Method for inhibiting seed germination and seedling growth of astragalus mongolicus / liquorice
By treating Astragalus membranaceus/Glycyrrhiza uralensis seeds or seedlings with bitter gourd extract, the problem of continuous cropping obstacles was solved, the inhibition of seed germination and seedling growth was achieved, and the sustainable use of arable land was promoted.
Patent Information
- Application Number
- CN202511704467.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-20
- Publication Date
- 2025-12-19
AI Technical Summary
The problem of continuous cropping obstacles between Astragalus membranaceus and Glycyrrhiza uralensis leads to soil nutrient imbalance and allelopathic autotoxicity, which severely inhibits the seed germination and seedling growth of subsequent crops, affecting yield and quality.
Soaking of Astragalus membranaceus/Glycyrrhiza uralensis seeds or irrigation of seedlings with bitter bean extract was performed. The concentration of bitter bean extract was 5 g/L to 40 g/L, the treatment time was 22-26 h, and the irrigation frequency was once every 5-8 days. The extract was derived from the stems or leaves of bitter bean, and direct contact with the stems and leaves was avoided.
It effectively inhibits the seed germination and seedling growth of Astragalus membranaceus and Glycyrrhiza uralensis, reduces the inhibitory effect of allelopathic substances, overcomes continuous cropping obstacles, and realizes the sustainable and intensive use of arable land.
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Figure CN121153558A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of agricultural biotechnology, in particular, to a method for inhibiting seed germination and seedling growth of Astragalus membranaceus var. mongholicus / Glycyrrhiza uralensis. BACKGROUND
[0002] Astragalus membranaceus var. mongholicus and Glycyrrhiza uralensis are important perennial leguminous medicinal plants, which play an important role in the Chinese medicinal material market. With the increasing market demand, the scale and intensive planting area of Astragalus membranaceus var. mongholicus and Glycyrrhiza uralensis continues to expand.
[0003] However, in actual production, the cultivation of Astragalus membranaceus var. mongholicus and Glycyrrhiza uralensis faces serious continuous cropping obstacles. Since both of them are perennial plants with developed root systems, they absorb specific nutrients from the deep soil during growth, leading to soil nutrient imbalance. More importantly, their root exudates and plant residue decompositions (such as flavonoids, saponins, and other secondary metabolites) accumulate in the soil, producing autotoxicity. These autotoxic substances inhibit the seed germination, seedling growth, and root development of the same or subsequent crops, resulting in significant yield and quality decline.
[0004] Currently, in the crop rotation system, if Astragalus membranaceus var. mongholicus or Glycyrrhiza uralensis is planted in the previous season, and other crops sensitive to such allelochemicals (such as certain vegetables or cereals) are planted in the next season, the allelochemicals left by the previous crop will severely inhibit the seed germination and seedling growth of the subsequent crop, becoming a key bottleneck restricting the efficient use of land in rotation.
[0005] Therefore, developing a method to inhibit the seed germination and seedling growth of Astragalus membranaceus var. mongholicus / Glycyrrhiza uralensis and a method to eliminate its inhibitory effect is of great significance for overcoming continuous cropping obstacles, achieving sustainable and intensive use of cultivated land, and ensuring the successful implementation of the rotation system. SUMMARY
[0006] To solve the above technical problems, the present application provides a method for inhibiting the seed germination and seedling growth of Astragalus membranaceus var. mongholicus / Glycyrrhiza uralensis. The method uses a Swainsona spp. extract to treat Astragalus membranaceus var. mongholicus / Glycyrrhiza uralensis seeds to inhibit seed germination, or uses a Swainsona spp. extract to irrigate Astragalus membranaceus var. mongholicus / Glycyrrhiza uralensis seedlings to inhibit seedling growth. The Swainsona spp. extract is derived from the stems or leaves of Swainsona spp.
[0007] Further, the concentration of the Swainsona spp. extract is any concentration between 5 g / L and 40 g / L.
[0008] Further, the seed soaking treatment time is 22-26 h, and the irrigation treatment frequency is once every 5-8 days.
[0009] Further, the irrigation site is the soil around the root system to avoid direct contact with the stems and leaves.
[0010] Further, the concentration of the Sphaerophysa seed extract is 40 g / L.
[0011] Further, the preparation method of the Sphaerophysa seed extract is as follows: S1, material collection: collect Sphaerophysa plants, separate stems and leaves, rinse, and dry to constant weight; then cut the dried stems and leaves into small pieces of about 1.5-2.5 cm, crush them into powder, and obtain Sphaerophysa powder; S2, initial mother liquor preparation: seal the Sphaerophysa powder in distilled water for 22-26 h after adding it, filter, and obtain the initial mother liquor; S3, concentration dilution: dilute the initial mother liquor with distilled water to the target concentration: 5-40 g / L, obtain the Sphaerophysa seed extract, store it at 4°C in the dark, and reserve it for use.
[0012] Further, the preparation method of the Sphaerophysa seed extract is as follows: S1, material collection: Collect Sphaerophysa plants without pests and with consistent growth, separate the stem and leaf parts; Rinse the stem and leaf surface impurities with pure water, and dry them to constant weight in an 80°C oven; Cut the dried stems and leaves into small pieces of about 1.5-2.5 cm, and crush them into powder with a crusher; S2, initial mother liquor preparation: Weigh 100 g of crushed stem or leaf samples, respectively, and place them in beakers; Add 1000 mL of distilled water, mix well, and seal for 22-26 h at room temperature (25±1°C); Filter the initial mother liquor with double-layer gauze, and then filter it again with qualitative filter paper to obtain the initial mother liquor of stems and leaves (concentration 100 g / L); S3, concentration dilution: Dilute the mother liquor with distilled water to the target concentration: 5 g / L-40 g / L; Store the diluted extract in a 4°C refrigerator in the dark for future use.
[0013] Further, the preparation method of the Sphaerophysa seed extract is as follows: S1, material collection: Collect Sphaerophysa plants without pests and with consistent growth, separate the stem and leaf parts; Rinse the stem and leaf surface impurities with pure water, and place them in an oven at 80℃ to dry to constant weight; Cut the dried stems and leaves into small pieces of about 2 cm, and pulverize them into powder with a pulverizer; S2, initial mother liquor preparation: Weigh 100 g of the pulverized stem or leaf sample into a beaker, respectively; Add 1000 mL of distilled water, mix well, and then seal and soak at room temperature (25±1℃) for 24 h; Filter the initial mother liquor with double-layer gauze, and then filter it again with qualitative filter paper to obtain the initial mother liquor of stems and leaves (concentration 100 g / L); S3, concentration dilution: Dilute the mother liquor with distilled water to the target concentration: 5 g / L-40 g / L; Store the diluted extract in a 4℃ refrigerator in the dark for standby use.
[0014] Further, the temperature for sealing and soaking in step S2 is 20-30℃, and the mixture is shaken and mixed every 6 h during the soaking process.
[0015] Further, the container for sealing and soaking in step S2 is a seed tray wrapped with sterile breathable filter paper or gauze.
[0016] Further, the method is used to inhibit at least one of the germination rate, germination potential, germination index, and vigor index of plant seeds.
[0017] Compared with the prior art, the beneficial effects of the present application are: 1. Mongolian astragalus and licorice are affected by allelopathy and autointoxication, which leads to continuous cropping obstacles and affects the planting of subsequent crops. The present application can inhibit the seed germination and seedling growth of Mongolian astragalus and licorice by using the extract of swainsona pacifica, which can reduce the inhibition of allelochemicals of the previous crop on the subsequent crop (same or other crops), and provide an effective means to overcome continuous cropping obstacles and realize sustainable and intensive use of farmland.
[0018] 2. The method provided by the present application can significantly reduce the germination rate, germination potential, and germination index of Mongolian astragalus and licorice as the concentration of the extract of swainsona pacifica increases. At a concentration of 40 g / L, the germination rate of Mongolian astragalus is reduced to 20.00%-25.17%, and the germination rate of licorice is reduced to 19.00%-21.00%, which is much lower than the control group (49.50% and 46.00%). At a concentration of 40 g / L, the extract of swainsona pacifica can reduce the radicle length of Mongolian astragalus by 20.3%-30.8% and the hypocotyl width by 29.3% compared with the control group. The radicle length and hypocotyl width of licorice also have significant decreases. By inhibiting seed germination, the method can reduce the influence of allelochemicals of the previous crop on the seed germination of the subsequent crop under continuous cropping conditions, thereby overcoming the continuous cropping obstacles.
[0019] 3、The provided Sophora alopecuroides extract can also affect the antioxidant enzyme activities (POD, SOD, CAT) and chlorophyll content of Mongolian milkvetch and licorice seedlings, and the leaf extract at a concentration of 40 g / L significantly reduces the POD activity of Mongolian milkvetch by 29.7% compared with the control group, and significantly reduces the chlorophyll content; while the SOD activity of licorice is promoted under the treatment of leaf extract, but the CAT activity shows a downward trend under the treatment of stem extract; by adjusting the antioxidant enzyme activity and photosynthetic pigment content, the physiological metabolism of plants can be affected, further inhibiting the growth of plants, and providing a scientific basis for understanding the allelopathy mechanism.
[0020] 4、In the present application, the allelopathy comprehensive effect index (SE) shows that the inhibitory effect on Mongolian milkvetch and licorice is enhanced with the increase of the concentration of Sophora alopecuroides extract, and the absolute value of SE reaches the highest at a concentration of 40 g / L, and the inhibitory effect of stem extract is generally stronger than that of leaf extract; which shows that this method can effectively inhibit the growth of Mongolian milkvetch and licorice, and provides a powerful tool for the management of continuous cropping obstacles in agricultural production. BRIEF DESCRIPTION OF DRAWINGS
[0021] Figure 1 Influence of Sophora alopecuroides leaf extract on the antioxidant enzyme activity and chlorophyll content of Mongolian milkvetch and licorice seedlings; Figure 2 Influence of Sophora alopecuroides stem extract on the antioxidant enzyme activity and chlorophyll content of Mongolian milkvetch and licorice seedlings; Figure 3 Correlation of three antioxidant enzyme activities and chlorophyll content of Mongolian milkvetch with seed germination and seedling growth indexes; Figure 4 Correlation of three antioxidant enzyme activities and chlorophyll content of licorice with seed germination and seedling growth indexes. DETAILED DESCRIPTION
[0022] Example 1 A method for inhibiting the seed germination of Mongolian milkvetch / licorice, which adopts Sophora alopecuroides extract to treat the seeds of Mongolian milkvetch / licorice to inhibit the seed germination of Mongolian milkvetch / licorice, and the Sophora alopecuroides extract is derived from the stem of Sophora alopecuroides.
[0023] Preferably, the concentration of the Sophora alopecuroides extract is 5 g / L.
[0024] Preferably, the seed treatment time is 22 h.
[0025] Preferably, the preparation method of the Sophora alopecuroides extract is as follows: S1, material collection: collect the Sphaerophysa salsula plant, separate the stems, rinse, and dry to a constant weight; then cut the dried stems into small pieces of about 1.5 cm, crush them into powder, and obtain Sphaerophysa salsula powder; S2, initial mother liquor preparation: seal the Sphaerophysa salsula powder in distilled water for 22 h, filter, and obtain the initial mother liquor; S3, concentration dilution: dilute the initial mother liquor with distilled water to a target concentration of 5 g / L to obtain a Sphaerophysa salsula extract, store it at 4°C in the dark, and reserve it for use.
[0026] Preferably, the temperature of the sealed soaking in step S2 is 20°C, and the mixture is shaken and mixed every 6 h during the soaking process.
[0027] Preferably, the container for the sealed soaking in step S2 is a seed tray wrapped with sterile breathable filter paper.
[0028] Preferably, the method is used to inhibit at least one of the germination rate, germination potential, germination index, and vigor index of the plant seeds.
[0029] Example 2 A method for inhibiting the germination of Astragalus mongholicus / Bupleurum smithikianum seeds, which uses a Sphaerophysa salsula extract to treat the seeds of Astragalus mongholicus / Bupleurum smithikianum to inhibit the germination of the seeds of Astragalus mongholicus / Bupleurum smithikianum, wherein the Sphaerophysa salsula extract is derived from the leaves of Sphaerophysa salsula.
[0030] Preferably, the concentration of the Sphaerophysa salsula extract is 40 g / L.
[0031] Preferably, the seed treatment time is 26 h.
[0032] Preferably, the preparation method of the Sphaerophysa salsula extract is as follows: S1, material collection: collect the Sphaerophysa salsula plant, separate the stems, rinse, and dry to a constant weight; then cut the dried stems into small pieces of about 1.5 cm, crush them into powder, and obtain Sphaerophysa salsula powder; S2, initial mother liquor preparation: seal the Sphaerophysa salsula powder in distilled water for 22 h, filter, and obtain the initial mother liquor; S3, concentration dilution: dilute the initial mother liquor with distilled water to a target concentration of 5 g / L to obtain a Sphaerophysa salsula extract, store it at 4°C in the dark, and reserve it for use.
[0033] Preferably, the temperature of the sealed soaking in step S2 is 20°C, and the mixture is shaken and mixed every 6 h during the soaking process.
[0034] Preferably, the container for the sealed soaking in step S2 is a seed tray wrapped with sterile breathable filter paper.
[0035] Preferably, the method is used to inhibit at least one of the germination rate, germination energy, germination index and vigor index of the plant seeds.
[0036] Embodiment 3 A method for inhibiting the germination of Astragalus mongholicus / Bupleurum smithikianum seeds, wherein the Astragalus mongholicus / Bupleurum smithikianum seeds are treated with a Sphaerophysa humilis extract to inhibit the germination of the Astragalus mongholicus / Bupleurum smithikianum seeds, and the Sphaerophysa humilis extract is derived from the stems of Sphaerophysa humilis.
[0037] Preferably, the concentration of the Sphaerophysa humilis extract is 20 g / L.
[0038] Preferably, the seed soaking treatment time is 24 h.
[0039] Preferably, the Sphaerophysa humilis extract is prepared as follows: S1, material collection: collect Sphaerophysa humilis plants, separate stems and leaves, rinse, and dry to constant weight; then cut the dried stems and leaves into small pieces of about 2 cm, and pulverize them into powder to obtain Sphaerophysa humilis powder; S2, initial mother liquor preparation: seal the Sphaerophysa humilis powder in distilled water for 24 h after adding it, filter, and obtain the initial mother liquor; S3, concentration dilution: dilute the initial mother liquor with distilled water to a target concentration of 20 g / L to obtain the Sphaerophysa humilis extract, which is stored at 4℃ in the dark and ready for use.
[0040] Preferably, the temperature for the sealed soaking in step S2 is 25℃, and the soaking process is mixed once every 6 h.
[0041] Preferably, the container for the sealed soaking in step S2 is a seed tray wrapped with sterile air-permeable filter paper or gauze.
[0042] Preferably, the method is used to inhibit at least one of the germination rate, germination energy, germination index and vigor index of the plant seeds.
[0043] Embodiment 4 A method for inhibiting the growth of Astragalus mongholicus / Bupleurum smithikianum seedlings, wherein the Astragalus mongholicus / Bupleurum smithikianum seeds are treated with a Sphaerophysa humilis extract to inhibit the growth of the Astragalus mongholicus / Bupleurum smithikianum seedlings, and the Sphaerophysa humilis extract is derived from the stems of Sphaerophysa humilis.
[0044] Preferably, the concentration of the Sphaerophysa humilis extract is 5 g / L.
[0045] Preferably, the irrigation treatment frequency is once every 5 days.
[0046] Preferably, the irrigation site is the soil around the root system to avoid direct contact with the stems and leaves.
[0047] Preferably, the Sphaerophysa humilis extract is prepared as follows: S1, material collection: collect Sphaerophysa salsula plants, separate stems, rinse, and dry to constant weight; then cut the dried stems into small pieces of about 1.5 cm, crush them into powder, and obtain Sphaerophysa salsula powder; S2, initial mother liquor preparation: seal the Sphaerophysa salsula powder in distilled water for 22 h, filter, and obtain the initial mother liquor; S3, concentration dilution: dilute the initial mother liquor with distilled water to a target concentration of 5 g / L, obtain Sphaerophysa salsula extract, and store it at 4°C in the dark for standby use.
[0048] Preferably, the temperature of the sealed soaking in step S2 is 20°C, and the mixture is shaken and mixed every 6 h during the soaking process.
[0049] Preferably, the container for the sealed soaking in step S2 is a seed tray wrapped with sterile breathable filter paper.
[0050] Preferably, the method is used to inhibit at least one of the germination rate, germination potential, germination index, and vigor index of the plant seeds.
[0051] Example 5 A method for inhibiting the growth of Astragalus mongholicus / Glycyrrhiza uralensis seedlings, wherein Sphaerophysa salsula extract derived from the leaves of Sphaerophysa salsula is used to irrigate Astragalus mongholicus / Glycyrrhiza uralensis seedlings to inhibit the growth of Astragalus mongholicus / Glycyrrhiza uralensis seedlings.
[0052] Preferably, the concentration of the Sphaerophysa salsula extract is 20 g / L.
[0053] Preferably, the irrigation treatment frequency is once every 6 days.
[0054] Preferably, the irrigation site is the soil around the root system to avoid direct contact with the stems and leaves.
[0055] Preferably, the preparation method of the Sphaerophysa salsula extract is as follows: S1, material collection: collect Sphaerophysa salsula plants, separate stems and leaves, rinse, and dry to constant weight; then cut the dried leaves into small pieces of about 2.5 cm, crush them into powder, and obtain Sphaerophysa salsula powder; S2, initial mother liquor preparation: seal the Sphaerophysa salsula powder in distilled water for 26 h, filter, and obtain the initial mother liquor; S3, concentration dilution: dilute the initial mother liquor with distilled water to a target concentration of 20 g / L, obtain Sphaerophysa salsula extract, and store it at 4°C in the dark for standby use.
[0056] Preferably, the temperature of the sealed soaking in step S2 is 30°C, and the mixture is shaken and mixed every 6 h during the soaking process.
[0057] Preferably, the container for sealing and soaking in step S2 is a seed tray wrapped with sterile air-permeable filter paper or gauze.
[0058] Preferably, the method is used to inhibit at least one of the germination rate, germination potential, germination index, and vigor index of the plant seeds.
[0059] Example 6 A method for inhibiting the growth of Astragalus mongholicus / Bupleurum chinense seedlings, wherein the seedlings of Astragalus mongholicus / Bupleurum chinense are irrigated with a Swainsona campylotropoides extract to inhibit the growth of the seedlings, and the Swainsona campylotropoides extract is derived from the stems or leaves of Swainsona campylotropoides.
[0060] Preferably, the concentration of the Swainsona campylotropoides extract is 40 g / L.
[0061] Preferably, the frequency of the irrigation treatment is once every 8 days.
[0062] Preferably, the irrigation site is the soil around the root system, avoiding direct contact with the stems and leaves.
[0063] Preferably, the preparation method of the Swainsona campylotropoides extract is as follows: S1, material collection: collect Swainsona campylotropoides plants, separate the leaves, rinse, and dry to constant weight; then cut the dried leaves into small pieces of about 2 cm, crush them into powder, and obtain Swainsona campylotropoides powder; S2, initial mother liquor preparation: seal and soak the Swainsona campylotropoides powder in distilled water for 24 h, filter, and obtain the initial mother liquor; S3, concentration dilution: dilute the initial mother liquor with distilled water to a target concentration of 40 g / L to obtain the Swainsona campylotropoides extract, which is stored at 4°C in the dark and ready for use.
[0064] Preferably, the temperature for sealing and soaking in step S2 is 25°C, and the mixture is shaken and mixed every 6 h during the soaking process.
[0065] Preferably, the container for sealing and soaking in step S2 is a seed tray wrapped with sterile air-permeable filter paper.
[0066] Preferably, the method is used to inhibit at least one of the germination rate, germination potential, germination index, and vigor index of the plant seeds.
[0067] Experimental section 1. Materials and methods 1.1. Materials The Swainsona campylotropoides used in this test was collected in Dalad Banner, Ordos, Inner Mongolia (40°24′N, 110°02′E) in June 2024. The seeds of Astragalus mongholicus were provided by the Baotou Guyang County Local Specialty Agricultural Products Cooperative, and the seeds of Bupleurum chinense were collected and provided by the Wushen Banner Rural Revitalization Bureau.
[0068] 1.2 Method 1.2.1 Preparation of Sophora alopecuroides extract The Sophora alopecuroides without pests and with consistent growth were collected, and the stems and leaves were collected respectively. The stems and leaves were washed with pure water to remove the surface impurities, and then were placed in an oven at 80 ℃ to dry to constant weight. The stems and leaves were cut into small pieces of about 2 cm and crushed. 100 g of each part after drying was weighed in a beaker, 1000 mL of distilled water was added, and the mixture was mixed uniformly and then sealed for 24 h at room temperature. The initial mother liquor of Sophora alopecuroides different parts was obtained by filtering with double-layer gauze, and then was filtered again with qualitative filter paper to prepare the extract mother liquor with a concentration of 100 g / L. The extract mother liquor of two parts was diluted with distilled water to obtain 5 g / L, 10 g / L, 20 g / L and 40 g / L extract solutions, which were stored in a 4 ℃ refrigerator for standby.
[0069] 1.2.2 Seed treatment and germination test The full, uniform and non-infested seeds of Astragalus mongholicus and Glycyrrhiza uralensis were selected, soaked in 75% ethanol for 15 s, washed with distilled water, repeated the disinfection step for 3 times, and then dried for standby. The germination test was carried out by the culture dish test paper method. Two layers of filter paper were laid in a sterile culture dish with a diameter of 9 cm, and Astragalus mongholicus and Glycyrrhiza uralensis seeds were used as receptors. 50 seeds of each were placed in each culture dish, 3 mL of corresponding extract solution was added, and distilled water treatment was used as control. Each treatment was repeated 4 times. The culture was placed in a constant temperature artificial climate box, and the temperature was set at (25±1) ℃, the light intensity was 16000 lx, and the light / dark cycle was 14 h light / 10 h dark per day, and the humidity was 60%. The filter paper was replaced every 2 days, and the corresponding treatment solution was added again. The germination was judged by the radicle breaking through the seed coat, and the observation and recording were carried out every day at the same time.
[0070] 1.2.3 Determination of seedling morphology and physiological indexes After 14 days of culture in the culture dish, 4 representative seedlings were randomly selected from each culture dish, and the radicle length and hypocotyl width of the seedlings were determined by SZ66 type research grade body microscope. When the seeds germinated for 14 days, the fresh seedlings of Astragalus mongholicus and Glycyrrhiza uralensis were taken to determine the physiological indexes. The peroxidase (POD) activity was determined by guaiacol method, the catalase (CAT) activity was determined by spectrophotometry, the superoxide dismutase (SOD) activity was determined by NBT method, and the chlorophyll content was determined by spectrophotometry.
[0071] 1.2.4 Calculation of seedling index and allelopathic effect evaluation index Germination rate = (number of germinated seeds after 7 days / number of tested seeds) x 100% Germination potential = (total number of germinated seeds after 4 days / number of tested seeds) x 100% Germination index (GI) =∑(Gt / Dt) (in the formula: Gt is the number of seeds germinated at t days; Dt is the corresponding germination time) Vigor index (VI) = S x GI (S is the total length of radicle at t time of germination, GI is the germination index) Allelopathic effect index (RI) = T / C - 1 (C is the control value, T is the treatment value. RI > 0 is promotion, RI < 0 is inhibition, and the absolute value is consistent with the strength of the effect) Allelopathic comprehensive effect index (SE) = (RI germination rate + RI germination potential + RI vigor index + RI germination index + RI radicle length + RI hypocotyl width + RI chlorophyll) / 7 1.3 Data analysis The data were recorded and arranged with Microsoft Excel 2019, and analyzed by variance analysis and multiple comparisons using IBM SPSS Statistics 26.0, and the graphs were drawn using Origin 2018 software.
[0072] 2 Results and analysis 2.1 Effects of Senna tora extract on seed germination of medicinal plants The results are shown in Table 1. The allelopathic effects of the leaf and stem extracts of Senna tora on Mongolian milkvetch and licorice were significant. The germination rate, germination potential, and germination index of the two receptor plants showed a downward trend. The allelopathic effect index (RI) corresponding to the seed germination indicators of the two plants was less than 0, and the inhibition intensity significantly increased with increasing concentration. Under the treatment of leaf extract at different concentrations, the germination rate, germination potential, and germination index of Mongolian milkvetch seeds were significantly lower than those of CK ( P < 0.05), and the allelopathic effect index RI was less than 0, indicating that the leaf extract of Senna tora inhibited the germination of Mongolian milkvetch seeds, and the higher the concentration of the leaf extract, the stronger the inhibition effect. The seed germination indicators of Mongolian milkvetch under the treatment of stem extract at different concentrations showed a stronger inhibition effect compared with the leaf extract. The response of licorice seed germination to the leaf and stem extracts of Senna tora was consistent with that of Mongolian milkvetch seeds. The leaf and stem extracts at different concentrations inhibited the germination of licorice seeds, and the higher the concentration, the more obvious the inhibition effect. The inhibition effect under the treatment of stem extract was stronger than that under the treatment of leaf extract.
[0073] Table 1 Effects of Senna tora extract from different parts on seed germination of Mongolian milkvetch and licorice
[0074] Note: The same plant in the same column, different lowercase letters represent P < 0.05 difference is significant. When RI > 0, it means allelopathy promotion; when RI < 0, it means allelopathy inhibition; the absolute value of RI can be used to judge the strength of allelopathy.
[0075] 2.2 Effects of Sophoridium japonicum extracts on radicle length and hypocotyl width of medicinal plants The two parts of Sophoridium japonicum had different allelopathic effects on the seedling development of two medicinal plants after seed germination, as shown in Table 2. With the increase of leaf extract concentration, the radicle length of Mongolian milkvetch seedlings showed an increasing trend first and then a decreasing trend. When the concentration was 5 g / L, the radicle length of Mongolian milkvetch was the longest, and it was significantly different from CK ( P < 0.05), RI > 0. With the increase of extract concentration, the length of radicle length decreased, but at the concentration of 10 g / L, the radicle length was still higher than CK, but the difference was not significant ( P > 0.05), and at the concentration of 40 g / L, the radicle length of Mongolian milkvetch was the smallest and decreased by 20.3% compared with CK ( P < 0.05). With the continuous increase of leaf extract concentration of Sophoridium japonicum, the hypocotyl width of Mongolian milkvetch showed a decreasing trend as a whole, and it was significantly lower than CK ( P < 0.05). The overall trend of radicle length and hypocotyl width of Mongolian milkvetch treated with stem extract of Sophoridium japonicum was similar to that treated with leaf extract, but the inhibition was stronger. At the concentration of 40 g / L, the radicle length decreased by 30.8% compared with CK ( P < 0.05), and the hypocotyl width decreased by 29.3% compared with CK ( P < 0.05).
[0076] The effects of Sophoridium japonicum leaf extract of different concentrations on the growth of radicle length and hypocotyl width of Glycyrrhiza uralensis showed a trend of promotion at low concentration and inhibition at high concentration. Under the treatment of 5 g / L Sophoridium japonicum leaf extract, the radicle length of Glycyrrhiza uralensis showed a promoting effect compared with CK, and it increased by 3.71% compared with CK, but it did not reach a significant promotion level ( P > 0.05). At the concentration of 10 g / L, it turned to inhibition, and with the increase of extract concentration, the length of radicle length also decreased. Under the treatment of 5 g / L and 10 g / L Sophoridium japonicum leaf extract, the hypocotyl width of Glycyrrhiza uralensis showed a promoting effect compared with CK, and with the increase of extract concentration to 20 g / L, it began to show an inhibitory effect, RI < 0. At the concentration of 40 g / L, the inhibitory effect reached the maximum, and it decreased by 28.3% compared with CK ( P< 0.05); the root length of Glycyrrhiza was significantly inhibited by the stem extract of S. fruticosum, and the root length of Glycyrrhiza showed a downward trend with the increasing concentration of the stem extract of S. fruticosum, and the difference was significant compared with CK ( P < 0.05), and the hypocotyl width was significantly promoted at 5 g / L, which was 7.4% higher than that of CK ( P < 0.05), and the inhibitory effect of the hypocotyl width of Glycyrrhiza showed a gradient increase with the increasing concentration of the extract, and the difference was significant ( P < 0.05), indicating that the different concentrations of the stem extract of S. fruticosum had significant effects on the growth of Glycyrrhiza seedlings, and the higher the concentration, the stronger the inhibitory effect.
[0077] Table 2 Effects of different parts of S. fruticosum extract on the root length and hypocotyl width of Mongolian milkvetch and Glycyrrhiza
[0078] Note: The same plant in the same column with different lowercase letters indicates P < 0.05, significant difference. When RI > 0, it indicates allelopathic promotion; when RI < 0, it indicates allelopathic inhibition; the absolute value of RI can be used to judge the strength of allelopathy.
[0079] 2.3 Effects of S. fruticosum extract on the antioxidant enzyme activity and photosynthetic pigment content of medicinal plants Figure 1 Effects of S. fruticosum leaf extract on the antioxidant enzyme activity and chlorophyll content of Mongolian milkvetch and Glycyrrhiza seedlings, Figure 2 Effects of S. fruticosum stem extract on the antioxidant enzyme activity and chlorophyll content of Mongolian milkvetch and Glycyrrhiza seedlings.
[0080] From Figure 1 It can be seen that (the same plant with different lowercase letters indicates P < 0.05, significant difference), the POD activity of Mongolian milkvetch was mainly inhibited by the leaf extract of S. fruticosum, and the POD activity of Mongolian milkvetch was the largest in CK, and with the increasing concentration of the extract, the POD activity began to decrease, and at 20 g / L, the POD activity increased sharply, but was still lower than that of CK, and at 40 g / L, it reached the lowest, which was 29.7% lower than that of CK ( P < 0.05), and the POD activity of Glycyrrhiza seedlings showed a trend of first increasing and then decreasing with the increasing concentration of the leaf extract of S. fruticosum, and reached the peak at 10 g / L, and reached the minimum at 40 g / L, but the POD activity was still significantly higher than that of CK ( P< 0.05); All concentrations of extracts from *Sophora mongholica* leaves inhibited the activity of superoxide dismutase (SOD) in *Astragalus membranaceus*. SOD activity decreased with increasing extract concentration, but increased at 40 g / L. *Sophora mongholica* leaf extract promoted SOD activity in *Glycyrrhiza uralensis*, with SOD activity decreasing slowly with increasing extract concentration. All concentrations of extracts from *Sophora mongholica* leaves promoted catalase (CAT) activity, with the most significant promotion at a concentration of 5 g / L. P < 0.05), the promoting effect began to decrease with increasing extract concentration. Licorice CAT activity showed a promoting effect under all concentrations of leaf extract, exhibiting a trend of first increasing and then decreasing. The peak value was reached at 5 g / L for leaf extract treatment, and the difference was significant. P < 0.05), its activity was 1.6 times that of CK; Mongolian Astragalus membranaceus, under treatment with various concentrations of leaf extract, inhibited chlorophyll content, showing varying degrees of decreasing trend and significant differences. P <0.05), with the lowest content at a concentration of 20 g / L, significantly reduced by 91.1% compared to the control (CK). P < 0.05), the chlorophyll content of licorice was highest when treated with 20 g / L leaf extract, while there was no significant change compared with the control at other concentrations.
[0081] Depend on Figure 2 It can be seen that (different lowercase letters represent different plant species) P < 0.05 (significant difference) Under treatment with the extract of *Smilax china* stems, the POD activities of *Astragalus membranaceus* and *Glycyrrhiza uralensis* showed varying degrees of decrease, and the differences were significant. P < 0.05), and the inhibitory effect was weakest when the concentration of both was 20 g / L; under the treatment of stem extract, the SOD activity of Astragalus membranaceus and Glycyrrhiza uralensis showed a trend of first decreasing, then increasing and then slowly decreasing, and both reached the peak at 10 g / L with no significant difference. P > 0.05); The CAT activity of Astragalus membranaceus decreased with increasing stem extract concentration, reaching its lowest value at 20 g / L, which was 66.15% of the control (CK). P <0.05), and the activity of licorice CAT increased slowly at a concentration of 40 g / L. Under different concentrations of stem extract, the activity showed a trend of first slowly increasing and then decreasing, reaching a maximum value at 5 g / L, which was 1.18 times that of the control (CK). P < 0.05); The chlorophyll content of Astragalus membranaceus was significantly reduced under partial extract treatment ( P< 0.05), recovered to CK level at 40 g / L, and the stem extract significantly promoted the chlorophyll content of licorice at 5 and 40 g / L. P < 0.05), and recovered to CK level at 10 and 20 g / L.
[0082] 2.4 Allelopathic effects of bitter bean extract on medicinal plants The results are shown in Table 3. Table 3 shows that the allelopathic inhibitory effects of extracts from different parts of *Sophora alopecuroides* on *Astragalus membranaceus* and *Glycyrrhiza uralensis* increased with increasing extract concentration. Furthermore, the allelopathic combined effect index (SE) of both medicinal plants at different concentrations and different parts was negative, indicating an inhibitory effect. The absolute SE value was highest at a concentration of 40 g / L for each part. Based on the mean allelopathic index, the inhibitory effect of *Sophora alopecuroides* stem extract on *Astragalus membranaceus* and *Glycyrrhiza uralensis* was stronger than that of leaf extract. *Astragalus membranaceus* was more sensitive to *Sophora alopecuroides* leaf and stem extracts than to *Glycyrrhiza uralensis*.
[0083] Table 3. Allelopathic combined effect index (SE) of extracts from different parts of bitter bean on Astragalus membranaceus and Glycyrrhiza uralensis.
[0084] Note: When SE > 0, it indicates allelochemical promotion; when SE < 0, it indicates allelochemical inhibition; the absolute value of SE represents the intensity of the allelochemical effect. 2.5 Correlation between the activities of three antioxidant enzymes and the content of photosynthetic pigments with seed germination and seedling growth indicators of medicinal plants See results Figure 3 , Figure 3 The results showed that there were positive correlations among seed germination indices and seedling growth indices of Astragalus membranaceus, and seedling growth indices were also positively correlated with germination indices. POD activity was mostly positively correlated with seed germination and growth indices, SOD activity had no significant effect on most indices, CAT activity was positively correlated with germination and growth indices and POD activity, but negatively correlated with SOD activity, chlorophyll content was positively correlated with seed germination indices and SOD activity, and negatively correlated with POD and CAT activities.
[0085] Figure 4 This indicates that there are positive correlations among licorice seed germination indicators and seedling growth indicators, and also among the indicators of both. The activities of the three antioxidant enzymes are all positively correlated with seed germination and growth indicators, and are also positively correlated with each other, but all are negatively correlated with chlorophyll content, and chlorophyll content is negatively correlated with all indicators.
Claims
1. A method for inhibiting seed germination and seedling growth of Astragalus mongholicus Bge. / Glycyrrhiza uralensis Fisch., characterized in that, The seed of Mongolian milkvetch / Gancao is treated by soaking with the extract of Sphaerophysa, or the seedling of Mongolian milkvetch / Gancao is irrigated with the extract of Sphaerophysa to inhibit the growth of the seedling, wherein the extract of Sphaerophysa is derived from the stem or leaf of Sphaerophysa.
2. The method according to claim 1, wherein the seed germination and seedling growth of Astragalus mongholicus Bge. and Glycyrrhiza uralensis Fisch. are inhibited. The concentration of the extract of Sphaerophysa is any concentration between 5 g / L and 40 g / L.
3. The method according to claim 1, wherein the method for inhibiting seed germination and seedling growth of Astragalus mongholicus Bge. / Glycyrrhiza uralensis Fisch. is characterized in that, The concentration of the extract of Sphaerophysa is 40 g / L.
4. The method according to claim 1, wherein the method for inhibiting seed germination and seedling growth of Astragalus mongholicus Bge. and Glycyrrhiza uralensis Fisch. is characterized in that, The seed treatment time is 22-26 h, and the irrigation frequency is once every 5-8 days.
5. The method according to claim 1, wherein the method for inhibiting seed germination and seedling growth of Astragalus mongholicus Bge. / Glycyrrhiza uralensis Fisch. is characterized in that, The irrigation site is the soil around the root system, avoiding direct contact with the stem and leaf.
6. The method according to claim 1, wherein the seed germination and seedling growth of Astragalus mongholicus Bge. and Glycyrrhiza uralensis Fisch. are inhibited. The preparation method of the extract of Sphaerophysa is as follows: S1, material collection: collect Sphaerophysa plants, separate stems and leaves, rinse, and dry to constant weight; then cut the dried stems and leaves into small pieces of about 1.5-2.5 cm, crush them into powder, and obtain Sphaerophysa powder; S2, initial mother liquor preparation: seal the Sphaerophysa powder in distilled water for 22-26 h, filter, and obtain the initial mother liquor; S3, concentration dilution: dilute the initial mother liquor with distilled water to the target concentration: 5-40 g / L, obtain the extract of Sphaerophysa, store it at 4℃ in the dark, and reserve it for use.
7. The method according to claim 6, wherein the seed germination and seedling growth of Astragalus mongholicus Bge. and Glycyrrhiza uralensis Fisch. are inhibited. The preparation method of the extract of Sphaerophysa is as follows: S1, material collection: collect Sphaerophysa plants, separate stems and leaves, rinse, and dry to constant weight; then cut the dried stems and leaves into small pieces of about 2 cm, crush them into powder, and obtain Sphaerophysa powder; S2, initial mother liquor preparation: seal the Sphaerophysa powder in distilled water for 24 h, filter, and obtain the initial mother liquor; S3, concentration dilution: dilute the initial mother liquor with distilled water to the target concentration: 40 g / L, obtain the extract of Sphaerophysa, store it at 4℃ in the dark, and reserve it for use.
8. The method according to claim 6 or 7, wherein the seed germination and seedling growth of Astragalus mongholicus Bge. / Glycyrrhiza uralensis Fisch. is inhibited. The temperature for sealing and soaking in step S2 is 20-30℃, and the mixture is shaken and mixed every 6 h during the soaking process.
9. The method for inhibiting seed germination and seedling growth of Astragalus mongholicus Bge. / Glycyrrhiza uralensis Fisch. according to claim 6 or 7, characterized in that, The container for sealing and soaking in step S2 is a seed tray wrapped with sterile breathable filter paper or gauze.
10. The method for inhibiting seed germination and seedling growth of Astragalus mongholicus Bge. / Glycyrrhiza uralensis Fisch. according to claim 1, characterized in that, The method can inhibit at least one of the germination rate, germination potential, germination index, and vigor index of the plant seed.