Application of plant growth regulator composition in cultivation of leguminous crops

Abstract

The invention relates to the technical field of biology, in particular to application of a plant growth regulator composition in cultivation of leguminous crops. The gibberellic acid A3, the gibberellic acid A4, the gibberellic acid A7 and uniconazole are compounded, so that the multiple effects of reducing flower pod falling, increasing the pod bearing number, remarkably improving the chlorophyll content and the photosynthetic rate, coordinating vegetative growth and reproductive growth balance and synchronously improving the grain weight, the grain number and the grain protein content are achieved, and the gibberellic acid compound has important agricultural application value.

Description

Technical Field

[0001] This invention relates to the field of biotechnology, and more particularly to the application of a plant growth regulator composition in the cultivation of legume crops. Background Technology

[0002] Studies have shown that the key issue currently limiting soybean yield improvement is severe flower and pod drop, leading to insufficient grains per plant. Flower and pod drop is a common phenomenon in soybeans, with flower drop rates generally around 50%, young pod drop rates around 40%, and flower bud drop rates around 10%. Flower and pod drop is significantly affected by climatic conditions and planting management methods. For example, the flower and pod drop rate for spring soybeans in northern China is generally 40%-70%, while the drop rate for summer soybeans in southern China is 50%-70%. With the promotion of high-density planting techniques for soybeans, increased flower and pod drop due to shading and excessive plant growth limits yield improvement.

[0003] Crop chemical control technology is currently a key and effective technology for regulating the growth, development, and yield formation of major grain, cotton, and oilseed crops such as cotton, corn, wheat, and soybean. However, current chemical control technologies mainly focus on shaping crop plant architecture and controlling height to prevent lodging, lacking products that can regulate soybean flower, pod, and grain formation. Traditional plant architecture regulators and other plant growth regulators reported to have flower-preserving effects cannot be directly used in regulating soybean flower and pod development. Current research largely focuses on monocotyledonous crops, such as rice. The biological processes of flower development and the physiological and biochemical mechanisms of hormone regulation differ significantly between monocotyledonous and dicotyledonous crops. In rice, flower organ differentiation occurs after the development of vegetative organs, while dicotyledonous crops like soybean undergo vegetative growth and flowering / pod formation simultaneously. Therefore, regulating soybean flower and pod development requires considering the growth of stems, nodes, and leaves to achieve coordination between source and sink organs. Otherwise, regulating only the "sink" organs (flowers and pods) may cause abnormal development of "source" organs such as stems, nodes, and leaves, resulting in weak, drooping stems and thin, narrow leaves, leading to flowering without fruiting and ultimately reducing yield. Furthermore, the sensitivity of floral and vegetative organs to the same regulator varies greatly. Even attempts to borrow or directly transplant existing regulators and application techniques generally report unstable effects, often resulting in problems such as delayed maturity, poor grain development, and reduced grain weight in soybeans, leading to yield reduction. Therefore, it is urgent to develop a plant growth regulation technology system based on the biological characteristics of soybean flower and pod development that can achieve synergistic regulation of vegetative and reproductive growth, conserve flower and pod development, and simultaneously improve yield and nutritional quality. Summary of the Invention

[0004] In view of this, the present invention proposes the application of a plant growth regulator composition in the cultivation of leguminous crops.

[0005] The technical solution of this invention is implemented as follows:

[0006] In a first aspect, the present invention provides an application of a composition in the cultivation of legume crops, the composition comprising a first component and a second component, wherein the first component is at least one of gibberellic acid A3, gibberellic acid A4 and gibberellic acid A7, and the second component is uniconazole.

[0007] In some specific embodiments, the mass ratio of the first component to the second component is 1:(1.25-10).

[0008] In some specific embodiments, the first component is a mixture of gibberellic acid A3, gibberellic acid A4, and gibberellic acid A7, wherein the molar ratio of gibberellic acid A3, gibberellic acid A4, and gibberellic acid A7 in the mixture is 1:1:1. Further, the mass ratio of the first component and the second component is 1:2.5 or 1:5, preferably 1:2.5.

[0009] In some specific embodiments, the composition is used to formulate an agricultural product, which further includes excipients, such as thickeners, dispersants, wetting agents, binders, emulsifiers, stabilizers, and solvents. Further, the agricultural product is formulated as a liquid, emulsion, suspension, powder, granule, wettable powder, or water-dispersible granule.

[0010] In some specific embodiments, the composition is applied by foliar spraying. Further, the foliar spraying period is from the initial flowering stage to the pod-setting stage, preferably during full bloom.

[0011] In some specific embodiments, the composition has the following effects on legumes: reducing flower and pod drop, increasing pod number, increasing leaf photosynthetic capacity, increasing grain weight, number of grains and grain protein content, and increasing yield.

[0012] The beneficial effects of the present invention include at least the following:

[0013] This invention provides an application of a plant growth regulator composition for legume crops. By combining gibberellic acid A3, gibberellic acid A4, gibberellic acid A7, and uniconazole, it achieves multiple effects such as reducing flower and pod drop, increasing pod number, significantly improving chlorophyll content and photosynthetic rate, coordinating the balance between vegetative and reproductive growth, and simultaneously increasing grain weight, grain number, and grain protein content. While ensuring the safety and environmental friendliness of the crop, the synergistic effect between the components achieves simultaneous improvement in yield and nutritional quality, which has significant agricultural application value. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0015] 1. Materials

[0016] compound supplier English name CAS purity gibberellic acid A3 Sigma-Aldrich Gibberellin A3 (abbreviated as GA3) 77-06-5 ≥95.0％ Gibberellic acid A4 Sigma-Aldrich Gibberellin A4 (abbreviated as GA4) 468-44-0 ≥95.0％ Gibberellic acid A7 Sigma-Aldrich Gibberellin A7 (abbreviated as GA7) 510-75-8 ≥95.0％ uniconazole Sigma-Aldrich Uniconazole 83657-22-1 ≥98.0％

[0017] 2. Solution preparation

[0018] In the following examples, three concentrations of gibberellic acid (pure product and mixture) at 5, 10, and 20 mg / L, and two concentrations of uniconazole at 25 and 50 mg / L were respectively arranged in various combinations, with a water control (CK). According to the following... Plant growth regulators Solution preparation table Prepare the required solution.

[0019] Plant growth regulator solution preparation table

[0020]

[0021] (Note) Preparation method: When preparing plant growth regulator solutions, first dissolve them in anhydrous ethanol (such as gibberellic acid), and then dilute with water to the working volume.

[0022]

[0023] (Note) Preparation method: (1) Dissolve gibberellic acid (GA3 / GA4 / GA7 pure substance or mixture) in anhydrous ethanol. (2) Dissolve uniconazole (U1 / U2) in anhydrous ethanol. (3) Mix the two and add water to make up to the working volume.

[0024] 3. Field experiments

[0025] All quantitative experiments in the embodiments were performed in triplicate.

[0026] In the summer of 2022, a field experiment was conducted in Wuqiao, Hebei Province, China, using Qihuang 34, Jidou 17, and Shi 936 soybean varieties as test varieties. The experiment adopted a randomized block design with three replicates. Each replicate had 21 plots (treatments) randomly assigned. Foliar spraying was carried out during the full bloom period (field spraying was conducted in the windless period from 16:00 to 18:00, with 30L of pesticide solution per acre. Before spraying, Tween-20 (CAS 9005-64-5) was added at a concentration of 0.5% (v / v) and sprayed once). The 21 plots were designated as the control (CK), A31, A42, A73, G1, G2, G3, U1, U2, A31U1, A31U2, A42U1, A42U2, A73U1, A73U2, G1U1, G1U2, G2U1, G2U2, G3U1, and G3U2 treatment areas. Each plot had an area of ​​12 m². Soybean rows were spaced 30 cm apart, with a density of 6000 plants per mu (approximately 0.067 hectares).

[0027] All data from the embodiments were analyzed using one-way ANOVA with SAS 9.2 software. If the ANOVA results showed a significant difference between groups (p<0.05), Duncan's multiple range test was used for further comparisons. The significance level was set at α = 0.05, and different letters indicated significant differences between groups.

[0028] Example 1: Flower and pod drop rate

[0029] In this embodiment, after the flowering period, the number of fallen flowers, the number of fallen pods, the total number of flowers, and the number of fallen pods per plant under different treatments were recorded by fixed-plant survey, and the flower and pod abscission rate was calculated.

[0030] Table 1 Effects of gibberellic acid and uniconazole on flower and pod abscission rate of different soybean varieties

[0031]

[0032]

[0033] Note: Different letters in the same column indicate significant differences between treatments.

[0034] The results are shown in Table 1. For the soybean variety Qihuang 34, gibberellic acid monomer and mixture treatments had no significant effect on the flower and pod abscission rate of soybeans, while different concentrations of tebuconazole treatments inhibited the flower abscission rate of soybeans by 10-12% and reduced the pod abscission rate by 7-9%.

[0035] When uniconazole was combined with gibberellic acid, the flower abscission rate was reduced by 19%-28%, and the pod abscission rate was reduced by 20-27%, both significantly higher than that of uniconazole alone. However, there was no significant difference between the corresponding concentrations of pure gibberellic acid and the gibberellic acid mixture in the combined treatment. The same pattern was observed for Jidou 17 and Shi 936, with Jidou 17 showing a 21-28% reduction in flower abscission rate and a 20-28% reduction in pod abscission rate, and Shi 936 showing a 20-28% reduction in flower abscission rate and a 19-28% reduction in pod abscission rate. This indicates that the treatment effect of the regulator was relatively stable across different varieties and showed good reproducibility.

[0036] Example 2: Number of pods

[0037] In this embodiment, the number of pods formed between the nodes of the main stem of soybean under different treatments was measured at harvest time, and the results are shown in Table 2.

[0038] Table 2 Effects of gibberellic acid and clopidogrel on the number of pods on internodes of main stems of different soybean varieties.

[0039]

[0040] Note: Different letters in the same column indicate significant differences between treatments.

[0041] Table 2 shows that for the three varieties Qihuang 34, Jidou 17, and Shi 936, treatment with a certain concentration of gibberellic acid mixture or pure substance, as well as treatment with uniconazole alone, all showed a trend of increasing the number of pods at the top nodes of soybeans, but the differences were not significant. However, treatment with a combination of different concentrations of gibberellic acid mixture or pure substance and uniconazole significantly increased the number of pods at the top nodes. For Qihuang 34, the number of pods increased by an average of 1.3-1.6 at the third node from the top and 1.5-1.7 at the fourth node from the top; for Jidou 17, the number of pods increased by an average of 1.5-2 at the third node from the top and 1.8-2.4 at the fourth node from the top; and for Shi 936, the number of pods increased by an average of 1.4-1.7 at the third node from the top and 1.6-2.1 at the fourth node from the top. This indicates that the combined treatment had a significant effect on flower and pod preservation, while the difference between the gibberellic acid mixture and the corresponding concentration of pure substance was not significant.

[0042] Example 3: Photosynthetic capacity of leaves during pod formation

[0043] In this embodiment, the chlorophyll content and photosynthetic rate of the newly unfolded leaves were measured during the grain-filling stage. Chlorophyll content was measured using a SPAD502 chlorophyll meter. Measurements were taken from the central leaflets of the newly unfolded leaves of 10 representative plants, with five measurements taken at different locations in the middle of each leaf, and the average value was recorded. The photosynthetic rate was measured using a LI6400 photosynthesis meter on the same leaflet. After clamping the leaflet in the leaf chamber, it was allowed to stand for 10-15 minutes until the instrument reading stabilized. The photosynthetic intensity was recorded at 5-second intervals, and five records were taken, with the average value recorded.

[0044] Table 3 Effects of gibberellic acid and uniconazole on chlorophyll content and photosynthetic rate in leaves of different soybean varieties.

[0045]

[0046] Note: Different letters in the same column indicate significant differences between treatments.

[0047] Table 3 shows that gibberellic acid (GAA) treatment, whether pure or mixed, had no significant effect on the chlorophyll content of the top leaves of soybeans during the grain-filling stage. However, the use of uniconazole alone significantly increased the chlorophyll content and photosynthetic rate of the top leaves of soybeans. Specifically, Qihuang 34 showed an increase of 11-14% in chlorophyll content and 10-15% in photosynthetic rate; Jidou 17 showed an increase of 9-12% in chlorophyll content and 12-14% in photosynthetic rate; and Shi 936 showed an increase of 12-14% in chlorophyll content and 13-14% in photosynthetic rate. Furthermore, the combination of different concentrations of GAA with uniconazole significantly enhanced the promoting effect on leaf chlorophyll content and photosynthetic rate. Qihuang 34 showed a 20-28% increase in chlorophyll and a 19-30% increase in photosynthetic rate compared to the control, nearly doubling the increase compared to uniconazole alone, demonstrating a significant synergistic effect after combination. Jidou 17 and Shi 936 also showed similar effects.

[0048] Example 4: Number of seeds per soybean plant, 100-seed weight, and yield

[0049] In this embodiment, the number of seeds per soybean plant, 100-seed weight, and yield under different treatments were measured at harvest. The measurement results are shown in Table 4.

[0050] Table 4. Effects of gibberellic acid and clopidogrel on seed number per plant, 100-seed weight, and yield of different soybean varieties.

[0051]

[0052] Note: Different letters in the same column indicate significant differences between treatments.

[0053] The results show that the regulator treatment did not change the density of the soybean population, and the use of gibberellin mixtures or their pure forms alone had no significant effect on the number and weight of soybean grains. The yield increase varied significantly within 10% for different varieties. While the use of uniconazole alone showed a relatively stable increasing trend in the number of grains per plant, the difference was not significant compared to the control, and the yield increase was stable between 10-14% for the three varieties. The combination of gibberellin mixtures and their pure forms with uniconazole significantly increased the number of grains per plant, consistent with the results on flower and pod drop and pod number in Examples 1 and 2. Simultaneously, the combined treatment also significantly increased grain weight, ultimately leading to a significant increase in yield. The yield increase from the combined regulator treatment reached 21-29% for Qihuang 34, 21-29% for Jidou 17, and 25-30% for Shi 936, demonstrating a significant yield increase effect. There were no significant differences between different gibberellin pure forms and their corresponding concentrations of mixtures, showing consistent effects.

[0054] Example 5: Soybean single pod grain weight

[0055] In this embodiment, the weight of soybean pods under different treatments was measured at harvest. Pods from each pod-bearing node of each plant were taken, threshed, and weighed. The weight of each pod was divided by the number of pods to obtain the average weight of pods per plant. The measurement results are shown in Table 6.

[0056] Table 5 Effects of gibberellic acid and clopidogrel on the average single pod weight of different soybean varieties

[0057]

[0058] Note: Different letters in the same column indicate significant differences between treatments.

[0059] The results show that when GA3, GA4, or GA7 were applied alone, the increase in single-pod grain weight was less than 1.7%; however, when a mixture of GA3, GA4, and GA7 gibberellic acid was applied, the increase in single-pod grain weight reached 2.9-5%, significantly higher than when a single type of gibberellic acid was applied alone. When uniconazole was applied alone, the increase in single-pod grain weight for different varieties was 3.1-4.5%.

[0060] When gibberellic acid and uniconazole are used in combination, the promoting effect on single pod grain weight is more significant, and the two have a clear synergistic effect, showing similar patterns in different soybean varieties. Specifically, when one of GA3, GA4, or GA7 is combined with uniconazole at a mass ratio of 1:(1.25-5), the increase in single pod grain weight in different varieties reaches 4.6-10.6%. When a mixture of gibberellic acid (GA3, GA4, and GA7) is combined with uniconazole at a mass ratio of 1:(2.5-10), the increase in single pod grain weight in different varieties is as high as 7.5-15.4%.

[0061] Example 6: Soybean Seed Protein Content

[0062] In this embodiment, the protein content of threshed soybeans was determined using a FORS near-infrared grain analyzer (referencing GB / T 24895). Five 120g soybean samples were randomly selected from each treatment for analysis.

[0063] Table 6. Effects of gibberellic acid and clopidogrel on protein content in soybean seeds of different varieties.

[0064]

[0065] The results are shown in Table 6. When GA3, GA4, or GA7 were applied alone, the increase in seed protein content for each variety was less than 2.3%. However, when a mixture of GA3, GA4, and GA7 gibberellic acid was applied, the increase in seed protein content reached 3.6-6.6%, significantly higher than the increase when a single type of gibberellic acid was applied alone. When uniconazole was applied alone, the increase in seed protein content for different soybean varieties was 3.9-6.0%.

[0066] When gibberellic acid and uniconazole are used in combination, the effect on promoting seed protein content is more significant, and the two have a clear synergistic effect. Specifically, when one of GA3, GA4, or GA7 is combined with uniconazole at a mass ratio of 1:(1.25-5), the increase in seed protein content of different soybean varieties reaches 5.8-13.7%. When a mixture of gibberellic acid (GA3, GA4, and GA7) is combined with uniconazole at a mass ratio of 1:(2.5-10), the increase in seed protein content is as high as 11.1-19.4%. Although the intensity of the effect varies among the three varieties, a similar pattern is generally observed.

[0067] Example 7: Length of internodes at the top of soybean main stem

[0068] In this embodiment, the length of the top internodes of soybean main stems under different treatments was measured at harvest. The measurement results are shown in Table 7.

[0069] Table 7 Effects of gibberellic acid and uniconazole on the length of the top internode of different soybean varieties.

[0070]

[0071] Note: Different letters in the same column indicate significant differences between treatments.

[0072] The results show that with increasing concentrations of gibberellic acid (A3, A4, and A7), the length of the top 2-4 internodes of soybean gradually increased. Similarly, with increasing concentrations of the gibberellic acid mixture, the length of the top internodes showed the same increasing trend, and there was no significant difference between the mixture and the corresponding pure substance at the same concentration. Excessively elongated internodes lead to weak and lodging upper parts of the plant, with thin, drooping leaves, severely affecting light interception and photosynthesis. Uniconazole treatment showed an inhibitory effect on internode length, and this inhibitory effect significantly increased with increasing treatment concentration. Excessively shortened internodes cannot provide sufficient space for the full development of flowers and pods, and reduce biomass during full bloom, decrease the accumulation of photosynthetic products, and affect yield.

[0073] When gibberellic acid (pure or mixed) was combined with uniconazole for treatment, compared with the control, it had no significant effect on the length of the top internodes of soybeans, and maintained the normal growth and development of vegetative organs such as internodes.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. The application of a composition in the cultivation of leguminous crops, characterized in that, The composition comprises a first component and a second component, wherein the first component is at least one of gibberellic acid A3, gibberellic acid A4 and gibberellic acid A7, and the second component is uniconazole.

2. The application according to claim 1, characterized in that, The mass ratio of the first component to the second component is 1:(1.25-10).

3. The application according to claim 1, characterized in that, The first component is a mixture of gibberellic acid A3, gibberellic acid A4 and gibberellic acid A7, wherein the molar ratio of gibberellic acid A3, gibberellic acid A4 and gibberellic acid A7 in the mixture is 1:1:

1.

4. The application according to claim 3, characterized in that, The mass ratio of the first component to the second component is 1:2.

5.

5. The application according to any one of claims 1-4, characterized in that, The composition is used to make agricultural products, which also include excipients, such as thickeners, dispersants, wetting agents, binders, emulsifiers, stabilizers, and solvents.

6. The application according to claim 5, characterized in that, The formulation of the agricultural product is one of the following: liquid, emulsion, suspension, powder, granule, wettable powder, and water-dispersible granule.

7. The application according to any one of claims 1-4, characterized in that, The composition is used by foliar spraying.

8. The application according to claim 7, characterized in that, The composition is to be applied as a foliar spray during the period from the initial flowering stage to the pod-setting stage.

9. The application according to claim 8, characterized in that, The composition is to be applied to the leaves during the peak flowering period.

10. The application according to any one of claims 1-4, characterized in that, The composition has the following effects on legumes: reducing flower and pod drop, increasing the number of pods, increasing the photosynthetic capacity of leaves, increasing grain weight, number of grains and grain protein content, and increasing yield.

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