Pharmaceutical composition for improving salt tolerance of industrial hemp and method for improving salt tolerance of industrial hemp

Abstract

The invention provides a pharmaceutical composition for improving the salt tolerance of industrial cannabis sativa and a method for improving the salt tolerance of the industrial cannabis sativa, and belongs to the technical field of agriculture. The invention provides a pharmaceutical composition for improving the salt tolerance of industrial cannabis sativa. The pharmaceutical composition comprises salicylic acid and abscisic acid which are separately subpackaged, the mass ratio of the salicylic acid to the abscisic acid is 1: (0.8-1.2). The invention further provides a method for improving the salt tolerance of the industrial hemp, salicylic acid and abscisic acid are alternately and circularly applied to the industrial hemp, the yellowing degree of leaves of the industrial hemp under the salt stress condition can be effectively reduced, meanwhile, extension of the leaves of the industrial hemp is promoted, the plant height, stem diameter, biomass and chlorophyll relative content of the industrial hemp are improved, and the salt tolerance of the industrial hemp is improved. And the method has important significance on salt-tolerant cultivation of industrial hemp.

Description

Technical Field

[0001] The present invention belongs to the technical field of agriculture, and particularly relates to a pharmaceutical composition for improving the salt tolerance of industrial hemp and a method for improving the salt tolerance of industrial hemp. Background Art

[0002] Industrial hemp (Cannabis sativa L.) is an annual herbaceous plant of the Cannabaceae family and the Cannabis genus. Industrial hemp refers to the type of hemp variety with a tetrahydrocannabinol (THC) content of less than 0.3%. Industrial hemp is a characteristic fiber crop with great development value. It can grow under harsh conditions, has a relatively low planting cost, and has biological characteristics such as resistance to barrenness and stress resistance. Developing industrial hemp cultivation on saline-alkali land is an important strategy to alleviate the contradiction between food and cash crops for land and promote the sustainable development of the industrial hemp industry.

[0003] However, during the entire growth cycle of industrial hemp, the seedling stage is particularly sensitive to salt stress. As the degree and duration of salt stress increase, the growth of seedlings slows down, the plant height decreases, and even growth stops, seriously hindering the development of the industrial hemp industry. Summary of the Invention

[0004] In view of this, the present invention provides a pharmaceutical composition for improving the salt tolerance of industrial hemp, which can alleviate the damage caused by salt stress to the growth of industrial hemp and increase the plant height, stem diameter, biomass, and SPAD value of industrial hemp.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a pharmaceutical composition, comprising separately packaged salicylic acid and abscisic acid;

[0007] The mass ratio of the salicylic acid to the abscisic acid is 1:(0.8 - 1.2).

[0008] The present invention provides the application of the pharmaceutical composition in the cultivation of industrial hemp.

[0009] Preferably, the cultivation of industrial hemp includes improving the salt tolerance of industrial hemp.

[0010] The present invention provides a method for improving the salt tolerance of industrial hemp, comprising the following steps: alternately and cyclically applying salicylic acid and abscisic acid in the cultivation of industrial hemp;

[0011] The working concentration of the salicylic acid or the abscisic acid is 150 - 270 mg / L.

[0012] Preferably, the method of alternately and cyclically applying salicylic acid and abscisic acid includes cyclic application in the order of first applying salicylic acid and then applying abscisic acid or cyclic application in the order of first applying abscisic acid and then applying salicylic acid.

[0013] Preferably, the number of cyclic applications of alternately and cyclically applying salicylic acid and abscisic acid is 2 to 3 times;

[0014] When alternately and cyclically applying salicylic acid and abscisic acid, the interval time between two adjacent applications is 1 to 3 days.

[0015] Preferably, the application method includes foliar spraying and / or irrigation application;

[0016] When foliar spraying, the application amount of salicylic acid or abscisic acid is 3 to 5 mL / plant;

[0017] When irrigation application, the application amount of salicylic acid or abscisic acid is 8 to 12 mL / plant.

[0018] Preferably, the starting time of alternately and cyclically applying salicylic acid and abscisic acid is the seedling stage of industrial hemp.

[0019] Preferably, the seedling stage of industrial hemp includes the four true leaf stage of industrial hemp.

[0020] Preferably, the industrial hemp includes Yunma No. 7 and / or Yunma No. 8.

[0021] The present invention has the following advantages compared with the prior art:

[0022] The present invention provides a pharmaceutical composition for improving the salt tolerance of industrial hemp, which comprises separately packaged salicylic acid (SA) and abscisic acid (ABA); the mass ratio of the salicylic acid to the abscisic acid is 1:(0.8-1.2). The salicylic acid and the abscisic acid can relieve the damage caused by salt stress to the growth of industrial hemp, and improve the plant height, stem diameter, biomass and SPAD value of industrial hemp. In an embodiment of the present invention, the effects of different exogenous hormones (salicylic acid, naphthalene acetic acid, abscisic acid) and their combinations (salicylic acid and naphthalene acetic acid, abscisic acid and naphthalene acetic acid, salicylic acid and abscisic acid) on the salt tolerance of industrial hemp when applied alone, mixed or alternately are compared. The results show that, compared with the control, the single application or combined application of exogenous hormones can improve the salt tolerance of industrial hemp; at the same time, compared with the single application of salicylic acid or abscisic acid, the alternate application of the two hormone combinations (SA-ABA, ABA-SA) can improve the salt tolerance of industrial hemp; compared with the single application of naphthalene acetic acid, abscisic acid or salicylic acid, the alternate application of the two hormone combinations (ABA-NAA, NAA-ABA, NAA-SA and SA-NAA) has no significant improvement in improving the salt tolerance of industrial hemp. It can be seen that the combination of salicylic acid and abscisic acid has the best effect on improving the salt tolerance of industrial hemp.

[0023] The present invention provides a method for improving the salt tolerance of industrial hemp, which comprises the following steps: alternately and cyclically applying salicylic acid and abscisic acid in the cultivation of industrial hemp; the working concentration of the salicylic acid or the abscisic acid is 150-270 mg / L. Alternately and cyclically applying salicylic acid and abscisic acid can act synergistically to improve the salt tolerance of industrial hemp. In the embodiment of the present invention, the effects of spraying salicylic acid or abscisic acid alone, spraying a mixture of salicylic acid and abscisic acid, and alternately spraying salicylic acid and abscisic acid on the salt tolerance of industrial hemp under salt stress are further compared. The results show that alternately spraying salicylic acid and abscisic acid has a better effect on improving the agronomic traits of industrial hemp under salt stress, and the group (T6) of spraying salicylic acid first and then abscisic acid has the best effect. Compared with the salt stress (T1), the degree of chlorosis and yellowing of the leaves of industrial hemp in T6 is reduced, new leaves emerge, the leaves are unfolded, and the plant height, stem diameter, biomass and SPAD value of Yunma No. 7 increase by 206.85%, 83.57%, 215.86% and 86.49% respectively, and those of Yunma No. 8 increase by 145.78%, 46.74%, 226.27% and 67.56% respectively. It can be seen that alternately applying salicylic acid and abscisic acid reduces the damage caused by salt stress to the growth of industrial hemp. The method of the present invention has important significance for the salt-tolerant cultivation of industrial hemp. In addition, the raw materials in the method of the present invention are easily available and the use method is simple, and it has the potential for large-scale production practice. Description of the Drawings

[0024] Figure 1 It is a diagram showing the effects of salt stress and different spraying treatments on the plant height of industrial hemp;

[0025] Figure 2 Graph showing the effects of salt stress and different spraying treatments on the stem diameter of industrial hemp;

[0026] Figure 3 Graph showing the effects of salt stress and different spraying treatments on the biomass of industrial hemp;

[0027] Figure 4 Graph showing the effects of salt stress and different spraying treatments on the root - shoot ratio of industrial hemp;

[0028] Figure 5 Graph showing the effects of salt stress and different spraying treatments on the SPAD value of industrial hemp;

[0029] Figure 6 Graph showing the growth of Yunma No. 7 under salt stress and different spraying treatments;

[0030] Figure 7 Graph showing the growth of Yunma No. 8 under salt stress and different spraying treatments. Detailed implementation mode

[0031] The present invention provides a pharmaceutical composition for improving the salt tolerance of industrial hemp, comprising separately packaged salicylic acid and abscisic acid;

[0032] The mass ratio of the salicylic acid to the abscisic acid is 1:(0.8 - 1.2).

[0033] In the present invention, the mass ratio of the salicylic acid to the abscisic acid is preferably 1:(0.9 - 1.1), and more preferably 1:1. In the present invention, alternately and cyclically applying salicylic acid and abscisic acid can act synergistically to improve the agronomic traits such as plant height, stem diameter, biomass and SPAD value of industrial hemp under salt stress, thereby improving the salt tolerance of industrial hemp. In an embodiment of the present invention, the effects of different exogenous hormones (salicylic acid, naphthalene acetic acid, abscisic acid) and their combinations (salicylic acid and naphthalene acetic acid, abscisic acid and naphthalene acetic acid, salicylic acid and abscisic acid) applied alone, mixed or alternately on the salt tolerance of industrial hemp were compared. The results show that compared with the control, the single application or combined application of exogenous hormones can improve the salt tolerance of industrial hemp. At the same time, compared with the single application of salicylic acid or abscisic acid, the alternate application of the two - hormone combinations (SA - ABA, ABA - SA) can improve the salt tolerance of industrial hemp; at the same time, compared with the single application of naphthalene acetic acid, abscisic acid or salicylic acid, the alternate application of the two - hormone combinations (ABA - NAA, NAA - ABA, NAA - SA and SA - NAA) does not have a significant improvement in improving the salt tolerance of industrial hemp. It can be seen that the combination of salicylic acid and abscisic acid has the best effect on improving the salt tolerance of industrial hemp.

[0034] In view of the characteristics that the pharmaceutical composition can improve the salt tolerance of industrial hemp, the present invention provides the application of the pharmaceutical composition in the cultivation of industrial hemp. The cultivation of industrial hemp preferably includes improving the salt tolerance of industrial hemp. The improvement of the salt tolerance of industrial hemp preferably includes improving at least one of the following traits of industrial hemp: plant height, stem diameter, biomass, and relative chlorophyll content.

[0035] The present invention provides a method for improving the salt tolerance of industrial hemp, which includes the following steps: alternately and cyclically applying salicylic acid and abscisic acid during the cultivation of industrial hemp; the working concentration of the salicylic acid or abscisic acid is 150-270 mg / L.

[0036] In the present invention, the industrial hemp is an industrial hemp variety with a THC mass percentage content of less than 0.3%. The industrial hemp variety is preferably a flower and leaf type variety, more preferably Yunma. In the embodiments of the present invention, Yunma No. 7 and / or Yunma No. 8 are used as representatives of industrial hemp to illustrate the method for improving the salt tolerance of industrial hemp.

[0037] In the present invention, the starting time for alternately and cyclically applying salicylic acid and abscisic acid is the seedling stage of industrial hemp, more preferably the stage of four true leaves of industrial hemp. The stage of four true leaves of industrial hemp is a sensitive period for the transition from heterotrophy to autotrophy. The root system penetrates shallowly and responds more sensitively to environmental changes. Starting to alternately and cyclically apply salicylic acid and abscisic acid at the stage of four true leaves of industrial hemp is beneficial to activating its stress response mechanism and alleviating the damage of industrial hemp seedlings in a salt stress environment.

[0038] In the present invention, the method for alternately and cyclically applying salicylic acid and abscisic acid preferably includes foliar spraying and / or irrigation application, more preferably foliar spraying. The embodiments of the present invention show that both foliar spraying and irrigation application can significantly improve the salt tolerance of industrial hemp, and the effect of leaf spraying is better.

[0039] In the present invention, when foliar spraying, the application amount of the salicylic acid or abscisic acid is 3-5 mL / plant, more preferably 4 mL / plant. When irrigation application is used, the application amount of the salicylic acid or abscisic acid is 8-12 mL / plant, more preferably 9-11 mL / plant, and most preferably 10 mL / plant. The working concentration of the salicylic acid or abscisic acid is preferably 180-260 mg / L, more preferably 200-255 mg / L, and most preferably 250 mg / L. The solvent of the salicylic acid or abscisic acid is preferably water. In the embodiments of the present invention, the purity of salicylic acid (SA) and abscisic acid (ABA) is ≥95%, and they are purchased from Beijing Solarbio Company.

[0040] In the present invention, the method of alternately and cyclically applying salicylic acid and abscisic acid preferably includes cyclic application in the order of first applying salicylic acid and then applying abscisic acid or cyclic application in the order of first applying abscisic acid and then applying salicylic acid, and more preferably cyclic application in the order of first applying salicylic acid and then applying abscisic acid. In the embodiments of the present invention, the effects of cyclic application in the order of first applying salicylic acid and then applying abscisic acid and cyclic application in the order of first applying abscisic acid and then applying salicylic acid on the salt tolerance of industrial hemp under salt stress were compared. The results showed that both methods could further improve the salt tolerance of industrial hemp under salt stress compared with single spraying, and the group with salicylic acid sprayed first and then abscisic acid (T6) had the best effect. Compared with salt stress (T1), the degree of chlorosis and yellowing of the leaves of industrial hemp in T6 decreased, new leaves emerged, the leaves were unfolded, and the plant height, stem diameter, biomass and SPAD value of Yunma No. 7 increased by 206.85%, 83.57%, 215.86% and 86.49% respectively, and those of Yunma No. 8 increased by 145.78%, 46.74%, 226.27% and 67.56% respectively. It can be seen that the alternate application of salicylic acid and abscisic acid reduced the damage caused by salt stress to the growth of industrial hemp.

[0041] In the present invention, when alternately and cyclically applying salicylic acid and abscisic acid, the number of cyclic applications is preferably 2 to 3 times, and the interval time between two adjacent applications is preferably 1 to 3 days, more preferably 1 to 2 days, and most preferably 2 days. In the embodiments of the present invention, the effects of different interval days (1 day, 2 days and 3 days) on the salt tolerance of industrial hemp were compared. The results showed that when the interval days between two adjacent applications were 2 days, the effect of improving the salt tolerance of industrial hemp was the best.

[0042] In order to further illustrate the present invention, a pharmaceutical composition for improving the salt tolerance of industrial hemp and a method for improving the salt tolerance of industrial hemp provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0043] 1. Preparation of test materials

[0044] Taking the seeds of Yunma No. 7 and Yunma No. 8 as test materials, they were planted by the sand culture method. The cultivation pots were round plastic flower pots with a diameter of 23 cm and a height of 18 cm. The substrate was quartz sand (particle size 1.0 - 2.0 mm). Each pot was filled with 5 kg of quartz sand washed with clean water. 15 plump and uniform seeds were sown in each pot. Before sowing, the seeds were treated with 0.1% KMnO 4The solution was disinfected for 5 min, then repeatedly rinsed clean with deionized water, allowed to dry naturally, and sown in plastic pots. After sowing, it was watered with distilled water until the first pair of true leaves fully expanded, and then 300 mL of 1 / 2 strength Hoagland nutrient solution (calcium nitrate 945 mg / L, potassium nitrate 607 mg / L, ammonium phosphate 115 mg / L) was added every 3 days. When the seedlings grew to the third pair of true leaves, thinning was carried out, and 7 evenly growing seedlings were planted in each pot.

[0045] After thinning, salt stress treatment was started. Salt stress was simulated with a 200 mM NaCl salt concentration. To avoid salt shock effects, the plants were watered in a way that the salt concentration increased each time, and the watering amount was based on a large amount of solution oozing out from the bottom of the pot, and it was watered once every other day. On the 1st day, 50 mM NaCl solution was watered, on the 3rd day, 100 mM NaCl solution was watered, on the 5th day, 150 mM NaCl solution was watered, on the 7th day, 200 mM NaCl solution was watered, and thereafter, 200 mM NaCl solution was continuously watered for 7 days to obtain salt-stressed seedlings for subsequent experiments.

[0046] Example 1

[0047] Effect of Foliar Spraying of Different Hormones on the Growth of Salt-Stressed Industrial Hemp

[0048] I. Experimental Design

[0049] Healthy salt-stressed seedlings with consistent growth were selected for treatment. 13 treatments were set for each industrial hemp variety: T1 - T13 (as shown in Table 1), and T1 - T13 were watered with 200 mM NaCl solution during the experiment;

[0050] Another group of healthy non-salt-stressed seedlings with consistent growth were selected as the control treatment: CK, and CK was watered with Hoagland nutrient solution during the experiment.

[0051] Each treatment was sprayed with hormones or water 4 times in total. Each spraying was carried out at 18:00 - 18:30, and the spraying method was foliar spraying (both sides of the leaves). The spraying amount was 3 - 5 ml / plant. The concentrations of ABA, SA, and NAA (naphthaleneacetic acid) were 250 mg / L, 250 mg / L, and 100 mg / L respectively. The interval between two adjacent sprayings was 2 days, and each treatment had 3 replicates.

[0052] Table 1 Foliar Spraying Treatments with Different Hormones

[0053] Number Spraying treatment Specific operation CK <![CDATA[0 mM NaCl + H 2 O]]> No stress + distilled water foliar spraying T1 <![CDATA[200 mM NaCl + H 2 O]]> NaCl stress + distilled water foliar spraying T2 200 mM NaCl + ABA NaCl stress + ABA alone foliar spraying T3 200 mM NaCl + SA NaCl stress + SA alone foliar spraying T4 200 mM NaCl + ABA + SA NaCl stress + ABA and SA (V:V = 1:1) mixed spraying T5 200 mM NaCl + ABA - SA NaCl stress + first ABA alone spraying, then SA alone spraying, alternating twice T6 200 mM NaCl + SA - ABA NaCl stress + first SA alone spraying, then ABA alone spraying, alternating twice T7 200 mM NaCl + NAA NaCl stress + NAA alone foliar spraying T8 200 mM NaCl + ABA + NAA NaCl stress + ABA and NAA (V:V = 1:1) mixed spraying T9 200 mM NaCl + NAA + SA NaCl stress + NAA and SA (V:V = 1:1) mixed spraying T10 200 mM NaCl + ABA - NAA NaCl stress + first ABA alone spraying, then NAA alone spraying, alternating twice T11 200 mM NaCl + NAA - ABA NaCl stress + first NAA alone spraying, then ABA alone spraying, alternating twice T12 200 mM NaCl + NAA - SA NaCl stress + first ABA alone spraying, then NAA alone spraying, alternating twice T13 200 mM NaCl + SA - NAA NaCl stress + first SA alone spraying, then NAA alone spraying, alternating twice

[0054] II. Data Processing and Analysis

[0055] On the 28th day after spraying treatment, the plant height, stem diameter, and SPAD value of the plants were measured. The SPAD value was measured using a SPAD-502 chlorophyll meter. The plants were harvested by single pot. After the roots, stems, and leaves were separated from the plants, the fresh weight was immediately measured. The surface salts were washed clean and placed in an oven at 85 °C until dried to a constant weight. After cooling to room temperature, the dry weights of the above-ground and underground parts were measured with a balance, and the root-shoot ratio was calculated.

[0056] The experimental data were processed using Microsoft Excel 2016, and one-way analysis of variance was performed using SPSS statistics 26.0 software. The LSD method was selected for multiple comparisons and significance tests of differences (P<0.05). The statistical results of the effects of different hormone foliar sprays on the growth of industrial hemp under salt stress are shown in Table 2.

[0057] Table 2 Effects of different hormone foliar sprays on the growth of industrial hemp under salt stress

[0058]

[0059]

[0060] Note: Different lowercase letters indicate the significance of differences between different treatment groups, P<0.05.

[0061] As can be seen from Table 2, the plant heights of Yunma 7 and Yunma 8 in T1-T13 were significantly lower than those of the control treatment (P<0.05, the same below), indicating that salt stress would significantly inhibit the normal growth of industrial hemp. The growth performance of industrial hemp in T2-T13 was significantly higher than that in T1, indicating that spraying exogenous ABA (T3), SA (T4), and NAA (T7) treatments under salt stress could all alleviate the inhibitory effects caused by salt stress to varying degrees. In Yunma 7, compared with the T1 treatment, the plant heights of T2-T13 increased by 44.52%, 45.89%, 7.19%, 67.12%, 80.82%, 40.75%, 44.18%, 34.25%, 47.26%, 31.51%, 33.90%, and 40.80% respectively, the stem diameters increased by 27.79%, 14.57%, 17.17%, 19.21%, 37.05%, 1.50%, 7.08%, 8.58%, 8.58%, 9.81%, 20.30%, and 18.37% respectively, and the SPAD values increased by 51.05%, 69.30%, 71.75%, 79.30%, 86.49%, 57.72%, 58.25%, 69.63%, 62.81%, 60.35%, 50.00%, and 43.53% respectively; the effect of Yunma 8 was the same as that of Yunma 7, and the best effect of alleviating salt damage was achieved by spraying SA first and then ABA in a cyclic order (T6).

[0062] Compared with the combined application of NAA with SA or ABA (T8 - T13), the combined application of ABA and SA has a better effect on alleviating salt stress. Among them, the alternating application of ABA and SA (T5 or T6) has a better effect than the mixed application of ABA and SA (T4), and the best effect of alleviating salt damage is achieved by spraying SA first and then ABA in a cyclic manner (T6).

[0063] GraphPad 8.0.2 was used to plot the data of CK and T1 - T6 in Table 2, and the results are shown in Figures 1 to 5 . Figure 6 It is the growth trend diagram of Yunma 7 under salt stress and different spraying treatments; Figure 7 It is the growth trend diagram of Yunma 8 under salt stress and different spraying treatments.

[0064] It can be seen from Figure 1 that the plant heights of Yunma 7 and Yunma 8 in T1 were significantly lower than those in the control treatment (P < 0.05, the same below), indicating that salt stress can significantly inhibit the normal growth of industrial hemp. Spraying exogenous ABA (T2) and SA (T3) under salt stress for the two industrial hemp varieties can alleviate this inhibitory effect to varying degrees, and the plant heights of T2 and T3 industrial hemp were significantly higher than that of T1. Spraying the mixture of exogenous ABA and SA (T4) did not show an obvious improvement compared with the separate spraying treatments of the two. The alternating spraying of the two exogenous substances ABA and SA (T5 and T6) had a higher ability to alleviate the plant height inhibition caused by salt stress than the separate spraying treatments of the two, and this phenomenon reflects that the alternating spraying has a significantly better effect on the plant height growth inhibition caused by salt stress than the separate spraying, and the best effect is achieved by spraying SA first and then ABA in a cyclic manner (T6).

[0065] It can be seen from Figure 2 that the effects of salt stress on the stem diameters of Yunma 7 and Yunma 8 were significant (P < 0.05, the same below). Compared with the control, the stem diameter of Yunma 7 decreased by 52.75% and that of Yunma 8 decreased by 42.15% under salt stress in T1. Compared with T1, spraying hormones (T2 - T6) had a significant effect on the stem diameter (P < 0.05). The stem diameters of Yunma 7 in T2 - T6 treatments increased by 49.26%, 53.46%, 56.93%, 59.67%, and 83.57% respectively, and the stem diameters of Yunma 8 in T3 - T6 treatments increased by 36.94%, 41.41%, 29.21%, 54.64%, and 46.74% respectively. The differences among the hormone treatments were not obvious, but the alternating spraying of ABA and SA (T5 and T6) for the two industrial hemp varieties had a slightly higher ability to alleviate the plant height inhibition caused by salt stress than the separate spraying treatments of the two.

[0066] As Figure 3It can be seen that salt stress has a significant effect on the total biomass of the two industrial hemp varieties (P<0.05), and spraying exogenous hormones under salt stress can significantly increase the total biomass of industrial hemp. Compared with the control, the total biomass of Yunma 7 decreased by 79.34% under salt stress in T1, and that of Yunma 8 decreased by 77.43%. Compared with T1, the total biomass of Yunma 7 in T2-T6 increased by 85.71%, 115.86%, 127.00%, 149.19%, and 215.86% respectively, and that of Yunma 8 in T2-T6 increased by 72.16%, 96.75%, 106.59%, 173.83%, and 226.27% respectively; Generally speaking, the total biomass of Yunma 7 is higher than that of Yunma 8, and the differences among hormone treatments are obvious. The effects of mixed spraying of ABA and SA (T4), and alternating spraying of ABA and SA (T5 and T6) are better than single spraying of the two, especially for Yunma 8.

[0067] As Figure 4 It can be seen that the effect of salt stress on the root-shoot ratio of industrial hemp is significantly different (P<0.05), and the effects of different treatments of exogenous hormones under salt stress on the root-shoot ratio of industrial hemp are not significantly different. Compared with T1, the root-shoot ratios of Yunma 7 in T2-T6 increased by -9.71%, 38.00%, 19.87%, 34.42%, and 46.80% respectively, and those of Yunma 8 in T2-T6 increased by 2.08%, -15.39%, 20.90%, 2.64%, and 27.78% respectively. Among them, cyclic spraying in the order of first spraying SA and then spraying ABA (T6) has the best effect on Yunma 7 and Yunma 8 under salt stress, especially for Yunma 7.

[0068] As Figure 5 It can be seen that the effect of salt stress on the SPAD values of Yunma 7 and Yunma 8 is significant (P<0.05, the same below). Compared with the control, the SPAD value of Yunma 7 in T1 decreased by 46.68%, and that of Yunma 8 in T1 decreased by 41.57%. Compared with T1, the root-shoot ratios of Yunma 7 in T2-T6 increased by 51.05%, 69.30%, 71.75%, 75.79%, and 86.49% respectively, and those of Yunma 8 in T2-T6 increased by 48.81%, 44.49%, 48.51%, 59.67%, and 67.56% respectively. There are differences among different hormone treatments, and the effect of cyclic spraying (T6) in the order of first spraying SA and then spraying ABA is better than single spraying and mixed spraying of the two.

[0069] Example 2

[0070] Effect of spraying hormones at different intervals on growth indexes of industrial hemp under salt stress

[0071] The experiment was carried out according to the treatment methods of the CK group and the T1-T6 groups in Example 1, with the only difference being that the spraying intervals between two adjacent exogenous hormones were adjusted to 1 day and 3 days respectively.

[0072] The data was processed and analyzed according to the method of Example 1. The effects of spraying hormones at different intervals on the growth indexes of salt-stressed industrial hemp are shown in Table 3.

[0073] Table 3 Effects of spraying hormones at different intervals on the growth indexes of salt-stressed industrial hemp

[0074]

[0075]

[0076] Note: Different lowercase letters indicate the significance of differences between different treatment groups, P < 0.05.

[0077] As can be seen from Table 3, compared with T1, the biomass of Yunma 7 at 1-day intervals in T2-T4 increased by 70.92%, 116.11%, and 117.71% respectively; the biomass of T5 and T6 increased by 143.49% and 182.20% respectively; the biomass of Yunma 7 at 3-day intervals in T2-T4 increased by 83.84%, 117.71%, 132.22%, and 132% respectively; the biomass of T5 and T6 increased by 127.38% and 161.25% respectively. The alleviating effects of different intervals on industrial hemp under salt stress were generally the same, but the effects of each group were the best at 2-day intervals. Therefore, the preferred interval is 2 days. The effects of T5 and T6 at 1-day intervals are better than those at 2-day intervals.

[0078] Example 3

[0079] Effects of different hormone root applications on the growth of salt-stressed industrial hemp

[0080] Healthy salt-stressed seedlings with consistent growth were selected for treatment. Six treatments were set for each industrial hemp variety: T1-T6 (as shown in Table 4), and 200 mM NaCl solution was irrigated during the experiment for T1-T6;

[0081] Another group of healthy non-salt-stressed seedlings with consistent growth was selected as the control treatment: CK, and Hoagland nutrient solution was irrigated during the experiment for CK.

[0082] Each treatment was root-applied with hormones or water 4 times in total. Each root application was carried out at 18:00-18:30, and 10 ml / plant was applied to the roots of industrial hemp each time. The concentrations of ABA, SA, and NAA (naphthaleneacetic acid) were 250 mg / L, 250 mg / L, and 100 mg / L respectively. The interval between two adjacent root applications was 2 days, and each treatment had 3 replicates.

[0083] The data was processed and analyzed according to the method of Example 1. The effects of different hormones applied to the roots on the growth of industrial hemp under salt stress are shown in Table 5.

[0084] Table 4 Treatments of different hormones applied to the roots

[0085] Number Root application treatment Specific operation CK <![CDATA[0 mM NaCl + H 2 O]]> No stress + distilled water root application T1 <![CDATA[200 mM NaCl + H 2 O]]> NaCl stress + distilled water root application T2 200 mM NaCl + ABA NaCl stress + ABA alone root application T3 200 mM NaCl + SA NaCl stress + SA alone root application T4 200 mM NaCl + ABA + SA NaCl stress + ABA and SA (V:V = 1:1) mixed root application T5 200 mM NaCl + ABA - SA NaCl stress + first ABA alone root application, then SA alone root application, alternating twice T6 200 mM NaCl + SA - ABA NaCl stress + first SA alone root application, then ABA alone root application, alternating twice

[0086] Table 5 Effects of different hormones applied to the roots on the growth of industrial hemp under salt stress

[0087]

[0088] Note: Different lowercase letters indicate the significance of differences between different treatment groups, P < 0.05.

[0089] As can be seen from Table 5, compared with T1, for Yunma 7, the plant heights of T2 - T6 with different hormones applied to the roots increased by 21.92%, 26.71%, 26.37%, 21.58% and 25.69% respectively, the stem diameters increased by 0.13%, 0.82%, 6.95%, 5.45% and 7.36% respectively, the SPAD values increased by 45.00%, 53.33%, 57.67%, 49.17% and 29.17% respectively, and the biomass increased by 30.28%, 46.07%, 42.12%, 53.97% and 59.22% respectively; compared with T1, for Yunma 8, the plant heights of T2 - T6 with different hormones applied to the roots increased by 7.47%, 14.29%, 20.78%, 44.48% and 49.35% respectively, the stem diameters increased by 12.89%, 22.51%, 28.35%, 27.84% and 29.04% respectively, the SPAD values increased by 16.67% / 16.27%, 22.83%, 17.45% and 18.90% respectively, and the biomass increased by 54.81%, 43.20%, 88.68%, 95.11% and 109.63% respectively. The best root application effect is T6. Compared with T1, for Yunma 7, the plant height, stem diameter, biomass and SPAD value of T6 increased by 206.85%, 83.57%, 215.86% and 86.49% respectively, and for Yunma 8, the plant height, stem diameter, biomass and SPAD value of T6 increased by 145.78%, 46.74%, 226.27% and 67.56% respectively. In summary, the effect of hormone foliar spraying is better than root application.

[0090] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, not all of them. Other embodiments can be obtained based on this embodiment without creative efforts, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A pharmaceutical composition, characterized in that Includes separately packaged salicylic acid and abscisic acid; The mass ratio of salicylic acid to abscisic acid is 1:(0.8-1.2).

2. Use of the pharmaceutical composition according to claim 1 in the cultivation of industrial hemp.

3. The application according to claim 2, characterized in that: The industrial hemp cultivation includes improving the salt tolerance of industrial hemp.

4. A method for improving the salt tolerance of industrial hemp, characterized in that: The method comprises the following steps: applying salicylic acid and abscisic acid in alternating cycles in industrial hemp cultivation; The working concentration of the salicylic acid or the abscisic acid is 150-270 mg / L.

5. The method according to claim 4, characterized in that: The method of alternately cyclically administering salicylic acid and abscisic acid comprises cyclically administering salicylic acid first and then abscisic acid or cyclically administering abscisic acid first and then salicylic acid.

6. The method according to claim 4, characterized in that: The alternating cycle of salicylic acid and abscisic acid is 2 to 3 times; When salicylic acid and abscisic acid are applied in an alternating cycle, the interval between two adjacent applications is 1 to 3 days.

7. The method according to claim 4, characterized in that: The application method includes foliar spraying and / or irrigation application; When spraying on the leaves, the application amount of salicylic acid or abscisic acid is 3-5 mL / plant; When the irrigation is used, the application amount of the salicylic acid or abscisic acid is 8 to 12 mL / plant.

8. The method according to claim 4, characterized in that: The starting time for the alternating cycle application of salicylic acid and abscisic acid is the seedling stage of industrial hemp.

9. The method according to claim 8, characterized in that: The industrial hemp seedling stage includes the stage when the industrial hemp has four pairs of true leaves.

10. The method according to any one of claims 4 to 9, characterized in that: The industrial hemp includes Yunma No. 7 and / or Yunma No. 8.

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