A fruit cracking prevention agent containing oligosaccharides and use method thereof

Abstract

The invention discloses a fruit cracking prevention agent containing oligosaccharides and a method of using the same, and belongs to the technical field of fruit cracking prevention preparations. The fruit cracking prevention agent contains one or two of sodium alginate oligosaccharides and 1-deoxynojirimycin, the average molecular weight of sodium alginate oligosaccharides is 500-3000Da, the content is 50-500mg / L, and the content of 1-deoxynojirimycin is 5-50mg / L. By spraying the fruit cracking prevention agent of the invention on crops such as cherries, litchi, winter dates, citrus, grapes, and loquats, the cracking and falling of fruits can be significantly reduced. The effective ingredients in the fruit cracking prevention agent of the invention are natural products, have no environmental pollution to the treated fruits, have no health hazards to the human body, and have the advantages of low cost, small application amount, wide spectrum of action, etc., and the application method is simple and easy to promote and apply.

Description

Technical Field

[0001] The invention belongs to the technical field of fruit anti-cracking preparations, in particular to an oligosaccharide-containing fruit anti-cracking preparation and a use method thereof. Background Art

[0002] Fruit cracking is a serious physiological disease of fruits. It occurs on many fruit trees. The common date has a 30% fruit cracking rate in general years, and the cherry has a 30% fruit cracking rate every year, which can reach 80% in severe cases. Grapes, sweet oranges and other fruits also have 50% fruit cracking every year. The fruit cracking rate of easy-to-crack tomatoes is almost 100%. Once the fruit cracks, it will seriously affect the commercial value of the fruit. It is an important problem that the fruit industry needs to solve urgently. Fruit cracking often occurs in the middle and late stages of maturity, and is mainly manifested in two phenomena: fruit collapse and cracking. When the fruit cracks, the flesh will be exposed, and then the cracked fruit will rot and become sour and cannot be eaten. After the fruit cracks, it is more likely to cause the invasion of pathogens such as anthrax, thereby accelerating decay and deterioration.

[0003] There are many factors that cause fruit cracking. Current research focuses on external environmental conditions such as climate, soil, water, and minerals, and internal factors such as fruit variety, endogenous hormones, and peel structure. The process of fruit cracking is relatively complex, and the most direct cause is the inconsistency between the growth stress of the flesh and the tensile strength of the peel.

[0004] At present, there are several main measures to prevent fruit cracking: 1. Improve varieties and water and fertilizer management measures, reduce the fruit cracking rate by selecting fruit tree resources that are resistant to fruit cracking, and take effective water and fertilizer management measures, such as replenishing soil moisture through irrigation during droughts, and timely drainage in rainy seasons to reduce the difference in soil moisture. 2. Bagging treatment, fruit bagging can reduce light burns to the fruit, and has a certain buffering effect on drastic changes in temperature and humidity, thereby increasing the extensibility and elasticity of the outer skin and reducing the occurrence of fruit cracking. It is also considered to be one of the effective measures to prevent fruit cracking. 3. Use plant growth regulators. The reasonable use of plant growth regulators such as gibberellins, ethephon, NAA and 0.3% paclobutrazol has a certain effect on reducing and preventing fruit cracking. It is a relatively efficient and labor-saving measure to prevent fruit cracking. It has been applied to fruit trees such as dates, grapes, and lychees. 4. Spraying Ca ions is a commonly used method for preventing and controlling fruit cracking in fruit trees. Studies have shown that calcium ions bind to pectin, one of the main components of plant cell walls, thereby increasing the stability of the cell walls and effectively maintaining the intercellular forces, thereby reducing and preventing fruit cracking. The above-mentioned variety improvement, water and fertilizer management, and bagging measures to prevent fruit cracking are costly. The use of plant growth regulators is difficult to control the dosage. Improper dosage will produce the opposite effect, such as poor fruit coloring, reduced single fruit weight, and deformed fruit. Spraying calcium fertilizer needs to be carried out in the early stage of fruit growth, usually starting before flowering, and it should be supplemented in time from the young fruit stage to the picking stage. This is because calcium has poor mobility in the plant body. When applying calcium fertilizer, it should be noted that it should be sprayed on the fruit and the leaves near the fruit. The effect of calcium supplementation in the late fruit stage is not very good. In the season of drought or heavy rain, the effect of preventing fruit cracking by calcium supplementation is also poor. Therefore, spraying calcium fertilizer is not ideal due to its strict application time requirements and relatively slow effect. At the same time, the application of calcium fertilizer will also increase the amount of chemical fertilizer. Although the sugar alcohol calcium products currently under development can increase the speed of calcium movement, sugar alcohol calcium needs to rely on plant transpiration to be absorbed and moved, and the effect will generally be affected by rainy weather. Frequent rainy weather is one of the main reasons for fruit cracking, which limits the use of sugar alcohol calcium to prevent fruit cracking.

[0005] Alginate oligosaccharide is an oligosaccharide composed of different segments (MM segment, GG segment and MG segment) connected by α-L-mannuronic acid (mannuronic acid, M) and bD-guluronic acid (guluronic acid, G) through 1,4-glycosidic bonds, and has the advantages of small relative molecular mass and strong absorbability; 1-deoxynojirimycin is an alkaloid extracted from mulberry leaves and root bark and is a natural product; however, there are no reports on the research, development and application of seaweed oligosaccharides or the combination of seaweed oligosaccharides and 1-deoxynojirimycin as fruit cracking inhibitors. Summary of the invention

[0006] In view of this, the object of the present invention is to provide a non-toxic, efficient, and oligosaccharide-containing fruit cracking preventive agent capable of effectively preventing fruit cracking, and a method for using the same.

[0007] To achieve the above object, the technical solution of the present invention is:

[0008] A fruit cracking preventive agent, wherein the solvent of the fruit cracking preventive agent is water and the agent contains one or two of sodium alginate oligosaccharide and 1-deoxynojirimycin.

[0009] Furthermore, the concentration of the sodium alginate oligosaccharide is 50-500 mg / L.

[0010] Furthermore, the concentration of 1-deoxynojirimycin is 5-50 mg / L.

[0011] Furthermore, the average molecular weight of the sodium alginate oligosaccharide is 500-3000Da.

[0012] Another aspect of the present invention provides a method for using the fruit anti-cracking agent, wherein the fruit anti-cracking agent is sprayed on the fruit surface during the bud stage, fruit swelling stage, color change stage or 6h-48h before the arrival of heavy rain; or, the fruit anti-cracking agent is sprayed on the fruit surface 7-20 days before the harvest period.

[0013] Furthermore, the spraying is performed 1-5 times.

[0014] Furthermore, the amount of fruit crack inhibitor used per fruit tree is 0.2-2 kg.

[0015] The invention also provides application of the fruit crack prevention agent in preventing and controlling fruit cracking and fruit falling and keeping the fruit fresh on the tree.

[0016] The present invention has the following advantages and beneficial effects:

[0017] (1) The oligosaccharide fruit cracking inhibitor provided by the present invention can effectively prevent the fruit cracking of various fruits during the physiological period. In the examples that have been carried out, the fruit cracking rate can be reduced by 75% compared with the control. At the same time, it also has the effect of preventing fruit drop during the physiological period and keeping the fruit fresh on the tree.

[0018] (2) The oligosaccharide fruit cracking inhibitor provided by the present invention is a natural product, and has the characteristics of safety, environmental protection, and low residue. Compared with the existing technology, it can reduce production costs and minimize the use of chemical fertilizers, and will not cause pesticide damage. It has the advantages of safety and environmental protection, and is a new, green fruit cracking inhibitor.

[0019] (3) The fruit cracking inhibitor provided by the present invention has a small dosage, a long-lasting and stable effect, is applicable to a wide range of fruits, has a simple application method, is low in cost, is easy to promote and apply, and has broad application prospects.

[0020] (4) The fruit crack prevention agent provided by the present invention also has the function of improving fruit quality and enhancing fruit resistance, and can play multiple positive roles in the process of preventing and controlling fruit cracking. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention, the drawings related to the embodiments are briefly introduced below.

[0022] Figure 1 This is the effect of the oligosaccharide anti-cracking agent in Example 6 on the activity of tomato fruit cell wall degrading enzymes (polygalacturonase PG, pectinesterase PE, pectin lyase PL and cellulase CEL). DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the embodiments, but the embodiments of the present invention are not limited thereto. Obviously, the embodiments described below are only partial embodiments of the present invention. For those skilled in the art, other similar embodiments obtained without creative labor all fall within the protection scope of the present invention.

[0024] Example 1 Effect of oligosaccharide fruit crack prevention agent on winter jujube fruit cracking

[0025] Take 100 mg of sodium alginate oligosaccharide (average molecular weight 1500) powder and 10 mg of 1-deoxynojirimycin, add 1 L of clean water and mix thoroughly to prepare fruit crack prevention agent I.

[0026] Experimental location: Huanghua, Hebei

[0027] Fruit variety: Huanghua winter jujube

[0028] Experimental method: 20 jujube trees with uniform growth and robustness were selected, and 4 experimental groups were set up: control group (clear water), oligosaccharide treatment group (100 mg / L), 1-deoxynojirimycin group (10 mg / L), and fruit cracking prevention agent group I. Each experimental group consisted of 5 jujube trees. The treatment was sprayed from the white ripe stage, twice, and the interval between the two sprays was 7 days. 14 days after the second spraying, the number of cracked fruits under natural conditions was investigated. Representative branches in the four directions of east, west, south, and north were selected for each tree. 25 fruits were selected in each direction for investigation, and the cracking rate was calculated. The calculation method of the cracking rate is as follows:

[0029] Fruit cracking rate = number of cracked fruits / number of investigated fruits*100%

[0030] Table 1 Effect of oligosaccharide anti-cracking agent on anti-cracking of winter jujube fruit

[0031]

[0032] The experimental results show that oligosaccharide anti-cracking agents can significantly inhibit the occurrence of fruit cracking in winter jujube fruits. Compared with the control group, the fruit cracking rate has dropped significantly, only 1 / 4 of the control group. At the same time, seaweed oligosaccharide treatment alone also has the effect of preventing fruit cracking, and the fruit cracking rate is less than 1 / 2 of the control group.

[0033] Example 2 Effect of oligosaccharide fruit crack prevention agent on citrus fruit crack prevention

[0034] Take 200 mg of sodium alginate oligosaccharide (average molecular weight 2000) powder and 20 mg of 1-deoxynojirimycin, add 1 L of clean water and mix thoroughly to prepare fruit crack prevention agent II.

[0035] Experimental location: Nanfeng, Jiangxi

[0036] Fruit variety: Mi Guang tangerine

[0037] Experimental method: 15 citrus trees with relatively consistent nutritional conditions were selected, and three experimental groups were set up: control group (clear water), oligosaccharide treatment group (200 mg / L), and fruit cracking inhibitor group II. Each experimental group consisted of 5 citrus trees, and the trees were sprayed three times in succession during the young fruit stage, with an interval of 10 days each time. After each spray concentration was prepared, it was sprayed with an electric sprayer, with the limit of leaf dripping, and about 1 kg of water was used for each tree. Representative branches in the four directions of east, west, south, and north were selected for each tree, and 25 fruits in each direction were selected as basic samples and marked. After the rainy season (late August), the number of cracked and fallen fruits under natural conditions was investigated, and the cracking rate and fruit drop rate were calculated.

[0038] Table 2 Effect of oligosaccharide anti-cracking agent on the anti-cracking effect of citrus fruit

[0039]

[0040] The experimental results show that oligosaccharide anti-cracking agent can significantly inhibit the occurrence of citrus fruit cracking. Compared with the control group, the fruit cracking rate has dropped significantly, about 22% of the control group. At the same time, seaweed oligosaccharide treatment alone also has the effect of preventing fruit cracking, and the fruit cracking rate is less than 40% of the control group. At the same time, the survey results show that oligosaccharide fruit cracking agent also has a good effect in preventing fruit drop during the physiological period. Compared with the control, the fruit drop rate is reduced by 17.2%.

[0041] Example 3 Effect of oligosaccharide fruit cracking inhibitor on loquat fruit cracking prevention

[0042] Take 500 mg of sodium alginate oligosaccharide (average molecular weight 3000) powder and 30 mg of 1-deoxynojirimycin, add 1 L of clean water and mix thoroughly to prepare fruit cracking inhibitor III.

[0043] Experimental location: Meizhou, Guangdong

[0044] Fruit variety: Jiefangzhong loquat

[0045] Experimental method: 20 loquat trees with relatively consistent nutritional conditions were selected, and 5 experimental groups were set up: control group (clear water), oligosaccharide fruit cracking inhibitor group I, II, III, and CaCl2 group (0.05%). Each experimental group consisted of 4 loquat trees, and the agent was applied once during the fruit swelling period. When spraying the agent, the water dripping from the leaves was limited, and about 1 kg of water was used for each plant. The number of cracked fruits was counted one month after the application of the agent. When calculating the cracking rate, representative branches in the four directions of east, west, south, and north were selected for each plant, and 25 fruits were selected in each direction for investigation.

[0046] Table 3 Effect of oligosaccharide anti-cracking agent on loquat fruit anti-cracking

[0047]

[0048] The experimental results showed that the three oligosaccharide anti-cracking agents could significantly inhibit the occurrence of loquat fruit cracking. Compared with the control group, the fruit cracking rate was significantly reduced, about 1 / 4 of that of the control group.

[0049] Example 4 Effect of oligosaccharide fruit crack prevention agent on cherry fruit cracking

[0050] Treatment agent: Fruit crack prevention agent I in Example 1.

[0051] Experimental location: Dalian, Liaoning

[0052] Fruit variety: Mei Zao

[0053] Experimental method: 15 cherry trees with consistent growth and robustness were selected, and three experimental groups were set up: control group (clear water), oligosaccharide treatment group (100 mg / L), and fruit cracking prevention agent group I. Each experimental group consisted of 5 jujube trees, and the treatment was sprayed twice during the hard core stage and the color change and swelling stage. During the harvest period, the number of cracked fruits under natural conditions was investigated and the quality of the fruits was measured. Representative branches in the four directions of east, west, south and north were selected for each tree, and 25 fruits were selected in each direction for investigation, and the cracking rate was calculated. 30 fruits were taken from each group for determination of Vc and TSS content. The Vc content was determined by 2,6-dichloroindophenol titration, and the TSS was determined by refractometer.

[0054] Table 4 Effect of oligosaccharide anti-cracking agent on the anti-cracking effect and quality of cherry fruit

[0055]

[0056] The experimental results show that oligosaccharide fruit cracking inhibitor and sodium alginate oligosaccharide treatment alone can significantly reduce the fruit cracking rate, and at the same time improve the quality of the fruit during the harvest period, with both Vc and soluble solids content increased.

[0057] Example 5 Effect of oligosaccharide fruit crack inhibitor on litchi fruit cracking

[0058] Treatment agent: Fruit crack prevention agent I in Example 1.

[0059] Experimental location: Zhaoqing, Guangdong

[0060] Fruit variety: glutinous rice cake

[0061] Experimental method: 15 litchi trees with uniform growth and robustness were selected, and three experimental groups were set up: control group (clear water), oligosaccharide treatment group (100 mg / L), and fruit cracking inhibitor group I. Each experimental group consisted of 5 litchi trees. Spraying began at the young fruit stage and was continued twice with an interval of 14 days. The number of cracked fruits under natural conditions was investigated when the top of the fruit turned red during the color change period. Representative branches in the four directions of east, west, south and north were selected for each tree. 25 fruits were selected in each direction for investigation and marking, and the cracking rate was calculated. 60 fruits were taken from each group at harvest time, of which 20 fruits were used for the determination of hardness on the harvest day, and the remaining 40 fruits were refrigerated and stored. After 15 days of storage, the fruit browning rate was calculated.

[0062] Litchi hardness was tested using a texture analyzer. Litchi of the same size and quality was selected, peeled, split into two, pits removed, and placed on the test bench with the flesh opening facing downward. A 25mm cylindrical probe was used, and the test parameters were: pre-test speed 100mm / min, test speed 60mm / min, upward speed after compression 100mm / min, compression deformation 40%, and trigger force 0.3N. 20 fruits were tested for each group of samples and the average value was taken.

[0063] Browning rate = number of browned fruits / total number of fruits*100%

[0064] Table 5 Effect of oligosaccharide anti-cracking agent on the anti-cracking effect and quality of litchi fruit

[0065]

[0066] The experimental results show that oligosaccharide fruit cracking inhibitor and sodium alginate oligosaccharide treatment alone can significantly reduce the cracking rate of litchi fruit. At the same time, it can also increase the hardness of the fruit during the harvest period, reduce the browning rate of the fruit during the storage period, and improve the storage resistance of the fruit.

[0067] Example 6 Effect of oligosaccharide fruit crack inhibitor on the prevention and control of tomato fruit cracking

[0068] Treatment agent: Fruit crack prevention agent I in Example 1.

[0069] Experimental location: Dalian, Liaoning

[0070] Fruit variety: Tailai No. 3

[0071] Experimental methods:

[0072] 60 tomato plants with consistent growth were selected and three experimental groups were set up: control group (clear water), oligosaccharide single treatment group (100 mg / L), fruit cracking agent group I, each experimental group had 20 tomato plants, fruit cracking agent was used twice in the green ripening stage and color change stage of the fruit, the number of cracked fruits was counted in the red ripening stage, and 5 fruits were randomly selected from each plant. 20 fruits were taken from each group, and 3 points were randomly selected around the diameter at a distance of 120° from the middle abdomen of the fruit. Peel samples with equal area of ​​intact peel were taken, with a thickness of 2 mm, and stored in liquid nitrogen for quick freezing. The cell wall polysaccharide composition and cell wall degrading enzyme activity of each sample were determined.

[0073] The contents of pectin and proto-pectin were determined by the m-hydroxybiphenyl method, the cellulose content was determined by the anthrone method, and the polygalacturonase PG, pectinesterase PE, pectin lyase PL and cellulase CEL were determined by the colorimetric method.

[0074] Table 6 Effect of oligosaccharide anti-cracking agent on the anti-cracking effect of tomato fruit

[0075]

[0076] Table 7 Effect of oligosaccharide crack inhibitor on cell wall composition of tomato fruit

[0077]

[0078] The experimental results show that oligosaccharide fruit cracking inhibitor and sodium alginate oligosaccharide treatment alone can significantly reduce the cracking rate of tomato fruit. At the same time, it can also affect the cell wall composition of the fruit, reduce the accumulation of soluble pectin, increase the cellulose content, and inhibit the activity of cell wall polysaccharide degrading enzymes.

[0079] Example 7 Effect of oligosaccharide fruit crack prevention agent on the prevention and control of grape fruit cracking

[0080] Treatment agent: Fruit crack prevention agent I in Example 1.

[0081] Experimental location: Panjin, Liaoning

[0082] Fruit variety: Rose fragrance

[0083] Experimental methods:

[0084] Twenty grape plants with strong tree vigor and similar growth were selected and divided into four treatment groups: control group, sodium alginate oligosaccharide group, fruit crack prevention agent I group and CaCl2 treatment group (0.1%), with 5 plants in each treatment. Ten crack-free fruit clusters were marked in each treatment and the agent was sprayed during the fruit color change period. 24 hours after treatment, the grape clusters were sprayed with a shade net to simulate rainy weather and the spraying was continued for 6 hours. After 3 days of simulated rainfall, the fruit cracking rate of the marked clusters was investigated.

[0085] Table 8 Effect of oligosaccharide anti-cracking agent on grape fruit anti-cracking

[0086]

[0087] The experimental results show that oligosaccharide fruit cracking inhibitor can be used before heavy rain, which can effectively alleviate the fruit cracking caused by long-term rainfall. Sodium alginate oligosaccharide treatment alone has similar effects, which can significantly reduce the cracking rate of grape fruit, and the effect is better than CaCl2 treatment.

[0088] Example 8 Effect of oligosaccharide fruit crack prevention agent on fruit cracking of Actinidia arguta

[0089] Treatment agent: Fruit crack prevention agent I in Example 1.

[0090] Experimental location: Dandong, Liaoning

[0091] Fruit variety: Longcheng No. 2

[0092] Experimental methods:

[0093] Fifteen kiwifruit trees with strong tree vigor and similar growth were selected and divided into three treatment groups: control group, sodium alginate oligosaccharide group, and fruit cracking inhibitor group I, with 5 trees in each treatment. The drugs were applied 4 weeks and 2 weeks before harvest at maturity, for a total of 2 applications. The number of fruit drops and cracks of kiwifruit in each treatment from spraying to harvest and 7 days after harvest was counted and investigated. The side branches in the four directions of east, west, south and north were investigated for each tree, and 25 fruits were marked on each side branch.

[0094] Table 9 Effect of oligosaccharide anti-cracking agent on the anti-cracking effect of Actinidia arguta fruit

[0095]

[0096] Experimental results: Oligosaccharide fruit crack inhibitor can significantly reduce the fruit cracking rate of Actinidia arguta during the ripening period. The treated group is less likely to drop the fruit during the ripening period, which can extend the fruit ripening and picking period and alleviate the contradiction of rotting caused by concentrated fruit marketing.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fruit cracking preventive agent, characterized in that: The solvent of the fruit crack prevention agent is water, and the effective ingredients are composed of sodium alginate oligosaccharide and 1-deoxynojirimycin; The concentration of the sodium alginate oligosaccharide is 100-500 mg / L; the concentration of the 1-deoxynojirimycin is 10-30 mg / L.

2. The fruit cracking inhibitor according to claim 1, characterized in that The average molecular weight of the sodium alginate oligosaccharide is 500-3000Da.

3. The method for using the fruit cracking inhibitor according to any one of claims 1 to 2, characterized in that: Spray the fruit anti-cracking agent on the fruit surface during the bud stage, fruit swelling stage, color change stage or 6h-48h before heavy rain; alternatively, spray the fruit anti-cracking agent on the fruit surface 7-20 days before harvest.

4. The method of use according to claim 3, characterized in that: The spraying times are 1 to 5 times.

5. The method of use according to claim 3, characterized in that: The dosage of fruit crack prevention agent for each fruit tree is 0.2-2 kg.

6. Use of the fruit crack prevention agent according to any one of claims 1 to 2 in preventing and controlling fruit cracking and fruit falling and in keeping fruits fresh on the tree.

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