Treatment method for improving cold resistance of pennisetum purpureum

Abstract

The invention relates to the technical field of pasture planting, and discloses a treatment method for improving cold resistance of pennisetum purpureum, according to the treatment method, a 1000 mg / L chitosan solution is used as an exogenous substance to be applied to the pennisetum purpureum, and more preferably, the 1000 mg / L chitosan solution and charcoal are jointly used as the exogenous substance to be applied to the pennisetum purpureum. Chitosan is used as a biological stimulant to stimulate the generation of cold-resistant substances in plants and help to protect plant cells from being damaged under a low-temperature condition, the chitosan solution is used for treating the pennisetum purpureum, the optimal use concentration for improving the cold resistance of the pennisetum purpureum is determined through tests, and the cold resistance of the pennisetum purpureum is remarkably enhanced. According to the method, the biochar is applied on the basis of applying the chitosan solution, so that the cold resistance of the pennisetum purpureum is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of forage grass planting, and in particular relates to a processing method for improving the cold resistance of elephant grass. Background Art

[0002] Elephant grass (Pennisetum purpureum) is a plant of the genus Pennisetum in the Poaceae family. It is an annual or perennial grass of the Poaceae family, with a plant height of up to 3-5m and a thick stem. Elephant grass has high nutritional value, high protein content and digestibility. It is soft and juicy, has good palatability and high utilization rate. It is a favorite food of cattle, horses, sheep, rabbits, ducks, geese, etc., and is also a good feed for pigs and fish in the young and tender period. In addition to providing green fodder for livestock and poultry in all seasons, it can also be prepared into hay or silage. In addition, elephant grass can also replace coal and oil for power generation. The energy generated by planting 1 hectare of elephant grass fuel can replace 36 barrels of oil. The root system of elephant grass is very developed. Planting it by the pond and embankment can play a role in protecting the embankment and soil. Elephant grass can also be mowed as a covering material for perennial crops. Therefore, elephant grass has a high economic value. However, elephant grass is sensitive to low temperature stress and lacks the ability to adapt and resist low temperature environments, which seriously limits its promotion and planting in temperate regions and cold areas with high altitudes. Improving the cold resistance of elephant grass and expanding its planting range are issues that need to be urgently addressed.

[0003] The ability of plants to adapt to and resist low temperatures is called plant cold resistance. Currently, the methods to improve plant cold resistance include reducing the harm of low temperatures to plants by improving agricultural measures, and using hybrid breeding or genetic engineering to cultivate varieties with superior cold resistance to reduce the adverse effects of low temperatures. However, improving agricultural measures is time-consuming and labor-intensive, the selection cycle of hybrid breeding is long, and genetic engineering technology is difficult. Recent studies have shown that spraying some exogenous substances on plants can effectively improve the cold resistance of plants. For example, chitosan plays a role in the resistance of cucumbers, peppers, bananas and other plants to low temperature stress, can promote plant growth, promote the synthesis of anti-osmotic substances, increase the activity of plant antioxidant enzymes, protect the membrane system, and thus enhance the resistance of the plant itself; exogenous spraying of 20mmol / L betaine can effectively improve the ability of grass plants to adapt to low temperatures. However, different exogenous substances may have different effects on crops, and no exogenous substances suitable for improving the cold resistance of elephant grass crops have been disclosed. Summary of the invention

[0004] In view of the problems raised in the above background technology, the purpose of the present invention is to provide a treatment method for improving the cold resistance of elephant grass, aiming to find exogenous substances suitable for improving the cold resistance of elephant grass and apply them reasonably to achieve the effect of improving the cold resistance of elephant grass, thereby broadening the planting range of elephant grass and meeting the needs of elephant grass in different regions.

[0005] In order to achieve the above technical effects, the technical solution of the present invention is implemented as follows:

[0006] The invention provides a treatment method for improving the cold resistance of elephant grass. The treatment method comprises the following steps: using 1000 mg / L chitosan solution as an exogenous substance and applying it to the elephant grass.

[0007] Furthermore, the chitosan solution is applied by foliar spraying at a rate of 6 to 7 L / m 2 Elephant grass.

[0008] More preferably, the foliar spraying rate of the chitosan solution is 6.4 L / m 2 Elephant grass.

[0009] Furthermore, the chitosan solution contains 0.3% mass concentration of Tween surfactant.

[0010] Furthermore, the Tween surfactant is Tween 20.

[0011] In some embodiments of the present invention, the treatment method further comprises applying biochar as an exogenous material to the elephant grass.

[0012] Furthermore, the biochar is applied through root application, wherein the biochar is mixed with elephant grass cultivated soil in a mass ratio of 1:10 and then used in areas where elephant grass roots are distributed.

[0013] Furthermore, the application rate of the biochar root application is 15-16 kg biochar / m 2 Elephant grass.

[0014] More preferably, the application rate of the biochar root application is 15.3 kg biochar / m 2 Elephant grass.

[0015] Chitosan (CTS) is a polyglucosamine, which is an anti-stress signal molecule induced by plants to respond to abiotic stress. Chitosan and its derivatives can remove excessive free radicals produced by cells under low temperature stress, promote photosynthesis and the synthesis of osmotic regulating substances in cells, so that plants can enhance their ability to resist low temperatures. It is the only alkaline polysaccharide that exists in large quantities in the biological world and is a non-toxic and non-polluting animal-derived hormone substance. Chitosan has the characteristics of solubility, biodegradability, induction of disease resistance and edibility, and is widely used in industry, agriculture and medicine. Chitosan can increase the absorption of nutrients, promote root development, improve plant photosynthesis, regulate crop growth and induce plant stress resistance by increasing the permeability of plant cells. Studies have shown that exogenous chitosan can induce plant defense responses, improve plant cold tolerance and promote plant growth.

[0016] The present invention utilizes chitosan as a biostimulant to stimulate the production of cold-resistant substances in plants, which helps to protect plant cells from damage under low temperature conditions. Chitosan solution is used to treat elephant grass, and the optimal concentration for improving the cold resistance of elephant grass is determined through experiments, thereby significantly enhancing the cold resistance of elephant grass.

[0017] Biochar is a product formed by the pyrolysis of agricultural and forestry waste biomass under anaerobic conditions. It is often used to improve soil because of its rich pores, large specific surface area and stable properties. Studies have shown that the application of biochar can affect the development of plant roots. Adding biochar to the rice seedling raising matrix in paddy field soil can promote the elongation and thickening of the seedling root system, which is conducive to the formation of a developed root system. Studies have found that biochar can improve the cold resistance of rice seedlings under low temperature stress. The present invention combines the application of biochar with the application of chitosan solution to further improve the cold resistance of elephant grass.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention provides a treatment method for improving the cold resistance of elephant grass, which significantly enhances the cold resistance of elephant grass by applying chitosan and biochar from exogenous sources. The method is easy to operate and has low use cost. Chitosan and biochar are both renewable resources and have no environmental pollution problems. The method is suitable for large-scale promotion and application in production practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The phenotypic photos of elephant grass before and after application of chitosan solutions of different concentrations under low temperature stress in Example 1 of the present invention;

[0021] Figure 2 This is a bar graph showing the relative conductivity of elephant grass after being subjected to low temperature stress by applying chitosan solutions of different concentrations according to Example 1 of the present invention;

[0022] Figure 3 This is a bar graph showing the chlorophyll content of elephant grass after being subjected to low temperature stress by applying chitosan solutions of different concentrations according to Example 1 of the present invention;

[0023] Figure 4 This is a bar graph showing the chlorophyll fluorescence of elephant grass after being subjected to low temperature stress by applying chitosan solutions of different concentrations according to Example 1 of the present invention;

[0024] Figure 5 This is a bar graph showing the malondialdehyde content in elephant grass after applying chitosan solutions of different concentrations under low temperature stress according to Example 1 of the present invention;

[0025] Figure 6 The phenotypic photos of elephant grass with different concentrations of biochar applied to its roots before and after low temperature stress in Example 2 of the present invention;

[0026] Figure 7This is a bar graph showing the relative conductivity of elephant grass with different concentrations of biochar applied to its roots after low temperature stress according to Example 2 of the present invention;

[0027] Figure 8 This is a bar graph showing the chlorophyll content of elephant grass with different concentrations of biochar applied to its roots after low temperature stress according to Example 2 of the present invention;

[0028] Fig. 9 This is a bar graph of chlorophyll fluorescence of elephant grass with different concentrations of biochar applied to its roots after low temperature stress according to Example 2 of the present invention;

[0029] Fig.10 This is a bar graph showing the malondialdehyde content in elephant grass after root application of different concentrations of biochar under low temperature stress according to Example 2 of the present invention;

[0030] Fig.11 The phenotypic photos of elephant grass in different treatment groups before and after low temperature stress in Example 3 of the present invention;

[0031] Fig.12 This is a bar graph showing the relative conductivity of elephant grass in different treatment groups after low temperature stress in Example 3 of the present invention;

[0032] Fig.13 This is a bar graph showing the relative water content of elephant grass in different treatment groups after low temperature stress in Example 3 of the present invention;

[0033] Fig.14 This is a bar graph of chlorophyll fluorescence of elephant grass in different treatment groups after low temperature stress in Example 3 of the present invention;

[0034] Fig.15 This is a bar graph showing the chlorophyll content in elephant grass of different treatment groups after low temperature stress in Example 3 of the present invention;

[0035] Fig.16 This is a bar graph showing the malondialdehyde content in elephant grass in different treatment groups after low temperature stress in Example 3 of the present invention.

[0036] The lowercase English letters connected to the columns in the above column data graph represent the results of significant difference analysis. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with specific embodiments.

[0038] Example 1: Experiment on the effect of exogenous spraying of chitosan solution on the cold resistance of grass

[0039] (1) Test materials:

[0040] Elephant grass variety: Yunmu No. 1;

[0041] Cultivated soil: field soil;

[0042] Test pot: diameter 10cm.

[0043] (2) Test method:

[0044] The middle and lower stems of elephant grass with strong growth were selected and soaked in water, then placed in a pot and covered with soil, and placed in a constant temperature and humidity environment (25°C during the day; 23°C at night; humidity 60%) for growth management. After the elephant grass grew for six weeks and sprouted seedlings, 50 mL of chitosan solution (containing 0.3 wt% Tween 20) of different concentrations was sprayed on its leaves. After spraying, it was air-dried and then placed in a light incubator for low temperature stress (4°C, 12 h) to observe its phenotypic changes. Figure 1 .

[0045] The concentration of chitosan solution (CTS) was set to six gradients: 0 mg / L (control), 250 mg / L, 500 mg / L, 1000 mg / L, 1500 mg / L, and 2000 mg / L.

[0046] (3) Physiological index measurement

[0047] The following physiological indices of elephant grass after low temperature stress were measured:

[0048] 1. Relative conductivity: Cut the leaves of the same part with a fresh weight of about 0.1g (FW), wrap them with ordinary absorbent paper, immerse the leaves in a 50ml centrifuge tube with 30ml water, and place them at room temperature for 24 hours before measuring the initial conductivity S1. Boil in a water bath until the plant tissue is completely killed, cool to room temperature, and measure the final conductivity S2. The relative conductivity is L = S1 / S2. The measurement data is shown in Figure 2 shown.

[0049] 2. Chlorophyll content: 0.15 g of fresh leaves were washed and immediately immersed in 15 ml of dimethyl sulfoxide (DMSO) solution at room temperature in the dark for 8 h, and the absorbance of the extract was measured at 663 and 645 nm using a spectrophotometer (Spectronic Instruments, Rochester, NY, USA). The measurement data are shown in Figure 3 shown.

[0050] 3. Chlorophyll fluorescence: Measure and record the Fv / Fm readings using a chlorophyll fluorescence meter. Figure 4 shown.

[0051] 4. Malondialdehyde content: Grind 0.15 g of fresh plant tissue in 2 ml of pre-cooled phosphate buffered saline (50 mM, pH 7.8) and centrifuge at 10,000 g for 15 minutes. The supernatant is used to determine the malondialdehyde (MDA) content. Add 0.5 ml of the supernatant to 1 ml of the reaction solution (20% w / v trichloroacetic acid and 0.5% w / v thiobarbituric acid), then heat at 100°C for 10 minutes. After cooling to room temperature, centrifuge the mixture at 8,000 g for 10 minutes, and measure the absorbance of the supernatant at 532 and 600 nm. See the measurement data. Figure 5 shown.

[0052] (4) Test results

[0053] See also Figure 1 As shown in the figure, after low temperature stress, the leaves of elephant grass wilt and curl to varying degrees, but with the increase of chitosan solution concentration, the degree of wilting first decreases and then increases. When the concentration of exogenous chitosan solution sprayed exceeds 1000 mg / L, the leaves of elephant grass wilt more obviously. Then this experiment further measured the relative conductivity, chlorophyll content, chlorophyll fluorescence and malondialdehyde content of elephant grass treated with different concentrations of chitosan solution after low temperature stress, see Figures 2 to 5 As shown in the figure, it was found that with the increase of chitosan solution concentration, the relative conductivity and malondialdehyde content of elephant grass showed a trend of first decreasing and then increasing, while the chlorophyll fluorescence and chlorophyll content showed a trend of first increasing and then decreasing. There was a significant difference between the treatment group sprayed with chitosan and the control group without chitosan spraying, and there was a significant difference between the treatment group sprayed with 1000mg / L chitosan solution and the treatment group sprayed with other concentrations of chitosan solution. The results showed that exogenous spraying of chitosan solution can improve the resistance of elephant grass under low temperature stress, and exogenous spraying of 1000mg / L chitosan solution achieved the best effect.

[0054] Example 2: Experiment on the effect of exogenous biochar on the cold resistance of grass

[0055] (1) Test materials:

[0056] Elephant grass variety: Yunmu No. 1;

[0057] Cultivated soil: field soil;

[0058] Test pot: diameter 10cm.

[0059] (2) Test method:

[0060] Select the middle and lower stems of elephant grass that are growing strong, soak them in water, put them in pots, cover them with soil, and place them in a constant temperature and humidity environment (25℃ during the day; 23℃ at night; humidity 60%) to manage their growth. After the elephant grass grows for six weeks and sprouts seedlings, root fertilization is carried out. Different concentrations of biochar are applied to the roots. The root fertilization method is to mix the biochar with 1.2kg of field soil according to different mass ratios and then use the mixture in the area where the roots of each pot of elephant grass are distributed. After growing for one week, place them in a light incubator for low temperature stress (4℃, 12h) to observe their phenotypic changes. Figure 6 .

[0061] The mass ratio of biochar (BC) to field soil in the mixture was set to five gradients: 0 (i.e., biochar concentration 0%, control), 3:100 (i.e., biochar concentration 3%), 5:100 (i.e., biochar concentration 5%), 10:100 (i.e., biochar concentration 10%), and 20:100 (i.e., biochar concentration 20%).

[0062] (3) Physiological index measurement

[0063] The physiological indexes of elephant grass after low temperature stress were measured. The measurement items and methods were the same as those in Example 1. The measurement data are shown in Figures 7 to 10 shown.

[0064] (4) Test results

[0065] See also Figure 6 As shown in the figure, after low temperature stress, the leaves of elephant grass wilt and curl to varying degrees, but with the increase in the concentration of biochar, the degree of wilting first decreases and then increases. When the concentration of exogenous root-applied biochar is ≤10%, the wilting degree of the elephant grass leaves gradually decreases with the increase of concentration, but when the concentration of exogenous root-applied biochar exceeds 10%, the leaves of elephant grass begin to wilt again. Then this experiment further measured the relative conductivity, chlorophyll content, chlorophyll fluorescence and malondialdehyde content of elephant grass treated with biochar after low temperature stress, see Figures 7 to 10 As shown in the results, it was found that with the increase in the concentration of biochar application, the relative conductivity and malondialdehyde content of elephant grass showed a trend of first decreasing and then increasing, while the chlorophyll fluorescence and chlorophyll content showed a trend of first increasing and then decreasing. There was a significant difference between the treatment group with biochar applied to the root and the control group without biochar applied to the root, and there was a significant difference between the treatment group with 10% biochar applied to the root and the treatment group with other concentrations of biochar applied to the root. The results showed that exogenous root-applied biochar can improve the resistance of elephant grass to low temperature stress, and the optimal effect was achieved at a concentration of 10% root-applied biochar.

[0066] Example 3: Experiment on the effect of different exogenous substances on the cold resistance of grass

[0067] (1) Test materials:

[0068] Elephant grass variety: Yunmu No. 1;

[0069] Cultivated soil: field soil;

[0070] Test pot: diameter 10cm.

[0071] (2) Test method:

[0072] The following six treatment groups and one control group were set up:

[0073] Control group (CK): no exogenous substances were applied;

[0074] Treatment group 1 (CTS): foliar spraying of 1000 mg / L chitosan solution (application method and application amount are the same as in Example 1);

[0075] Treatment group 2 (BC): 10% biochar was applied to the roots (the application method and application amount were the same as in Example 2);

[0076] Treatment group 3 (CTS+BC): foliar spraying of 1000 mg / L chitosan solution + root application of 10% biochar (the chitosan solution application method and application amount are the same as in Example 1, and the biochar application method and application amount are the same as in Example 2);

[0077] Treatment group 4 (CTS+GB): foliar spraying of 1000 mg / L chitosan solution + 20 mmol / L betaine (the application method and application amount of the chitosan solution were the same as those in Example 1, and the application method and application amount of betaine were the same as those in Example 1, except that the chitosan solution in Example 1 was replaced with betaine);

[0078] Treatment group 5 (BC+GB): foliar spraying of 20 mmol / L betaine + root application of 10% biochar (the application method and amount of biochar were the same as in Example 2, and the application method and amount of betaine were the same as in Treatment group 5);

[0079] Treatment group 6 (CTS+BC+GB): foliar spraying of 1000 mg / L chitosan solution + 20 mmol / L betaine + root application of 10% biochar (the application method and application amount of chitosan solution are the same as in Example 1, the application method and application amount of biochar are the same as in Example 2, and the application method and application amount of betaine are the same as in Treatment Group 5).

[0080] The phenotypic changes of elephant grass in each treatment group before and after low temperature stress are shown in Fig.11 .

[0081] (3) Physiological index measurement

[0082] The physiological indexes of elephant grass after low temperature stress were measured. The measurement items and methods were the same as those in Example 1. The measurement data are shown in Figures 12 to 16 shown.

[0083] Relative water content: Cut about 0.1g of leaves and immerse them in a 10ml centrifuge tube filled with water. After the leaves are saturated with water for 24 hours, take out the leaves, wipe off the surface moisture, weigh the saturated fresh weight, and then put them in an oven at 105℃ for 45 minutes, then dry them at 75℃ to constant weight, and weigh their dry weight. Calculation formula: Relative water content (%) = (fresh weight-dry weight) / (saturated fresh weight-dry weight)×100%. Determination data see Fig.13 shown.

[0084] (4) Test results

[0085] See also Fig.11 As shown in the results, the leaves of the control group and each treatment group were wilted and curled to varying degrees after low temperature stress, and the wilting degree of the elephant grass in treatment group 3 (CTS+BC) was the smallest. Then, the relative conductivity, chlorophyll fluorescence, chlorophyll content, relative water content and malondialdehyde content of the control group and each treatment group after low temperature stress were further determined. It was found that the relative conductivity and malondialdehyde content showed a downward trend, and the treatment groups were significantly different from the control group, and the treatment group 3 (CTS+BC) was significantly different from the other treatment groups; chlorophyll fluorescence, chlorophyll content and relative water content showed an upward trend, and the treatment groups were significantly different from the control group, and the treatment group 3 (CTS+BC) was significantly different from the other treatment groups. The results show that the combination of exogenous chitosan and biochar can more effectively improve the resistance of elephant grass under low temperature stress.

[0086] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for improving the cold resistance of elephant grass, characterized in that: The treatment method is to use 1000 mg / L chitosan solution as an exogenous substance and apply it to the elephant grass.

2. The processing method according to claim 1, characterized in that: The chitosan solution is applied by foliar spraying at a rate of 6 to 7 L / m 2 Elephant grass.

3. The processing method according to claim 2, characterized in that: The foliar spraying rate of the chitosan solution was 6.4 L / m 2 Elephant grass.

4. The processing method according to claim 1, characterized in that: The chitosan solution contains 0.3% mass concentration of Tween surfactant.

5. The processing method according to claim 4, characterized in that: The Tween surfactant is Tween 20.

6. The processing method according to claim 1, characterized in that: The treatment method also includes using biochar as an exogenous material applied to the elephant grass.

7. The processing method according to claim 6, characterized in that: The biochar application method is root application, and the biochar is mixed with elephant grass cultivated soil in a mass ratio of 1:10 and then used in the area where the elephant grass root system is distributed.

8. The processing method according to claim 7, characterized in that: The application rate of the biochar root fertilizer is 15-16 kg biochar / m 2 Elephant grass.

9. The processing method according to claim 8, characterized in that: The application rate of the biochar root application is 15.3 kg biochar / m 2 Elephant grass.

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