the conventional method is only 15.15±1.21%, a difference of 61.45%. Therefore, the petiole buds of scion cultivated by the conventional method are not suitable for mass production of seed-grafted seedlings.

[0068] Table 7 Seed-grafting propagation efficiency Unit: %

[0069]

[0070] As shown in Table 7, the method for mass production of rubber tree seed-grafted scions and seed-grafted seedlings provided by the present invention has a high seed-grafted seedling propagation efficiency, with an overall mean of 56.08±0.44%, which is 16.66% higher than that of the conventional method (39.42%).

[0071] It is worth noting that the leaf buds with petioles of the scion cultivated by the conventional method are large, which do not match the seedling rootstock, have poor survival, and have low germination rate and emergence rate. It is not used for mass production of seed-grafted seedlings. Therefore, the breeding efficiency of seed-grafted seedlings cultivated by the conventional method is much lower than that of this comparative example.

[0072] Table 8 Growth of seedlings in large-scale production when they are transplanted

[0073]

[0074] As can be seen from Table 8, the three types of buds of the scion cultivated by the present invention can be used to mass-produce seed-grafted seedlings, and the seed-grafted seedlings have good growth potential. When they are transplanted, the overall mean stem thickness of the seed-grafted seedlings is 4.26±0.20mm, and the overall mean seedling height is 33.64±1.51cm; among them, the growth potential of the seed-grafted seedlings with petioles and leaf buds is equivalent to that of the other two types of buds, with an average stem thickness of 4.32±0.27mm and an average seedling height of 34.57±0.95cm, which are only 0.05mm and 0.13cm less than those of the seed-grafted seedlings with petioles and leaf buds, respectively, and 0.21mm and 0.93cm more than those of the seed-grafted seedlings with scale buds.

[0075] In addition, it is worth noting that in conventional methods, leaf buds with petioles are not conducive to budding due to their large size, and the budding survival rate, germination rate and nursery rate are low. Therefore, various methods of reducing the volume of petioles and leaf buds to improve the budding survival rate are considered, but the results are not ideal, as follows:

[0076] (1) Manually screen out thin green twigs from the first-level branches as scions: First, manual screening requires a lot of manpower and is not worth the effort, and the buds on other relatively sturdy green branches cannot be effectively utilized, so they are of little practical value. In addition, the thin green twigs on the first-level branches are not suitable for the production of seed-grafted seedlings, because in the first-level branches, the green twigs are mostly drooping branches or bottom branches, and they cannot compete with the upright or upper branches for light and nutrition. The quality of the buds is poor, and the seedlings produced are weak. In addition, because these branches have been grown under hidden conditions for a long time, the phloem and xylem are not easy to separate during bud grafting, and the bud grafting operation is very difficult.

[0077] (2) Further cultivation on the basis of secondary branches: The tertiary branches are about 5.76-9.18 mm thick, matching the size of the seedling rootstock. However, the poles are sawn in April and May, and by September to December, most of the tertiary branches have only one leaf, which is the time for bud grafting of seed-grafted seedlings. Although there are many buds, each has only one leaf, and the number of available buds is very small, about 1 / 3 of the scion cultivated in the present invention. Therefore, it is not suitable to cultivate scions by cultivating the tertiary branches method when mass-producing seed-grafted seedlings.

[0078] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A method for mass-producing rubber tree seed grafting and scion grafting, characterized in that, The following steps are involved: S1: saw the main trunk of the budding plant 50 to 60 cm above the ground to promote the growth of new branches; S2: When the primary branches of the budding plants grow to 10-15 cm, the primary branches are cut off; when the primary branches grow the second fluffy leaves, the tops are cut off from the dense node buds, and fertilizer is applied to promote the germination of large leaf buds of the new branches to form secondary branches; when the secondary branches grow to 10-15 cm, the secondary branches are cut off, and the retained secondary branches grow to form green small branches with more than 2 fluffy leaves after 3-4 months of growth; S3: 20 to 30 days before the seed-grafted seedling production, the petioles of the leaves on the green twigs are trimmed to promote the petioles to fall off, and when the petioles are completely fallen off and the top leaves are in a stable or sprouting stage or an elongation stage, the rubber tree seed-grafted scion is obtained.

2. The method according to claim 1, characterized in that: The ear-collecting plant is selected from one of the asexual varieties of rubber trees, Yunyan 73-46, Yunyan 80-1983, and Yunyan 73-477.

3. The method according to claim 1, characterized in that: In step S1, the sawing of the rod is carried out in April and May every year.

4. The method according to claim 1, characterized in that: In step S1, urea is applied 2 to 4 days after the sawing to promote the germination of new buds.

5. The method according to claim 1, characterized in that: In step S2, after the primary branches are pruned, 3 to 4 primary branches are retained on each trunk.

6. The method according to claim 1, characterized in that: In step S2, the fertilization is the application of nitrogen, phosphorus and potassium fertilizers.

7. The method according to claim 1, characterized in that: In step S2, after the secondary branches are cut off, 2 to 3 secondary branches are retained for each primary branch.

8. A method for mass production of seed-grafted seedlings, characterized in that: The following steps are involved: The petiolate leaf buds, depetiolate leaf buds and scale buds of the rubber tree seed grafting scion obtained by the methods described in claims 1 to 7 are respectively selected for seedling bud grafting, and then transplanted into a seedling bag filled with a substrate, and placed in a seedling bed according to the type of buds. After conventional management for 6 to 8 months, the seed grafted seedlings are cultivated.

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