Method for improving yellow heart degree of Chinese cabbage by exogenously applying asparagine and application of method

Abstract

The invention discloses a method for improving the yellow heart degree of Chinese cabbage by exogenously applying asparagine and application of the method, and aims to improve the carotenoid content of brassica plants and the yellow heart degree of the brassica plants. In particular discloses application of asparagine or salt thereof or solvates thereof in improving carotenoid content of brassica plants and yellow heart degree of brassica plants, and the substance is applied to the brassica plants, so that the carotenoid content can be improved, the yellow heart degree can be increased, and the substance can be applied to agricultural production.

Description

Technical Field

[0001] The invention relates to the technical field of molecular biology, in particular to a method for improving the yellow heart degree of Chinese cabbage by exogenously applying asparagine and an application thereof. Background Art

[0002] Chinese cabbage (Brassica rapa L.ssp.pekinensis) originates in my country, with an annual planting area of approximately 27 million mu (approximately 1.5 million hectares). It is one of the largest cultivated major vegetable crops in my country and plays an important role in year-round vegetable supply and emergency response. Yellow-heart Chinese cabbage is increasingly in demand due to its bright yellow bulb leaves, good commercial value, high lutein content, and rich nutrition. Although yellow-heart Chinese cabbage has been available in my country since ancient times, the market did not particularly demand the degree of yellowness of the Chinese cabbage bulb, and therefore this trait did not receive sufficient attention. In recent years, due to the high demand for yellow-heart traits in kimchi processing, Japan and South Korea have improved the yellowness of the Chinese cabbage bulb leaves, quality, and bolting resistance, and now occupy a majority of the market share. Therefore, the cultivation of fresh yellow-heart, high-quality Chinese cabbage is extremely urgent. How to improve the degree of yellowness of Chinese cabbage bulbs is a technical problem faced by those in this field. Summary of the Invention

[0003] The technical problem solved by the present invention is to improve the yellowing degree and carotenoid content of Brassica plants. The use of the above-mentioned substance in Brassica plants can improve the carotenoid content and increase the yellowing degree of the heart.

[0004] In a first aspect, the present invention provides a method for increasing the yellowness and carotenoid content of Brassica plants, the method comprising the step of applying asparagine or a salt thereof, or a product containing asparagine or a salt thereof, to the Brassica plants during cultivation of the Brassica plants.

[0005] In another aspect, the present invention provides a method for cultivating a Brassica plant, the method comprising the step of applying asparagine or a salt thereof, or a product comprising asparagine or a salt thereof, to the Brassica plant.

[0006] In certain embodiments, the product includes a composition, a coating agent, and / or a plant growth promoter.

[0007] In certain embodiments, it is characterized in that the administration time is from the rosette stage to the heading stage.

[0008] In certain embodiments, the asparagine is administered in an amount of 100-300 mg per Brassica plant.

[0009] In certain embodiments, the amount administered is 200 mg per Brassica plant.

[0010] In certain embodiments, the asparagine is administered at a concentration of 20-60 mg / mL.

[0011] In certain embodiments, the administered concentration is 40 mg / mL.

[0012] In certain embodiments, the asparagine is administered twice a week.

[0013] In another aspect, the present invention provides a composition comprising asparagine or a salt thereof, or a solvate thereof, or any combination thereof.

[0014] In certain embodiments, the composition is a core-coating agent or a plant growth-promoting agent.

[0015] In certain embodiments, the time of administration is 17:00-18:00.

[0016] In certain embodiments, the time of administration is 17:01, 17:02, 17:03, 17:04, 17:05, 17:06, 17:07, 17:08, 17:09, 17:10, 17:11, 17:12, 17:13, 17:14, 17:15, 17:16, 17:17, 17:18, 17:19, 17:20, 17:21, 17:22, 17:23, 17:24, 17:25, 17:26, 17:27, 17:28, 17:29, 17:30 29. 17:30, 17:31, 17:32, 17:33, 17:34, 17:35, 17:36, 17:37, 17:38, 17:39, 17:40, 17:41, 17:42, 17:43, 17:44, 17:45, 17:46, 17:47, 17:48, 17:49, 17:50, 17:51, 17:52, 17:53, 17:54, 17:55, 17:56, 17:57, 17:58, 17:59, 18:00.

[0017] Use of asparagine or its salt or solvate thereof in increasing the carotenoid content and / or increasing the yellowing degree of Brassica plants.

[0018] In another aspect, the present invention provides a composition comprising asparagine or a salt thereof, or a solvate thereof, or any combination thereof;

[0019] In certain embodiments, the composition is used to improve agronomic traits in plants.

[0020] In certain embodiments, the improving an agricultural trait comprises increasing the degree of yellow heart.

[0021] In certain embodiments, the composition is applied to plants during the rosette to head stage.

[0022] In certain embodiments, the composition is formulated as a solid preparation or a liquid preparation.

[0023] In certain embodiments, the composition further comprises excipients and / or additives.

[0024] In certain embodiments, the adjuvant comprises an agriculturally or horticulturally acceptable diluent, filler, solvent, spontaneity promoter, carrier, emulsifier, dispersant, thickener, binder, or any combination thereof.

[0025] In certain embodiments, the additive comprises an agriculturally or horticulturally acceptable preservative, adjuvant, synergist, microbial additive, antifreeze agent, or any combination thereof.

[0026] In certain embodiments, the composition is a liquid formulation.

[0027] In certain embodiments, the liquid formulation comprises an emulsifiable concentrate, a soluble concentrate, an oily concentrate, a dispersible concentrate, an electrostatic spray concentrate, a suspension, a microcapsule suspension, an oil suspension, a suspoemulsion, an aqueous emulsion, a microemulsion, a nanoemulsion, or any combination thereof.

[0028] In certain embodiments, in the liquid formulation, the asparagine is in an agriculturally or fertilizer-acceptable carrier.

[0029] In certain embodiments, the content of asparagine in the liquid formulation is 20-60 mg / mL.

[0030] In certain embodiments, in the liquid formulation, the content of asparagine is 40 mg / mL.

[0031] In certain embodiments, the liquid formulation is used for root dipping, foliar spraying, spraying, composting, seed soaking, coating, field flooding, drip irrigation of plants or plant organs, painting plants or plant organs, or dripping plants or plant organs, or any combination thereof.

[0032] In certain embodiments, the composition is a solid formulation.

[0033] In certain embodiments, in the solid formulation, the asparagine is in an agriculturally or fertilizer-acceptable carrier.

[0034] In certain embodiments, the solid formulation is used for composting, applying to plants or plant organs, or any combination thereof.

[0035] In certain embodiments, the solid formulation is used to formulate the liquid formulation described above.

[0036] In certain embodiments, the solid formulation or liquid formulation is selected from a foliar treatment formulation, a soil treatment formulation, a seed treatment formulation, a stem treatment formulation, a root treatment formulation, or any combination thereof.

[0037] In certain embodiments, the plant is a rosette to head stage plant.

[0038] In another aspect, the present invention provides a core-coating agent, which comprises any of the above compositions.

[0039] In another aspect, the present invention provides a plant growth promoting agent, comprising any one of the above compositions.

[0040] In another aspect, the present invention provides a method for cultivating Brassica plants, comprising the step of applying asparagine or a salt thereof, any of the above compositions, the above-mentioned core-coating agent, and the above-mentioned plant growth promoter to Brassica plant tissues and / or organs.

[0041] In certain embodiments, the applying comprises one or more of root dipping, foliar spraying, spraying, composting, seed soaking, coating, flooding, dripping plants or plant organs, painting plants or plant organs, and dripping plants or plant organs.

[0042] In certain embodiments, the administration is performed from the rosette stage to the head stage.

[0043] In certain embodiments, the asparagine is used at a concentration of 20-60 mg / mL in the foliar spraying.

[0044] In certain embodiments, the asparagine is used at a concentration of 40 mg / mL in the foliar spraying.

[0045] In certain embodiments, in the foliar spraying, the amount of the foliar spraying is 5 mL / plant.

[0046] In certain embodiments, the foliar spraying is performed at a frequency of 2 times per week.

[0047] In certain embodiments, the methods are used to obtain Brassica plants that are high in carotenoids.

[0048] In certain embodiments, the carotenoid content of the high-carotenoid Brassica plant is higher than the carotenoid content of the Brassica plant obtained without applying the composition, the core-coating agent, or the plant growth promoter.

[0049] In certain embodiments, the methods are used to obtain Brassica plants with a high degree of yellow core.

[0050] In certain embodiments, the high yellowing degree of the Brassica plant has a higher yellowing degree than the yellowing degree of the Brassica plant obtained without applying the composition, the heart-encapsulating agent, or the plant growth-promoting agent.

[0051] In certain embodiments, the yellow core degree is the area ratio or volume ratio of the yellow region.

[0052] In certain embodiments, the high yellowing degree is a high yellowing degree during the heading stage.

[0053] In certain embodiments, the carotenoid content is a high carotenoid content at the heading stage.

[0054] On the other hand, the present invention provides a method for increasing the degree of yellowing of the heart of Brassica plants, which comprises applying asparagine or its salt, any of the above compositions, the above-mentioned heart-coating agent, and the above-mentioned plant growth promoter to the Brassica plants during cultivation of the Brassica plants.

[0055] In certain embodiments, the Brassica plant comprises Brassica plant tissue and / or organs.

[0056] In certain embodiments, the Scape plant tissue and / or organ comprises roots, stems, leaves, flowers, fruits, seeds, or any combination thereof.

[0057] In certain embodiments, the applying comprises one or more of root dipping, foliar spraying, spraying, composting, seed soaking, coating, flooding, dripping plants or plant organs, painting plants or plant organs, and dripping plants or plant organs.

[0058] In certain embodiments, the administration is performed from the rosette stage to the head stage.

[0059] In certain embodiments, the asparagine is used at a concentration of 20-60 mg / mL in the foliar spraying.

[0060] In certain embodiments, the asparagine is used at a concentration of 40 mg / mL in the foliar spraying.

[0061] In certain embodiments, in the foliar spraying, the amount of the foliar spraying is 5 mL / plant.

[0062] In certain embodiments, the foliar spraying is performed at a frequency of 2 times per week.

[0063] In certain embodiments, the methods are used to obtain Brassica plants that are high in carotenoid content.

[0064] In certain embodiments, the carotenoid content of the high-carotenoid Brassica plant is higher than the carotenoid content of the Brassica plant obtained without applying the composition, the core-coating agent, or the plant growth promoter.

[0065] In certain embodiments, the methods are used to obtain Brassica plants with a high degree of yellow core.

[0066] In certain embodiments, the high yellowing degree of the Brassica plant is higher than the yellowing degree of the Brassica plant obtained without applying the composition, the heart-encapsulating agent, or the plant growth-promoting agent.

[0067] In certain embodiments, the yellow core degree is the area ratio or volume ratio of the yellow region.

[0068] In certain embodiments, the high yellowing degree is a high yellowing degree during the heading stage.

[0069] In certain embodiments, the carotenoid content is a high carotenoid content at the heading stage.

[0070] In another aspect, the present invention provides use of any of the above-described compositions, the above-described core-coating agent, and the above-described plant growth promoter in increasing the carotenoid content and the degree of yellowing of the core of Brassica plants.

[0071] In certain embodiments, the yellow core degree is the area ratio or volume ratio of the yellow region.

[0072] In certain embodiments, the plant is a plant leaf.

[0073] In certain embodiments, the asparagine is L-asparagine.

[0074] In certain embodiments, in any of the above compositions, the above-mentioned core-coating agents, the above-mentioned plant growth promoters, the above-mentioned methods or the above-mentioned uses, the Brassica plant is selected from Chinese cabbage, Chinese cabbage, Chinese cabbage heart, or any combination thereof.

[0075] In certain embodiments, the Chinese cabbage is selected from Tianjin Qingmaye, Yutian Baojian Chinese cabbage, Jincai No. 3, Jiaozhou Chinese cabbage, Fushan Baotou, Beijing New No. 3, Taiyuan Erbaotou, Luoyang Dabaotou, Beijing Xiaoza No. 56, Lubai No. 6, Chundajiang, Jinguan, Ziyi, or any combination thereof.

[0076] In certain embodiments, the pakchoy is selected from Shanghai green, Suzhou green, Aijiaohuang, Jianganbai, Hangzhou Youdonger, Maertou, or any combination thereof.

[0077] In certain embodiments, the Chinese cabbage is selected from Sijiu Chinese cabbage, Youqing Beet Chinese cabbage, Liuye Zao Chinese cabbage, Qingliuye Chinese cabbage, Huangye Xinxin, Chixin 2, Sanyueqing, Hongfu 1, Yueyou 1, or any combination thereof. In another aspect, the present invention provides a use of asparagine or a salt thereof, or a solvate thereof, for increasing the carotenoid content and the degree of yellowing of the heart of a Brassica plant.

[0078] In certain embodiments, the yellow core degree is the area ratio or volume ratio of the yellow region.

[0079] In certain embodiments, the plant is a plant leaf.

[0080] In certain embodiments, the asparagine is L-asparagine.

[0081] In certain embodiments, the Brassica plant is selected from Chinese cabbage, pakchoy, choy sum, or any combination thereof.

[0082] In certain embodiments, the Chinese cabbage is Chinese cabbage Beijing New No. 3.

[0083] In certain embodiments, the use is to prepare a related product. The product is a composition.

[0084] In certain embodiments, the composition further comprises one or more chemical drugs.

[0085] In certain embodiments, the composition further comprises an agriculturally or horticulturally acceptable diluent, filler, solvent, spontaneity promoter, carrier, emulsifier, preservative, dispersant, antifreeze agent, thickener, adjuvant, synergist, microbial additive, binder, plant growth regulator or any combination thereof.

[0086] In certain embodiments, the dispersants and / or emulsifiers include all nonionic, anionic or cationic dispersants conventionally used in the formulation of active agricultural chemical ingredients.

[0087] In certain embodiments, examples of preservatives include, but are not limited to, dichlorophen and benzyl alcohol hemiformal.

[0088] In certain embodiments, examples of the binder include, but are not limited to, starch, polyvinyl alcohol, and gelatin.

[0089] In certain embodiments, examples of the dispersant include, but are not limited to, sodium dodecylbenzenesulfonate and sodium butylnaphthalenesulfonate.

[0090] In certain embodiments, examples of the stabilizer include, but are not limited to, white carbon black, talc, and dicyandiamide.

[0091] In certain embodiments, examples of the enhancer include, but are not limited to, sodium nitrophenolate and vitamin C.

[0092] In certain embodiments, examples of the filler include, but are not limited to, volcanic rock powder and ammonium bicarbonate.

[0093] In certain embodiments, examples of the plant growth regulator include, but are not limited to, 28-homobrassinolide, brassinolide, and natural pigments (such as β-carotene).

[0094] In certain embodiments, examples of agriculturally or horticulturally acceptable diluents include aqueous solutions of monosaccharides, polysaccharides, molasses, gums, lignin sulfonates, glycerol, sorbitol, propylene glycol, water, vegetable oils, and mineral oils.

[0095] In certain embodiments, the carrier may include alginate beads, durum wheat flour particles, silica, clay, clay minerals, gelatin, cellulose, cellulose derivatives, calcium chlorite, talc solids, diatomaceous earth, activated carbon, animal bone charcoal, peat, vermiculite, lignite, sawdust, and / or corn cobs.

[0096] In certain embodiments, the chemical is selected from the group consisting of herbicides, pesticides, antimicrobial agents, antiviral agents, plant growth regulators, antibiotics, fertilizers, or any combination thereof.

[0097] In certain embodiments, the antibacterial agent is selected from propamocarb hydrochloride, carbendazim, fluazinam, thiophanate-methyl, pentachloronitrobenzene, thiram, fosetyl-aluminum, metalaxyl-M, metalaxyl-M fludioxonil, or any combination thereof.

[0098] Preferably, the insecticide is selected from thiamethoxam, dinotefuran, lambda-cyhalothrin, propylbromide, or any combination thereof.

[0099] In certain embodiments, the fertilizer is selected from urea, ammonium sulfate, Huanzhitian, Antangkeli, potassium dihydrogen phosphate, or any combination thereof.

[0100] In certain embodiments, asparagine is used for foliar spraying to produce the above-mentioned technical effects. Asparagine enters the plant body to exert its effects, and asparagine can be transported to plant leaves or other plant organs through the xylem. Therefore, those skilled in the art can conclude that the corresponding technical effects can be achieved by selecting root soaking, foliar spraying, spraying, composting, seed soaking, coating, field flooding, drip irrigation of plants or plant organs, smearing plants or plant organs, and dripping on plants or plant organs.

[0101] In certain embodiments, the composition is a liquid fertilizer.

[0102] In certain embodiments, in the composition, the asparagine is in a fertilely acceptable carrier.

[0103] In certain embodiments, the liquid fertilizer is a clear liquid fertilizer or a suspension fertilizer.

[0104] In certain embodiments, the liquid fertilizer comprises asparagine in an amount of 20-60 mg / mL. In certain embodiments, the liquid fertilizer comprises asparagine in an amount of 21-59 mg / mL, 22-58 mg / mL, 23-57 mg / mL, 24-66 mg / mL, 25-55 mg / mL, 26-54 mg / mL, 27-53 mg / mL, 28-52 mg / mL, 29-51 mg / mL, 30-50 mg / mL, 31-49 mg / mL, 32-48 mg / mL, 33-47 mg / mL, 34-46 mg / mL, 35-45 mg / mL, 36-44 mg / mL, 37-43 mg / mL, 38-42 mg / mL, 39-41 mg / mL, or 40 mg / mL.

[0105] In certain embodiments, the asparagine content is 40 mg / mL.

[0106] In certain embodiments, the composition is used for one or more of root dipping, foliar spraying, spraying, composting, seed soaking, coating, field flooding, drip irrigation of plants or plant organs, painting plants or plant organs, and dripping plants or plant organs.

[0107] In certain embodiments, the above operation is from the rosette stage to the head stage.

[0108] In certain embodiments, the above operation is 5 mL per plant.

[0109] In certain embodiments, the foliar spray is L-asparagine.

[0110] In certain embodiments, the composition is a solid fertilizer or a powdered fertilizer.

[0111] In certain embodiments, in the composition, the asparagine is in a fertilely acceptable carrier.

[0112] In certain embodiments, the composition is used for composting, applying to plants or plant organs, or any combination thereof.

[0113] In certain embodiments, the powdered fertilizer is used to formulate the liquid fertilizer described above.

[0114] In certain embodiments, the composition is a powder fertilizer, which is used to prepare the above-mentioned liquid fertilizer or solid fertilizer.

[0115] In another aspect, the present invention provides a core-coating agent, which comprises the above composition, the above liquid fertilizer, the above solid fertilizer or powder fertilizer.

[0116] In another aspect, the present invention provides a plant growth promoting agent, comprising the above composition, the above liquid fertilizer, the above solid fertilizer or powder fertilizer.

[0117] In another aspect, the present invention provides a method for cultivating Chinese cabbage, comprising any one of the following:

[0118] (1) The method comprises the steps of applying the above composition, the above liquid fertilizer, the above solid fertilizer, the above core-coating agent and / or the above plant growth promoting agent to Chinese cabbage tissue and / or organs to obtain Chinese cabbage with a high carotenoid content, wherein the carotenoid content of the Chinese cabbage with a high carotenoid content is higher than the carotenoid content of the Chinese cabbage obtained without applying the above or the above products;

[0119] (2) The method comprises the steps of applying the above-mentioned composition, the above-mentioned liquid fertilizer, the above-mentioned solid fertilizer, the above-mentioned heart-coating agent and / or the above-mentioned plant growth-promoting agent to Chinese cabbage tissues and / or organs to obtain Chinese cabbage with a high degree of yellow heart, wherein the degree of yellow heart of the Chinese cabbage with a high degree of yellow heart is higher than the degree of yellow heart of the Chinese cabbage obtained without applying the above-mentioned or the aforementioned products.

[0120] In certain embodiments, the yellow core degree is the area ratio or volume ratio of the yellow region.

[0121] In certain embodiments, the applying comprises one or more of root dipping, foliar spraying, spraying, composting, seed soaking, coating, flooding, dripping plants or plant organs, painting plants or plant organs, and dripping plants or plant organs.

[0122] In certain embodiments, the foliar spraying is 5 mL / plant, twice / week.

[0123] In certain embodiments, the foliar spraying is 5 mL / plant, once every 3.5 days.

[0124] In certain embodiments, the administration is performed from the rosette stage to the head stage.

[0125] In certain embodiments, the high yellowing degree is a high yellowing degree during the heading stage.

[0126] In certain embodiments, the carotenoid content is a high carotenoid content at the heading stage.

[0127] Beneficial effects

[0128] L-Asparagine (L-Asn) is a common amino acid in living organisms and has a wide range of applications. In medicine, it can be used to treat heart disease, liver disease, hypertension, and fatigue. In industry, it can be used as a food additive to enhance the nutritional value and taste of food. In agriculture, it can be used as a plant growth regulator to promote plant growth and improve crop quality.

[0129] The invention discloses a method for increasing the yellowness of Chinese cabbage by exogenously applying asparagine and an application thereof, and solves the technical problem of increasing the carotenoid content and the yellowness of Brassica plants. The invention specifically discloses the use of asparagine or its salts, or solvates thereof, in increasing the carotenoid content and the yellowness of Brassica plants. The use of the above substances in Brassica plants can increase the carotenoid content and the yellowness, and can be used in agricultural production. BRIEF DESCRIPTION OF THE DRAWINGS

[0130] Figure 1 The yellow heart phenotypes of Chinese cabbage in different treatment groups provided in Example 1 of the present invention.

[0131] Figure 2 The total carotenoid content of the heart leaves of Chinese cabbage in different treatment groups provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0132] The present invention will be further described in detail below in conjunction with specific embodiments. The examples provided are only for illustrating the present invention and are not intended to limit the scope of the present invention. The examples provided below can serve as a guide for further improvements by those skilled in the art and are not intended to limit the present invention in any way.

[0133] Unless otherwise specified, the experimental methods in the following examples are conventional methods and were performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials and reagents used in the following examples, unless otherwise specified, were all commercially available.

[0134] The data in the following examples were processed using SPSS 11.5 statistical software. The experimental results were expressed as mean ± standard deviation and tested using One-way ANOVA. P < 0.05 (*) indicated a significant difference, and P < 0.01 (**) indicated a very significant difference.

[0135] Unless otherwise indicated, scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. Furthermore, terms and laboratory procedures related to protein and nucleic acid chemistry, molecular biology, cell and tissue culture, microbiology, and immunology used herein are those widely used in the respective fields and are standard procedures. To facilitate a better understanding of the present invention, definitions and explanations of relevant terms are provided below.

[0136] As used herein, the term "Trp" refers to tryptophan, also known as β-indolylalanine, an organic compound with the chemical formula C 11 H 12 N2O2. Specifically, it refers to L-tryptophan (L-Trp) in the embodiment, and its structural formula is as follows:

[0137]

[0138] As used herein, the term "Asn" refers to aspartic acid, also known as aspartic acid, an organic compound with the chemical formula C4H7NO4. In the examples, it specifically refers to L-asparagine (L-Asn), whose structural formula is as follows:

[0139]

[0140] As used herein, the terms "include", "comprising", "having", "containing", etc. are open-ended terms, meaning including but not limited to.

[0141] As used herein, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. Furthermore, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0142] As used herein, the terms "optionally," "optional," or "optionally" generally mean that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

[0143] As used herein, the term "rosette stage" refers to the transition period from the end of the seedling stage to the beginning of the head stage, and specifically refers to the period from the beginning of the growth of eight true leaves of Chinese cabbage to the beginning of the head stage.

[0144] As used herein, the term "heading stage" refers to the stage in Chinese cabbage when the outer leaves (rosette leaves) stop growing and the heart leaves begin to curl inward to form a head.

[0145] As used herein, the term "yellow heart degree" refers to the degree to which leaves inside the head turn yellow, and is commonly used to evaluate the quality of leafy vegetables such as Chinese cabbage and kale.

[0146] Example 1: Exogenous application of L-asparagine (L-Asn)

[0147] The experimental material was Chinese cabbage variety Beijing New No. 3, which came from the Vegetable Research Institute of Beijing Academy of Agricultural and Forestry Sciences. It was sown and planted at the Sijiqing Farm of the Vegetable Research Institute of Beijing Academy of Agricultural and Forestry Sciences and cultivated and managed in a conventional manner.

[0148] This experiment was divided into three groups: a control group, an L-Asn group (experimental group), and an L-Trp group (the control group was sprayed with H₂O, the L-Trp group was sprayed with L-Trp, and the L-Asn group (experimental group) was sprayed with L-Asn). Each group had five replicates. Previously, we conducted an experiment to screen the optimal L-Asn spraying method. The selected spraying times ranged from 7:00-10:00 AM, 11:00-2:00 PM, and 4:00-7:00 PM; the selected spraying concentration ranged from 10 mg / mL to 80 mg / mL; and the selected spraying frequency ranged from 1 to 7 times per week. Ultimately, we determined the optimal L-Asn spraying method: starting from the rosette stage, evenly spray a 40 mg / mL L-Asn solution onto the cabbage leaves as a mist from 5:00 PM to 6:00 PM, twice weekly, until the heading stage.

[0149] Example 2: Investigation of agronomic traits of different treatment groups

[0150] Chinese cabbage Beijing New 3 (from the Vegetable Research Institute of Beijing Academy of Agricultural and Forestry Sciences) was sown on August 10, 2024, in the Sijiqing Farm of the Vegetable Research Institute of Beijing Academy of Agricultural and Forestry Sciences, and cultivated and managed conventionally. In this experiment, Chinese cabbage Beijing New 3 was randomly divided into 3 groups, namely the control group, the L-Asn group (experimental group), and the L-Trp group (the control group was sprayed with H2O, the L-Trp group was sprayed with L-Trp, and the L-Asn group (experimental group) was sprayed with L-Asn). Each group had 5 plants, and each group had 3 replicates. When Chinese cabbage Beijing New 3 grew to the rosette stage, Between 5:00 PM and 6:00 PM, the experimental group evenly sprayed 5 mL of a 40 mg / mL L-Asn solution (solvent: water) onto the leaves of Chinese cabbage plants. The control group was sprayed with an equal amount of solvent (water) using the same method, and the L-Trp group was sprayed with an equal amount of a 40 mg / mL L-Trp solution (solvent: water) using the same method. All groups were sprayed twice weekly until the head formation stage. Three uniformly growing plants were selected from the treatment groups and measured for plant height, plant spacing, barren weight, net weight, head height, head width, and center column length. Plant height was significantly reduced in plants sprayed with L-Asn compared to those sprayed with H2O or L-Trp, while other agronomic traits showed no significant differences (see Table 1).

[0151] Plant height: From the soil surface to the top of the tallest leaf.

[0152] Plant spacing: the distance between the two farthest leaves.

[0153] Bare weight: The weight of the entire plant (excluding the part below the soil surface).

[0154] Net weight: The weight of the entire leaf ball (excluding the part below the soil surface and the outer leaves).

[0155] Ball height: the vertical height from the base of the ball to the top of the ball.

[0156] Bulb width: The horizontal distance from one edge to the other edge of the widest part of the bulb.

[0157] Center column length: the vertical length from the base to the top of the center column.

[0158] Table 1. Agronomic traits of different treatment groups

[0159]

[0160]

[0161] Example 3: Investigation of yellow heart characteristics and determination of carotenoid content in different treatment groups

[0162] The yellow heart characteristics of Chinese cabbage Beijing New No. 3 at the heading stage in Example 2 were investigated and the carotenoid content was determined as follows:

[0163] Three plants with uniform growth were selected from each treatment group (control group, L-Asn group and L-Trp group) and named H2O-1, H2O-2, H2O-3, L-Asn-1, L-Asn-2, L-Asn-3, L-Trp-1, L-Trp-2 and L-Trp-3, respectively, for investigation of yellow heart traits and determination of carotenoid content.

[0164] The results showed that the yellowing degree of plants increased significantly after spraying L-Asn compared with those after spraying H2O and L-Trp ( Figure 1 , Figure 1 In the experiment, H2O (H2O-1, H2O-2 and H2O-3) was the control group, L-Asn (L-Asn-1, L-Asn-2 and L-Asn-3) was the L-Asn group, and L-Trp (L-Trp-1, L-Trp-2 and L-Trp-3) was the L-Trp group).

[0165] Then, 0.2 g of heart leaves (the innermost 5 cm of the bulb) from the same location in each treatment group were selected, cut into small pieces, and placed in 10 mL of 80% acetone solution. The extract was then immersed in the dark for 24 hours at room temperature. The absorbance of the extract at 470 nm was measured using a DU800 UV spectrophotometer, with three biological replicates for each sample. The carotenoid content was calculated according to the Arnon (1949) method: Carotenoid content = (1000 × OD470 × V / W - 3.27 × Chl a - 104 × Chl b) / 198; where OD470 is the absorbance value on the DU800 UV spectrophotometer; V: total volume of the extract (mL); and W: fresh weight of the leaf (g). The results showed that the carotenoid content of plants sprayed with L-Trp had no significant change compared with that sprayed with H2O; however, the carotenoid content of plants sprayed with L-Asn increased significantly compared with that sprayed with H2O and L-Trp ( Figure 2 , Figure 2 In the experiment, H2O was the control group, L-Asn was the L-Asn group, and L-Trp was the L-Trp group).

[0166] In summary, the present invention provides a method for increasing the degree of yellowing of Chinese cabbage heads by exogenously applying L-Asn, which can simply, safely, economically and efficiently increase the degree of yellowing of Chinese cabbage heads and the carotenoid content. The method can be applied to Chinese cabbage head quality breeding and is of great significance for the study of the molecular mechanism of yellowing formation.

[0167] The present invention has been described in detail above. It will be apparent to those skilled in the art that the present invention may be practiced over a wide range of parameters, concentrations, and conditions without departing from the spirit and scope of the present invention and without unnecessary experimentation. Although specific embodiments have been given herein, it should be understood that further modifications may be made to the present invention. In summary, this application is intended to encompass any variations, uses, or improvements to the present invention, including those made by conventional techniques known in the art that depart from the scope of the present invention. Applications of the essential features may be made within the scope of the following claims.

Claims

1. A method for increasing the yellowness of Brassica plants and / or the carotenoid content, characterized in that: The method comprises the step of applying asparagine or a salt thereof, or a product containing asparagine or a salt thereof, to the Brassica plant during cultivation of the Brassica plant.

2. A method for cultivating Brassica plants, characterized in that: The method comprises the step of applying asparagine or a salt thereof, or a product comprising asparagine or a salt thereof, to a Brassica plant.

3. The method according to claim 1 or 2, wherein: The application is selected from root dipping, foliar spraying, spraying, composting, seed soaking, coating, field flooding, drip irrigation of plants or plant organs, painting plants or plant organs or dripping plants or plant organs, or any combination thereof.

4. The method according to claim 1 or 2, wherein: The application time is from the rosette stage to the heading stage.

5. The method according to claim 1 or 2, wherein: The amount of asparagine applied is 100-300 mg per Brassica plant.

6. The method according to claim 1 or 2, wherein: The asparagine was administered at a concentration of 20-60 mg / mL.

7. The method according to claim 1 or 2, wherein: The frequency of asparagine administration was 2 times per week.

8. The method according to claim 1 or 2, wherein: The application time is 17:00-18:

00.

9. Use of asparagine or a salt thereof, or a solvate thereof for increasing the carotenoid content and / or the degree of yellowing of the heart of a Brassica plant.

10. The method according to claim 1 or 2 or the use according to claim 9, characterized in that The Brassica plant is selected from Chinese cabbage, Chinese cabbage, Chinese cabbage, or any combination thereof.

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