Application of β-cyclocitral solution in improving salt tolerance of cucumber seedlings

Abstract

The present invention relates to the field of crop cultivation technology, and in particular to the application of a β-cyclocitral solution in improving the salt tolerance of cucumber seedlings. The present invention provides the application of a β-cyclocitral solution in improving the salt tolerance of cucumber seedlings. After the cucumber seedlings are treated with a β-cyclocitral solution, the salt tolerance of the cucumber seedlings can be preferably improved in a short period of time, and the operation is simple and the cost is low.

Description

Technical Field

[0001] The invention relates to the technical field of crop cultivation, in particular to application of a beta-cyclocitral solution in improving the salt tolerance of cucumber seedlings. Background Art

[0002] The molecular formula of beta-Cyclocitral is C 10 H 16 O, with a molecular weight of 152.2334. β-Cyclocitral, a naturally occurring carotenoid derived from β-carotene, is a cheap, effective, low-concentration, and topical natural compound.

[0003] With the rapid development of greenhouse agriculture, secondary soil salinization, which is used in greenhouse agriculture, has become increasingly serious, leading to reduced photosynthesis and resistance of greenhouse crops, and reduced yield and quality. Secondary soil salinization has become one of the major stresses restricting greenhouse vegetable production.

[0004] Cucumber is a melon crop with the largest cultivated area in my country's vegetable industry. It has a shallow root system, large leaf area, and weak root absorption capacity. It has high soil requirements and is prone to cucumber erosion, resulting in yield reduction. It is a salt-sensitive vegetable. Salt stress in saline-alkali land and greenhouse production can lead to decreased cucumber seed vigor, incomplete development of lateral roots in the young embryo after germination, overall water loss and shrinkage of cucumber seedlings, reduced dry and fresh quality of aboveground parts, and yellowing and withering of leaves, resulting in a significant decline in yield and quality, seriously restricting the development of my country's cucumber industry. Therefore, taking effective measures to improve cucumber salt tolerance is of great guiding significance for solving problems such as greenhouse cucumber production obstacles caused by secondary soil salinization.

[0005] Breeding salt-tolerant varieties is the most fundamental and effective way to improve cucumber salt tolerance, but the breeding cycle is long, the operation is complex, and the investment cost is high. Therefore, it is urgent to find a method to improve the salt tolerance of cucumber seedlings in a short period of time. Summary of the Invention

[0006] In order to solve the above problems, the present invention provides the use of a β-cyclocitral solution in improving the salt tolerance of cucumber seedlings. After the cucumber seedlings are treated with the β-cyclocitral solution, the salt tolerance of the cucumber seedlings can be improved in a short period of time, and the operation is simple and the cost is low.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] The invention provides application of a beta-cyclocitral solution in improving salt tolerance of cucumber seedlings. The concentration of the beta-cyclocitral in the beta-cyclocitral solution is 75 μM.

[0009] The invention provides a method for improving salt tolerance of cucumber seedlings. The method comprises: performing root treatment on the cucumber seedlings by utilizing a beta-cyclocitral solution; the concentration of the beta-cyclocitral in the beta-cyclocitral solution is 75 μM.

[0010] Preferably, the root application treatment is performed when the cucumber seedlings have two leaves and one heart.

[0011] Preferably, the sowing density of the cucumbers is 4000 to 4200 plants per mu; and the dosage of the β-cyclocitral solution is 60 to 63 L per mu.

[0012] Preferably, the salt content of the soil for sowing the cucumber seedlings is 150 mM.

[0013] Preferably, the root application method includes drip irrigation or root irrigation.

[0014] Beneficial effects: The present invention provides an application of a β-cyclocitral solution in improving the salt tolerance of cucumber seedlings, wherein the concentration of β-cyclocitral in the β-cyclocitral solution is 75 μM. The present invention uses a β-cyclocitral solution of a specific concentration to treat cucumber seedlings, which can significantly improve the salt tolerance of cucumber seedlings in a short period of time; and the β-cyclocitral solution is easy to prepare, has the characteristics of low price, and is effective at low concentrations. It can be seen that the β-cyclocitral solution of the present invention, while improving the salt tolerance of cucumber seedlings, ensures the safety of cucumber use and the physical and mental health of the people, and also promotes fruit and vegetable processing companies to improve the production quality of their products.

[0015] Moreover, the present invention also provides a method for improving the salt tolerance of seedlings. The method is a non-transgenic technology with high safety, high efficiency, simple operation and easy promotion. It can significantly improve the salt tolerance of cucumbers and effectively solve the problem of production obstruction of facility cucumbers due to secondary salinization of soil. The results of the embodiment of the present invention show that after the β-cyclocitral solution is applied to the roots of cucumber seedlings, the plant height, stem diameter, whole plant fresh weight, total chlorophyll content, etc. of the cucumber seedlings can be significantly improved; the treatment of the β-cyclocitral solution with the root application is compared with the effect of salt stress treatment alone. The plant height increased by 10.16%, the stem diameter increased by 12.39%, the whole plant fresh weight increased by 18.46%, and the total chlorophyll content increased by 41.54%. DETAILED DESCRIPTION

[0016] The present invention provides the use of a β-cyclocitral solution in improving the salt tolerance of cucumber seedlings, wherein the concentration of β-cyclocitral in the β-cyclocitral solution is 75 μM. In the present invention, the solute of the β-cyclocitral solution is preferably β-cyclocitral, and the solvent is preferably methanol. The present invention does not particularly limit the sources of the β-cyclocitral and methanol, and those conventionally purchased by those skilled in the art can be used; the methanol is preferably pure methanol. Treating cucumber seedlings with a β-cyclocitral solution of a specific concentration can significantly improve the salt tolerance of the cucumber seedlings in a short period of time, which is specifically reflected in the increase in plant height, stem thickness, fresh weight, relative conductivity and chlorophyll content; and the β-cyclocitral solution is easy to prepare, and has the characteristics of low price and low concentration effectiveness.

[0017] The present invention provides a method for improving salt tolerance in cucumber seedlings, comprising: applying root application to the cucumber seedlings with a β-cyclocitral solution; the β-cyclocitral concentration in the β-cyclocitral solution is 75 μM. In the present invention, the root application is preferably performed when the cucumber seedlings have two leaves and one heart. If salt stress occurs during this period, the phenotype of plant damage is clearly visible. In the present invention, the sowing density of the cucumbers is preferably 4,000 to 4,200 plants per mu (approximately 1 acre); the dosage of the β-cyclocitral solution is 60 to 63 L per mu (approximately 1 acre), more preferably 60.5 to 62.5 L per mu (approximately 1 acre). In the present invention, the root application method is preferably drip irrigation or root irrigation. The root application method of the present invention can effectively prevent the volatilization of β-cyclocitral. The method of the present invention is preferably suitable for soils with a salt content of 150 mM. If the experiment is conducted in a laboratory, the dosage of the β-cyclocitral solution is preferably 15 mL per plant.

[0018] The method of the present invention can effectively improve the salt tolerance of cucumber seedlings. Results from specific examples of the present invention show that root application of a β-cyclocitral solution to cucumber seedlings significantly increased plant height, stem diameter, whole plant fresh weight, whole plant dry weight, and total chlorophyll content. Compared with salt stress treatment alone, root application of the β-cyclocitral solution increased plant height by 8.78%, stem diameter by 14.1%, whole plant fresh weight by 11.85%, whole plant dry weight by 7.69%, and total chlorophyll content by 41.54%.

[0019] To further illustrate the present invention, the application of the β-cyclocitral solution provided by the present invention in improving the salt tolerance of cucumber seedlings is described in detail below in conjunction with the examples, but they should not be construed as limiting the scope of protection of the present invention.

[0020] Example 1

[0021] Cucumber seedlings with uniform growth and two leaves and one heart were treated with root irrigation of 75 μM β-cyclocitral solution at a dosage of 15 mL / plant. Pure methanol was used as the solvent for the 75 μM β-cyclocitral solution. Salt stress treatment was performed after root irrigation, specifically: 50 mM NaCl solution was used for salt treatment on the 3rd day of root application, 100 mM NaCl solution was used for salt treatment on the 4th day, and 150 mM NaCl solution was used for salt treatment on the 5th day. There were 16 cucumber seedlings. During the salt treatment, the specific application method of NaCl solution was root irrigation, recorded as 75β; three parallel experiments were performed for this treatment.

[0022] Comparative Example 1

[0023] The steps are the same as those in Example 1, except that water is used instead of the 75 μM β-cyclocitral solution, which is recorded as 0β.

[0024] Comparative Example 2

[0025] The steps are the same as those in Example 1, except that a 25 μM β-cyclocitral solution is used instead of a 75 μM β-cyclocitral solution, which is recorded as 25β.

[0026] Comparative Example 3

[0027] The steps are the same as those in Example 1, except that a 50 μM β-cyclocitral solution is used instead of a 75 μM β-cyclocitral solution, which is recorded as 50β.

[0028] Comparative Example 4

[0029] The steps are the same as those in Example 1, except that a 100 μM β-cyclocitral solution is used instead of a 75 μM β-cyclocitral solution, which is recorded as 100β.

[0030] Test Example 1

[0031] On the 8th day after the β-cyclocitral root irrigation treatment, the indexes measured were plant height, stem diameter, fresh weight, relative conductivity, dry weight, and chlorophyll content. The specific measurement method was as follows:

[0032] Use a tape measure and vernier caliper to measure the plant height and stem diameter of cucumber seedlings: use a tape measure to measure from the junction of the root and stem to the latest growth point of the plant to get the plant height; use a vernier caliper to measure the thickest part of the base of the aboveground part to get the stem diameter.

[0033] The measurement method of dry and fresh weight is as follows: take samples from the above-ground and underground parts of cucumber seedlings respectively, rinse them with tap water 2 to 3 times, then rinse them with distilled water twice, dry them with absorbent paper, and weigh the mass of the fresh sample to obtain the fresh weight; fix them at 105℃ for 15 minutes, dry them at 65℃ to a constant weight, and weigh the mass of the dry sample to obtain the dry weight.

[0034] The chlorophyll content of treated cucumber seedlings and control cucumber seedlings was measured using Arnon's method: take the first true leaf of each cucumber, remove the main vein, and cut it into thin strips. After mixing, weigh 0.2g of each into a brown volumetric flask, add 95% anhydrous ethanol by volume to extract, and stopper it to block light; the extraction time is 24h, and the extract is shaken and measured and calculated using an ultraviolet spectrophotometer at wavelengths of 665nm and 649nm.

[0035] Conductivity was measured as follows: Rinse cucumber leaves twice with deionized water, then rinse with clean filter paper to remove surface moisture. Punch a sample (from the leaf). Place 10 discs in a 50-mL centrifuge tube containing 20 mL of distilled water and shake at 180 rpm for 2 hours. The conductivity value was measured and recorded as EC1. Boil for 15 minutes, cool to room temperature, and shake for another 2 hours. The conductivity value was measured again, recorded as EC2. The distilled water control was used as a control, and the conductivity value was recorded as EC0. Conductivity was calculated as follows: Relative conductivity = (EC1 - EC0) / (EC2 - EC0) * 100%.

[0036] The test results of Example 1 and Comparative Examples 1 to 4 are shown in Tables 1-1 to 1-2 and Tables 2-1 to 2-2.

[0037] Table 1-1 Test results of plant height, stem diameter, fresh weight and relative conductivity in Example 1 and Comparative Examples 1 to 4

[0038] deal with Plant height / cm Stem diameter / mm Above ground fresh weight / g Comparative Example 1 0β 6.78±0.27 3.31±0.12ab 3.91±0.12 Comparative Example 2 25β 6.31±0.20 3.38±0.19ab 3.95±0.16 Comparative Example 3 50β 6.81±0.24 3.45±0.14a 3.74±0.34 Example 1 75β 6.24±0.15 2.94±0.13b 3.99±0.20 Comparative Example 4 100β 6.89±0.19 3.26±0.15ab 3.97±0.19

[0039] Note: The data in the table are rounded to 2 decimal places. Different letters in the same column of data in the table represent significant differences. If there are no letters in the same column of data, it means that there is no significant difference between the data. The same applies to the following table.

[0040] Table 1-2 Test results of plant height, stem diameter, fresh weight and relative conductivity in Example 1 and Comparative Examples 1 to 4

[0041]

[0042]

[0043] Table 2-1 Test results of dry weight and chlorophyll content in Example 1 and Comparative Examples 1 to 4

[0044]

[0045] Table 2-2 Test results of dry weight and chlorophyll content in Example 1 and Comparative Examples 1 to 4

[0046]

[0047] Relative conductivity is a key indicator of plant salt tolerance; lower relative conductivity is better. Tables 1-1 to 1-2 and 2-1 to 2-2 show that cucumber seedlings treated with a 25 μM β-cyclocitral solution showed an increase in stem diameter, chlorophyll content, and plant dry weight, while conductivity decreased. However, plant height and plant fresh weight decreased. Cucumber seedlings treated with a 50 μM β-cyclocitral solution showed an increase in plant height, stem diameter, chlorophyll content, and conductivity, but a decrease in plant dry weight. Cucumber seedlings treated with a 75 μM β-cyclocitral solution showed a decrease in plant height and stem diameter, but decreased conductivity, while chlorophyll content and plant dry weight increased. Cucumber seedlings treated with 100 μM β-cyclocitral solution showed an increase in plant height and a decrease in electrical conductivity, but stem diameter, chlorophyll content, and plant dry and fresh weight all showed a decrease. Cucumber seedlings treated with 75 μM β-cyclocitral solution had lower relative electrical conductivity, while other indicators performed well overall. Therefore, 75 μM β-cyclocitral solution was selected as the most suitable root application concentration.

[0048] Example 2

[0049] Cucumber seedlings with uniform growth and two leaves and one heart were treated with root irrigation of 75 μM β-cyclocitral solution at a dosage of 15 mL / plant. Pure methanol was used as the solvent for the 75 μM β-cyclocitral solution. Salt stress treatment was performed after root irrigation, specifically: 50 mM salt treatment was performed on the 3rd day of root application, 100 mM salt treatment was performed on the 4th day, and 150 mM salt treatment was performed on the 5th day. There were 16 cucumber seedlings, and different concentrations of NaCl solutions were used for salt treatment. The specific application method of salt treatment was root irrigation, recorded as βcyc+NaCl. Three parallel experiments were conducted for this treatment.

[0050] Comparative Example 5

[0051] The steps were the same as those in Example 2, except that the roots were irrigated with a 75 μM β-cyclocitral solution, and no salt stress treatment was performed, which was recorded as βcyc.

[0052] Comparative Example 6

[0053] The steps were the same as those in Example 2, except that the same amount of water was used for root irrigation and no salt stress treatment was performed, which was recorded as CK.

[0054] Comparative Example 7

[0055] The steps were the same as those in Example 2, except that the same amount of water was used for root irrigation and salt stress treatment was performed, recorded as NaCl.

[0056] Eight days after root irrigation with β-cyclocitral, the plants of Example 2 and Comparative Examples 5 to 7 were measured for plant height, stem diameter, fresh weight, relative conductivity, dry weight, and chlorophyll content. The specific testing methods were the same as those used in Test Example 1. The test results are shown in Tables 3-1 to 3-2 and Tables 4-1 to 4-2.

[0057] Table 3-1 Test results of plant height, stem diameter, fresh weight and relative conductivity in Example 2 and Comparative Examples 5 to 7

[0058]

[0059] Note: Example 1 and Comparative Examples 1 to 4 used the same batch of seeds (referred to as the first batch of seeds), while Example 2 and Comparative Examples 5 to 7 used the same batch of seeds (referred to as the second batch of seeds), and the experimental time of the two batches of seeds was different. Therefore, it is reasonable that there are differences between the various indicators.

[0060] Table 3-2 Test results of plant height, stem diameter, fresh weight and relative conductivity in Example 2 and Comparative Examples 5 to 7

[0061]

[0062] Table 4-1 Test results of dry weight and chlorophyll content in Example 2 and Comparative Examples 5 to 7

[0063]

[0064] Table 4-2 Test results of dry weight and chlorophyll content in Example 2 and Comparative Examples 5 to 7

[0065]

[0066]

[0067] As shown in Tables 3-1 to 3-2 and 4-1, compared with CK (Comparative Example 6), the aboveground fresh weight, underground fresh weight and stem diameter of cucumber seedlings under NaCl stress (Comparative Example 7) significantly decreased by 27.30%, 45.83% and 12.36%, respectively. Compared with βcyc (Comparative Example 5), the aboveground fresh weight, whole plant fresh weight and plant height of cucumber seedlings under NaCl stress (Comparative Example 7) significantly decreased by 28.28%, 29.35% and 18.15%, respectively. Compared with NaCl stress alone (Comparative Example 7), the whole plant fresh weight, plant height and stem diameter of cucumber seedlings under NaCl stress (Example 2) after root application of β-cyclocitral were significantly increased by 18.46%, 10.16% and 12.39%, respectively. Root application of β-cyclocitral has a significant alleviating effect on the accumulation of total fresh weight and stem diameter of cucumber seedlings under NaCl stress.

[0068] As shown in Tables 3-2 and 4-2, compared with CK (Comparative Example 6), the contents of chlorophyll a, chlorophyll b and total chlorophyll of cucumber seedlings under NaCl stress (Comparative Example 7) decreased significantly by 51.90%, 25.53% and 42.07%, respectively. Compared with NaCl stress alone (Comparative Example 7), the contents of chlorophyll a and total chlorophyll of cucumber seedlings under NaCl stress (Example 2) after root application of β-cyclocitral increased significantly by 59.04% and 36.15%, respectively. This shows that under NaCl stress conditions, the addition of exogenous β-cyclocitral can significantly inhibit the reduction of photosynthetic pigment content in cucumber seedling leaves. Compared with CK (Comparative Example 6), the relative electrical conductivity of the leaves of cucumber seedlings under NaCl stress (Comparative Example 7) increased significantly by 2.34 times; compared with βcyc (Comparative Example 5), the relative electrical conductivity of the leaves of cucumber seedlings under NaCl stress increased significantly by 2.15 times. Compared with NaCl stress alone (Comparative Example 7), the relative electrical conductivity of the leaves of cucumber seedlings under NaCl stress (Example 2) after root application of β-cyclocitral was significantly reduced by 1.68 times, thereby improving the salt tolerance of the cucumber seedlings.

[0069] In summary, the present invention uses a specific concentration of β-cyclocitral solution to process cucumber seedlings, which can significantly improve the salt tolerance of cucumber seedlings in a short period of time; and β-cyclocitral solution is easy to prepare, and has the characteristics of low price and low concentration being effective. It can be seen that the β-cyclocitral solution of the present invention, while improving the salt tolerance of cucumber seedlings, ensures the safety of use of cucumbers and the physical and mental health of the people, and also promotes fruit and vegetable processing companies to improve the production quality of products. Moreover, the method is a non-transgenic technology with high safety, high efficiency, simple and easy operation and easy promotion, which can significantly improve the salt tolerance of cucumbers and can effectively solve the problem of production obstruction caused by secondary salinization of soil in facility cucumbers.

[0070] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. Application of β-cyclocitral solution in improving salt tolerance of cucumber seedlings, characterized in that: The concentration of β-cyclocitral in the β-cyclocitral solution is 75 μM; the dosage of the β-cyclocitral solution is 15 mL / plant.

2. A method for improving salt tolerance of cucumber seedlings, characterized in that: include: β-cyclocitral solution is used for root treatment of cucumber seedlings; the concentration of β-cyclocitral in the β-cyclocitral solution is 75 μM; the sowing density of the cucumbers is 4000-4200 plants / mu; and the dosage of the β-cyclocitral solution is 60-63 L / mu.

3. The method according to claim 2, characterized in that The root application treatment is carried out when the cucumber seedlings have two leaves and one heart.

4. The method according to claim 2, characterized in that The salt content of the soil for sowing the cucumber seedlings is 150 mM.

5. The method according to claim 2, characterized in that The root application method includes drip irrigation or root irrigation.

Images