A plant-derived inhibitor and method for inhibiting the growth of invasive plant Tribulus terrestris

Abstract

The invention relates to a plant-derived inhibitor and a method for inhibiting the growth of an invasive plant Tribulus terrestris, and belongs to the technical field of biological control. The invention verifies through experiments that a biological agent containing 50g / L to 100g / L of lepedeza davurica, oats, chinensis, alfalfa, or 100g / L of sweet clover and Astragalus adoxaceae extract or a mixture of at least two of them is used to irrigate an area where Tribulus terrestris grows, which has an obvious growth inhibition effect and has a good prospect for preventing and controlling Tribulus terrestris.

Description

Technical Field

[0001] The invention relates to the field of ecological prevention and control, in particular to the field of biological prevention and control of the invasive plant Tribulus terrestris. Background Art

[0002] Biological invasion seriously affects the ecological security, economic development and human health of the invaded areas, and is considered to be one of the three most difficult environmental problems at present. Cenchrus incertus M.A.Curtis, a plant of the genus Cenchrus incertus of the Poaceae family, is a malignant invasive weed that spreads rapidly from point to surface, invading a large number of farmland, grasslands, woodlands and other areas. The invasion of Cenchrus incertus has seriously affected the normal utilization of grassland resources and community composition, causing irreversible damage, and also caused great losses to the daily life of local farmers and herdsmen and animal husbandry production. Therefore, it is urgent to carry out effective measures to prevent and control Cenchrus incertus. In the issue of alien plant invasion control, the most commonly used methods today are biological control, chemical control and mechanical control. Among them, chemical control and mechanical control can control the growth of Cenchrus incertus by spraying chemical agents and low-position mowing at the seedling stage of Cenchrus incertus, but the disadvantages are obvious.

[0003] The use of allelopathic interactions between plants to carry out biological control to control invasive plants has attracted much attention because it will not cause a new round of ecological security problems. At present, domestic and foreign scholars have conducted in-depth research on the allelopathic effects of plants such as Xanthium strumarium L., Peganum multisectum (Maxim.) Bobr., and Ageratina adenophora (Spreng.) RMKing et H.Rob., and most of the research directions are the allelopathic effects of alien species on local species. There are few reports on the allelopathic effects of using local species to control Tribulus terrestris. Summary of the invention

[0004] In view of the limited means of controlling Tribulus terrestris at present, the purpose of the present invention is to provide a method based on biological control, environmental protection, and effective inhibition of the growth of the invasive plant Tribulus terrestris.

[0005] The method comprises the steps of using a biological preparation containing one of water extracts of Lespedeza daurica (Laxm.) Schindl., oats (Avena sativa L.), Leymus chinensis (Trin.) Tzvel., Medicagosativa L., Melilotus officinalis (L.) Pall., and Astragalus laxmannii Jacquin., or a mixture of at least two of them, to irrigate an area where Tribulus terrestris grows. The concentration of the water extracts of Lespedeza daurica, oats, Leymus chinensis, and alfalfa is 50 g / L to 100 g / L, and the concentration of the water extracts of Melilotus officinalis and Astragalus laxmannii Jacquin is 100 g / L.

[0006] Furthermore, the concentration of the water extract of Lespedeza davurica, oats, Leymus chinensis and alfalfa is 100 g / L.

[0007] Furthermore, the water extract adopts one of the whole plant water extract, stem and leaf water extract, root water extract, rhizosphere soil water extract or a mixture of at least two of them.

[0008] Furthermore, a biological agent containing a water extract of the rhizosphere soil of Lespedeza davuri was used to irrigate the area where Tribulus truncatula was growing.

[0009] Furthermore, a biological preparation containing an aqueous extract of stems and leaves of Leymus chinensis and / or an aqueous extract of rhizosphere soil of Leymus chinensis and / or an aqueous extract of stems and leaves of oats and / or an aqueous extract of roots of oats is used to irrigate the area where Tribulus terrestris grows.

[0010] Furthermore, the preparation method of the water extract of the whole plant of Lespedeza davurica, oats, Leymus chinensis, alfalfa, Sweet Clover, and Astragalus astragalus is as follows: respectively take Lespedeza davurica, oats, Leymus chinensis, alfalfa, Sweet Clover, and Astragalus astragalus astragalus astragalus astragalus, grind them, put them into a container with distilled water in a ratio of 1:10, and filter them twice with gauze and a microporous filter membrane to prepare a 100 g / L water extract.

[0011] Furthermore, the pore diameter of the microporous filter membrane is 0.45 μm.

[0012] The present invention also provides a plant-derived inhibitor for eliminating or inhibiting the growth of the invasive plant Tribulus truncatula, comprising a biological preparation containing one of the water extracts of Lespedeza davurica, oats, Leymus chinensis, alfalfa, Sweet Clover, and Astragalus astragali with a concentration of 25 g / L to 100 g / L, or a mixture of at least two of them.

[0013] The present invention also provides the use of the plant-derived inhibitor in preventing and controlling the growth of the invasive plant Tribulus terrestris.

[0014] The present invention found that the extracts of Lespedeza davurica, oats, Leymus chinensis, alfalfa, Sweet Clover, and Astragalus membranaceus all had significant changes in the germination rate of Tribulus terrestris seeds. From the allelopathic effect index, it can be seen that the allelopathic effects all showed an inhibitory effect. The extracts of Lespedeza davurica, oats, Leymus chinensis, alfalfa, Sweet Clover, and Astragalus membranaceus all had an effect on the leaf area of ​​Tribulus terrestris, among which the extract of Lespedeza rhizosphere soil water had a significant effect on the leaf area of ​​Tribulus terrestris, with the leaf area reduced by 66% compared with the control, greatly inhibiting the effective photosynthetic capacity of the leaves of Tribulus terrestris; at the same time, it may be limited by the insufficient photosynthesis intensity, and the plant body cannot accumulate enough nutrients for its growth, resulting in a significant decrease in the plant height and fresh weight of the Tribulus terrestris seedlings compared with the control. The reduction in plant height and the reduction in the content of substances in the plant body will further reduce the competitiveness of the recipient plant.

[0015] In particular, the high-concentration water extract of the rhizosphere soil of Lespedeza davuri completely inhibited the seeds of Tribulus truncatula. The oat 100g / L treatment group had the strongest inhibitory effect on the germination rate and root length of Tribulus truncatula seeds. The oat 100g / L concentration of stem, leaf and root water extract treatment group also had a strong inhibitory ability on the germination of Tribulus truncatula seeds. During the growth stage of Tribulus truncatula seedlings, the high-concentration water extracts of the stems and leaves of Lespedeza chinensis, rhizosphere soil and rhizosphere soil of Lespedeza chinensis had a greater effect on the leaf area and plant height of the seedlings. Since the comprehensive allelopathic effect index (SE) of the stems and leaves, roots and rhizosphere soil water extracts of alfalfa on Tribulus truncatula ranked at the top, it also has the potential to prevent and control Tribulus truncatula. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 .The comprehensive allelopathic effect index of Tribulus terrestris under treatment with different concentrations of water extracts from the stems and leaves of six forage grasses.

[0017] Figure 2 .The comprehensive allelopathic effect index of Tribulus terrestris under the treatment of different concentrations of water extracts from the roots of 6 kinds of forage grasses.

[0018] Figure 3 .The comprehensive allelopathic effect index of Tribulus terrestris treated with different concentrations of water extracts from the rhizosphere soil of six forage species. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below in conjunction with the embodiments and effect examples, but the scope of the present invention is not limited. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0020] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0021] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0022] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0023] Test materials

[0024] The seeds of Tribulus terrestris required for the experiment were collected near Toyota Town, Tongliao City, Inner Mongolia (43°53′N, 122°06′E) in September 2020 (because the germination rate of seeds collected that year was low, the experiment used seeds that had been stored at room temperature for one year); the alfalfa (Crown), Astragalus membranaceus, oats (Sweet Swallow No. 1), and Leymus chinensis (Jinong No. 1) required for the experiment were sourced from the perennial artificial grassland planted in the Science and Technology Demonstration Park of Inner Mongolia University for Nationalities, and the Lespedeza (Lespedeza davurica) and Sweet Melilotus (Sweet Melilotus rubra) were sourced from perennial natural forages grown in the park. The sampling time of each forage was July 1, 2021, and the sampling time was the flowering period of each forage.

[0025] The sampling time of rhizosphere soil of each forage grass is the same as the sampling time of fresh samples of each forage grass. After the fresh samples of forage grass are brought back to the laboratory, the large pieces of soil at the roots of the forage grass are peeled off, and then the roots of the forage grass are gently shaken to shake off the thicker soil. Finally, the remaining soil at the roots of the forage grass is brushed off with a brush that has been sterilized in advance for later use.

[0026] Example water extract preparation

[0027] Take appropriate amounts of alfalfa, Astragalus membranaceus, Sweet Clover, oats, Leymus chinensis, and Lespedeza davurica materials (the stems, leaves, and roots are crushed, and the rhizosphere soil is ground and sieved before use), put them into a 500 ml beaker, and the mass ratio of distilled water to material is 10:1. Place the beaker in an oscillator for 24 hours, and then filter twice with gauze and a microporous filter membrane (diameter 0.45 μm). Finally, dilute the original solution (100 g / L) with distilled water into 50, 25, and 12.5 g / L treated solutions, and store them in a 4°C refrigerator.

[0028] Embodiment Effects of water extracts of Lespedeza davurica, oats, Leymus chinensis, alfalfa, sweet clover, and Astragalus astragali on the germination of Tribulus truncatula seeds:

[0029] In order to simulate the seed germination environment of Horqin sandy land, a sand-based culture method was adopted (the sand came from the sampling site of Tribulus terrestris seeds, and the sand was washed with clean water before use to remove the chemical substances contained therein to the greatest extent). Full and uniform-sized Tribulus terrestris seeds (thorny buds) were selected, disinfected with 2% NaClO3 solution for 15 minutes, and repeatedly rinsed with distilled water for later use. About 100g of dried sand was placed in each culture dish, and 30 seeds of Tribulus terrestris were evenly placed in the sand. At the beginning of the experiment, 20ml of water extract or distilled water (blank control group) was added at one time, and the dishes were placed in an intelligent light incubator. The temperature was set to 25±1℃, the humidity was 50%, and the light-dark cycle was 16 / 8. According to the "International Seed Inspection Procedure", the root length reaching 1mm was used as the germination standard, and the germination end standard was that no new seeds germinated for more than 48h. The germination was observed and recorded every 24h. After 7d, 10 seeds that had germinated were randomly washed out from each dish, and their root length and shoot length were measured with a digital vernier caliper with an accuracy of 0.01.

[0030] Direct observation method was used to determine germination indices including germination rate, germination potential, root length and bud length.

[0031] Germination rate = (number of germinated seeds / total number of seeds per dish) × 100%

[0032] Germination potential = (number of seeds germinated on the third day / total number of seeds per dish) × 100%

[0033] Allelopathic response index (RI): The allelopathic effects of the water extracts of organs and rhizosphere soil of six forage grasses were evaluated according to Williamson's evaluation method, and RI was used to indicate the intensity of allelopathic effect.

[0034] RI=1-CK / T(T≧CK) or RI=T / CK-1(T<CK)

[0035] In the formula, CK is the control value; T is the treatment value. RI>0 is promotion, RI<0 is inhibition, and the absolute value of RI indicates the intensity of allelopathic effect.

[0036] From the analysis in Table 1, it can be seen that each treatment group had a significant effect on the germination rate of Tribulus truncatula seeds (P < 0.05), and all showed an inhibitory effect, among which:

[0037] Under the treatments of various forage grass stem and leaf water extracts, the oat 100g / L treatment group had the strongest inhibitory effect on the germination rate of Tribulus truncatula seeds, and the allelopathic effect index reached the highest level of -0.38.

[0038] Under the treatments of various herbage root water extracts, the oat 100g / L treatment group had the strongest inhibitory effect on the germination rate of Tribulus terrestris seeds, with the allelopathic effect index reaching -0.40, and the changing trend was that the inhibitory effect gradually increased with the increase of water extract concentration.

[0039] Under the treatments of rhizosphere soil-water extracts of various forage grasses, the group treated with 100 g / L Lespedeza had the strongest inhibitory effect on the seed germination rate of Tribulus terrestris, reducing the seed germination rate of Tribulus terrestris to 0%, achieving complete inhibition of seed germination. Among them, the groups treated with 100 g / L Sweet Clover and 100 g / L Leymus chinensis also had a significant inhibitory effect on the seed germination rate of Tribulus terrestris.

[0040] Table 1 Effects of the extracts of various organs and rhizosphere soil of 16 forage grasses on the allelopathic effect index (RI) of the germination rate of Tribulus truncatula seeds

[0041]

[0042]

[0043] From the analysis in Table 2, it can be seen that under the treatment of water extracts of stems and leaves of various forages, the germination potential of Tribulus terrestris seeds was significantly different (P < 0.05), and it showed a trend of gradual strengthening with the increase of water extract concentration. Among them, under the treatment of water extracts of stems and leaves of alfalfa, sweet clover, and Lespedeza davurica, the germination potential of Tribulus terrestris seeds showed a trend of gradual strengthening of inhibition with the increase of water extract concentration. Under the treatment of water extracts of stems and leaves of Astragalus, oats, and Leymus chinensis, the germination potential of Tribulus terrestris seeds showed a phenomenon of "low promotion and high inhibition" with the increase of water extract concentration, and inhibition appeared under the treatment of 100g / L water extract concentration.

[0044] Under the treatment of various herbage root water extracts, the 100g / L treatment group of Melilotus officinalis had the strongest inhibitory effect on the germination potential of Tribulus truncatus seeds, and the allelopathic effect index reached -0.26. Under the action of the three treatment groups of Astragalus membranaceus, Leymus chinensis, and Oats, the germination potential of Tribulus truncatus seeds showed a significant promoting effect, and the higher the concentration of water extract, the stronger the promoting effect, and the strongest promoting effect was achieved under the treatment of 12.5g / L water extract of Astragalus membranaceus and Oats.

[0045] Under the treatment of rhizosphere soil water extracts of various forage grasses, the 100g / L treatment group of Lespedeza davuri had the strongest inhibitory effect on the germination potential of Tribulus truncatula seeds, and the allelopathic effect index reached -1, which was completely inhibited. Except for the oat treatment group, the other treatment groups showed a promoting effect under the treatment of 0-25g / L water extract, and showed an inhibitory effect under the treatment of 50-100g / L water extract as the concentration of water extract increased. The overall effect was low concentration promotion and high concentration inhibition; and the oat treatment group had an inhibitory effect except for the 100g / L treatment, and the rest were promoting.

[0046] Table 2 Effects of the rhizosphere soil water extracts of various organs of 6 forage grasses on the allelopathic effect index (RI) of Tribulus truncatula seeds

[0047]

[0048]

[0049] As shown in Table 3, under the treatment of the water extracts of the stems and leaves of various forage grasses, the water extracts of the four treatment groups of alfalfa, chinensis, lespedeza, and oats at various concentrations significantly inhibited the growth of the roots of Tribulus truncatula. Among the treatment groups, the oat water extract at 100 g / L had the strongest inhibitory effect on the seed roots of Tribulus truncatula.

[0050] Under the treatment of various herbage root water extracts, the concentrations of sweet clover, lepsodactyla davuri and oats gradually showed an inhibitory effect as the concentration of water extracts increased; while alfalfa, astragalus and chinensis all showed an inhibitory effect when the water extract concentration reached 100g / L. Under the treatment of 100g / L water extract of oats, the inhibitory effect on the seed root growth of Tribulus truncatula was the strongest, reaching -0.67.

[0051] Under the treatment of rhizosphere soil water extracts of various forage grasses, the root length of Tribulus truncatula seeds was inhibited, but the inhibitory effects were different; among them, except for the complete inhibition of the 100g / L Lespedeza davurica treatment group, the inhibitory effect of the 100g / L Leymus chinensis treatment group was also significantly higher than that of other treatments (P<0.05).

[0052] Table 3 Effects of the extracts of various organs and rhizosphere soil of 6 forage grasses on the allelopathic effect index (RI) of the root growth of Tribulus truncatula seeds

[0053]

[0054] As shown in Table 4, compared with the control, different kinds of forage water extracts had a significant effect on the seed bud length of Tribulus terrestris (P < 0.05). Among them, under the treatment of different kinds of forage stem and leaf water extracts, the inhibitory effect of the treatment groups of Leymus chinensis and Oats gradually increased with the increase of water extract concentration, and finally reached the strongest at the 100g / L concentration treatment, and the bud length was reduced by 10% and 73% respectively compared with the control. Under the treatment of various concentrations of alfalfa and Astragalus membranaceus, the bud length of Tribulus terrestris showed a phenomenon of "low promotion and high inhibition", while the water extracts of various concentrations of Sweet Clover and Lespedeza showed a promoting effect on the buds of Tribulus terrestris.

[0055] Under the treatment of different kinds of grass root water extract, the 100g / L water extract of Astragalus membranaceus had the strongest inhibitory effect on the bud length of Tribulus terrestris, with an allelopathic effect index of -0.28, while the maximum concentrations of alfalfa, Astragalus membranaceus and oats reduced the bud length of Tribulus terrestris by 23%, 28% and 19%, respectively. Under the treatment of different concentrations of water extract of Sweet Clover and Lespedeza, the bud length of Tribulus terrestris was promoted, but the effects were different, and the strongest promotion effect was 0.44 under the treatment of 100g / L Lespedeza.

[0056] Under the treatment of rhizosphere soil water extracts of different forage species, the inhibitory effect reached the strongest at -1 under the treatment of 100g / L water extract of Lespedeza davurica, while the promotion effect reached the strongest at 0.42 under the treatment of 12.5g / L water extract of Astragalus membranaceus. Among all forage treatment groups, except for the treatment of 12.5g / L water extract, the differences among treatments were significant (P<0.05), and the differences among other treatments were not significant (P>0.05).

[0057] Table 4 Effects of rhizosphere soil water extracts of various organs of 6 forage grasses on the allelopathic effect index (RI) of Tribulus truncatula seed bud growth

[0058]

[0059]

[0060] Embodiment Effects of water extracts of Lespedeza davurica, oats, Leymus chinensis, alfalfa, Sweet clover, and Astragalus astragali on seedlings of Tribulus terrestris:

[0061] A flower pot with an upper diameter of 18 cm and a height of 15 cm was selected, and the soil matrix was a mixture of sandy loam and vermiculite in a ratio of 1:1. On June 20, 2021, the seeds of Tribulus terrestris were planted in flower pots, with 100 seeds per pot (60 plants were uniformly fixed after emergence), and distilled water was used for watering and maintenance during the period. On July 5, 2021, when Tribulus terrestris was at least three-leaf stage, 500 ml of the corresponding water extract was irrigated into the soil at the base of the plant every three days for the Tribulus terrestris seedlings, and distilled water was stopped during the period until August 20 (a total of 45 days of treatment). On August 20, the plant height, leaf area, and fresh weight of the aboveground part of Tribulus terrestris under each treatment were measured. The above indicators were measured by randomly selecting 20 Tribulus terrestris plants with consistent growth in each pot, and the third leaf (functional leaf) was selected for the physiological index determination.

[0062] The plant height of Tribulus terrestris in its natural state was directly measured with a ruler (the natural height refers to the distance from the ground to the highest point of the plant in its natural state); the fresh weight of the aboveground part of Tribulus terrestris was measured by direct observation and recording (the electronic balance was accurate to 0.001g); the leaf area of ​​the third leaf (functional leaf) of Tribulus terrestris was measured using the YMJ-CH intelligent leaf area measurement system, and the leaves were cut off at the same level as the stems for measurement.

[0063] As shown in Table 5, different types of forage grass also have a significant effect on the leaf area of ​​Tribulus truncatula seedlings (P < 0.05). Among them, under the treatment of the water extract of the stems and leaves of each forage grass, the treatment group of Astragalus membranaceus showed a promoting effect on the leaf area of ​​Tribulus truncatula seedlings, and under the treatment of 12.5g / L water extract concentration, the promoting effect was the strongest, and the allelopathic effect index reached 0.45. With the increase of the concentration of water extract, the promoting effect gradually decreased. Under the treatment of various concentrations of Sweet Sweet Meadow and Lespedeza davuri, compared with the control, the leaf area of ​​Tribulus truncatula seedlings was promoted under the treatment of 0-50g / L concentration, and inhibited under the treatment of 100g / L concentration. Under the treatment of alfalfa, Leymus chinensis and oats, the allelopathic effect index showed a trend of gradually increasing with the increase of concentration.

[0064] Under the treatment of various herbage root water extracts, the 100g / L water extract of Melilotus sutchuenensis had the strongest inhibitory effect on the leaf area of ​​Tribulus truncatus seedlings, and the allelopathic effect index reached -0.51; under the treatment of 12.5g / L water extract of Lespedeza sutchuenensis, the leaf area of ​​Tribulus truncatus seedlings increased by 21.03% compared with the control. Under the treatment of various concentrations of water extracts of alfalfa, Melilotus sutchuenensis and oats, the leaf area of ​​Tribulus truncatus showed a promoting effect at the treatment of 12.5g / L concentration, and the other concentrations showed an inhibitory effect. Under the treatment of various concentrations of water extracts of Astragalus membranaceus and Lespedeza davurica, the leaf area of ​​Tribulus truncatus showed a promoting effect at the treatment of 12.5-25g / L concentration of water extract, and a promoting effect at the treatment of 50-100g / L concentration of water extract.

[0065] Under the treatment of water extracts of rhizosphere soil of various forage grasses, the treatment groups of alfalfa and oats at various concentrations showed an inhibitory effect on the leaf area of ​​Tribulus terrestris, and with the increase of water extract concentration, the inhibitory effect gradually increased, and the maximum reduction of leaf area was 36% and 43% compared with the control. Under the treatment of water extracts of various concentrations in the other treatment groups, compared with the control, the leaf area of ​​Tribulus terrestris was promoted under the treatment of water extracts at concentrations of 12.5-25g / L, with the maximum promotion intensity of 86%. With the increase of water extract concentration, it gradually showed an inhibitory effect, and when the concentration of Lespedeza davurica was 100g / L, the inhibitory effect reached the strongest, and the allelopathic effect index was -0.66.

[0066] Table 5 Effects of the water extracts from the rhizosphere soil of 56 forage grass organs on the allelopathic effect index (RI) of the leaf area of ​​Tribulus truncatula seedlings.

[0067]

[0068] As shown in Table 6, the effects of various forages on the plant height of Tribulus truncatus seedlings were significantly different (P < 0.05). Under the treatment of the water extracts of the stems and leaves of various forages, the treatment groups of alfalfa, Leymus chinensis and oats at various concentrations showed an inhibitory effect on the plant height of Tribulus truncatus, while the water extracts of Astragalus membranaceus, Sweet Clover and Lespedeza davurica at various concentrations showed a trend of promoting and then inhibiting the plant height of Tribulus truncatus seedlings with the increase of water extract concentration. When the concentration of Leymus chinensis water extract was 100 g / L, the inhibitory effect reached the strongest, and the allelopathic effect index was -0.47. When the concentration of Astragalus membranaceus water extract was 12.5 g / L, the promoting effect reached the strongest, and the allelopathic effect index was 1.05.

[0069] Under the treatment of various herbage root water extracts, the concentration treatment groups of Astragalus membranaceus had the greatest effect on the plant height of Tribulus terrestris. Compared with other treatment groups, the effects of Lespedeza and Oats on the plant height of Tribulus terrestris were weaker. Under the treatment of low concentration water extracts, it mainly promoted the effect. At the concentration of 100g / L water extract, the strongest inhibition was -0.14 and -0.12 respectively. Under the treatment of alfalfa extract, with the increase of extract concentration, the plant height of Tribulus terrestris gradually decreased compared with the control, and after the treatment of 50g / L concentration, the plant height no longer changed. The allelopathic inhibition ability of the root extract of Leymus chinensis was slightly stronger than that of the root extract of alfalfa. The change trend was the same as that of the root extract of alfalfa. With the increase of concentration, the inhibition ability gradually increased, and reached the maximum of -0.57 in the 100g / L treatment group.

[0070] Under the treatment of rhizosphere soil water extracts of various forage grasses, water extracts of various concentrations in the treatment groups of alfalfa and oats had an inhibitory effect on the plant height of Tribulus truncatus seedlings, but the effects were different. The treatment groups of Astragalus adansinoides, Sweet Clover, Leymus chinensis and Lespedeza davurica mainly showed a "low-promoting and high-inhibiting" effect on the plant height of Tribulus truncatus seedlings, while the Leymus chinensis treatment group showed a promoting effect at a concentration of 12.5 g / L water extract, while other concentrations showed an inhibitory effect. With the increase of concentration, the allelopathic effect index was -0.13, -0.59, and -0.62, respectively. At the maximum concentration, the inhibitory effect was the strongest. The inhibitory effect of the rhizosphere soil extract of oats on the plant height of Tribulus truncatus seedlings was slightly lower than that of Leymus chinensis, but at the lowest concentration, the inhibitory ability of oats was higher than that of Leymus chinensis.

[0071] Table 6 Effects of the rhizosphere soil water extracts of various organs of 6 forage species on the allelopathic effect index (RI) of Tribulus truncatula seedlings

[0072]

[0073]

[0074] As shown in Table 7, the effects of various forages on the aboveground fresh weight of Tribulus truncatus seedlings were significantly different (P < 0.05). Among them, under the treatment of the water extracts of the stems and leaves of various forages, the concentrations of Melilotus officinalis and Leymus chinensis treatment groups all showed a promoting effect on the aboveground fresh weight of Tribulus truncatus seedlings, but the effect gradually decreased with the increase of the concentration of the water extract; when the concentration of Melilotus officinalis water extract was 12.5 g / L, the promoting effect was the strongest, and the allelopathic effect index was 1.2. In addition to the above two treatment groups, the effects of the other four treatment groups on the aboveground fresh weight of Tribulus truncatus seedlings showed an allelopathic effect of "low promotion and high inhibition" with the increase of the concentration of the water extract, and the inhibition reached the strongest at -0.60 when the concentration of alfalfa was 100 g / L.

[0075] Under the treatment of various herbage root water extracts, the 12.5g / L water extract of Melilotus officinalis had the greatest effect on the aboveground fresh weight of Tribulus truncatula seedlings, mainly showing a promoting effect, with an allelopathic effect index of 1.13. As the concentration of the water extract increased, the promoting effect showed a downward trend, but all showed a promoting effect. The effect trend of Lespedeza davurica was the same as that of Melilotus officinalis. In the treatment groups of alfalfa, Astragalus adansinoides and Leymus chinensis, as the concentration of the water extract increased, the inhibitory effect gradually increased. Under the treatment of Melilotus officinalis 100g / L water extract, the inhibitory effect reached the strongest -0.87.

[0076] Under the treatments of rhizosphere soil water extracts of various forage grasses, compared with other treatment groups, the alfalfa treatment group had the strongest effect on the aboveground fresh weight of Tribulus terrestris seedlings. With the increase of water extract concentration, the allelopathic effect index reached -0.13, -0.53, -0.60, and -0.67, respectively. Under the treatments of various concentrations of Adansonia ovata, the aboveground fresh weight of Tribulus terrestris seedlings increased by 120% and 20% respectively under high concentration treatment compared with the control. With the increase of concentration, it gradually showed an inhibitory effect.

[0077] Table 7 Effects of rhizosphere soil water extracts of organs of six forage grasses on the allelopathic effect index (RI) of aboveground fresh weight of Tribulus truncatula seedlings

[0078]

[0079] Embodiment Effect of water extracts of Lespedeza davurica, oats, Leymus chinensis, alfalfa, sweet clover, and Astragalus astragali on the allelopathic comprehensive effect index of Tribulus truncatula:

[0080] Synthetical effect of Allelopathy (SE) is the arithmetic mean of the RI of various indicators (germination rate, root length, shoot length, fresh weight of aboveground part, plant height, leaf area) of the donor to the same receptor. The absolute value of SE is used to comprehensively evaluate the intensity of the allelopathy.

[0081] SE=(RI 发芽率 +RI 发芽势 +RI 根长 +RI 芽长 +RI 株高 +RI 叶面积 +RI 地上部分鲜重 ) / 7

[0082] Depend on Figure 1 It can be seen that the water extracts of the stems and leaves of the six forage grasses have a certain inhibitory effect on Tribulus terrestris. The comprehensive allelopathic effect indexes of the five forage grasses, Leymus chinensis, Astragalus membranaceus, Avena sativa, Lespedeza davurica and Sweet Clover, all showed a promoting effect at low concentrations and an inhibitory effect at high concentrations, and the inhibitory effect was strongest at the maximum treatment concentration; in the treatment of 100 g / L water extract concentration, the comprehensive inhibitory ability was ranked as Oats>Medicago truncatula>Leymus chinensis>Lespedeza davurica>Astragalus membranaceus>Saccharum officinale.

[0083] Depend on Figure 2It can be seen that the allelopathic effects of different species and concentrations of water extracts of forage grass roots on Tribulus terrestris are different; under the treatment of water extract of sheep fescue roots, the inhibitory effect gradually increases with the increase of water extract concentration; while under the treatment of water extracts of five kinds of forage grass roots, including alfalfa, Astragalus membranaceus, oats, Lespedeza davurica and Sweet Clover, the allelopathic effect showed an overall promotion effect at low concentration and inhibition effect at high concentration. Sheep fescue showed a promotion effect under the treatment of 12.5-50g / L, and the inhibitory effect gradually increased with the further increase of water extract concentration; Lespedeza had a weak inhibitory effect except for the treatment of 50-100g / L concentration.

[0084] Depend on Figure 3 It can be seen that different concentrations of rhizosphere soil water extracts have allelopathic effects on Tribulus truncatus. Under the treatment of alfalfa and oats, the inhibitory effect gradually increased with the increase of water extract concentration, while under the treatment of different concentrations of rhizosphere soil water extracts of other forages, the allelopathic effect was promoted at low concentrations and inhibited at high concentrations. The inhibitory effect of water extracts of the six forages was Lespedeza davurica> Leymus chinensis> Alfalfa> Sweet Ligustrum lucidum> Oats> Astragalus astragali.

[0085] Finally, it is necessary to explain here that the above embodiments are only used to further illustrate the technical solution of the present invention in detail and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by technicians in this field based on the above content of the present invention all fall within the scope of protection of the present invention.

Claims

1. A method for inhibiting the growth of an invasive plant Tribulus terrestris, Features: The method comprises the following steps: watering an area where Tribulus terrestris grows by using a biological preparation containing an oat water extract, wherein the concentration of the oat water extract is 50 g / L to 100 g / L.

2. A method for inhibiting the growth of the invasive plant Tribulus terrestris according to claim 1, Features: The concentration of the oat water extract is 100 g / L.

3. A method for inhibiting the growth of the invasive plant Tribulus terrestris according to claim 1 or 2, Features: The oat water extract adopts one of the whole plant water extract, stem and leaf water extract, root water extract, rhizosphere soil water extract or a mixture of at least two of them.

4. A method for inhibiting the growth of the invasive plant Tribulus terrestris according to claim 1 or 2, Features: The biological preparation containing water extract of oat stems and leaves and / or water extract of oat roots is used to irrigate the area where Tribulus terrestris grows.

5. A method for inhibiting the growth of the invasive plant Tribulus terrestris according to claim 3, Features: The preparation method of the oat stem and leaf water extract and the root water extract is: take the oat stem and leaf or root system, grind it, put it into a container with distilled water in a ratio of 1:10, and filter it twice with gauze and a microporous filter membrane respectively to prepare a 100 g / L water extract.

6. A method for inhibiting the growth of the invasive plant Tribulus terrestris according to claim 5, Features: The pore diameter of the microporous filter membrane is 0.45 μm.

7. Use of oat water extract in preventing and controlling the growth of the invasive plant Tribulus terrestris. Features: The concentration of the oat water extract is 50 g / L to 100 g / L.

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