Composite plant growth regulator and application thereof in improving cold resistance of cotton in seedling stage

Abstract

The invention discloses a composite plant growth regulator and application thereof in improving the cold resistance of cotton in a seedling stage. 2, 4-epibrassinolide and prohexadione calcium are compounded for the first time, the compounded compound growth regulator is sprayed on cotton seedlings after cold stress, and the result shows that compared with a contrast, the compound growth regulator effectively increases the relative chlorophyll content, plant height and dry weight and fresh weight of stems and leaves of the cotton seedlings in the recovery stage, and the recovery rate of the cotton seedlings is increased. Therefore, the growth of leaves and stalks of the cotton seedlings after cold stress can be quickly recovered, the material accumulation of the cotton seedlings after cold stress is promoted, and the optimal ratio (EBR 0.04 mg / L + PC 30 mg / L) is explored. The compound growth regulator eliminates the adverse effect of cold stress to a certain extent, guarantees the healthy growth of cotton seedlings, effectively solves the agricultural production problem of Xinjiang cotton, and has important significance for guaranteeing the high and stable yield of cotton.

Description

Technical Field

[0001] The present invention relates to the field of biotechnology, and in particular to a composite plant growth regulator and its application in improving the cold tolerance of cotton seedlings, and in particular to a composite plant growth regulator of 2,4-epibrassinolide and prohexadione calcium and its application in improving the cold tolerance of cotton seedlings. Background Art Plant growth regulators are a class of substances with physiological and biological effects similar to those of plant hormones, which are used to artificially regulate plant growth and development so that they develop in the desired direction. Plant growth regulators can be artificially synthesized or natural products extracted from organisms. At present, the number of registered active ingredients of plant growth regulators in my country is complex, with a total of more than 60, and this number is rising year by year at a steady pace. However, although plant growth regulators have shown great potential in agricultural production, their practical application faces a series of challenges, the most notable of which is the limitation of the efficacy of a single type of plant growth regulator. The traits of plants are often controlled by multiple dimensions, so the regulatory ability of using a single type of plant growth regulator is limited. Therefore, it is of great significance for agricultural production to explore the application strategy of compound plant growth regulators, that is, to achieve multi-level and all-round regulation of the plant growth and development process through scientific proportioning of multiple active ingredients, in order to break through the efficiency bottleneck of a single type of regulator.

[0002] Xinjiang is the main cotton planting and production area in my country, but cotton seedlings are facing severe challenges. Under the influence of large temperature differences between day and night and unstable spring temperatures, cold stress has become a key factor restricting the robust growth of cotton seedlings and affecting subsequent yield and quality, which seriously restricts cotton growth in Xinjiang production areas. Therefore, the development and promotion of compound agents with cold resistance and improved resilience can not only solve the urgent needs in current agricultural production, but also is a key measure to promote agricultural scientific and technological progress, agricultural modernization and sustainable development. Summary of the invention

[0003] The technical problem to be solved by the present invention is how to improve the cold tolerance of cotton in the seedling stage so as to promote cotton growth, increase cotton yield and improve cotton quality.

[0004] In order to solve the above technical problems, the present invention first provides a composite plant growth regulator.

[0005] The active ingredients of the composite plant growth regulator provided by the invention include 2,4-epibrassinolide and prohexadione-calcium.

[0006] Furthermore, the concentration of 2,4-epibrassinolide in the composite plant growth regulator may be 0.01-0.1 mg / L or 0.01-0.04 mg / L or 0.04-0.1 mg / L, specifically 0.01 mg / L or 0.04 mg / L or 0.1 mg / L, preferably 0.04 mg / L.

[0007] The concentration of prohexadione-calcium in the composite plant growth regulator may be 20-100 mg / L or 20-30 mg / L or 30-60 mg / L or 60-100 mg / L, specifically 20 mg / L or 30 mg / L or 60 mg / L or 100 mg / L, preferably 30 mg / L.

[0008] Furthermore, the active ingredients of the composite plant growth regulator consist of 2,4-epibrassinolide and prohexadione-calcium.

[0009] In one embodiment of the present invention, the composite plant growth regulator is prepared according to the following method: 2,4-epibrassinolide solution, prohexadione calcium solution and water are mixed to obtain the composite plant growth regulator; the preparation method of the 2,4-epibrassinolide solution is as follows: 2,4-epibrassinolide is dissolved in an ethanol solution to obtain a 2,4-epibrassinolide mother liquor (such as a 2,4-epibrassinolide mother liquor with a concentration of 1000 mg / L), and then the 2,4-epibrassinolide mother liquor is mixed with water to obtain the 2,4-epibrassinolide solution; the preparation method of the prohexadione calcium solution is as follows: prohexadione calcium (such as prohexadione calcium with a total active ingredient content of 15% and a dosage form of a suspension) is mixed with water to obtain the prohexadione calcium solution.

[0010] In practical applications, according to actual needs, the composite plant growth regulator may also contain other ingredients, such as synergists, cosolvents, etc.

[0011] In order to solve the above technical problems, the present invention also provides a new use of the above composite plant growth regulator.

[0012] The present invention provides application of the composite plant growth regulator in improving the cold tolerance of plants.

[0013] The present invention also provides the use of the composite plant growth regulator in preparing a product for improving the cold tolerance of plants.

[0014] In order to solve the above technical problems, the present invention finally provides a method for improving the cold tolerance of plants.

[0015] The method for improving the cold tolerance of plants provided by the present invention comprises the step of spraying the above-mentioned composite plant growth regulator on the plants.

[0016] Furthermore, the spraying site is leaves.

[0017] Furthermore, the spraying dosage is 2 ml / plant.

[0018] In any of the above-mentioned uses or methods, the cold tolerance is cold tolerance at the seedling stage.

[0019] The improvement of plant cold tolerance is embodied in any one of the following A1)-A6): A1) Increase the chlorophyll content in plant leaves after cold stress treatment (such as relative chlorophyll content); A2) Increase plant height after cold stress treatment; A3) Increase the fresh weight of plant stems after cold stress treatment; A4) Increase the fresh weight of plant leaves after cold stress treatment; A5) Increased stem dry weight of plants after cold stress treatment; A6) Increase the dry weight of plant leaves after cold stress treatment.

[0020] In any of the above-mentioned uses or methods, the plant is any one of the following C1)-C4): C1) monocots or dicots; C2) Malvaceae; C3) cotton plants; C4) Cotton (such as medium cotton 113).

[0021] In any of the above applications or methods, the chemical name of the 2,4-epibrassinolide (EBR) is (22R,23R,24R)-2Α,3Α,22,23-tetrahydroxy-Β-homo-7-oxa-5Α-ergoster-6-one, and the molecular formula is C 28 H 48 O6, CAS number is 78821-43-9.

[0022] In any of the above applications or methods, the chemical name of the prohexadione calcium (PC) is 3-oxo-5-oxo-4-propionylcyclohex-3-enecarboxylate calcium, and the molecular formula is C 10 H 10 CaO5, CAS number is 127277-53-6.

[0023] The present invention compounded 2,4-epibrassinolide and calcium prohexadione for the first time, and sprayed the compounded composite growth regulator on cotton seedlings after cold stress. The results showed that compared with the control, the composite growth regulator effectively increased the relative chlorophyll content, plant height, dry weight and fresh weight of stems and leaves of cotton seedlings in the recovery stage, indicating that it can quickly restore the growth of leaves and stems of cotton seedlings after cold stress, promote the accumulation of substances in cotton seedlings after cold stress, and explore the optimal ratio (EBR0.04 mg / L + PC 30 mg / L). The composite growth regulator of the present invention eliminates the adverse effects of cold stress to a certain extent, ensures the healthy growth of cotton seedlings, effectively solves the problem of agricultural production of cotton in Xinjiang, and is of great significance for ensuring high and stable yields of cotton. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Cold stress inhibits the growth of cotton seedlings.

[0025] Figure 2 This is the phenotype of cotton seedlings 3 days after treatment with the combination agent.

[0026] Figure 3 Compound agent treatment promotes the accumulation of substances during the recovery period. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0028] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0029] The chemical name of 2,4-epicrassinolide (EBR) in the following examples is (22R,23R,24R)-2Α,3Α,22,23-tetrahydroxy-Β-homo-7-oxa-5Α-ergoster-6-one, and the molecular formula is C 28 H 48 O6, CAS No. 78821-43-9. The 2,4-epibrassinolide in the present invention is a product of Shanghai Yuanye Biotechnology Co., Ltd., with a product No. S18014-100mg.

[0030] The chemical name of prohexadione calcium (PC) in the following examples is 3-oxo-5-oxo-4-propionylcyclohex-3-enecarboxylate calcium, and its molecular formula is C 10 H10 CaO5, CAS No. 127277-53-6. The prohexadione calcium (with a total active ingredient content of 15% and a suspension form) in the present invention is a product of Heli Technology Co., Ltd.

[0031] The cotton variety "Zhongmian 113" in the following embodiments is recorded in the literature "Wang L, Lin M, Han Z, et al. Simulating the effects of drought stress timing and the amount irrigation on cotton yield using the CSM-CROPGRO-cotton model[J]. Agronomy, 2023, 14(1):14." and "Yan P, Han Q, Feng Y, et al. Estimating lai for cotton usingmultisource uav data and a modified universal model[J]. Remote Sensing, 2022,14(17): 4272.".

[0032] Example 1: A composite plant growth regulator and its application in improving the cold tolerance of cotton 1. Cultivation of cotton seedlings 1. Select plump and uniform cotton seeds, the variety used is "Zhongmian 113", add 75% ethanol and shake to mix for 15 minutes, let it stand and pour out the upper layer of ethanol.

[0033] 2. Add sterile water, invert to mix, remove suspended impurities and sterile water, repeat 5 times, and soak the seeds in sterile water for 6 hours after rinsing to achieve seed swelling.

[0034] 3. After soaking the seeds, dry the moisture from the seeds appropriately and place them on sterile filter paper for cultivation. Place them in a constant temperature box (28°C) for germination for 1 day.

[0035] 4. Select white seeds and sow them in soil (peat soil: vermiculite = 2:1), place them in a light incubator (28℃ light for 12h, 25℃ dark for 12h daily) and culture them for 7 days to obtain cotton seedlings with uniform growth.

[0036] 2. Experimental treatment 1. Select seedlings with consistent growth for cold stress treatment and place them in a light incubator (6°C light for 12 h, 4°C dark for 12 h per day) for 3 days (simulating the cold stress environment of Xinjiang cotton seedlings) to obtain cold stress cotton seedlings.

[0037] At the same time, normal cotton seedlings cultured in a normal environment (28°C light for 12 h, 25°C dark for 12 h per day) without cold stress for 3 days were used as controls.

[0038] 2. After the cold stress ended, the leaves of the cold-stressed cotton seedlings were sprayed with pesticides. The dosage per plant was 2 ml to ensure that each leaf was exposed to the liquid. After spraying, they were placed in a normal environment (28°C light for 12 hours and 25°C dark for 12 hours per day) for recovery. According to the different spraying treatment methods, they were divided into the following groups: CK group: 2 ml of water was sprayed on normal cotton seedlings.

[0039] Group A1: 2 ml of water was sprayed on the cold-stressed cotton seedlings.

[0040] Group A2: 2 ml of 0.04 mg / L EBR solution was sprayed on cold-stressed cotton seedlings.

[0041] Group A3: 2 ml of 60 mg / L PC solution was sprayed on cold-stressed cotton seedlings.

[0042] Group A4: 2 ml of the compound solution was sprayed on the cold-stressed cotton seedlings. The EBR concentration in the compound solution was 0.04 mg / L and the PC concentration was 60 mg / L.

[0043] Group A5: 2 ml of the compound solution was sprayed on the cold-stressed cotton seedlings. The EBR concentration in the compound solution was 0.04 mg / L and the PC concentration was 30 mg / L.

[0044] Group A6: 2 ml of the compound solution was sprayed on the cold-stressed cotton seedlings. The EBR concentration in the compound solution was 0.1 mg / L and the PC concentration was 60 mg / L.

[0045] Group A7: 2 ml of the compound solution was sprayed on the cold-stressed cotton seedlings. The EBR concentration in the compound solution was 0.1 mg / L and the PC concentration was 30 mg / L.

[0046] The preparation method of the EBR solution is as follows: dissolving EBR in an ethanol solution to obtain an EBR mother solution with a concentration of 1000 mg / L, and then diluting the EBR mother solution with water to a desired concentration to obtain an EBR solution.

[0047] The preparation method of the PC solution is as follows: dilute prohexadione calcium (total active ingredient content is 15%, the dosage form is a suspension) with water to a desired concentration to obtain a PC solution.

[0048] The preparation method of the composite solution is as follows: the EBR solution and the PC solution are mixed with water, and the EBR and PC are diluted with water to a desired concentration to obtain a composite solution.

[0049] 3. After 3 days of recovery, phenotypic acquisition and agronomic trait determination were performed to determine the degree of recovery. Agronomic trait determinations included SPAD (relative chlorophyll content), plant height, stem fresh weight, stem dry weight, leaf fresh weight, and leaf dry weight. Among them, SPAD (relative chlorophyll content) was measured on live leaves using a SPAD chlorophyll meter (SPAD-502, Minolta Camera Co., Ltd., Osaka, Japan). The same leaf was measured 5 times, and the average value was taken to represent the relative chlorophyll content of this leaf.

[0050] 3. Experimental Results 1. Cold stress inhibits the growth of cotton seedlings After 3 days of cold stress treatment, the growth of cotton seedlings was severely inhibited ( Figure 1 ). Compared with the control without cold stress, cold stress caused the cotton seedlings to have bent stems, wilted leaves, and almost stopped growing. Before spraying plant growth regulators, the cold-stressed cotton seedlings grew uniformly.

[0051] 2. Treatment with compound plant growth regulators restored the growth of leaves and stems of cotton seedlings After 3 days of treatment with plant growth regulators at various concentrations, phenotypes were obtained and agronomic traits were measured. The phenotypes showed that cold stress inhibited the growth of cotton seedlings. After 3 days of recovery, there was still a large gap between the growth of cotton seedlings and normal growth ( Figure 2 ). However, spraying plant growth regulators restored the inhibitory effect of cold stress to a certain extent, promoted leaf growth and increased plant height.

[0052] Among them, the SPAD (relative chlorophyll content) and plant height data results showed that cold stress caused SPAD and plant height to decrease by 21.9% and 53.4%, respectively. Among them, the average SPAD (relative chlorophyll content) of CK group, A1 group, A2 group, A3 group, A4 group, A5 group, A6 group, and A7 group were 41.7, 32.5, 34.8, 33.1, 35.3, 37.2, 36.8, and 35.6, respectively, and the average plant height of CK group, A1 group, A2 group, A3 group, A4 group, A5 group, A6 group, and A7 group were 16.4 cm, 7.7 cm, 10.0 cm, 8.8 cm, 10.4 cm, 11.4 cm, 10.9 cm, and 9.6 cm, respectively.

[0053] Compared with the single cold stress treatment, all concentrations of plant growth regulators can restore the inhibitory effect caused by cold stress to a certain extent. The treatment of compound treatment group A5 (EBR 0.04 mg / L + PC 30 mg / L) significantly increased the SPAD value and plant height by 14.3% and 49.3%. At the same time, the effects of compound treatment groups (A4, A5, A6 and A7) were better than those of single treatment groups (A2 and A3, commercial single use concentrations). Specifically, compared with the single treatment group A2 (EBR 0.04 mg / L), the treatment of compound treatment group A5 (EBR 0.04 mg / L + PC 30 mg / L) significantly increased the SPAD value and plant height by 14.1% and 7.0%, respectively. Compared with the single treatment group A3 (PC 60 mg / L), the combined treatment group A5 (EBR 0.04 mg / L + PC 30 mg / L) significantly increased the SPAD value and plant height by 29.6% and 12.4%, respectively. The above results show that the combined EBR and PC have synergistic effects and can effectively restore the inhibitory effect of cold stress, among which the combined treatment group A5 (EBR 0.04 mg / L + PC 30mg / L) has the best treatment effect.

[0054] 3. Treatment with compound plant growth regulators promotes substance accumulation in cotton seedlings after cold stress Consistent with the above trends of chlorophyll content and plant height, cold stress severely inhibited the growth of stems and leaves, making it difficult to recover to normal levels. The average stem fresh weights of CK, A1, A2, A3, A4, A5, A6 and A7 groups were 0.8303 g, 0.3105 g, 0.3975 g, 0.3517 g, 0.4106 g, 0.4790 g, 0.4699 g and 0.4428 g, respectively; the average leaf fresh weights of CK, A1, A2, A3, A4, A5, A6 and A7 groups were 1.1624 g, 0.4668 g, 0.5826 g, 0.5166 g, 0.6470 g, 0.7012 g, 0.6701 g and 0.6233 g, respectively; the average stem dry weights of CK, A1, A2, A3, A4, A5, A6 and A7 groups were 0.0804 g, The average leaf dry weights of CK group, A1 group, A2 group, A3 group, A4 group, A5 group, A6 group and A7 group were 0.1269 g, 0.0507 g, 0.0639 g, 0.0560 g, 0.0661 g, 0.0754 g, 0.0733 g and 0.0672 g, respectively.

[0055] Compared with the single cold stress treatment, all concentrations of plant growth regulators can restore the inhibitory effect caused by cold stress to a certain extent. At the same time, the effect of the combined treatment group is better than that of the single treatment group. Specifically, compared with the single treatment group A2 (EBR 0.04 mg / L), the combined treatment group A5 (EBR 0.04 mg / L + PC 30 mg / L) significantly increased the stem fresh weight, leaf fresh weight, stem dry weight and leaf dry weight by 20.5%, 20.4%, 20.9% and 18.0%, respectively. Compared with the single treatment group A3 (PC 60 mg / L), the combined treatment group A5 (EBR 0.04 mg / L + PC 30 mg / L) significantly increased the stem fresh weight, leaf fresh weight, stem dry weight and leaf dry weight by 36.2%, 35.7%, 31.2% and 34.6%, respectively. Therefore, the combined treatment group had better effects than the single treatment group, among which the combined treatment group A5 (EBR 0.04 mg / L + PC 30 mg / L) had the best treatment effect.

[0056] The present invention has been described in detail above. It will be apparent to those skilled in the art that the present invention may be implemented in a wide range under equivalent parameters, concentrations and conditions without departing from the spirit and scope of the present invention and without the need for unnecessary experimentation. Although the present invention provides specific embodiments, it should be understood that further improvements may be made to the present invention. In short, according to the principles of the present invention, this application intends to include any changes, uses or improvements to the present invention, including changes made by conventional techniques known in the art that depart from the scope disclosed in this application. Applications of some of the basic features may be made within the scope of the following appended claims.

Claims

1. A composite plant growth regulator, characterized in that: The active ingredients of the composite plant growth regulator include 2,4-epibrassinolide and prohexadione calcium.

2. The composite plant growth regulator according to claim 1, characterized in that: The concentration of the 2,4-epibrassinolide in the composite plant growth regulator is 0.04 mg / L.

3. The composite plant growth regulator according to claim 1 or 2, characterized in that: The concentration of prohexadione calcium in the composite plant growth regulator is 30 mg / L.

4. The composite plant growth regulator according to any one of claims 1 to 3, characterized in that: The active ingredients of the composite plant growth regulator consist of 2,4-epibrassinolide and prohexadione calcium.

5. Use of the composite plant growth regulator according to any one of claims 1 to 4 in improving the cold tolerance of plants.

6. Use of the composite plant growth regulator according to any one of claims 1 to 4 in the preparation of a product for improving plant cold tolerance.

7. A method for improving the cold tolerance of plants, comprising the step of spraying the composite plant growth regulator according to any one of claims 1 to 4 on the plants.

8. The use according to claim 5 or 6 or the method according to claim 7, characterized in that: The cold tolerance is cold tolerance at the seedling stage.

9. The use according to claim 5 or 6 or the method according to claim 7, characterized in that: The improvement of plant cold tolerance is embodied in any one of the following A1)-A6): A1) Increase the chlorophyll content in plant leaves after cold stress treatment; A2) Increase plant height after cold stress treatment; A3) Increase the fresh weight of plant stems after cold stress treatment; A4) Increase the fresh weight of plant leaves after cold stress treatment; A5) Increased stem dry weight of plants after cold stress treatment; A6) Increase the dry weight of plant leaves after cold stress treatment.

10. The use according to claim 5 or 6 or the method according to claim 7, characterized in that: The plant is any one of the following C1)-C4): C1) monocots or dicots; C2) Malvaceae; C3) cotton plants; C4) Cotton.

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