Method for promoting germination and seedling raising of cassava seeds

Abstract

The invention provides a method for promoting cassava seed germination and seedling raising, which comprises the following steps: screening healthy and full seeds, and exposing the seeds under the sun for 1-2 hours during germination acceleration; after the seeds are exposed in the sun, soaking the seeds for three times, namely soaking the seeds for the first time with water, soaking the seeds for the second time with a plant root accelerating agent and soaking the seeds for the third time with water again to obtain soaked cassava seeds; germination accelerating is conducted on the soaked cassava seeds at constant temperature, and seeds with white buds are selected to be cultivated and then moved into matrix soil to be cultivated. The matrix soil is prepared from fermented cassava residue powder, coco coir, garden soil and organic fertilizer. According to the method, the budding time is shortened, the cassava seeds are orderly budded, the seedling rate is high, the cassava cultivation period is shortened, and the survival rate and the seedling raising efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of crop cultivation, and particularly relates to a method for promoting the germination of cassava seeds and seedling raising. Background Art

[0002] The tuberous roots of cassava are rich in starch and are known as the "underground granary" and the "king of starch", and are important raw materials for feed and energy processing. Cassava is drought-tolerant and barren-tolerant, and has relatively loose requirements for planting conditions, and is a good food source for humans and other animals. In agricultural production, cassava is mainly propagated by stem cuttings, and the cultivation of new varieties is mainly by hybridization. Due to the low hybridization seed setting rate of cassava, difficult seed acquisition, and low seed germination rate, the cassava cross-breeding is restricted. A large number of studies have shown that the germination rate of untreated cassava seeds is less than 5%, and the germination rate can be adjusted to 30%-50% after special treatment; the special treatment methods include mechanical treatment, chemical drug soaking, etc. However, the mechanical treatment of seeds is relatively complex, time-consuming, and costly. Cassava, as an important food crop and industrial raw material, is widely planted in tropical and subtropical regions. However, the germination rate of cassava seeds and the seedling raising efficiency have always been the key factors restricting the cultivation of new cassava varieties. The traditional cassava seedling raising methods have many deficiencies, which are mainly manifested in the following aspects: inaccurate control of germination conditions: the traditional methods often rely on natural conditions such as temperature and humidity, which are difficult to accurately control, resulting in unstable germination rates and long seedling raising cycles; single seed treatment method: the traditional methods for treating cassava seeds are relatively simple, lacking effective pretreatment measures, which is not conducive to improving the germination rate and seedling quality; extensive seedling raising management: the traditional seedling raising management is extensive, lacking scientific seedling raising techniques and management measures, resulting in low seedling raising efficiency and uneven growth of seedlings. To sum up, the traditional cassava seedling raising methods have many deficiencies and are difficult to meet the needs of the development of the modern cassava industry. Therefore, developing a method for promoting the germination of cassava seeds and seedling raising is of great significance for improving the germination rate of cassava seeds and the seedling raising efficiency and promoting the sustainable development of the cassava industry. Summary of the Invention

[0003] In view of the above problems, this experiment proposes a method for improving the germination rate of cassava seeds and the survival rate of seedling raising, providing new technical support for cassava cross-breeding.

[0004] The technical solution of the present invention is realized as follows:

[0005] A method for promoting the germination of cassava seeds and seedling raising includes the following steps:

[0006] S1, screening healthy and plump seeds, and exposing them to the sun for 1-2 hours during germination;

[0007] S2. After the seeds are sun-dried, soak them three times. For the first time, soak them in water. For the second time, soak them in a plant quick-rooting agent. For the third time, soak them in water again to obtain soaked cassava seeds. The plant quick-rooting agent is prepared from the following raw materials: indolebutyric acid solution, seaweed oligosaccharide powder, chondracric acid powder, and potassium nitrate solution.

[0008] S3. Germinate the soaked cassava seeds at a constant temperature, select the seeds with white tips after germination, cultivate them, and then transfer them to the substrate soil for cultivation.

[0009] Further, in step S2, the plant quick-rooting agent includes indolebutyric acid solution, seaweed oligosaccharide powder, chondracric acid powder, and potassium nitrate solution in a mass ratio of 10-12:1-1.5:0.2-0.4:0.6-0.8.

[0010] Further, the concentration of the indolebutyric acid solution is 95-105 mg / L, and the mass concentration of the potassium nitrate solution is 0.08%-0.12%.

[0011] Further, in step S2, for the three soakings, for the first time, soak in water at 45-50 °C for 4-4.5 hours. For the second time, soak in the plant quick-rooting agent for 7-8 hours. For the third time, soak in water at 25-30 °C for 10-12 hours.

[0012] Further, in step S3, for the constant-temperature germination, the germination temperature is 28-32 °C, and the germination time is 9-10 days. For the cultivation of the seeds with white tips, place the seeds with white tips on a wet paper towel soaked with gibberellin, and cultivate them in a sealed and light-shielded environment. The mass-volume concentration of the gibberellin is 190-210 mg / L.

[0013] Further, in step S3, the cultivation time of the seeds with white tips is 48-52 hours, and the length of the germinated seed hypocotyl is 1-1.2 cm.

[0014] Further, in step S3, the composition of the substrate soil includes fermented cassava residue powder, coconut coir, garden soil, and organic fertilizer in a mass ratio of 5-6:5-6:2-3:1-2.

[0015] Further, the fermented cassava residue powder is obtained by crushing and fermenting fresh cassava stalks. The crushing diameter is 0.8-1.2 cm. The method for fermenting the cassava residue is anaerobic fermentation. Seal it with a plastic film for fermentation. After the fermentation temperature reaches 58-60 °C, turn it over. Turn it over once every 6-10 days, for a total of 3-4 times. After fermentation, use it to feed earthworms. After being decomposed by earthworms for 10-15 days, sieve it through a 40-mesh screen to obtain the fermented cassava residue powder.

[0016] Further, for the fermented cassava residue powder, the fermentation microorganisms are composed of Aspergillus niger and Pichia kluyveri. The mass ratio of the cassava residue powder, Aspergillus niger, and Pichia kluyveri is 45-50:1-2:4-6.

[0017] Furthermore, after the cassava residue powder is fermented, gypsum is added, and the addition amount of gypsum is 2%-5% of the mass of the cassava residue powder.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] (1) Improve the germination rate: The present invention adopts a specific germination promotion technology. By adjusting the pretreatment conditions of cassava seeds, such as temperature, humidity, and light, etc., it can effectively promote the germination of cassava seeds and improve the germination rate.

[0020] (2) Shorten the seedling raising period: The present invention optimizes the seedling raising management method, shortens the seedling raising period of cassava seeds, accelerates the growth rate of cassava, and improves the survival rate of cassava seedlings.

[0021] (3) Improve the planting success rate: Since the present invention can improve the germination rate of cassava seeds and shorten the seedling raising period, it can improve the planting success rate of cassava and reduce the risk of planting failure caused by poor seed germination. Description of the Drawings

[0022] Figure 1 : Growth diagram of cassava seeds in Example 1 for 15 days. In the figure, (a) is the seed soaking on the 0th day; (b) is the showing of white tips on the 4th day; (c) is the growth of radicle and hypocotyl on the 6th day; (d) is the transplanting of seedlings into cups on the 9th day; (e) is the growth of seedlings on the 15th day. Detailed Embodiments

[0023] To better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention. The experimental methods used in the embodiments of the present invention are all conventional methods unless otherwise specified.

[0024] The materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial channels unless otherwise specified.

[0025] Aspergillus niger: Product number TS280918, viable bacteria count greater than 15 billion CFU / g, microbial source: Shaanxi Institute of Microbiology, C20, purchased from Ningbo Taisituo Biotechnology Co., Ltd. Pichia kluyveri: Product number TS343290, viable bacteria count greater than 12 billion CFU / g, microbial source: Hunan Light Industry Research Institute, purchased from Ningbo Taisituo Biotechnology Co., Ltd.

[0026] Example 1

[0027] A method for promoting the germination and seedling raising of cassava seeds, comprising the following steps:

[0028] Step (1): Select healthy and plump seeds, and take them out to be exposed to the sun for 1 hour during germination.

[0029] Step (2): After the seeds are exposed to the sun, soak them three times. For the first soaking, soak them in water at 45°C for 4 hours; for the second soaking, soak them in a plant root-promoting agent for 7 hours. The plant root-promoting agent includes indolebutyric acid solution, seaweed oligosaccharide powder, chondrophycic acid powder, and potassium nitrate solution with a mass ratio of 10:1:0.2:0.6. The concentration of the indolebutyric acid solution is 95 mg / L, and the mass concentration of the potassium nitrate solution is 0.08%; for the third soaking, soak them in water at 25°C for another 10 hours to obtain soaked cassava seeds.

[0030] Step (3): Germinate the soaked cassava seeds obtained in step (2) at a constant temperature. The germination temperature is 28°C, and the germination time is 10 days. After constant-temperature germination, select the seeds with white tips, place the seeds with white tips on wet paper towels soaked with gibberellin, and cultivate them in a sealed and light-shielded environment. The mass-volume concentration of gibberellin is 190 mg / L, and the cultivation time is 48 hours. After cultivating until the hypocotyl length of the seeds reaches 1 cm, transfer them to the substrate soil for cultivation. The composition of the substrate soil includes fermented cassava residue powder, coconut coir, garden soil, and organic fertilizer with a mass ratio of 5:5:2:1. Among them, the fermented cassava residue powder is made from fresh cassava stalks crushed and fermented, with a crushing diameter of 0.8 cm. The fermentation method of cassava residue is anaerobic fermentation, sealed with plastic film for fermentation. After the fermentation temperature reaches 58°C, turn it over, turn it over once every 8 days, and turn it over a total of 3 times. After fermentation, use it to feed earthworms. After being decomposed by earthworms for 10 days, sieve it through a 40-mesh screen to obtain fermented cassava residue powder. The fermented microorganisms in the fermented cassava residue powder consist of Aspergillus niger and Pichia kluyveri, and the mass ratio of cassava residue powder, Aspergillus niger, and Pichia kluyveri is 45:1:4. Gypsum is added to the fermented cassava residue powder after fermentation, and the addition amount of gypsum is 2% of the mass of the cassava residue powder.

[0031] Example 2

[0032] A method for promoting the germination and seedling raising of cassava seeds, comprising the following steps:

[0033] Step (1): Select healthy and plump seeds, and take them out to be exposed to the sun for 2 hours during germination.

[0034] Step (2): After the seeds are exposed to the sun, soak them three times. For the first soaking, soak them in water at 50°C for 4.5 hours; for the second soaking, soak them in a plant root-promoting agent for 8 hours. The plant root-promoting agent includes indolebutyric acid solution, seaweed oligosaccharide powder, chondrophycic acid powder, and potassium nitrate solution with a mass ratio of 12:1.5:0.4:0.8. The concentration of the indolebutyric acid solution is 105 mg / L, and the mass concentration of the potassium nitrate solution is 0.12%; for the third soaking, soak them in water at 25°C for another 12 hours to obtain soaked cassava seeds.

[0035] Step (3): Germinate the soaked cassava seeds at a constant temperature. The germination temperature is 32 °C and the germination time is 10 days. After constant-temperature germination, select the seeds with white tips, place the seeds with white tips on wet paper towels soaked with gibberellin, and cultivate them in a sealed and light-shielded environment. The mass-volume concentration of gibberellin is 210 mg / L, and the cultivation time is 52 hours. After the seed hypocotyl length reaches 1.2 cm, transfer them to the substrate soil for cultivation. The composition of the substrate soil includes fermented cassava residue powder, coconut coir, garden soil, and organic fertilizer with a mass ratio of 6:6:3:2. Among them, the fermented cassava residue powder is made from fresh cassava stalks after crushing and fermentation. The crushing diameter is 1.2 cm. The method for fermenting cassava residue is anaerobic fermentation. Seal it with a plastic film for fermentation. After the fermentation temperature reaches 60 °C, turn it over once every 10 days, and turn it over a total of 3 times. After fermentation, it is used to feed earthworms. After being decomposed by earthworms for 11 days, it is sieved through a 40-mesh screen to obtain fermented cassava residue powder. The fermented microorganisms in the fermented cassava residue powder consist of Aspergillus niger and Pichia kluyveri. The mass ratio of cassava residue powder, Aspergillus niger, and Pichia kluyveri is 50:2:6. After the cassava residue powder is fermented, gypsum is added, and the addition amount of gypsum is 5% of the mass of the cassava residue powder.

[0036] Example 3

[0037] A method for promoting the germination and seedling raising of cassava seeds, comprising the following steps:

[0038] Step (1): Screen healthy and plump seeds, and take them out to be exposed to the sun for 1.5 hours during germination;

[0039] Step (2): After the seeds are exposed to the sun, soak them three times. For the first soaking, soak them in water at 46 °C for 4.3 hours; for the second soaking, soak them in a plant quick-rooting agent for 7.5 hours. Among them, the plant quick-rooting agent includes indolebutyric acid solution, seaweed oligosaccharide powder, chondrophycic acid powder, and potassium nitrate solution with a mass ratio of 11:1.2:0.3:0.7. The concentration of the indolebutyric acid solution is 100 mg / L, and the mass concentration of the potassium nitrate solution is 0.1%; for the third soaking, soak them in water at 28 °C for another 11 hours to obtain soaked cassava seeds;

[0040] Step (3): Germinate the soaked cassava seeds at a constant temperature. The germination temperature is 30°C and the germination time is 10 days. After constant-temperature germination, select the seeds with white tips, place the seeds with white tips on wet paper towels soaked with gibberellin, and cultivate them in a sealed and light-shielded environment. The mass-volume concentration of gibberellin is 200 mg / L, and the cultivation time is 50 hours. After the embryo axis length of the seeds reaches 1.1 cm, transfer them to the substrate soil for cultivation. The composition of the soil substrate includes fermented cassava residue powder, coconut coir, garden soil, and organic fertilizer with a mass ratio of 5.5:6:3:1.5. The fermented cassava residue powder is made from fresh cassava stalks crushed and fermented. The crushing diameter is 1.0 cm. The cassava residue fermentation method is anaerobic fermentation. Seal it with a plastic film for fermentation. After the fermentation temperature reaches 60°C, turn it over. Turn it over once every 8 days, for a total of 3 times. After fermentation, use it to feed earthworms. After 10 days of decomposition by earthworms, sieve it through a 40-mesh screen to obtain the fermented cassava residue powder. The fermented microorganisms in the fermented cassava residue powder consist of Aspergillus niger and Pichia kluyveri. The mass ratio of cassava residue powder, Aspergillus niger, and Pichia kluyveri is 48:1.5:5. Gypsum is added to the fermented cassava residue powder, and the addition amount of gypsum is 3% of the mass of the cassava residue powder.

[0041] Comparative Example 1

[0042] The main difference between Comparative Example 1 and Example 3 is that in step (2), the seaweed oligosaccharide powder and chondrophycic acid powder are removed from the components of the plant quick-rooting agent. The plant quick-rooting agent consists of indolebutyric acid solution and potassium nitrate solution with a mass ratio of 11:0.7. The remaining seed soaking and germination methods and dosages are the same as those in Example 3.

[0043] Comparative Example 2

[0044] The main difference between Comparative Example 2 and Example 3 is that in step (2), the three-time soaking is changed to two-time soaking, and the first soaking is removed; the step of feeding earthworms is removed when fermenting the cassava residue powder. The remaining preparation methods and dosages are the same as those in Example 3.

[0045] Comparative Example 3

[0046] The main difference between Comparative Example 3 and Example 3 is that in step (3), the fermented cassava residue powder is removed from the composition of the soil substrate. The remaining preparation methods and dosages are the same as those in Example 3.

[0047] Comparative Example 4

[0048] The main difference between Comparative Example 4 and Example 3 is that in step (3), the step of placing the seeds with white tips in the gibberellin solution is removed. The remaining preparation methods and dosages are the same as those in Example 3.

[0049] Comparative Example 5

[0050] The main difference between Comparative Example 5 and Example 3 is that during seedling raising, the seeds are not selected, not soaked, not germinated in an incubator, and are directly sown in the seedling cups. The seedling substrate is garden soil, and the remaining preparation methods and dosages are the same as those in Example 3.

[0051] Comparative Example 6

[0052] The main difference between Comparative Example 6 and Example 3 is that during seedling raising, plump seeds are selected and soaked in warm water at a constant temperature of 30°C for 24 hours, not germinated in an incubator, and directly sown into the seedling cups. The seedling substrate is garden soil, and the remaining preparation methods and dosages are the same as those in Example 3.

[0053] Comparative Example 7

[0054] The main difference between Comparative Example 7 and Example 3 is that during seedling raising, plump seeds are selected and soaked in warm water at a constant temperature of 30°C for 24 hours, and then germinated in an incubator at 30°C. When the seeds show white tips, they are transplanted into the seedling cups. The seedling substrate is garden soil, and the remaining preparation methods and dosages are the same as those in Example 3.

[0055] Experiment

[0056] Germination rate experiment: Randomly select seeds of 3 varieties for the germination rate experiment. For each variety in each example and comparative example, 100 seeds are selected, totaling 1000 cassava seeds. Seed source: Select the naturally set seeds of three materials, SC5, BRA001554, and CAS36-2, from the National Cassava Germplasm Repository located in Baodao New Village, Danzhou City, Hainan Province. Germination rate = number of germinated seeds / total number of experimental seeds × 100; survival rate % = number of surviving seeds / total number of experimental seeds × 100. The germination rate statistics of SC5 are shown in Table, the germination statistics of BRA001554 are shown in Table 2, the germination rate statistics of CAS36-2 are shown in Table 3, and the survival rate statistics of SC5, BRA001554, and CAS36-2 are shown in Table 4. The germination rates and survival rates of the 3 varieties (SC5, BRA001554, and CAS36-2) germinated from cassava seeds and raised seedlings according to the methods in Examples 1-3 are significantly higher than those in Comparative Examples 1-7.

[0057] Table 1 Statistics of SC5 Germination Rate

[0058]

[0059]

[0060] Table 2 Statistics of BRA001554 Germination

[0061]

[0062] Table 3 Statistics of CAS36-2 Germination Rate

[0063]

[0064]

[0065] Table 4 Survival Rate Statistics

[0066]

[0067] Summary of test results: The cassava seed germination tests conducted according to the methods of Examples 1-3 showed that the overall germination rate of the three varieties SC5, BRA001554, and CAS36-2 ranged from 88% to 96% and the overall survival rate ranged from 88% to 95%, which were significantly higher than those of Comparative Examples 1-7. In Comparative Example 1, the seaweed oligosaccharide powder and chondrophycic acid powder were removed from the components of the plant rooting agent; in Comparative Example 2, the three immersions were changed to two immersions, and the first immersion was removed; in Comparative Example 3, the fermented cassava residue powder was removed from the composition of the soil substrate; in Comparative Example 4, the step of putting the germinated seeds into the gibberellin immersion was removed, all of which significantly reduced the germination rate and survival rate of cassava seeds. In Comparative Examples 5-7, the germination temperature and immersion time of the seeds were changed and the seedling-raising substrate was changed, which also significantly reduced the germination rate and survival rate of cassava seeds. It shows that the method for promoting cassava seed germination and seedling raising provided by the present invention has the application effect of improving the germination rate and survival rate of cassava seeds.

[0068] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for promoting germination of cassava seeds and raising seedlings, characterized in that: The following steps are involved: S1, select healthy and plump seeds, and expose them to the sun for 1-2 hours for germination; S2, after the seeds are exposed to the sun, they are soaked three times, the first time, they are soaked in water, the second time, they are soaked in a plant root-accelerating agent, and the third time, they are soaked in water again, so as to soak the cassava seeds; the plant root-accelerating agent includes the following raw materials: indolebutyric acid solution, seaweed oligosaccharide powder, domoic acid powder and potassium nitrate solution. S3, soaking cassava seeds and germinating them at a constant temperature, selecting white seeds for cultivation, and then transferring them to matrix soil for cultivation.

2. A method for promoting cassava seed germination and seedling raising according to claim 1, characterized in that, In step S2, the mass ratio of the indolebutyric acid solution, the seaweed oligosaccharide powder, the domoic acid powder and the potassium nitrate solution is 10-12:1-1.5:0.2-0.4:0.6-0.

8.

3. A method for promoting cassava seed germination and seedling raising according to claim 2, characterized in that, The concentration of the indolebutyric acid solution is 95-105 mg / L, and the mass concentration of the potassium nitrate solution is 0.08%-0.12%.

4. A method for promoting cassava seed germination and seedling raising according to claim 1, characterized in that, Step S2, the soaking is three times, the first time, soaking in 45-50℃ water for 4-4.5 hours, the second time, soaking in plant root accelerating agent for 7-8 hours, and the third time, soaking in 25-30℃ water for another 10-12 hours.

5. A method for promoting cassava seed germination and seedling raising according to claim 1, characterized in that: Step S3, the constant temperature germination, the germination temperature is 28-32° C., the germination time is 9-10 days, the whitening seeds are cultivated, the whitening seeds are placed on a wet paper towel soaked with gibberellin, and the cultivation is closed and shaded, and the mass volume concentration of gibberellin is 190-210 mg / L.

6. A method for promoting cassava seed germination and seedling raising according to claim 5, characterized in that: Step S3, the cultivation time of the white seeds is 48-52 hours, and the length of the embryonic axis of the cultivated seeds is 1-1.2 cm.

7. A method for promoting cassava seed germination and seedling raising according to claim 1, step S3, the composition of the matrix soil includes fermented cassava residue powder, coconut chaff, garden soil and organic fertilizer in a mass ratio of 5-6:5-6:2-3:1-2.

8. A method for promoting cassava seed germination and seedling raising according to claim 7, characterized in that: The fermented cassava residue powder is made by crushing and fermenting fresh cassava stems, with a crushing diameter of 0.8-1.2 cm. The cassava residue fermentation method is anaerobic fermentation, and the fermentation is sealed with a plastic film. The fermentation temperature reaches 58-60°C and the residue is turned over once every 6-10 days, with a total of 3-4 times. After fermentation, the residue is used to feed earthworms. After the earthworms decompose it for 10-15 days, the residue is sieved with a 40-mesh gauze to obtain the fermented cassava residue powder.

9. A method for promoting germination of cassava seeds and raising seedlings according to claim 7, characterized in that: The fermented cassava residue powder is fermented by microorganisms consisting of Aspergillus niger and Pichia kluyveri, and the mass ratio of the cassava residue powder, Aspergillus niger and Pichia kluyveri is 45-50:1-2:4-6.

10. A method for promoting germination and seedling raising of cassava seeds according to claim 7, characterized in that: After the cassava residue powder is fermented, gypsum is added, and the added amount of the gypsum is 2%-5% of the mass of the cassava residue powder.

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