A method for improving drought resistance of tall fescue

Abstract

A method for improving the drought resistance of tall fescue comprises four stages: seed disinfection, breeding, seedling determination and seedling acclimatization. The method is characterized in that the expanded arbuscular mycorrhizal fungi are added to the culture matrix of the breeding step, and the arbuscular mycorrhizal fungi are one or two of Glomus juvenile and Glomus mosese. In the plant seed breeding stage, the arbuscular mycorrhizal fungi are added to the culture matrix of the seeds, so that the arbuscular mycorrhizal fungi infect the plant root system and then coexist and form a union, thereby enhancing the activities of CAT, SOD, POD and proline in the plant, thereby enhancing the ability of the plant leaf tissue to resist antioxidant damage and osmotic regulation, so that the tall fescue can better cope with the damage caused by drought adversity.

Description

Technical Field

[0001] The invention relates to the field of planting technology, in particular to a method for improving the drought resistance of tall fescue. Background Art

[0002] Tall fescue (Festuca arundinacea Schreb.), also known as reed fescue, is a perennial herb of the Poaceae family, subgenus Fescue. It has extremely high nutritional value and is an important Poaceae forage in the world. Because of its resistance to barrenness, disease resistance, and wide adaptability, it is widely used in the construction of urban greening and sports venues, and shows significant social, ecological and environmental benefits. Tall fescue is increasingly valued as a lawn grass.

[0003] However, as a lawn grass, the planting area of ​​tall fescue is constantly expanding due to demand. However, as an artificial lawn in the city, it is not as drought-resistant as natural grass, especially its thirst resistance is very poor. The lawn root system is shallow and is not enough to absorb enough water in the soil, so it can only be irrigated manually. In the dry season, the lawn needs to be watered once a day, and even in the rainy season, it needs to be watered at least twice a month. A lot of water is needed for management, especially in seasons with little rain or areas with relatively scarce water resources. Once water is lacking, the lawn will grow poorly. Therefore, it is urgent to cultivate new varieties of tall fescue that are drought-resistant and water-saving.

[0004] In view of this, this application is hereby filed. Summary of the invention

[0005] The invention aims to provide a method for improving the drought resistance of tall fescue. The method comprises the following steps: adding arbuscular mycorrhizal fungi into a culture matrix of the seeds during the seed breeding stage of the tall fescue, so that the arbuscular mycorrhizal fungi infect the root system of the tall fescue and then coexist and form a union, thereby improving the activities of CAT, SOD, POD and proline in the tall fescue plants, thereby improving the ability of the leaf tissue of the tall fescue to resist antioxidant damage and the osmotic regulation ability, and enabling the tall fescue to better cope with the damage caused by drought adversity.

[0006] An embodiment of the present invention is achieved as follows: a method for improving the drought resistance of tall fescue, including a breeding stage, characterized in that expanded arbuscular mycorrhizal fungi are added to the culture medium in the breeding stage, and the arbuscular mycorrhizal fungi are one or both of Glomus juvenile and Glomus mosseae.

[0007] Furthermore, a seedling acclimatization stage is provided after the breeding stage, and the seedling acclimatization stage includes the step of increasing the SLs content (strigolactones) in tall fescue plants.

[0008] Furthermore, the step of increasing the SLs content in tall fescue plants during the seedling growth stage is: spraying the leaves of tall fescue with a strigolactone analogue.

[0009] Furthermore, the concentration of the strigolactone analogue was 0.2 μmol·L -1 The spraying frequency is once a day, for a total of 10 days.

[0010] Furthermore, the spraying degree is such that the leaves are covered with dew without dripping.

[0011] Furthermore, a seed disinfection stage is provided before the breeding stage, and the seed disinfection stage comprises: selecting tall fescue seeds with full grains and uniform size, soaking them in 75% alcohol for 1-3 minutes, rinsing them with distilled water for 3-4 times, then soaking them in 84 disinfectant for 2-5 minutes, and rinsing them with distilled water for 3-4 times.

[0012] Furthermore, the breeding stage is hole tray breeding, firstly, the culture matrix is ​​filled to 2 / 3 of each seedling tray, watered, and then tall fescue seeds are sown, covered with 0.5 cm sterilized matrix, watered the bottom of the seedling tray, and then moved to the light culture room for culture.

[0013] Furthermore, a seedling determination stage is provided before the seedling acclimatization stage, wherein the seedlings of tall fescue grow to the two-leaf stage 14 days after breeding, and 1 / 4-1 / 3 of the seedlings are retained in each plug tray.

[0014] Furthermore, the method for propagating arbuscular mycorrhizal fungi mainly comprises the following steps:

[0015] ①. Seed disinfection: Soak sorghum and corn seeds in 40% formaldehyde solution for 15 minutes, then rinse with water several times;

[0016] ② Matrix sterilization: Use vermiculite and perlite matrix in a weight ratio of 1:1, steam sterilize at 95℃ twice, each time for 1-2 hours, with a 24-hour interval in between;

[0017] ③. Cultivation: Fill the sterilized culture medium to 2 / 3 of the plastic pot, evenly spread the strains of the arbuscular mycorrhizal fungi on the medium in a thin layer, then cover with 2 cm of sterilized medium, water, sow sorghum seeds, cover with 0.5 cm of sterilized medium, and then move to a light room for cultivation for 3-4 months. ④. Harvest.

[0018] Furthermore, the culture conditions in the light room mainly include: light time: 14h white / 10h dark; light intensity: 8000lx; temperature: 20℃-30℃; humidity: 60%.

[0019] The beneficial effects of the embodiments of the present invention are:

[0020] 1. A method for improving drought resistance of tall fescue provided in an embodiment of the present invention comprises adding arbuscular mycorrhizal fungi (mainly one or two of Glomus juveniles and Glomus mosesi) into a culture matrix of tall fescue seeds during the breeding stage of tall fescue seeds, so that the arbuscular mycorrhizal fungi infect the root system of tall fescue and then coexist and form a union, thereby improving the activities of CAT, SOD, POD and proline in tall fescue plants, thereby improving the ability of leaf tissue of tall fescue to resist antioxidant damage and osmotic regulation, so that tall fescue can better cope with the damage caused by drought adversity.

[0021] 2. A method for improving the drought resistance of tall fescue provided in an embodiment of the present invention comprises adding arbuscular mycorrhizal fungi (mainly one or two of Glomus juveniles and Glomus mosseae) into the culture medium of tall fescue seeds during the seed breeding stage of tall fescue, so that the grown tall fescue can still maintain the growth of plant height, leaf width, leaf length and leaf root under drought stress, so that the tall fescue plants maintain a good growth trend and can withstand the test of drought conditions on artificial turf.

[0022] 3. An embodiment of the present invention provides a method for improving the drought resistance of tall fescue. In order to further increase the activities of CAT, SOD, POD, and proline in tall fescue plants, and also to increase the content of strigolactones in the plants, this embodiment sprays strigolactone analogs on the leaves of tall fescue plants in the seedling stage, and synergistically enhances the activities of CAT, SOD, POD, and proline in the plants with arbuscular mycorrhizal fungi, thereby further improving the drought resistance of tall fescue plants. The synergistic effect of SLs and AMF can alleviate the damage caused by drought adversity, alleviate the oxidative damage caused by drought adversity, regulate the osmotic pressure of cell tissues, and enhance the stress resistance of plants.

[0023] 4. A method for improving the drought resistance of tall fescue provided in an embodiment of the present invention, wherein spraying the leaves of tall fescue with a strigolactone analogue during the seedling growth stage can increase the content of strigolactone in the plant, and SLs in the plant can also enhance the infection effect of AMF on the host plant and promote the formation of a symbiotic relationship between AMF and the plant.

[0024] In general, the method for improving the drought resistance of tall fescue provided in the embodiment of the present invention can cultivate tall fescue plants with strong drought resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 This is the phenotype diagram of tall fescue after treatment in Experimental Example 1 of the present invention;

[0027] Figure 2 This is a graph showing the SLs content in the roots of tall fescue after treatment in Experimental Example 1 of the present invention;

[0028] Figure 3 This is a graph showing the effect of the treatment of Experimental Example 1 of the present invention on the growth index of tall fescue;

[0029] Figure 4 This is a graph showing the effect of the treatment of Experimental Example 1 of the present invention on the physiological and biochemical indicators of tall fescue;

[0030] Figure 5 This is a picture of AMF spores after expansion in Example 1-3 of the present invention;

[0031] Figure 6 This is the phenotype diagram of tall fescue after treatment in Experimental Example 2 of the present invention;

[0032] Figure 7 The AMF infection rate and infection diagram after treatment in Experimental Example 2 of the present invention;

[0033] Figure 8 This is a graph showing the effect of AMF on the growth indexes of tall fescue after treatment in Experimental Example 2 of the present invention;

[0034] Fig. 9 This is a graph showing the effect of AMF on the physiological and biochemical indices of tall fescue after treatment in Experimental Example 2 of the present invention;

[0035] Fig.10 This is the phenotype diagram of tall fescue after treatment in Experimental Example 3 of the present invention;

[0036] Fig.11 This is a graph showing the SLs content of tall fescue after treatment in Experimental Example 3 of the present invention;

[0037] Fig.12 The AMF infection rate and infection diagram after treatment in Experimental Example 3 of the present invention;

[0038] Fig.13 This is a graph showing the growth index of tall fescue after treatment in Experimental Example 3 of the present invention;

[0039] Fig.14 This is a graph showing the effect of treatment in Experimental Example 3 of the present invention on the physiological and biochemical indicators of tall fescue; DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0041] Example

[0042] The present embodiment provides a method for improving the drought resistance of tall fescue, which mainly includes three stages: seed disinfection, breeding, and seedling acclimatization. It is characterized in that the expanded arbuscular mycorrhizal fungi are added to the culture medium in the breeding step, and the arbuscular mycorrhizal fungi are one or both of Glomus juveniles and Glomus mosseae.

[0043] The present embodiment provides a method for improving the drought resistance of tall fescue, which mainly includes four stages: seed disinfection, breeding, seedling determination, and seedling acclimatization. It is characterized in that the expanded arbuscular mycorrhizal fungi are added to the culture medium in the breeding step, and the arbuscular mycorrhizal fungi are one or both of Glomus juveniles and Glomus mosseae.

[0044] In this embodiment, the propagated arbuscular mycorrhizal fungi include spores, hyphae, mycorrhizal segments and culture matrix.

[0045] In this solution, the seeds of tall fescue can be bred in a seedling tray or directly sowed in the soil.

[0046] Furthermore, the method also includes the step of increasing the content of strigolactones (SLs) in tall fescue plants during the seedling recovery period.

[0047] Furthermore, the step of increasing SLs in tall fescue plants during the seedling growth stage is: spraying the leaves of tall fescue with a strigolactone analogue.

[0048] Furthermore, the concentration of the strigolactone analogue was 0.2 μmol·L -1 The spraying frequency is once a day, for a total of 10 days.

[0049] Furthermore, the spraying degree is such that the leaves are covered with dew without dripping.

[0050] Furthermore, the seed disinfection step includes: selecting tall fescue seeds with full grains and uniform size, soaking them in 75% alcohol for 1-3 minutes, rinsing them with distilled water for 3-4 times, then soaking them in 84 disinfectant for 2-5 minutes, and rinsing them with distilled water for 3-4 times.

[0051] Furthermore, the breeding step is hole tray breeding, first filling the culture matrix to 2 / 3 of each seedling tray, watering, then sowing tall fescue seeds, covering with 0.5 cm sterilized matrix, watering the bottom of the seedling tray, and then moving to a light culture room for culture.

[0052] Furthermore, the step of determining the seedlings includes retaining 1 / 4 to 1 / 3 of the seedlings in each plug tray when the tall fescue seedlings grow to the two-leaf stage 14 days after breeding.

[0053] Example 1

[0054] This example provides a method for propagating arbuscular mycorrhizal fungi. The tested strain of arbuscular mycorrhizal fungi in this example is Glomus etunicatum (BEG QH01B, referred to as QH01B), which was purchased from the Institute of Plant Nutrition and Resources, Beijing Academy of Agricultural and Forestry Sciences.

[0055] The main steps include:

[0056] 1. Seed disinfection: Seeds need to be disinfected before sowing. Soak sorghum and corn seeds in 40% formaldehyde solution for 15 minutes, and then rinse with water several times.

[0057] 2. Matrix sterilization: Use vermiculite and perlite matrix in a ratio of 1:1. Matrix sterilization kills existing AMF, pathogens and weed seeds, thereby ensuring that there are no pathogenic microorganisms in the planting area. Steam sterilize at 95℃ for 1-2 hours, twice, with a 24-hour interval in between, and place for 1-2 weeks before use. All containers must be disinfected and sterilized before use. They can be soaked in 10% sodium hypochlorite (bleaching powder) solution for 30 minutes. Wash and drain. It can also be soaked or wiped with 70-75% ethanol solution.

[0058] 3. Cultivation: Fill the sterilized culture medium to 2 / 3 of the plastic pot, evenly spread the above-mentioned spare inoculant (20g) on ​​the medium in a thin layer, or evenly drop the above-mentioned spare spores (test strains) on the medium, and then cover the sterilized medium with 2cm, water, sow 25-30 sorghum seeds / pot or 4-5 corn seeds / pot, cover with 0.5cm sterilized medium, and then move to the light room for cultivation for 3-4 months (lighting time: 14h white / 10h dark; light intensity: 8000lx; temperature: 20℃-30℃; humidity: 60%), use Hoagland (reduced phosphorus) nutrient solution (Table 3-1-1), water the nutrient solution once a week, 30-100ml / pot each time. When harvesting, first cut off the above-ground stems and leaves of the plant, place the pot in a room with relatively stable temperature and humidity to dry (about 1-2 weeks), and then harvest all the cultures in the pot (including plant roots, hyphae, spores and matrix).

[0059] 4. Harvest operation: First wipe and disinfect the operating table with 70% alcohol. Cover the table with 3 layers of clean paper (new newspaper or new copy paper), pour the culture in the pot onto the paper, and chop it with a sterilized hatchet. Roll up the chopped culture with two pieces of paper, and insert one end of the paper tube into a clean plastic bag that can be sealed in advance. When all the culture is transferred into the bag, gently remove the paper and seal the bag. Do not let your hands touch the potted culture at any time. Then put another plastic bag of the same size on the outside, and put a special BGC label between the two plastic bags. Then place it in a cold room or a 4℃ refrigerator for storage according to the species order on the label.

[0060] Example 2

[0061] The present embodiment provides a method for propagating arbuscular mycorrhizal fungi. The test strains of arbuscular mycorrhizal fungi in the present embodiment are: 1 strain of Glomus etunicatum (BEG QH01B, referred to as QH01B) and 1 strain of Glomus mosseae (BEG KH01, referred to as KH01). The two strains were purchased from the Institute of Plant Nutrition and Resources, Beijing Academy of Agriculture and Forestry Sciences.

[0062] The main steps include:

[0063] 1. Seed disinfection: Seeds need to be disinfected before sowing. Soak sorghum and corn seeds in 40% formaldehyde solution for 15 minutes, and then rinse with water several times.

[0064] 2. Matrix sterilization: Use vermiculite and perlite matrix in a ratio of 1:1. Matrix sterilization kills existing AMF, pathogens and weed seeds, thereby ensuring that there are no pathogenic microorganisms in the planting area. Steam sterilize at 95℃ for 1-2 hours, twice, with a 24-hour interval in between, and place for 1-2 weeks before use. All containers must be disinfected and sterilized before use. They can be soaked in 10% sodium hypochlorite (bleaching powder) solution for 30 minutes. Wash and drain. It can also be soaked or wiped with 70-75% ethanol solution.

[0065] 3. Cultivation: Fill the sterilized culture medium to 2 / 3 of the plastic pot, evenly spread the above-mentioned spare inoculant (20g) on ​​the medium in a thin layer, or evenly drop the above-mentioned spare spores on the medium, and then cover the sterilized medium by 2cm, water, sow 25-30 sorghum seeds / pot or 4-5 corn seeds / pot, cover with 0.5cm sterilized medium, and then move to the light room for cultivation for 3-4 months (lighting time: 14h white / 10h dark; light intensity: 8000lx; temperature: 20℃-30℃; humidity: 60%), use Hoagland (reduced phosphorus) nutrient solution (Table 3-1-1), water the nutrient solution once a week, 30-100ml / pot each time. When harvesting, first cut off the above-ground stems and leaves of the plant, place the pot in a room with relatively stable temperature and humidity to dry (about 1-2 weeks), and then harvest all the cultures in the pot (including plant roots, hyphae, spores and matrix).

[0066] 4. Harvest operation: First wipe and disinfect the operating table with 70% alcohol. Cover the table with 3 layers of clean paper (new newspaper or new copy paper), pour the culture in the pot onto the paper, and chop it with a sterilized hatchet. Roll up the chopped culture with two pieces of paper, and insert one end of the paper tube into a clean plastic bag that can be sealed in advance. When all the culture is transferred into the bag, gently remove the paper and seal the bag. Do not let your hands touch the potted culture at any time. Then put another plastic bag of the same size on the outside, and put a special BGC label between the two plastic bags. Then place it in a cold room or a 4℃ refrigerator for storage according to the species order on the label.

[0067] Example 3

[0068] The present embodiment provides a method for propagating arbuscular mycorrhizal fungi. The strain of arbuscular mycorrhizal fungi in the present embodiment is Glomus mosseae (BEG KH01, referred to as KH01), which is purchased from the Institute of Plant Nutrition and Resources, Beijing Academy of Agricultural and Forestry Sciences.

[0069] The main steps include:

[0070] 1. Seed disinfection: Seeds need to be disinfected before sowing. Soak sorghum and corn seeds in 40% formaldehyde solution for 15 minutes, and then rinse with water several times.

[0071] 2. Matrix sterilization: Use vermiculite and perlite matrix in a ratio of 1:1. Matrix sterilization kills existing AMF, pathogens and weed seeds, thereby ensuring that there are no pathogenic microorganisms in the planting area. Steam sterilize at 95℃ for 1-2 hours, twice, with a 24-hour interval in between, and place for 1-2 weeks before use. All containers must be disinfected and sterilized before use. They can be soaked in 10% sodium hypochlorite (bleaching powder) solution for 30 minutes. Wash and drain. It can also be soaked or wiped with 70-75% ethanol solution.

[0072] 3. Cultivation: Fill the sterilized culture medium to 2 / 3 of the plastic pot, evenly spread the above-mentioned spare inoculant (20g) on ​​the medium in a thin layer, or evenly drop the above-mentioned spare spores on the medium, and then cover the sterilized medium by 2cm, water, sow 25-30 sorghum seeds / pot or 4-5 corn seeds / pot, cover with 0.5cm sterilized medium, and then move to the light room for cultivation for 3-4 months (lighting time: 14h white / 10h dark; light intensity: 8000lx; temperature: 20℃-30℃; humidity: 60%), use Hoagland (reduced phosphorus) nutrient solution (Table 3-1-1), water the nutrient solution once a week, 30-100ml / pot each time. When harvesting, first cut off the above-ground stems and leaves of the plant, place the pot in a room with relatively stable temperature and humidity to dry (about 1-2 weeks), and then harvest all the cultures in the pot (including plant roots, hyphae, spores and matrix).

[0073] 4. Harvest operation: First wipe and disinfect the operating table with 70% alcohol. Cover the table with 3 layers of clean paper (new newspaper or new copy paper), pour the culture in the pot onto the paper, and chop it with a sterilized hatchet. Roll up the chopped culture with two pieces of paper, and insert one end of the paper tube into a clean plastic bag that can be sealed in advance. When all the culture is transferred into the bag, gently remove the paper and seal the bag. Do not let your hands touch the potted culture at any time. Then put another plastic bag of the same size on the outside, and put a special BGC label between the two plastic bags. Then place it in a cold room or a 4℃ refrigerator for storage according to the species order on the label.

[0074] Example 4

[0075] This embodiment provides a method for improving the drought resistance of tall fescue. This embodiment uses "Hound No. 5" tall fescue seeds as materials, and mainly includes the following steps:

[0076] 1. Seed disinfection: Select tall fescue seeds with full seeds and uniform size. Soak them in 75% alcohol for 1 minute, rinse them with distilled water 3-4 times, soak them in 84 disinfectant for 2 minutes, and rinse them with ultrapure water 3-4 times.

[0077] 2. Breeding, using a seedling tray (4×8 grids, a total of 32 grids, upper diameter: 60 mm; bottom 28 mm; depth 53 mm), first fill the test substrate (nutrient soil: vermiculite = 1:1) to 2 / 3 of each seedling tray, and evenly spread the AM fungi after propagation in Example 1 on the substrate in a thin layer, about 20 g, and then cover with 2 cm of sterilized substrate, water, sow 6-8 tall fescue seeds / box, cover with 0.5 cm of sterilized substrate, pour tap water at the bottom of the seedling tray, and then move to the light culture room for cultivation.

[0078] 3. Transplanting: After 14 days, the tall fescue seedlings will grow to the two-leaf stage, and two seedlings will be retained in each small box.

[0079] 4. Slow down the growth of seedlings: water and carry out slow growth of seedlings.

[0080] Example 5

[0081] This embodiment provides a method for improving the drought resistance of tall fescue. This embodiment uses "Hound No. 5" tall fescue seeds as materials and mainly includes the following steps

[0082] 1. Seed disinfection: Select tall fescue seeds with full seeds and uniform size. Soak them in 75% alcohol for 1 minute, rinse them with distilled water 3-4 times, soak them in 84 disinfectant for 2 minutes, and rinse them with ultrapure water 3-4 times.

[0083] 2. Breeding, using seedling trays (4×8 grids, a total of 32 grids, upper diameter: 60 mm; bottom 28 mm; depth 53 mm), first fill the test matrix (nutrient soil: vermiculite = 1:1) to 2 / 3 of each seedling tray, and evenly spread the AM fungi after propagation in Example 2 on the substrate in a thin layer, about 20 g, and then cover with 2 cm of sterilized matrix, water, sow 6-8 tall fescue seeds / box, cover with 0.5 cm of sterilized matrix, pour tap water on the bottom of the seedling tray, and then move to the light culture room for cultivation.

[0084] 3. Transplanting: After 14 days, the tall fescue seedlings will grow to the two-leaf stage, and two seedlings will be retained in each small box.

[0085] 4. Slow down the growth of seedlings: water and carry out slow growth of seedlings.

[0086] Example 6

[0087] This embodiment provides a method for improving the drought resistance of tall fescue. This embodiment uses "Hound No. 5" tall fescue seeds as materials and mainly includes the following steps

[0088] 1. Seed disinfection: Select tall fescue seeds with full seeds and uniform size. Soak them in 75% alcohol for 1 minute, rinse them with distilled water 3-4 times, soak them in 84 disinfectant for 2 minutes, and rinse them with ultrapure water 3-4 times.

[0089] 2. Breeding, using a seedling tray (4×8 grids, a total of 32 grids, upper diameter: 60 mm; bottom 28 mm; depth 53 mm), first fill the test substrate (nutrient soil: vermiculite = 1:1) to 2 / 3 of each seedling tray, and evenly spread the AM fungi after propagation in Example 3 on the substrate in a thin layer, about 20 g, and then cover with 2 cm of sterilized substrate, water, sow 6-8 tall fescue seeds / box, cover with 0.5 cm of sterilized substrate, pour tap water at the bottom of the seedling tray, and then move to the light culture room for cultivation.

[0090] 3. Transplanting: After 14 days, the tall fescue seedlings will grow to the two-leaf stage, and two seedlings will be retained in each small box.

[0091] 4. Slow down the growth of seedlings: water and carry out slow growth of seedlings.

[0092] Example 7

[0093] This embodiment provides a method for improving the drought resistance of tall fescue. This embodiment uses "Hound No. 5" tall fescue seeds as materials and mainly includes the following steps

[0094] 1. Seed disinfection: Select tall fescue seeds with full seeds and uniform size. Soak them in 75% alcohol for 1 minute, rinse them with distilled water 3-4 times, soak them in 84 disinfectant for 2 minutes, and rinse them with ultrapure water 3-4 times.

[0095] 2. Breeding, using a seedling tray (4×8 grids, a total of 32 grids, upper diameter: 60 mm; bottom 28 mm; depth 53 mm), first fill the test substrate (nutrient soil: vermiculite = 1:1) to 2 / 3 of each seedling tray, and evenly spread the AM fungi after propagation in Example 1 on the substrate in a thin layer, about 20 g, and then cover with 2 cm of sterilized substrate, water, sow 6-8 tall fescue seeds / box, cover with 0.5 cm of sterilized substrate, pour tap water at the bottom of the seedling tray, and then move to the light culture room for cultivation.

[0096] 3. Transplanting: After 14 days, the tall fescue seedlings will grow to the two-leaf stage, and two seedlings will be retained in each small box.

[0097] 4. Slow growth of seedlings: Water and spray 0.2 μmol·L-1 of strigolactone analogue (made by dissolving strigolactone analogue (GR24) in acetone) on the leaves of seedlings; spray the leaves continuously every day until the leaves are covered with dew without dripping, keep the soil sufficiently moist, and continue spraying for 10 days.

[0098] Comparative Example 1

[0099] This embodiment provides a method for improving the drought resistance of tall fescue. This embodiment uses "Hound No. 5" tall fescue seeds as materials, and mainly includes the following steps:

[0100] 1. Seed disinfection: Select tall fescue seeds with full seeds and uniform size. Soak them in 75% alcohol for 1 minute, rinse them with distilled water 3-4 times, soak them in 84 disinfectant for 2 minutes, and rinse them with ultrapure water 3-4 times.

[0101] 2. Breeding, using seedling trays (4×8 grids, 32 grids in total, upper diameter: 60 mm; bottom 28 mm; depth 53 mm), first fill the test matrix (nutrient soil: vermiculite = 1:1) to 2 / 3 of each seedling tray, then cover with 2 cm of sterilized matrix, water, sow 6-8 tall fescue seeds / box, cover with 0.5 cm of sterilized matrix, pour tap water at the bottom of the seedling tray, and then move to the light culture room for culture.

[0102] 3. Transplanting: After 14 days, the tall fescue seedlings will grow to the two-leaf stage, and two seedlings will be retained in each small box.

[0103] 4. Slow down the growth of seedlings: water and carry out slow growth of seedlings.

[0104] Comparative Example 2

[0105] This embodiment provides a method for improving the drought resistance of tall fescue. This embodiment uses "Hound No. 5" tall fescue seeds as materials and mainly includes the following steps

[0106] 1. Seed disinfection: Select tall fescue seeds with full seeds and uniform size. Soak them in 75% alcohol for 1 minute, rinse them with distilled water 3-4 times, soak them in 84 disinfectant for 2 minutes, and rinse them with ultrapure water 3-4 times.

[0107] 2. Breeding, using a seedling tray (4×8 grids, a total of 32 grids, upper diameter: 60 mm; bottom 28 mm; depth 53 mm), first fill the test substrate (nutrient soil: vermiculite = 1:1) to 2 / 3 of each seedling tray, and evenly spread the AM fungi after propagation in Example 1 on the substrate in a thin layer, about 20 g, and then cover with 2 cm of sterilized substrate, water, sow 6-8 tall fescue seeds / box, cover with 0.5 cm of sterilized substrate, pour tap water at the bottom of the seedling tray, and then move to the light culture room for cultivation.

[0108] 3. Transplanting: After 14 days, the tall fescue seedlings will grow to the two-leaf stage, and two seedlings will be retained in each small box.

[0109] 4. Slow down the growth of seedlings: water and spray pure water on the leaves of seedlings; spray the leaves continuously every day until the leaves are covered with dew without dripping, keep the soil sufficiently moist, and continue spraying for 10 days.

[0110] Comparative Example 3

[0111] This embodiment provides a method for improving the drought resistance of tall fescue. This embodiment uses "Hound No. 5" tall fescue seeds as materials and mainly includes the following steps

[0112] 1. Seed disinfection: Select tall fescue seeds with full seeds and uniform size. Soak them in 75% alcohol for 1 minute, rinse them with distilled water 3-4 times, soak them in 84 disinfectant for 2 minutes, and rinse them with ultrapure water 3-4 times.

[0113] 2. Breeding, using a seedling tray (4×8 grids, a total of 32 grids, upper diameter: 60 mm; bottom 28 mm; depth 53 mm), first fill the test substrate (nutrient soil: vermiculite = 1:1) to 2 / 3 of each seedling tray, and evenly spread the AM fungi after propagation in Example 1 on the substrate in a thin layer, about 20 g, and then cover with 2 cm of sterilized substrate, water, sow 6-8 tall fescue seeds / box, cover with 0.5 cm of sterilized substrate, pour tap water at the bottom of the seedling tray, and then move to the light culture room for cultivation.

[0114] 3. Transplanting: After 14 days, the tall fescue seedlings will grow to the two-leaf stage, and two seedlings will be retained in each small box.

[0115] 4. Slow down the growth of seedlings: water and spray the leaves of seedlings with 5 μmol·L of strigolactone inhibitor. -1 (Prepared by dissolving the strigolactone inhibitor (TIS108) in acetone); spray the leaves continuously every day to the extent that the leaves are covered with dew without dripping, keep the soil sufficiently moist, and continue spraying for 10 days.

[0116] Experimental Example 1 Effect of strigolactone on drought resistance of tall fescue

[0117] 1.1 Materials and reagents

[0118] 1.1.1 Plant materials

[0119] The tall fescue “Hound No. 5” was used as plant material and planted in the greenhouse of Guizhou Grassland Research Institute (light intensity was 700 μmol·m -2 s -1 , temperature 20℃-25℃, light time 14h, dark time 10h, humidity 60%)

[0120] 1.1.2 Reagents

[0121] Weigh 100 mg of strigolactone inhibitor (TIS108), add 10 ml of acetone and stir until it is completely dissolved. The concentration is 10 mg mL -1 The mother solution was stored at 4℃ away from light for later use. Weigh 10 mg of the strigolactone analog (GR24), add 10 ml of acetone and stir until it is completely dissolved to prepare a concentration of 1 mg mL -1 The mother solution was stored at 4°C away from light for future use; the SOD, CAT and POD kits of Shanghai Zhuocai Biotechnology Co., Ltd. were used.

[0122] 1.2 Experimental design

[0123] Select tall fescue seeds with full grains and uniform size. Soak in 75% alcohol for 1 min, rinse with distilled water 3-4 times, soak in 84 disinfectant for 2 min, rinse with ultrapure water 3-4 times, and place in a 30℃ constant temperature culture room for germination. After the seeds germinate naturally, select seedlings with good growth and uniform growth, and use seedling trays (upper diameter 60mm, bottom 28mm, depth 53mm) for seedling cultivation. The matrix in the seedling tray is 1:1 with nutrient soil and vermiculite. When the two leaves are cultivated, the experiment sets up a blank control group (CK) and 5μmol·L-1TIS108 (the best concentration screened in the preliminary test) treatment, each treatment has three biological replicates, a total of 360 plants. Spray the leaves continuously at 15:00 every day, the spraying degree is that the leaves are covered with dew without dripping, keep the soil water sufficient, and continue the treatment for 7 days. According to the changes in leaf characteristics, the leaves are continuously dried for 15 days under natural conditions, and then rehydrated for 5 days, and the physiological and biochemical indicators are measured.

[0124] 1.3 Test methods

[0125] 1.3.1 Phenotype of tall fescue plants

[0126] The appearance phenotype of tall fescue before and after drought treatment was photographed with a SLR camera (model: Canon EOS 6D), and then the photos were simply processed using PS software.

[0127] 1.3.2 Determination of tall fescue growth index

[0128] The plant height, root length, leaf length (fifth leaf), and leaf width (fifth leaf) of tall fescue were measured using a ruler (accuracy 0.1 cm) and a vernier caliper (accuracy 0.01 cm), and the data were recorded.

[0129] 1.3.3 Biomass determination of tall fescue

[0130] Take the treated tall fescue plants out of the culture tray, wash the soil attached to the roots, dry the water with filter paper, weigh them on a balance, and record the fresh weight. After the fresh weight is measured, quickly put each treatment into an oven at 110℃ for 20 minutes, adjust the oven to 60℃, and bake for 24 hours until constant weight is reached, weigh them on a balance, and record the dry weight.

[0131] 1.3.4 Determination of biochemical indexes of tall fescue

[0132] Select the 3rd to 7th functional leaves of tall fescue, wipe off the surface stains, and then quickly freeze them with liquid nitrogen and store them at -80°C for later use.

[0133] 1.3.5 Determination of SLs content in tall fescue

[0134] 1.3.6 Statistical analysis

[0135] Excel 2010 was used for statistical analysis and drawing of data. SPSS24.0 software was used for correlation analysis and one-way analysis of variance (ANOVA). Multiple comparisons were performed using the Duncan method at α = 0.05. The results are expressed as mean ± standard error.

[0136] 1.4 Experimental Results and Analysis

[0137] 1.4.1 Effects of SLs on phenotypic characteristics of tall fescue

[0138] Depend on Figure 1 It can be seen that: under drought conditions, spraying 5μmol·L -1 After the inhibitor TIS108 was added, the tolerance of tall fescue to drought was significantly reduced, showing obvious wilting, curling and drooping of leaves, scorching of leaf tips and leaf bases, and shortened roots. This may be due to the failure to water the leaves in time due to the extreme lack of water under continuous drought stress. The leaves of the control (CK) and tall fescue grew well, and the drought phenotype was significantly weakened.

[0139] 1.4.2 Effect of SLs on SLs content in tall fescue

[0140] The content of SLs (5-DS) in the roots of tall fescue was detected by liquid chromatography-mass spectrometry. Figure 2 It can be seen that after spraying SLs inhibitor TIS108 on tall fescue under drought conditions, the SLs content in the roots of tall fescue decreased by 75.5%, which was significantly different from the control (CK). The reduction of SLs content in the roots indicates that SLs plays an important role in the drought resistance of tall fescue.

[0141] 1.4.3 Effects of SLs on growth parameters of tall fescue

[0142] Depend on Figure 3 It can be seen that after spraying the SLs inhibitor TIS108 on tall fescue under drought stress, the external morphological and structural characteristics of the plants changed significantly. The leaf width, root length, fresh weight, and dry weight of tall fescue were significantly different from those of the control (CK), while there were no significant differences in leaf length and plant height (P<0.05). The leaf width decreased by 30.4%, the root length decreased by 19.7% compared with CK, the fresh weight was 0.7 times that of the control, and the dry weight decreased by 48.7% compared with CK. Spraying the inhibitor caused significant changes in some morphological indicators of tall fescue, which shows that SLs have an important effect on the drought resistance of tall fescue.

[0143] 1.4.4 Effects of SLs on physiological and biochemical parameters of tall fescue

[0144] In drought stress, the antioxidant enzymes (CAT, POD, SOD) of plants work together to remove active oxygen in the plant body or repair macromolecules damaged by oxidation. The strength of their activity is closely related to the antioxidant capacity of the plant. Figure 4 It can be seen that after spraying the SLs inhibitor TIS108, the SOD, POD, and CAT of tall fescue leaves under drought stress were significantly different from those of the control (CK), decreasing by 11.3%, 22.9%, and 24.8%, respectively. Spraying the inhibitor greatly reduced the activity of CAT, POD, and SOD enzymes in tall fescue leaves, and thus failed to alleviate the oxidative damage caused by drought stress to tall fescue leaves.

[0145] Table 1 Survival rate of tall fescue

[0146] Table 2-5-1 Fescue survival rate

[0147]

[0148] Note: Different lowercase letters represent significant differences between the same indicators (P<0.05)

[0149] Note: Different lowercase letters represent significant differences between the same indicators (P<0.05)

[0150] Experimental Example 2 Effects of Arbuscular Mycorrhizal Fungi on Drought Resistance of Tall Fescue

[0151] 1.1 Materials and reagents

[0152] 1.1.1 Experimental Materials

[0153] Experimental reagents: SOD, CAT, POD and proline kits were obtained from Shanghai Zhuocai Biotechnology Co., Ltd.

[0154] 1.2 Experimental process

[0155] The experiment set up ① comparative experimental example 1, ② embodiment 4, ③ embodiment 6, ④ embodiment 5, a total of four treatment groups, using seedlings in the seedling stage. 14 days after the seedlings were settled, the tall fescue seedlings grew to the two-leaf stage, and two seedlings were retained in each small box, with three biological replicates for each treatment, for a total of 768 plants. Normal watering was performed in the early stage, and the seedling slowing treatment was performed. After 15 days of growth, according to the changes in leaf characteristics, the leaf physiological and biochemical indicators were measured after continuous drought treatment for 14 days under natural conditions.

[0156] 1.3 Test methods

[0157] 1.3.1 AMF spore detection

[0158] AM fungal spores were isolated by wet sieve decantation-sucrose centrifugation method.

[0159] 1.3.2 AMF infection detection

[0160] The infection rate needs to be determined by staining. The steps for determining the infection rate include: fixation, transparency, staining, slide preparation, observation and estimation.

[0161] 1.3.3 Determination of tall fescue growth index

[0162] Chapter methods for testing growth indicators of tall fescue (plant height, leaf length, leaf width, root length, dry weight, fresh weight).

[0163] 1.3.4 Physiological and biochemical index determination of tall fescue

[0164] 1.3.5 Statistical analysis of physiological and biochemical indicators (SOD, POD, CAT) of tall fescue

[0165] Excel 2010 was used for statistical analysis and drawing. SPSS24.0 software was used for correlation analysis and one-way analysis of variance (ANOVA). Multiple comparisons were performed by Duncan's method at α = 0.05. The results were expressed as mean ± standard error. The membership function analysis method was used to comprehensively evaluate the effects of different types of AMF on the drought resistance of tall fescue, referring to the method of Wang Mengke (2021).

[0166] The indicator formula for positive correlation: Yi = (Xi-Ximin) / (Ximax-Ximin)

[0167] Negative correlation indicator formula: Yi = 1-(Xi-Ximin) / (Ximax-Ximin)

[0168] Among them, Yi is the membership function value of the i-th indicator under a certain treatment, Xi is the indicator value under a certain treatment, Ximax and Ximin are the maximum and minimum values ​​of the i-th indicator in all treatments, respectively.

[0169] 1.4 Results and Analysis

[0170] 1.4.1 AMF propagation

[0171] Depend on Figure 5 It can be seen that after the strains KH01 and QH01B in the four treatment groups were propagated by sorghum and corn, the spores and hyphae in the culture medium were clearly visible, which laid the foundation for the subsequent AMF drought resistance experiment and ensured the smooth progress of the subsequent experiments.

[0172] 1.4.2 Effects of AMF on phenotypic characteristics of tall fescue

[0173] Depend on Figure 6It can be seen that after the tall fescue was inoculated with KH01 strains (Example 6) and QH01B strains (Example 4) and mixed inoculation with the two strains (Example 5) under drought stress, the tall fescue leaves grew well and the drought phenotype was significantly weakened. The tolerance of comparative example 1 to drought was significantly reduced, showing obvious wilting, curling and drooping of leaves, scorching of leaf tips and leaf bases, shortening of plant height, shortening of root length, etc., which may be caused by the failure to water the leaves in time due to extreme water shortage under continuous drought stress. Among them, the drought resistance effect of the plant inoculated with QH01B strains (plants in Example 4) was the best.

[0174] 1.4.3 Effect of AMF on mycorrhizal infection of tall fescue

[0175] Depend on Figure 7 It can be seen that after the tall fescue was cultured with AMF, the AMF mycorrhiza in the root system and the hyphae were clearly visible, and the infection rates were 33.37% for the Example 6 group, 52.6% for the Example 4 group, and 35.55% for the Example 5 group. Among them, the infection rate of the Example 4 group was the highest, the increase was the largest, and the difference was significant. This shows that the QH01B bacteria has the best mycorrhizal infection effect on the tall fescue under drought stress.

[0176] 1.4.4 Effects of AMF on Growth Indicators of Tall Fescue

[0177] Depend on Figure 8 It can be seen that after inoculation of different types of AMF under drought stress, the morphological structure of tall fescue was inconsistent. Compared with the control group, the plant height, leaf width, leaf length, root length, fresh weight and dry weight of tall fescue were significantly different (P<0.05); among them, the Example 6 group increased by 17.3%, 37.6%, 35.1%, 17.3%, 72.3% and 74.1% respectively; the Example 4 group increased by 39.9%, 88.0%, 61.6%, 31.2%, 173.3% and 153.8% respectively; the Example 5 group increased by 10.0%, 41.7%, 32.8%, 15.1%, 20.7% and 30.4% respectively; it can be seen that the inoculation of QH01B strain is significantly better than other treatment groups.

[0178] 1.4.5 Effects of AMF on Physiological and Biochemical Parameters of Tall Fescue

[0179] Under drought stress, the content of drought-resistant enzymes and osmotic regulating substances in plants is positively correlated with the drought resistance of plants. Fig. 9It can be seen that after inoculation with AMF under drought conditions, the contents of CAT, SOD, POD and proline in the leaves of tall fescue were significantly different from those in the control (CK) (P<0.05). Among them, CAT activity: the Example 6 group, the Example 4 group, and the Example 5 group increased by 60.3%, 154.9%, and 130.6%, respectively; SOD activity: the Example 6 group, the Example 4 group, and the Example 5 group increased by 53.2%, 173.1%, and 104.1%, respectively; POD activity: the Example 6 group, the Example 4 group, and the Example 5 group increased by 49.2%, 63.9%, and 50.9%, respectively; Proline content: the Example 6 group, the Example 4 group, and the Example 5 group increased by 29.0%, 64.8%, and 40.0%, respectively; Inoculation with QH01B strains was superior to other treatment groups, and the tall fescue leaf tissue had a strong ability to resist antioxidant damage and osmotic regulation, so that the tall fescue could better cope with the damage caused by drought adversity.

[0180] Experimental Example 3 Effect of the interaction between strigolactones and arbuscular mycorrhizal fungi on drought resistance of tall fescue

[0181] 1.1 Materials and reagents

[0182] 1.1.1 Experimental Materials

[0183] Plant material: The tall fescue “Hound No. 5” was used as the plant material and planted in the greenhouse of Guizhou Grassland Research Institute (light intensity was 700 μmol·m -2 s -1 , temperature is 20℃-25℃, light time is 14h, dark time is 10h, and humidity is 60%).

[0184] 1.2 Experimental design

[0185] The experiment was divided into ① comparative example 2; ② embodiment 7; ③ comparative example 3, three treatment groups, each treatment group selected tall fescue seedlings grown to the two-leaf stage 14 days after the seedlings were fixed, three biological replicates were performed for each treatment, 64 seedlings were planted in each biological replicate, and a total of 576 seedlings were sprayed on the leaves continuously at 15:00 every day, and the spraying degree was such that the leaves were covered with dew without dripping, and the soil was kept sufficiently moist. After continuous spraying for 10 days, according to the changes in leaf characteristics, the physiological and biochemical indicators were determined after continuous drought treatment for 15 days in a natural state and rehydration for 5 days.

[0186] 1.3 Test methods

[0187] 1.3.1 Phenotype of tall fescue plants

[0188] For the phenotyping of tall fescue, refer to the method in Section 2.3.1.

[0189] 1.3.2 Detection of mycorrhizal infection of tall fescue

[0190] For mycorrhizal infection of tall fescue, refer to the method in Section 3.3.2.

[0191] 1.3.3 Determination of tall fescue growth index

[0192] For tall fescue growth indicators (root length, plant height, leaf width, leaf length, dry weight, fresh weight), refer to methods in sections 1.3.2-2.3.3.

[0193] 1.3.4 Physiological and biochemical index determination of tall fescue

[0194] For the physiological and biochemical indicators of tall fescue (SOD, POD, CAT, proline), please refer to the methods in Section 3.3.4.

[0195] 1.3.5 Determination of SLs content in tall fescue

[0196] The SLs content in the aboveground and underground parts of tall fescue refers to the method in Section 2.3.5.

[0197] 1.3.6 Statistical analysis

[0198] Excel 2010 was used for statistical analysis and drawing of data. SPSS24.0 software was used for correlation analysis and one-way analysis of variance (ANOVA). Multiple comparisons were performed using the Duncan method at α = 0.05. The results are expressed as mean ± standard error.

[0199] 1.4 Results and Analysis

[0200] 1.4.1 Phenotypic characteristics of tall fescue

[0201] Under drought stress, the tall fescue inoculated with AMF was sprayed with 5 μmol·L -1 TIS108 and 0.2 μmol·L -1 GR24, by Fig.10 It can be seen that the leaves of the tall fescue in Example 7 grew well, and the drought phenotype was significantly weakened. The tolerance of the tall fescue in the comparative example 3 to drought was significantly reduced, showing obvious wilting, curling and drooping of leaves, scorching of leaf tips and leaf bases, and shortening of roots. It can be seen that spraying GR24 on the tall fescue inoculated with AMF under drought conditions can enhance the drought resistance of the plants.

[0202] 1.4.2 SLs content in tall fescue

[0203] Under drought stress, the tall fescue inoculated with AMF was sprayed with 5 μmol·L -1 TIS108 and 0.2 μmol·L -1 GR24, comparison of SLs (5-DS) content in aboveground and underground parts of tall fescue, by Fig.11It can be seen that the SLs content of the aboveground and underground parts of the Example 7 group is significantly higher than that of the Comparative Example 2 group, increasing by 99.86% and 84.19%; the SLs content of the aboveground and underground parts of the Comparative Example 3 treatment group is significantly lower than that of the Comparative Example 2 group, decreasing by 56.12% and 48.97%. It can also be seen from the experimental results that the change range of the SLs content in the aboveground part is greater than that in the underground part.

[0204] 1.4.3 Mycorrhizal infection of tall fescue

[0205] Depend on Fig.12 It can be seen that under drought stress, spraying 5 μmol·L -1 TIS108 and 0.2 μmol·L -1 GR24, AM fungal mycorrhiza in the root system of tall fescue, hyphae are clearly visible. The infection rates of the three treatment groups were 45.0%, 53.5%, and 66.0%, respectively. Among them, the infection rate of the root system of tall fescue in Example 7 was the highest, and the root system infection rate of the comparative example 3 was the lowest, and both of them were significantly different from the comparative example 2 group. This shows that SLs can enhance the infection effect of AMF on host plants and promote the formation of a symbiotic relationship between AMF and plants.

[0206] 1.4.4 Growth indicators of tall fescue

[0207] Depend on Fig.13 It can be seen that under drought stress, spraying 5 μmol·L -1 TIS108 and 0.2 μmol·L -1 GR24, the plant height, leaf width, leaf length, root length, fresh weight and dry weight of tall fescue were significantly different from those of the control (P<0.05); the Example 7 group increased by 32.35%, 5.89%, 28.73%, 17.94%, 25.33% and 28.65%, respectively. The Comparative Example 3 group decreased by 16.49%, 10.35%, 25.08%, 23.7%, 24.24% and 35.91%, respectively, and the two treatment groups were significantly different from the Comparative Example 2 group. It shows that under drought stress, the synergistic effect of SLs and AMF can alleviate the damage caused by drought adversity.

[0208] 1.4.5 Physiological and biochemical indicators of tall fescue

[0209] The changes of antioxidant enzymes and proline content in plants under different treatments were different. Fig.14 It can be seen that under drought stress, spraying 5 μmol·L -1 TIS108 and 0.2 μmol·L -1GR24, the SOD, CAT, POD enzyme activities and proline content of tall fescue were significantly different from those of the control (P<0.05); the comparison group 3 decreased by 36.75%, 36.31%, 78.88%, and 31.17%, respectively; the example group 7 increased by 75.29%, 38.60%, 77.51%, and 21.11%, respectively. This shows that under drought stress, the synergistic effect of SLs and AMF can alleviate the oxidative damage caused by drought stress and regulate the osmotic pressure of cell tissues, thereby enhancing the stress resistance of plants.

[0210] Table 2 Survival rate of tall fescue

[0211] Table 4-5-1 Fescue survival rate

[0212]

[0213] Note: Different lowercase letters represent significant differences between the same indicators (P<0.05)

[0214] Note: Different lowercase letters represent significant differences between the same indicators (P<0.05)

[0215] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for improving the drought resistance of tall fescue, comprising a breeding stage, characterized in that: The culture medium in the breeding stage is added with expanded arbuscular mycorrhizal fungi, and the arbuscular mycorrhizal fungi are one or two of Glomus juvenile and Glomus mosesi. A seedling acclimatization stage is also provided after the breeding stage, and the seedling acclimatization stage includes the step of increasing the content of strigolactones in tall fescue plants. The step of increasing the content of strigolactones in tall fescue plants in the seedling acclimatization stage is as follows: spraying the leaves of tall fescue with a strigolactone analogue GR24; the concentration of the strigolactone analogue is 0.2 µmol·L-1, and the spraying frequency is once a day, for a total of 10 days.

2. The method for improving drought resistance of tall fescue according to claim 1, characterized in that: The spraying degree is such that the leaves are covered with dew without dripping.

3. The method for improving drought resistance of tall fescue according to claim 1 or 2, characterized in that: A seed disinfection stage is also provided before the breeding stage, and the seed disinfection stage comprises: selecting tall fescue seeds with full grains and uniform size, soaking them in 75% alcohol for 1-3 minutes, rinsing them with distilled water for 3-4 times, and then soaking them in 84 disinfectant for 2-5 minutes, and rinsing them with distilled water for 3-4 times.

4. The method for improving drought resistance of tall fescue according to claim 1 or 2, characterized in that: The breeding stage is hole tray breeding, firstly, the culture matrix is ​​filled to 2 / 3 of each seedling tray, watered, and then tall fescue seeds are sown, covered with 0.5 cm sterilized matrix, watered the bottom of the seedling tray, and then moved to the light culture room for culture.

5. The method for improving drought resistance of tall fescue according to claim 1 or 2, characterized in that: There is a seedling determination stage before the seedling acclimatization stage. The seedling determination stage includes when the tall fescue seedlings grow to the two-leaf stage 14 days after breeding, and each plug tray retains 1 / 4-1 / 3 of the seedlings.

6. The method for improving drought resistance of tall fescue according to claim 1, characterized in that: The method for propagating arbuscular mycorrhizal fungi mainly comprises the following steps: ①. Seed disinfection: Soak sorghum and corn seeds in 40% formaldehyde solution for 15 minutes, then rinse with water several times; ② Matrix sterilization: Use vermiculite and perlite matrix in a weight ratio of 1:1, steam sterilize at 95°C twice, 1-2 hours each time, with a 24-hour interval in between; ③. Cultivation: Fill the sterilized culture medium to 2 / 3 of the plastic pot, evenly spread the strains of the arbuscular mycorrhizal fungi on the medium in a thin layer, then cover with 2 cm of sterilized medium, water, sow sorghum seeds, cover with 0.5 cm of sterilized medium, and then move to a light room for cultivation for 3-4 months; ④. Harvest.

7. The method for improving drought resistance of tall fescue according to claim 6, characterized in that: The culture conditions in the light room mainly include: light time: 14 h white / 10 h dark; light intensity: 8000 lx; ​​temperature: 20°C-30°C; Humidity: 60%.

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