Method for promoting root formation and growth of macadamia nuts

Abstract

The invention discloses a method for promoting root formation and growth of macadamia nuts. The method comprises the following steps: culturing macadamia nut seedlings by using a nutrient growth solution A, irrigating 200-400mL of the nutrient growth solution A to each seedling once every 2-3 days, and continuously irrigating for 9-10 days; after the nutrient growth solution A is cultured, the nutrient mixed solution is used for culturing, 300-400 mL of the nutrient mixed solution is applied to each seedling, the nutrient mixed solution is applied once every 2-3 days, and the operation lasts for 25-30 days; the nutrient mixed solution comprises 40 to 100 [mu] mol / L of naphthylacetic acid (NAA), 10 to 40 [mu] mol / L of strigolactones and a nutrient growth solution B; after the culture period of the nutrient mixed solution is completed, the macadamia nut seedlings can form abundant macadamia nut roots, and the macadamia nut can absorb nutrients in the soil easily. In the growth process, a mode of combining a nutrient solution, strigolactone and naphthylacetic acid is adopted, so that the rooting ability of the macadamia nuts is promoted, and the root formation of the macadamia nuts is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of fruit tree planting, and particularly relates to a method for promoting root formation and growth of macadamia nuts. Background Art

[0002] Macadamia (Macadamia integrifolia M.Tetraphylla), also known as macadamia nuts, are evergreen trees belonging to the genus Macadamia of the family Proteaceae. Macadamia nuts are native to the subtropical rainforests of Australia. They are of high economic value and rich in nutrition. They are rich in fat, protein and a large number of mineral elements necessary for the human body. They are known as the "Queen of Dried Fruits". my country began to introduce and trial-plant macadamia nuts in the late 1990s. It has become the main economic tree developed in southern my country, such as Yunnan, Guangxi, Guizhou, and Guangdong. It is an important source of income for farmers in tropical and subtropical areas.

[0003] The root system is the main organ for plants to absorb nutrients and water, and its early development status directly affects the construction of the plant root system and the absorption and utilization of nutrients during the entire growth period. The row root is a special lateral root structure formed by the root system of macadamia nuts. It has a strong ability to adapt to nutrient stress and plays an important role in the absorption and utilization of nutrients in macadamia nuts. Therefore, promoting the formation and growth of row roots in production plays a key role in the sustainable production of macadamia nuts. In the prior art, the rooting ability of macadamia nuts is improved mainly by using a single rooting agent or a combination of rooting agents to promote the rooting of macadamia seedlings, but it does not pay attention to the formation and growth of row roots, which is the most important for the absorption and utilization of nutrients in macadamia nuts, which is not conducive to the green, efficient and sustainable development of the macadamia nut industry. Summary of the invention

[0004] The purpose of the present invention is to provide a method for promoting the root formation and growth of macadamia nuts, which promotes the rooting ability of macadamia nuts and increases the root formation of macadamia nuts by combining nutrient solution, strigolactone and naphthylacetic acid during the growth process, while reducing the excessive use of various rooting agents, reducing soil pollution and slowing down the development of drug resistance in macadamia nuts.

[0005] To achieve the above object, the solution provided by the present invention is as follows:

[0006] A method for promoting root formation and growth of macadamia nuts, characterized by:

[0007] (1) The macadamia seedlings were first cultured with nutrient growth solution A, with 200-400 mL per seedling applied every 2-3 days for 9-10 days;

[0008] (2) After the nutrient growth solution A is cultivated, the nutrient mixture solution is used for cultivation. Each seedling is irrigated with 300-400 mL of the nutrient mixture solution every 2-3 days for 25-30 days.

[0009] The nutrient mixture includes 40-100 μmol / L naphthaleneacetic acid (NAA), 10-40 μmol / L strigolactone and nutrient growth solution B;

[0010] The nutrient growth solution B comprises: 1500-2000 μmol / L Ca(NO3)2, 50-100 μmol / L KH2PO4, 800-850 μmol / L K2SO4, 80-100 μmol / L KCl, 600-650 μmol / L MgSO4, 1-2 μmol / L MnSO4, 1-2 μmol / L ZnSO4, 0.1-0.2 μmol / L CuSO4, 1-2 μmol / L H3BO3, 0.005-0.01 μmol / L Na2MoO4, 80-100 μmol / L Fe-EDTA, which are mixed according to the concentration of each reagent, and then the pH value is adjusted to 5.0-5.5;

[0011] (3) After the nutrient mixture culture cycle is completed, the macadamia seedlings can form abundant macadamia roots, which is beneficial for macadamia to absorb nutrients in the soil.

[0012] As a preferred technical solution, the nutrient solution A includes 1500-2000μmol / L Ca(NO3)2, 450-500μmol / L KH2PO4, 600-625μmol / L K2SO4, 80-100μmol / L KCl, 600-650μmol / L MgSO4, 1-2μmol / LMnSO4, 1-2μmol / L ZnSO4, 0.1-0.2μmol / L CuSO4, 1-2μmol / L H3BO3, 0.005-0.01μmol / LNa2MoO4, and 80-100μmol / L Fe-EDTA. The nutrient solution A is prepared and mixed according to the concentration of each reagent, and the pH value is adjusted to 5.0-5.5.

[0013] As a preferred technical solution, the concentration of naphthylacetic acid (NAA) is 80 μmol / L.

[0014] As a preferred technical solution, the concentration of strigolactone is 20 μmol / L.

[0015] As a preferred technical solution, the nutrient growth solution B includes: 2000μmol / L Ca(NO3)2, 50μmol / LKH2PO4, 850μmol / L K2SO4, 100μmol / L KCl, 650μmol / L MgSO4, 1μmol / L MnSO4, 1μmol / LZnSO4, 0.1μmol / L CuSO4, 1μmol / L H3BO3, 0.005μmol / L Na2MoO4, 100μmol / L Fe-EDTA, which are prepared and mixed according to the concentration of each reagent, and then the pH value is adjusted to 5.0-5.5.

[0016] The present invention has the following beneficial effects:

[0017] 1. The present invention first uses nutrient solution A to cultivate the root system for a period of time so that it can fully absorb nutrients. After 10 days of cultivation. A mixed solution of naphthaleneacetic acid (NAA), strigolactone and nutrient growth solution B is used for cultivation to promote the formation and differentiation of row roots. The naphthaleneacetic acid in the present invention promotes cell division and expansion, and induces the formation of adventitious roots. Strigolactone can be secreted by the roots of plants into the rhizosphere to promote seed germination and root growth; it can also stimulate plants to absorb phosphates and other minerals from the soil to promote their growth and development, and promote the absorption of nutrients in the nutrient growth solution B by the root system. The nutrient growth solution B is rich in mineral elements required by a variety of plants and can meet the nutrient requirements of the root system. The phosphorus content in the nutrient growth solution B is lower than that in the nutrient growth solution A, because under low phosphorus conditions, it can induce the formation of row roots. Because row roots are related to plant phosphorus nutrient absorption, row root formation is a low-phosphorus resistance characteristic of macadamia nuts. Therefore, the present invention can promote the formation of row roots under the cultivation of the mixed solution.

[0018] 2. The method of the present invention is simple and easy to implement, and has good effects. The present invention uses 800 μmol / L naphthaleneacetic acid (NAA), 20 μmol / L strigolactone and nutrient growth solution B to spray macadamia nut seedlings, and the number of roots can reach 124 in 30 days. The root system is very rich, which is beneficial to promote the absorption of nutrients by the root system and accelerate the growth rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Bar graph of the number of roots of macadamia seedlings under different strigolactone concentrations;

[0020] Figure 2 Bar graph of the number of roots of macadamia seedlings under different concentrations of naphthaleneacetic acid treatments;

[0021] Figure 3 Comparison of root formation in macadamia seedlings under treatment with different concentrations of naphthaleneacetic acid.

[0022] Figure 4 This is a diagram showing the growth status of each group of macadamia seedlings after being cultured in nutrient mixture for 30 days. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with embodiments:

[0024] Example

[0025] 1. Sources of test materials

[0026] 1. Experimental variety: The macadamia variety is “Guire 1”, with uniform growth, healthy and disease-free seedlings, provided by the macadamia breeding team of the South Asia Institute of Guangxi Academy of Agricultural Sciences.

[0027] 2. Nutrient growth solution A: 2000μmol / L Ca(NO3)2, 500μmol / L KH2PO4, 625μmol / L K2SO4, 100μmol / L KCl, 650μmol / L MgSO4, 1μmol / L MnSO4, 1μmol / L ZnSO4, 0.1μmol / L CuSO4, 1μmol / LH3BO3, 0.005μmol / L Na2MoO4, 100μmol / L Fe-EDTA. Nutrient growth solution A is prepared according to the concentration of each reagent, and the pH value of the mixed solution is adjusted to 5.0-5.5.

[0028] 3. Nutrient growth solution B: 2000μmol / L Ca(NO3)2, 50μmol / L KH2PO4, 850μmol / L K2SO4, 100μmol / L KCl, 650μmol / L MgSO4, 1μmol / L MnSO4, 1μmol / LZnSO4, 0.1μmol / L CuSO4, 1μmol / LH3BO3, 0.005μmol / L Na2MoO4, 100μmol / L Fe-EDTA. Nutrient growth solution B is prepared according to the concentration of each reagent, and the pH value of the mixed solution is adjusted to 5.0-5.5.

[0029] 4. Hormone type:

[0030] ① Auxin (IAA): Naphthaleneacetic acid (NAA), provided by Shanghai Yuanye Biotechnology Co., Ltd.

[0031] ②Strigolactones (SLs): GR24, an artificial synthetic analogue of strigolactone, was provided by Shanghai Yuanye Biotechnology Co., Ltd.

[0032] 2. The impact of nutrient growth solution on root growth.

[0033] The experiment was conducted in the solar greenhouse of Guangxi South Asian Tropical Agricultural Science Research Institute. Plastic pots (upper diameter 20cm, lower diameter 15cm, height 22cm) were used for cultivation. There were 2 treatments, each with 5 replicates, for a total of 10 pots. The specific operation steps are as follows:

[0034] (1) Loading the substrate: Take 10 plastic flower pots with trays of the same specifications, clean them, and dry them; place a double layer of newspaper at the bottom of the flower pots to prevent the soil from flowing out; place sterilized quartz sand into the test pots, compact it layer by layer until it is flush with the top of the pot, place a tray at the bottom of the flower pots, mark each flower pot and affix a label; fully moisten the quartz sand in each pot with sterile water and let it equilibrate for 2 days.

[0035] (2) Sowing: Select 10 healthy and disease-free macadamia seedlings with uniform growth and vigour, and water them with a small amount of sterile water to keep them moist for 2 days.

[0036] (3) Nutrient solution A culture: At 5-6 pm, 400 mL of nutrient solution A was applied to each seedling in each pot every 2 days for 10 days. During the culture period, the tray under each pot was removed and the nutrient solution was poured back into the original pot to avoid nutrient solution loss. If drought occurs 2 cm below the surface sand, each pot was irrigated with an equal amount of sterile water.

[0037] (4) Comparative culture: The experiment was conducted in groups, with watering every 2 days for 30 consecutive days.

[0038] Control group: 400 mL of clean water was applied to each seedling in each pot.

[0039] Experimental group: 400 mL of nutrient growth solution B was used to irrigate each seedling in each pot.

[0040] During the cultivation period, the tray under each flower pot was removed and the leaked liquid was poured back into the original pot. If drought occurs 2 cm below the surface sand, each pot was irrigated with an equal amount of sterile water. The position of the flower pot was changed once a week during the period to avoid the influence of environmental factors on the experiment.

[0041] (5) Root count: After 30 days of cultivation in each group, three seedling pots were randomly selected for each treatment. The above-ground part was cut off from the base, and the entire root system was taken out intact. The root system was cleaned with tap water, and the number of roots was counted and recorded in Table 1.

[0042] Table 1 Effects of nutrient solution on root formation of macadamia seedlings

[0043] Piece / Strain Control group Experimental Group Number of rows 18.67 20.33

[0044] 3. Screening of the concentration of strigolactone solution

[0045] The experiment was conducted in the solar greenhouse of Guangxi South Asian Tropical Agricultural Science Research Institute. Plastic pots (upper diameter 20cm, lower diameter 15cm, height 22cm) were used for cultivation. There were 5 treatments, each with 12 pots, for a total of 60 pots. The operation steps are as follows:

[0046] (1) Loading the substrate: Take 60 plastic flower pots with trays of the same specifications, clean them, and dry them; place a double layer of newspaper at the bottom of the flower pots to prevent the soil from flowing out; place sterilized quartz sand into the test pots, compact it layer by layer until it is flush with the top of the pot, place the tray at the bottom of the flower pots, mark each flower pot and affix a label; fully moisten the quartz sand in each pot with sterile water and let it equilibrate for 2 days.

[0047] (2) Sowing: Select 60 healthy and disease-free macadamia seedlings with uniform growth and vigour, and water them with a small amount of sterile water to keep them moist for 2 days.

[0048] (3) Nutrient solution A culture: At 5-6 pm, 400 mL of nutrient solution A was applied to each seedling in each pot every 2 days for 10 days. During the culture period, the tray under each pot was removed and the nutrient solution was poured back into the original pot to avoid nutrient solution loss. If drought occurs 2 cm below the surface sand, each pot was irrigated with an equal amount of sterile water.

[0049] (4) Cultivation with different treatments: The experiment was conducted according to the five treatment groups that were set. Every two days, 400 mL of five different treatment solutions were irrigated to each seedling in each pot. The treatment solutions were as follows:

[0050] ①CK: 0μmol / L strigolactone (SLs) + nutrient growth solution B;

[0051] ②T1: 5μmol / L strigolactone (SLs) + nutrient growth solution B;

[0052] ③T2: 10 μmol / L strigolactone (SLs) + nutrient growth solution B;

[0053] ④T3: 20μmol / L strigolactone (SLs) + nutrient growth solution B;

[0054] ⑤T4: 40μmol / L strophanthocyanin (SLs) + nutrient growth solution B.

[0055] During the cultivation period, the tray under each flower pot was removed and the nutrient solution was poured back into the original pot to avoid nutrient solution loss. If drought occurs 2 cm below the surface sand, each pot was irrigated with an equal amount of sterile water. The position of the flower pot was changed once a week during the period to avoid the influence of environmental factors on the experiment.

[0056] (5) Root count: After 30 days of cultivation in each group, 6 seedlings were randomly selected from each treatment. The aboveground part was cut off from the base, and the entire root system was taken out intact. The root system was cleaned with tap water, and the number of roots was counted and recorded in Table 1. A graph of the number of roots of macadamia seedlings treated with different concentrations of strigolactone was drawn (see Table 1). Figure 1 shown).

[0057] Table 1 Root formation of macadamia seedlings under treatment with different concentrations of strigolactone

[0058] Piece / Strain CK T1 T2 T3 T4 Number of rows 20.12 31.22 55.64 92.18 64.45

[0059] Depend on Figure 1 As shown in Table 1, after 30 days of cultivation in a mixture of 5-40 μmol / L SLs + nutrient growth solution B, the average number of root formation in the root system of macadamia seedlings was 31.22-92.18 per plant, which was 11.10, 35.52, 72.06 and 44.33 more than the control treatment (20.12 per plant), respectively. Among them, the average number of root formation in the root system of macadamia seedlings after 30 days of cultivation in a mixture of 20 μmol / L SLs + nutrient growth solution B was 92.18 per plant, which was 4.58 times that of the control treatment (20.12 per plant). This shows that an appropriate amount of SLs helps promote root formation, with a good and stable effect, and the ratio is relatively low in cost and green and safe.

[0060] 4. Naphthaleneacetic acid solution concentration screening

[0061] The experiment was conducted in the solar greenhouse of Guangxi South Asian Tropical Agricultural Science Research Institute. Plastic pots (upper diameter 20cm, lower diameter 15cm, height 22cm) were used for cultivation. There were 6 treatments, each with 12 pots, for a total of 72 pots. The specific operation steps are as follows:

[0062] 1. Install the substrate: Take 72 plastic flower pots with the same specifications and bottom trays, clean them and dry them; put a double layer of newspaper at the bottom of the flower pots to prevent the soil from flowing out; put the sterilized quartz sand into the test pots, compact it in layers to make it flush with the top of the pot, put the bottom tray at the bottom of the flower pots, mark and label each flower pot; fully moisten the quartz sand in each pot with sterile water and balance it for 2 days.

[0063] 2. Sowing: Select 72 healthy and disease-free macadamia seedlings with uniform growth and sprinkle with a small amount of sterile water to keep them moist for 2 days.

[0064] 3. Nutrient solution A culture: At 5-6 pm, irrigate each pot and each seedling with 400 mL of nutrient growth solution A, once every 2 days, for 10 days. During the culture period, remove the tray under each pot and pour the nutrient solution back into the original pot to avoid nutrient solution loss. If drought occurs 2 cm below the surface sand, irrigate each pot with an equal amount of sterile water.

[0065] 4. Cultivation with different mixed solutions: 2 days after the cultivation with nutrient solution A, the experiment was carried out according to the set 6 treatment groups. Every 2 days, 400 mL of the treatment mixed solution was irrigated to each seedling in each pot for 30 consecutive days. The conditions of each mixed solution were as follows:

[0066] ①CK: 0μmol / L naphthaleneacetic acid (NAA) + 20μmol / L strigolactone + nutrient growth solution B;

[0067] ②T1: 10μmol / L naphthaleneacetic acid (NAA) + 20μmol / L strigolactone + nutrient growth solution B;

[0068] ③T2: 20μmol / L naphthaleneacetic acid (NAA) + 20μmol / L strigolactone + nutrient growth solution B;

[0069] ④T3: 40μmol / L naphthaleneacetic acid (NAA) + 20μmol / L strigolactone + nutrient growth solution B;

[0070] ⑤T4: 80μmol / L naphthaleneacetic acid (NAA) + 20μmol / L strigolactone + nutrient growth solution B;

[0071] ⑥T5: 100μmol / L naphthaleneacetic acid (NAA) + 20μmol / L strigolactone + nutrient growth solution B.

[0072] During the cultivation period, the tray under each flower pot was removed and the nutrient solution was poured back into the original pot to avoid nutrient solution loss. If drought occurs 2 cm below the surface sand, each pot was irrigated with an equal amount of sterile water. The position of the flower pot was changed once a week during the period to avoid the influence of environmental factors on the experiment.

[0073] 5. Root count: After 30 days of treatment in step (4), 6 seedlings were randomly selected from each treatment. The aboveground part was cut off from the base, the entire root system was taken out intact, and the root system was cleaned with tap water. The number of roots was counted and recorded in Table 2. A graph of the number of roots of macadamia seedlings treated with different concentrations of naphthaleneacetic acid was drawn (see Table 2). Figure 2 Take photos to record the rooting conditions of different treatment groups, such as Figure 3 shown.

[0074] Table 2 Root formation of macadamia seedlings under different concentrations of naphthaleneacetic acid treatments

[0075] Piece / Strain CK T1 T2 T3 T4 T5 Number of rows 34.67 45.47 60.67 90.89 124.65 100.52

[0076] From Table 2, Figure 2 and Figure 3 It can be seen that after 30 days of cultivation in a mixture of 10-100μmol / L naphthaleneacetic acid (NAA) + 20μmol / L strigolactone + nutrient growth solution B, the average number of roots formed by the root system of macadamia seedlings was 45.47-124.65 per plant, which was an increase of 10.80, 26.00, 56.22, 89.98 and 65.85 per plant respectively compared with the control treatment (34.67 per plant). Among them, after 30 days of cultivation in a mixture of 80μmol / L naphthaleneacetic acid (NAA) + 20μmol / L strigolactone + nutrient growth solution B, the average number of roots formed by the root system of macadamia seedlings was 124.65 per plant, which was 3.60 times that of the control treatment (34.67 per plant). In particular, Figure 3 It can be seen that the root system is particularly dense, which shows that an appropriate amount of naphthylacetic acid helps promote root formation.

[0077] Although the above describes the specific implementation methods of the present invention, it is not intended to limit the scope of protection of the invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A method for promoting root formation and growth of macadamia nuts, characterized in that: (1) The macadamia seedlings were first cultured with nutrient growth solution A, with 200-400 mL per seedling applied every 2-3 days for 9-10 days; (2) After the nutrient growth solution A is cultivated, the nutrient mixture solution is used for cultivation. Each seedling is irrigated with 300-400 mL of the nutrient mixture solution every 2-3 days for 25-30 days. The nutrient mixture includes 40-100 μmol / L naphthaleneacetic acid (NAA), 10-40 μmol / L strigolactone and nutrient growth solution B; The nutrient growth solution B comprises: 1500-2000 μmol / L Ca(NO3)2, 50-100 μmol / L KH2PO4, 800-850 μmol / L K2SO4, 80-100 μmol / L KCl, 600-650 μmol / L MgSO4, 1-2 μmol / L MnSO4, 1-2 μmol / L ZnSO4, 0.1-0.2 μmol / L CuSO4, 1-2 μmol / L H3BO3, 0.005-0.01 μmol / L Na2MoO4, 80-100 μmol / L Fe-EDTA, which are mixed according to the concentration of each reagent, and then the pH value is adjusted to 5.0-5.5; (3) After the nutrient mixture culture cycle is completed, the macadamia seedlings can form abundant macadamia roots, which is beneficial for macadamia to absorb nutrients in the soil.

2. The method for promoting root formation and growth of macadamia nuts according to claim 1, characterized in that: The nutrient solution A includes 1500-2000 μmol / L Ca(NO3)2, 450-500 μmol / L KH2PO4, 600-625 μmol / L K2SO4, 80-100 μmol / L KCl, 600-650 μmol / L MgSO4, 1-2 μmol / L MnSO4, 1-2 μmol / L ZnSO4, 0.1-0.2 μmol / L CuSO4, 1-2 μmol / L H3BO3, 0.005-0.01 μmol / L Na2MoO4, and 80-100 μmol / L Fe-EDTA. The nutrient solution A is mixed according to the concentration of each reagent, and the pH value is adjusted to 5.0-5.

5.

3. The method for promoting root formation and growth of macadamia nuts according to claim 1, characterized in that: The concentration of naphthaleneacetic acid (NAA) is 80 μmol / L.

4. The method for promoting root formation and growth of macadamia nuts according to claim 1, characterized in that: The concentration of strigolactone is 20 μmol / L.

5. The method for promoting root formation and growth of macadamia nuts according to claim 1, characterized in that: The nutrient growth solution B includes: 2000μmol / L Ca(NO3)2, 50μmol / L KH2PO4, 850μmol / L K2SO4, 100μmol / L KCl, 650μmol / L MgSO4, 1μmol / L MnSO4, 1μmol / L ZnSO4, 0.1μmol / LCuSO4, 1μmol / L H3BO3, 0.005μmol / L Na2MoO4, and 100μmol / L Fe-EDTA. The reagents are mixed according to their concentrations, and the pH value is adjusted to 5.0-5.5.

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