Application of fucoidan in promoting the ripening and yellowing of tobacco leaves and / or improving the quality of tobacco leaves, composition and its application

Abstract

The present invention relates to the technical field of promoting tobacco growth, in particular to the application of fucoidan in promoting the maturation and yellowing of tobacco leaves and / or improving the quality of tobacco leaves, a composition and its application. The present invention has proven through experiments that fucoidan or a composition containing fucoidan can promote the maturation and yellowing of tobacco leaves, and can effectively accelerate the degradation of chlorophyll in the later stage of flue-cured tobacco; the quality of flue-cured tobacco is significantly improved, with more oil content, stronger color intensity, loose structure, and a high proportion of orange-yellow tobacco; and it significantly improves the agronomic traits such as the leaf length and leaf width of the upper and middle tobacco leaves, and significantly increases the output value and economic benefits of flue-cured tobacco; at the same time, fucoidan is naturally sourced, has the characteristics of low cost, biodegradability, non-toxicity, and ecological friendliness, and can avoid phytotoxicity to tobacco leaves.

Description

Technical Field

[0001] The present invention relates to the technical field of promoting tobacco growth, and in particular to the application of brown algae polysaccharide in promoting tobacco leaf maturation and yellowing and / or improving tobacco leaf quality, a composition and its application. Background Art

[0002] During the flue-cured tobacco baking process, tobacco leaves with good maturity and yellowing are easy to bake and produce high-quality tobacco leaves to meet industrial needs. Due to factors such as excessive pursuit of high tobacco yields, excessive application of chemical fertilizers, and inadequate field management, tobacco leaves are difficult to mature, have high moisture content, thick leaves, and cannot yellow normally. Maturity is an important factor affecting tobacco quality and runs through the entire process of tobacco production and processing. Maturity, as the primary quality factor in the national standard for flue-cured tobacco, is the core of tobacco production and quality. In addition, domestic upper tobacco leaves currently have problems such as poor maturity, tight leaf structure, high starch content, inconsistent internal chemical composition, heavy impurities, poor smoke quality, and poor industrial availability. Therefore, how to promote the degradation of pigments and macromolecular substances in mature tobacco leaves, promote the maturity and yellowing of tobacco leaves, and improve the quality of baked tobacco leaves needs to be solved urgently.

[0003] At present, chemical control measures are mainly used to promote the maturity and yellowing of tobacco leaves. Chemical control measures mainly include hormone regulation and chemical regulation. Hormone regulation measures mainly involve spraying ABA, ethylene, methyl jasmonate, etc. on tobacco leaves to accelerate the aging process of leaves. In practice, Chinese patents CN108142139A or CN111348959A disclose plant hormones such as ethephon and abscisic acid as yellowing-promoting agents, but plant hormones have high requirements for use technology and have very strict restrictions on the use period and dosage. Once an error occurs, it may cause phytotoxicity to crops and cause unnecessary losses. Summary of the invention

[0004] In order to solve the above problems, the present invention provides an application of brown algae polysaccharide in promoting the maturity and yellowing of tobacco leaves and / or improving the quality of tobacco leaves, a composition and its application. The brown algae polysaccharide or a composition containing brown algae polysaccharide provided by the present invention solves the problem that in the actual production process of tobacco, the maturity of tobacco leaves is low in the late stage of harvesting and curing, and the leaves cannot turn yellow normally, which affects the quality of the cured tobacco leaves.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides the use of brown algae polysaccharide in promoting the maturity and yellowing of tobacco leaves and / or improving the quality of tobacco leaves.

[0007] The present invention also provides a composition for promoting the ripening and yellowing of tobacco leaves. The composition comprises fucoidan, potassium dihydrogen phosphate, potassium sulfate and sodium bicarbonate; the mass ratio of fucoidan, potassium dihydrogen phosphate, potassium sulfate and sodium bicarbonate is (1-5):(8-12):(3-5):(1-2); the mass percentage content of potassium element in the composition is 28%-36%.

[0008] The present invention also provides the application of the composition described in the above technical solution in promoting the ripening and yellowing of tobacco leaves and / or improving the quality of tobacco leaves.

[0009] The present invention also provides a method for promoting the ripening and yellowing of tobacco leaves and / or improving the quality of tobacco leaves, comprising the following steps:

[0010] Mix fucoidan or the composition described in the above technical solution with water to obtain a promoter; spray the promoter on the leaves.

[0011] Preferably, the concentration of fucoidan in the promoter is 1-5 g / L.

[0012] Preferably, the dosage of each spraying of the promoter is 45-60 L / mu.

[0013] Preferably, the starting time of spraying is 10-14 days before tobacco leaf harvesting.

[0014] Preferably, the number of spraying times is 1-2 times.

[0015] Preferably, when the number of spraying times is 2 times, the time interval between sprayings is 7 days.

[0016] Preferably, after obtaining the promoter, adopt the double-sided spraying method to spray the promoter on the leaves; the spraying time is before 9:00 am or after 5:00 pm. If it rains within 12 h after spraying, re-spray.

[0017] Beneficial effects:

[0018] The present invention provides the application of fucoidan in promoting the ripening and yellowing of tobacco leaves and / or improving the quality of tobacco leaves. The present invention proves through experiments that fucoidan or a composition containing fucoidan can promote the ripening and yellowing of tobacco leaves, and can effectively accelerate the degradation of chlorophyll in the later stage of flue-cured tobacco; the quality of flue-cured tobacco is significantly improved, with more oil content, stronger color intensity, loose structure and a high proportion of orange-yellow tobacco; and it significantly improves the agronomic characters such as the leaf length and leaf width of the upper and middle tobacco leaves, and significantly increases the output value and economic benefits of flue-cured tobacco; at the same time, fucoidan is natural in source, has the characteristics of low cost, biodegradability, non-toxicity and ecological friendliness, and can avoid phytotoxicity to tobacco leaves. Description of the drawings

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments.

[0020] Figure 1 It is the plastid pigment content in tobacco leaves treated with different yellowing accelerators;

[0021] Figure 2 It is the effect of different yellowing accelerators on the content of cell wall substances in tobacco leaves;

[0022] Figure 3 It is the result of the activities of sucrose metabolism-related enzymes in different treatment groups. Specific Embodiments

[0023] The present invention provides the application of fucoidan in promoting the ripening and yellowing of tobacco leaves and / or improving the quality of tobacco leaves.

[0024] The present invention proves through experiments that fucoidan can effectively accelerate the degradation of chlorophyll in the later stage of flue-cured tobacco, promote the ripening and yellowing of tobacco leaves; in addition, fucoidan can significantly improve the quality of flue-cured tobacco, with more oil content, stronger color intensity, loose structure, and a high proportion of orange-yellow tobacco; and significantly improve the agronomic traits such as the leaf length and leaf width of the middle and upper tobacco leaves, significantly increase the output value and economic benefits of flue-cured tobacco; moreover, fucoidan is naturally sourced, with rich materials, low cost, and environmental friendliness.

[0025] The present invention also provides a composition for promoting the ripening and yellowing of tobacco leaves, the composition comprising fucoidan, potassium dihydrogen phosphate, potassium sulfate, and sodium bicarbonate; the mass ratio of fucoidan, potassium dihydrogen phosphate, potassium sulfate, and sodium bicarbonate is (1 - 5):(8 - 12):(3 - 5):(1 - 2); the mass percentage content of potassium element in the composition is 28% - 36%, preferably 28.24% - 35.68%, and more preferably 34.75%.

[0026] The mass percentage content of potassium element in the present invention is preferably calculated based on the content of K2O, that is, the mass percentage content of potassium element in potassium dihydrogen phosphate is preferably 34%, and the mass percentage content of potassium element in potassium sulfate is preferably 54%.

[0027] Unless otherwise specified, the present invention has no special requirements for the sources of the components of the composition, and commercially available products well-known to those skilled in the art can be used.

[0028] Calculated by mass parts, the composition of the present invention comprises 1 - 5 parts of fucoidan, preferably 1 part.

[0029] Based on the mass parts of the fucoidan, the mass parts of potassium dihydrogen phosphate are 8 - 12 parts, preferably 10 parts,

[0030] Based on the parts by mass of the fucoidan, the parts by mass of potassium sulfate are 3 to 5 parts, preferably 4 parts;

[0031] The potassium salt in the present invention can antagonize the absorption of magnesium ions by tobacco, reduce the chlorophyll content, and promote the ripening and yellowing of the upper tobacco leaves.

[0032] Based on the parts by mass of the fucoidan, the composition of the present invention includes 1 to 2 parts by mass of sodium bicarbonate, preferably 1 part. The sodium bicarbonate in the present invention can affect ethylene production, accelerate the senescence of tobacco leaves, and promote the ripening and yellowing of the upper tobacco leaves.

[0033] The composition provided by the present invention can alleviate the false ripening caused by potassium and sodium salts through the compounding of appropriate components. Compared with the single application of fucoidan, it can further promote the ripening and yellowing of tobacco leaves and improve the quality of tobacco leaves, significantly increasing the output value and economic benefits of flue-cured tobacco.

[0034] The present invention also provides the application of the composition described in the above technical solution in promoting the ripening and yellowing of tobacco leaves and / or improving the quality of tobacco leaves.

[0035] The present invention also provides a method for promoting the ripening and yellowing of tobacco leaves and / or improving the quality of tobacco leaves, comprising the following steps:

[0036] Mix fucoidan or the composition described in the above technical solution with water to obtain a promoter;

[0037] Spray the promoter on the leaves.

[0038] In the present invention, the promoter obtained by mixing fucoidan with water is denoted as promoter 1, and the promoter obtained by mixing the composition with water is denoted as promoter 2. The concentration of fucoidan in promoter 1 or promoter 2 is preferably 1 to 5 g / L, more preferably 1 g / L.

[0039] The promoter prepared by mixing fucoidan or the composition described in the above technical solution with water in the present invention can significantly promote the ripening and yellowing of tobacco leaves and improve the quality of tobacco leaves, and the preparation method is simple and easy to implement, facilitating popularization and application.

[0040] After obtaining the promoter, the present invention sprays the promoter on the leaves.

[0041] In the present invention, the preferred time to start spraying is the mature stage of tobacco leaves, more preferably 10 to 14 days before tobacco leaf harvesting.

[0042] In the present invention, the number of spraying times is preferably 1 to 2 times, more preferably 2 times; when the number of spraying times is 2 times, the time interval between sprayings is preferably 7 days; each time of spraying, the spraying dosage of the promoter is preferably 45 to 60 L / mu, more preferably 45 L / mu; the timing of spraying is preferably: after obtaining the promoter, adopting the double-sided spraying method to spray the promoter on the leaves; the spraying time is before 9:00 am or after 5:00 pm, and if it rains within 12 h after spraying, spraying shall be carried out again.

[0043] The method provided by the present invention can significantly promote the ripening and yellowing of tobacco leaves and improve the quality of tobacco leaves, and the spraying method is simple and easy to implement, facilitating popularization and application.

[0044] In order to further illustrate the present invention, the application of fucoidan in promoting the ripening and yellowing of tobacco leaves and / or improving the quality of tobacco leaves, the composition and its application provided by the present invention will be described in detail below with reference to the drawings and examples, but they should not be construed as limiting the protection scope of the present invention.

[0045] Potassium dihydrogen phosphate and potassium sulfate used in the following examples or comparative examples are both of analytical grade.

[0046] Example 1

[0047] A composition for promoting the ripening and yellowing of tobacco leaves, the composition is composed of fucoidan, potassium dihydrogen phosphate, potassium sulfate and sodium bicarbonate; the mass ratio of fucoidan, potassium dihydrogen phosphate, potassium sulfate and sodium bicarbonate is 1:10:4:1; the mass percentage content of potassium element in the composition is 34.75%.

[0048] Example 2

[0049] A reagent for promoting the ripening and yellowing of tobacco leaves, the reagent is composed of the following components in concentration: 1 g / L of fucoidan, 10 g / L of potassium dihydrogen phosphate, 4 g / L of potassium sulfate and 1 g / L of sodium bicarbonate.

[0050] Example 3

[0051] A reagent for promoting the ripening and yellowing of tobacco leaves, the reagent is an aqueous solution of fucoidan; the concentration of the aqueous solution of fucoidan is 1 g / L.

[0052] Example 4

[0053] A reagent for promoting the ripening and yellowing of tobacco leaves, the reagent is an aqueous solution of fucoidan; the concentration of the aqueous solution of fucoidan is 5 g / L.

[0054] Example 5

[0055] A composition for promoting the ripening and yellowing of tobacco leaves, the composition is composed of fucoidan, potassium dihydrogen phosphate, potassium sulfate and sodium bicarbonate; the mass ratio of fucoidan, potassium dihydrogen phosphate, potassium sulfate and sodium bicarbonate is 1:8:3:1; the mass percentage content of potassium element in the composition is 33.38%.

[0056] Example 6

[0057] A composition for promoting the ripening and yellowing of tobacco leaves, the composition is composed of fucoidan, potassium dihydrogen phosphate, potassium sulfate and sodium bicarbonate; the mass ratio of fucoidan, potassium dihydrogen phosphate, potassium sulfate and sodium bicarbonate is 5:12:5:2; the mass percentage content of potassium element in the composition is 28.24%.

[0058] Example 7

[0059] A composition for promoting the ripening and yellowing of tobacco leaves, the composition is composed of fucoidan, potassium dihydrogen phosphate, potassium sulfate and sodium bicarbonate; the mass ratio of fucoidan, potassium dihydrogen phosphate, potassium sulfate and sodium bicarbonate is 1:12:5:1; the mass percentage content of potassium element in the composition is 35.68%.

[0060] Example 8

[0061] A reagent for promoting the ripening and yellowing of tobacco leaves, the reagent is composed of components with the following concentrations: 1 g / L of fucoidan, 8 g / L of potassium dihydrogen phosphate, 3 g / L of potassium sulfate and 1 g / L of sodium bicarbonate.

[0062] Example 9

[0063] A reagent for promoting the ripening and yellowing of tobacco leaves, the reagent is composed of components with the following concentrations: 5 g / L of fucoidan, 12 g / L of potassium dihydrogen phosphate, 5 g / L of potassium sulfate and 2 g / L of sodium bicarbonate.

[0064] Example 10

[0065] A reagent for promoting the ripening and yellowing of tobacco leaves, the reagent is composed of components with the following concentrations: 1 g / L of fucoidan, 12 g / L of potassium dihydrogen phosphate, 5 g / L of potassium sulfate and 1 g / L of sodium bicarbonate.

[0066] Comparative Example 1

[0067] A reagent for promoting the ripening and yellowing of tobacco leaves, the reagent is composed of components with the following concentrations: 10 g / L of potassium dihydrogen phosphate, 4 g / L of potassium sulfate and 1 g / L of sodium bicarbonate.

[0068] Comparative Example 2

[0069] A reagent for promoting the ripening and yellowing of tobacco leaves, the concentration of fucoidan in the reagent is 1 g / L, and the concentration of potassium dihydrogen phosphate is 10 g / L.

[0070] Comparative Example 3

[0071] A reagent for promoting the ripening and yellowing of tobacco leaves, wherein the concentration of fucoidan in the reagent is 1 g / L and potassium sulfate is 4 g / L.

[0072] Comparative Example 4

[0073] A reagent for promoting the ripening and yellowing of tobacco leaves, wherein the concentration of fucoidan in the reagent is 1 g / L and sodium bicarbonate is 1 g / L.

[0074] Comparative Example 5

[0075] A reagent for promoting the ripening and yellowing of tobacco leaves, wherein the reagent consists of components with the following concentrations: the concentration of fucoidan is 1 g / L, potassium dihydrogen phosphate is 10 g / L, and sodium bicarbonate is 1 g / L.

[0076] Comparative Example 6

[0077] A reagent for promoting the ripening and yellowing of tobacco leaves, wherein the reagent consists of components with the following concentrations: the concentration of fucoidan is 1 g / L, potassium sulfate is 4 g / L, and sodium bicarbonate is 1 g / L.

[0078] Comparative Example 7

[0079] A reagent for promoting the ripening and yellowing of tobacco leaves, wherein the reagent consists of components with the following concentrations: the concentration of fucoidan is 1 g / L, potassium sulfate is 4 g / L, and potassium dihydrogen phosphate is 10 g / L.

[0080] Comparative Example 8

[0081] A reagent for promoting the ripening and yellowing of tobacco leaves, wherein the reagent is an aqueous solution of fucoidan; the concentration of the aqueous solution of fucoidan is 20 g / L.

[0082] Comparative Application Example 1

[0083] In August 2021, a field experiment was conducted in a tobacco field in Jiaozhou, Qingdao. The flue-cured tobacco variety planted was Zhongyan 100. A total of 12 treatment groups were set up: a control group, a fucoidan group, a potassium-sodium fertilizer group, and a compound group. The 12 groups were treated as follows:

[0084] Control group: In August 2021, during the maturity period of the tobacco leaves, 10 days before the tobacco leaves were harvested, on cloudy days or in the evening on sunny days when there was no wind and no rain, clear water was sprayed onto the tobacco leaves until the surfaces of the tobacco leaves were wet. The spraying amount was 45 L / mu.

[0085] Fucoidan group: In August 2021, during the maturity period of the tobacco leaves, 10 days before the tobacco leaves were harvested, on cloudy days or in the evening on sunny days when there was no wind and no rain, the reagent prepared in Example 3, Example 4, or Comparative Example 8 was sprayed onto the tobacco leaves until the surfaces of the tobacco leaves were wet. The spraying amount was 45 L / mu.

[0086] Potassium and sodium fertilizer group: In August 2021, during the mature period of tobacco leaves, 10 days before tobacco leaf harvesting, on a cloudy day or in the evening of a sunny day without wind and rain, the reagent prepared in Comparative Example 1 was sprayed onto the tobacco leaves until the surfaces of the tobacco leaves were wet, and the spraying amount was 45 L / mu;

[0087] Compound group: In August 2021, during the mature period of tobacco leaves, 10 days before tobacco leaf harvesting, on a cloudy day or in the evening of a sunny day without wind and rain, the reagents prepared in Examples 2, 8, 9, 10 or Comparative Examples 2-7 were sprayed onto the tobacco leaves until the surfaces of the tobacco leaves were wet, and the spraying amount was 45 L / mu.

[0088] The agronomic traits were measured on the 7th day after spraying clear water or the reagent. The leaf length, leaf width and leaf area were measured according to the "Investigation and Measurement Method for Tobacco Agronomic Traits". There was one experimental field for each group, and there were 50 tobacco plants in each experimental field. The measurement results are shown in Table 1.

[0089] Table 1 Effects of different reagents on the agronomic traits of middle and upper tobacco leaves

[0090] Group Leaf length (cm) Leaf width (cm) <![CDATA[Leaf area (cm 2 )]]> Control 62.25±2.52 33.25±3.06 1314.37±153.86 Example 2 70.00±2.08 41.75±3.06 1851.47±90.72 Example 3 64.33±2.89 35.00±0.71 1427.63±29.61 Example 4 64.00±2.12 35.33±1.41 1435.87±106.33 Example 8 71.67±1.15 40.00±1.00 1793.10±24.31 Example 9 68.67±0.71 38.67±0.71 1687.81±13.91 Example 10 70.33±0.58 40.25±2.08 1814.46±83.19 Comparative Example 1 63.67±2.08 33.33±1.53 1346.62±76.49 Comparative Example 2 66.67±1.41 34.45±1.00 1453.01±91.53 Comparative Example 3 69.67±4.04 39.00±1.00 1722.46±67.02 Comparative Example 4 64.67±3.54 35.00±0.71 1436.72±106.33 Comparative Example 5 66.00±1.00 35.67±0.58 1493.61±33.26 Comparative Example 6 68.00±2.83 36.33±1.41 1567.64±127.42 Comparative Example 7 69.33±2.12 40.33±4.62 1774.91±57.88 Comparative Example 8 59.00±1.73 32.33±1.15 1211.26±78.03

[0091] As can be seen from Table 1, the reagent provided by the present invention can improve the agronomic traits of middle and upper tobacco leaves. However, the lack of a certain component, inappropriate compounding ratio or too high concentration of fucoidan (20 g / L) has no obvious improvement effect on the agronomic traits of middle and upper tobacco leaves, and even has an inhibitory effect.

[0092] Comparative Application Example 2

[0093] In August 2022, a field experiment was carried out in the tobacco field of Jiaozhou, Qingdao. The flue-cured tobacco variety planted was Zhongyan 100. A total of 4 treatment groups were set up: control group, fucoidan group, potassium and sodium fertilizer group and compound group. The 4 groups were treated as follows:

[0094] Control group: On August 23, 2022, during the mature period of tobacco leaves, 10 days before tobacco leaf harvesting, on a cloudy day or in the evening of a sunny day without wind and rain, clear water was sprayed onto the tobacco leaves until the surfaces of the tobacco leaves were wet, and the spraying amount was 45 L / mu;

[0095] Fucoidan group: On August 23, 2022, during the mature period of tobacco leaves, 10 days before tobacco leaf harvesting, on a cloudy day or in the evening of a sunny day without wind and rain, the reagent prepared in Example 3 was sprayed onto the tobacco leaves until the surfaces of the tobacco leaves were wet, and the spraying amount was 45 L / mu;

[0096] Potassium and sodium fertilizer group: On August 23, 2022, during the mature period of tobacco leaves, 10 days before tobacco leaf harvesting, on a cloudy day or in the evening of a sunny day without wind and rain, the reagent prepared in Comparative Example 1 was sprayed onto the tobacco leaves until the surfaces of the tobacco leaves were wet, and the spraying amount was 45 L / mu;

[0097] Compound group: On August 23, 2022, during the mature period of tobacco leaves, 10 days before harvesting the tobacco leaves, on a cloudy day or in the evening of a sunny day without wind and rain, the reagent prepared in Example 2 was sprayed onto the tobacco leaves until the surfaces of the tobacco leaves were wet, and the spraying amount was 45 L per mu.

[0098] The agronomic traits were measured on the 7th day after spraying water or the reagent. According to the "Investigation and Measurement Method for Tobacco Agronomic Traits", the leaf color (light green, yellowish green, yellow), leaf length, leaf width, and leaf area were measured. There was one experimental field for each group, and each experimental field had 50 tobacco plants. The measurement results are shown in Table 2.

[0099] Table 2 Effects of different compound preparations on the agronomic traits of the upper and middle parts of tobacco leaves

[0100] Leaf length (cm) Leaf width (cm) <![CDATA[Leaf area (cm 2 )]]> Leaf color Control 61.0±1.8 24.5±3.4 1027.9±156.0 50% light green + 50% yellowish green Potassium and sodium fertilizer 61.7±2.9 27.5±4.0 1082.3±209.5 75% yellowish green + 25% yellow Fucoidan 63.7±2.6 27.7±2.2 1123.5±117.8 25% light green + 50% yellowish green + 25% yellow Compound 65.2±2.1 28.7±2.2 1189.5±85.8 25% yellowish green + 75% yellow

[0101] As can be seen from Table 2, all treatment groups can promote the yellowing of tobacco leaves to varying degrees and improve the performance of agronomic traits. For example, the leaf length, leaf width, and leaf area are all higher than those of the control group. Among them, when using the fucoidan group alone, the yellowing performance of tobacco leaves is not as good as that of the potassium and sodium fertilizer group. The combination of potassium and sodium fertilizer and fucoidan has the best effect, which can not only significantly increase the leaf length, leaf width, and leaf area of tobacco leaves but also significantly promote the yellowing of tobacco leaves.

[0102] Refer to the ethanol method to determine the contents of chlorophyll and carotenoids in tobacco leaves 10 days after spraying. The method is as follows:

[0103] Take 0.1 g of leaves, cut them into pieces, put them into a mortar, add an appropriate amount of quartz sand and calcium carbonate, add 2 mL of 95% ethanol, and grind them into a homogenate; rinse the mortar and pestle several times, and make the volume of the homogenate up to 25 mL; centrifuge the homogenate at 4000 r / min for 10 min, take the supernatant, and measure the absorbance values at 440 nm, 649 nm, and 665 nm respectively. The measured absorbance values are recorded as A 440 、A 649 and A 665 . Calculate the contents of chlorophyll a, chlorophyll b, and total chlorophyll according to the following formulas; the calculation formulas are:

[0104] Chlorophyll a concentration (Ca, mg / L) = 12.71×A 665 - 2.59×A 649 ;

[0105] Chlorophyll b concentration (Cb, mg / L) = 22.88×A 649 - 4.67×A 665 ;

[0106] Among them, Ca is the chlorophyll a concentration, and Cb is the chlorophyll b concentration; the measurement results are shown in Figure 1 and Table 3.

[0107] Table 3 Determination results of chlorophyll content in different groups

[0108]

[0109] From Figure 1 and Table 3, it can be seen that the total chlorophyll content of different treatment groups is significantly lower than that of the control group. Among them, the compound group of potassium-sodium fertilizer and fucoidan can accelerate chlorophyll degradation, thereby promoting the yellowing of tobacco leaves.

[0110] The leaves of the 4 groups were collected 7 days after spraying, blanched at 105 °C and dried at 80 °C. Referring to the agricultural industry standard "Determination of cellulose, hemicellulose and lignin in agricultural biomass raw materials (NY / T 3494-2019)", the contents of cell wall substances such as cellulose, hemicellulose and lignin in the leaves were detected. The total content of cell wall substances is the sum of the above three substances. According to the tobacco industry standard "Determination of water-soluble sugars in tobacco and tobacco products - Continuous flow method (YC / T 159-2002)", the content of soluble sugars in the leaves was detected. The results are shown in Figure 2 and Table 4.

[0111] Table 4 Determination results of cell wall substance content and soluble sugar content in different groups

[0112] Cell wall substance content (%) Soluble sugar content (mg / g.DW) Control 40.69±2.99 2.91±0.13 Potassium and sodium fertilizer 36.50±1.80 3.05±0.12 Fucoidan 35.11±1.30 3.24±0.22 Compound 30.34±1.86 3.57±0.15

[0113] From Figure 2 and Table 4, it can be seen that the content of cell wall substances in tobacco leaves of different treatment groups decreases, and the content of soluble sugar non-structural carbohydrates increases. When the content of cell wall substances is high, the flue gas has strong irritation, coughing, astringency, and a strong smell of scorching and woodiness, which affects the taste of tobacco leaves. Appropriately reducing the content of cell wall substances in tobacco leaves and converting them into small molecular weight carbohydrates can improve the quality of tobacco leaves. Among them, the compound group can significantly degrade the structural substances of the cell wall, increase the content of soluble sugars, and improve the quality of tobacco leaves.

[0114] The method of Zhang Jianbo (Effect of growth temperature on sucrose metabolism in tobacco at different growth stages, Genomics and Applied Biology, 2015, Vol. 34, No. 10, pp. 2225-2244) was used to determine the activities of sucrose metabolism-related enzymes in different treatment groups. The determination results are shown in Figure 3 and Table 5.

[0115] Table 5 Sucrose metabolism-related enzyme activities in different treatment groups

[0116]

[0117] From Figure 3As can be seen from Table 5, different treatments can affect the activities of sucrose metabolism-related enzymes and the metabolism and transportation of sucrose. Among them, the activities of sucrose metabolism-related enzymes in the compound group are the strongest, indicating that it can significantly promote sugar metabolism in tobacco leaves, increase the content of soluble sugars, and improve the quality of tobacco leaves.

[0118] The tobacco leaf samples were baked by a three-stage baking process. The specific stages and baking parameters were as follows: Yellowing stage: dry bulb temperature 38°C, wet bulb temperature 37°C, increasing the temperature by 0.5°C per hour until 42°C and then baking for 24 hours for yellowing; Fixing color stage: dry bulb temperature 42°C, wet bulb temperature 36 - 40°C, increasing the temperature by 0.5°C per hour until 54°C and then baking for 12 hours for dry slices; Stem drying stage: dry bulb temperature 54°C, wet bulb temperature 40 - 42°C, increasing the temperature by 1°C per hour until 68°C and then baking for 24 hours for stem drying. Take the upper and middle tobacco leaves after baking, 2 kg for each treatment group, and use a Fourier transform infrared spectrometer to conduct chemical composition analysis respectively. Analyze the nicotine, total sugar, protein, total nitrogen, chlorine, and potassium in the tobacco leaves after baking, and compare the quality differences among the treatments. The results are shown in Table 6.

[0119] Table 6 Effects of the yellowing-promoting preparation on the chemical components of the upper and middle tobacco leaves in the field after baking

[0120] Total sugar Reducing sugar Total nicotine Total nitrogen Potassium Chlorine Sugar - alkali ratio Potassium - chlorine ratio Control 18.09 16.65 2.45 2.66 2.39 0.72 6.80 3.32 Potassium and sodium fertilizer 16.97 15.19 2.13 2.6 2.37 0.64 7.13 3.70 Fucoidan 21.00 19.82 2.05 2.29 2.61 0.68 9.67 3.84 Compound 23.77 21.70 2.03 2.26 2.59 0.62 10.69 4.18

[0121] As can be seen from Table 6, after baking, the total sugar and reducing sugar in the tobacco leaves decreased. The total nicotine content in the tobacco leaves treated with fucoidan and the compound preparation decreased, while the contents of total sugar and reducing sugar increased, and the sugar-alkali ratio and potassium-chlorine ratio increased. Among them, the compound preparation had a better effect. Thus, it can be seen that the present invention can effectively reduce the harmful substances in tobacco leaves, increase the sugar content, and make the chemical components in tobacco leaves more coordinated.

[0122] In summary, the fucoidan or composition provided by the present invention can accelerate the degradation of chlorophyll in the later stage of flue-cured tobacco, and the yellowing of flue-cured tobacco is obvious in the later stage of field production; in addition, it can increase the sugar content in tobacco leaves, significantly improve the quality of flue-cured tobacco, with more oil, stronger color intensity, loose structure, and more orange-yellow tobacco; and it significantly improves the agronomic traits such as the leaf length and leaf width of the upper and middle tobacco leaves, and significantly increases the output value and economic benefits of flue-cured tobacco.

[0123] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, not all embodiments. People can also obtain other embodiments according to these embodiments without creative efforts, and these embodiments all belong to the protection scope of the present invention.

Claims

1. A reagent for promoting the maturity and yellowing of tobacco leaves, characterized in that, The reagent consists of fucoidan, potassium dihydrogen phosphate, potassium sulfate, sodium bicarbonate and water; the concentrations of each component in the reagent are: fucoidan 1 g / L, potassium dihydrogen phosphate 10 g / L, potassium sulfate 4 g / L and sodium bicarbonate 1 g / L.

2. Use of the reagent according to claim 1 in degrading the structural substances of the tobacco leaf cell wall, increasing the soluble sugar content of the tobacco leaf, increasing the total sugar content of the tobacco leaf and increasing the sugar-alkali ratio of the tobacco leaf.

3. A method for promoting the maturity and yellowing of tobacco leaves, characterized in that, It includes the following steps: Spray the reagent according to claim 1 on the leaves.

4. The method according to claim 3, wherein The dosage of each spraying of the reagent is 45 - 60 L / acre.

5. The method according to claim 3, characterized in that, The starting time of spraying is 10 - 14 days before tobacco leaf harvesting.

6. The method according to claim 3 or 5, characterized in that The number of sprayings is 1 - 2 times.

7. The method according to claim 6, wherein When the number of sprayings is 2 times, the time interval between sprayings is 7 days.

8. The method according to claim 3, wherein After obtaining the reagent, use the double-sided spraying method to spray the reagent on the leaves; the spraying time is before 9:00 am or after 5:00 pm. If it rains within 12 h after spraying, re-spray.

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