Method for improving polysaccharide of polygonatum cyrtonema by using LED light source

Abstract

The present application belongs to the technical field of Chinese herbal medicine cultivation, and specifically relates to a method for improving Polygonatum cyrtonema Hua polysaccharide by using an LED light source. The present application provides different LED light sources for irradiation of Polygonatum cyrtonema seedlings, and finds that under the condition of a light quality ratio of 2:3, blue-white, green-white, yellow-white, red-white or ultraviolet (UV-B) white light can all promote the accumulation and improvement of Polygonatum cyrtonema polysaccharide in Polygonatum cyrtonema Hua, and the improvement degree of red-white light is the highest. The irradiation time is controlled to be 12 h per day, the indoor temperature is controlled to be (25-31) DEG C, the irradiation time is 30-90 days, and the optimal irradiation time is 60 days. The method of the present application is simple in operation, high in efficiency and low in cost, is beneficial to realize large-scale planting of Polygonatum cyrtonema Hua, is beneficial to improve the yield and quality of Polygonatum cyrtonema polysaccharide, and further meets the demand of the medical field for high-quality Polygonatum cyrtonema polysaccharide.

Description

Technical Field

[0001] This invention belongs to the field of Chinese medicinal herb cultivation technology. Specifically, this invention relates to a method for enhancing the polysaccharide content of Polygonatum odoratum using LED light sources. Background Technology

[0002] Polygonatum multiflorum ( Polygonatum cyrtonema Polygonatum multiflorum (Hua) is a perennial herb belonging to the genus Polygonatum in the family Asparagaceae. Because its rhizome resembles ginger, it is also known as "ginger-shaped Polygonatum." It contains abundant active ingredients, such as Polygonatum polysaccharides, steroidal saponins, flavonoids, and alkaloids. Due to its anti-tumor, antioxidant, anti-aging, anti-fatigue, blood sugar and lipid-lowering, anti-atherosclerotic, and antibacterial and anti-inflammatory activities, Polygonatum multiflorum has become an important traditional Chinese medicine. Polygonatum polysaccharides are one of the main active ingredients in Polygonatum multiflorum, exhibiting significant antioxidant, immune-regulating, memory-enhancing, and sleep-improving effects. Therefore, increasing the content of Polygonatum polysaccharides in Polygonatum multiflorum is of great significance.

[0003] The light environment is one of the important ecological factors for plant growth and development. Among them, light quality is an important regulatory factor affecting plant growth and development. Studies have shown that plants are sensitive to the spectrum of 290-850 nm, specifically including ultraviolet, blue, green, yellow, and red light. Different wavelengths of light have different effects on the growth, development, and quality components of different plants.

[0004] In recent years, the application of LED light sources has become increasingly widespread. In agriculture, LED lights offer advantages such as energy saving, environmental friendliness, long lifespan, and adjustable spectrum. In particular, their spectral adjustment capability allows for the selection of specific light quality ratios according to the growth needs of crops, effectively promoting plant growth, flowering, and fruiting. For example, LED blue light can significantly increase the content of solanetarin in eggplant peel, generally by 50%, with a maximum increase of 73.6%. Using LED red light or a red-blue combination can increase the content of flavonoids and total phenols in tomatoes. The accumulation of lycopene and anthocyanins in tomato fruits is influenced by LED blue light treatment. Enhanced UV-B radiation increases the production of flavonoids in plants. Green light directly acts on chloroplasts, thus affecting plant growth and development. CN201810196985.8 discloses the induction of polysaccharide content in *Anoectochilus roxburghii* using LED red light. The method employed LED red light as the light source, with a light intensity of 600-1200 lx and a photoperiod of 12 h·d⁻¹, controlled at an indoor temperature of (25±1)℃, and an irradiation time of 3-6 months. The polysaccharide content reached a maximum of 26.06% after 90 days of cultivation at 1000 lx, significantly increasing the polysaccharide content. However, the effects of LED light on the accumulation of active substances in other plants, especially other traditional Chinese medicines, require further research. Summary of the Invention

[0005] This invention aims to provide a method for increasing the content of Polygonatum polysaccharides in Polygonatum multiflorum using LED light sources. By precisely controlling the spectrum, light intensity, and illumination time of the LED light source, the physiological metabolic processes of Polygonatum multiflorum are effectively promoted, thereby increasing the synthesis and accumulation of Polygonatum polysaccharides within the plant. Therefore, the purpose of this invention is to provide an efficient, environmentally friendly, and controllable technical means to optimize the cultivation conditions of Polygonatum multiflorum, increase the content of its active ingredients, and enhance its efficacy.

[0006] This invention provides a method for enhancing the polysaccharide content of Polygonatum multiflorum using an LED light source, the method comprising:

[0007] (4) Provide healthy Polygonatum seedlings free from diseases and pests;

[0008] (5) Irradiate the Polygonatum seedlings with a combination of blue-white, green-white, yellow-white, red-white or ultraviolet (UV-B) white LED lights;

[0009] (6) Light and temperature management: The light exposure time is controlled to 12 hours per day, and the indoor temperature is controlled at (25±1)℃.

[0010] In this invention, the ratio of the number of LED lamps with different light qualities to white light is 2:3, wherein the white LED has a wavelength of 453nm, the supplementary blue LED has a wavelength of 464nm, the green LED has a wavelength of 519nm, the yellow LED has a wavelength of 595nm, the red LED has a wavelength of 660nm, and the ultraviolet (UV-B) lamp has a wavelength of 280-320nm.

[0011] In this invention, a 2:3 red-white light combination is preferably used to irradiate Polygonatum.

[0012] In this invention, the light treatment time is 30-90 days, preferably 60 days.

[0013] In this invention, watering is carried out appropriately according to the transplanting time. If it is during the high temperature period in summer, watering is carried out once every 5 days. If it is during spring and autumn, the watering interval can be appropriately increased according to the soil moisture.

[0014] This invention can improve the growth efficiency of Polygonatum: LED light source has high light efficiency, which can not only save energy, but also the selectivity of irradiation wavelength will be beneficial to the growth of Polygonatum multiflorum.

[0015] This invention utilizes an environmentally friendly LED light source: LED light sources consume little power and have minimal environmental impact. LED light sources also have a long lifespan, reducing the frequency of replacement and disposal, and thus lowering the burden on the environment.

[0016] This invention utilizes the highly adjustable LED light source: LED plant lighting equipment offers advantages such as soft and uniform light, effectively avoiding localized overheating issues associated with traditional light sources and ensuring the healthy growth of Polygonatum odoratum. LED plant lighting can precisely control light intensity, spectral distribution, and illumination time according to the growth needs of Polygonatum odoratum, optimizing lighting conditions, promoting photosynthesis and metabolism, and thereby increasing the content of Polygonatum odoratum polysaccharides. Beneficial effects

[0017] This invention optimizes plant photosynthesis by using LED light sources of specific wavelengths, thereby increasing the yield of Polygonatum polysaccharides. This method is safe and efficient, resulting in a higher accumulation of Polygonatum polysaccharides compared to conventional cultivation methods.

[0018] This invention can save on planting costs: LED plant lighting uses the semiconductor light-emitting principle, which has high energy conversion efficiency and can significantly reduce energy consumption compared to traditional light sources, thus helping to reduce planting costs. Furthermore, the high efficiency, long lifespan, and low maintenance requirements of LED light sources can save substantial maintenance and energy costs over long-term use.

[0019] The method of this invention is simple to operate, highly efficient and low in cost, which is conducive to the large-scale cultivation of Polygonatum multiflorum and also to improving the yield and quality of Polygonatum polysaccharides, further meeting the demand of the pharmaceutical field for high-quality Polygonatum polysaccharides. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. Unless otherwise specified, the equipment and reagents used in the embodiments and experimental examples are commercially available. Unless otherwise stated, all reagents used in this invention are analytical grade reagents. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Example 1:

[0021] 1. Seedling selection and transplanting: Select disease-free and pest-free two-year-old Polygonatum odoratum seedlings for transplanting. Disinfect the roots of the two-year-old Polygonatum odoratum seedlings with a 1% carbendazim solution, place them in a cool place until there is no dripping water, and then transplant them into plastic pots. Use yellow clay soil and substrate with a volume ratio of 1:3, mix them together and plant them. Transplant 1-2 Polygonatum odoratum seedlings into each pot and conduct light tests with different LED light sources.

[0022] 2. Light Quality Processing: Six different light quality processes were set up, with the ratio of different light quality LEDs to white light LEDs being 2:3. These included blue-white, green-white, yellow-white, red-white, UV-B white, and pure white light. The white LED wavelength was 453nm, the supplementary blue LED wavelength was 464nm, the green LED wavelength was 519nm, the yellow LED wavelength was 595nm, the red LED wavelength was 660nm, and the UV-B wavelength was 280-320nm.

[0023] 3. Light and temperature management: The lighting time is controlled to 12 hours per day (7:00-19:00), and the indoor temperature is controlled at (25±1)℃.

[0024] 4. Watering Management: Since the transplanting time is during the high temperature period of summer, water once every 5 days. In spring and autumn, the watering interval can be appropriately increased according to the soil moisture.

[0025] Comparative Example 1:

[0026] The selection and transplanting of seedlings, light, temperature management, and watering management are the same as in Example 1. The difference from Example 1 is that the light quality treatment conditions are different.

[0027] Six different light quality treatments were set up in the light quality processing, with the ratio of the number of LED tubes of different light quality to white light being 3:2. These six treatments were blue-white, green-white, yellow-white, red-white, ultraviolet (UV-B) white, and pure white light. The wavelength of the white LED was 453nm, the wavelength of the supplementary blue LED was 464nm, the wavelength of the green LED was 519nm, the wavelength of the yellow LED was 595nm, the wavelength of the red LED was 660nm, and the wavelength of the ultraviolet (UV-B) lamp was 280-320nm.

[0028] result:

[0029] Polysaccharide content was determined in the Polygonatum odoratum seedlings treated in Example 1 and Comparative Example 1: The growth changes of Polygonatum odoratum plants were observed and recorded. Two months later, until all leaves fell off naturally, three plants were randomly selected from each treatment group, sliced, dried at 60 degrees Celsius, and then powdered. Polysaccharide content was determined by water extraction and alcohol precipitation according to the Chinese Pharmacopoeia (2020 edition) using the sulfuric acid-anthrone method.

[0030] After two months of treatment with different light sources, the polysaccharide content of Polygonatum multiflorum was determined to be beneficial to the accumulation of polysaccharides after irradiation with different LED light sources. Different wavelengths of light had different effects on the polysaccharide content: pure white light treatment resulted in a polysaccharide content of 7.375%; 40% blue light supplementation resulted in 8.618%; and 60% blue light supplementation resulted in 7.925%. 40% green light supplementation resulted in 9.295%; and 60% blue light supplementation resulted in 6.912%. 40% yellow light supplementation resulted in 10.192%; and 60% yellow light supplementation resulted in 8.313%. 40% UV-B light supplementation resulted in 10.764%; and 60% UV-B light supplementation resulted in 7.235%. The optimal concentration of polysaccharides in Polygonatum odoratum was 11.751% when supplemented with 40% red light (red + white, light quality ratio 2:3). Further increases in red light reduced polysaccharide accumulation. Therefore, supplementing with appropriate amounts of LED light can effectively increase polysaccharide content. Supplementing with more than 50% different light qualities increases plant stress and affects polysaccharide accumulation in the rhizomes of Polygonatum odoratum. Thus, supplementing with 40% light source has a better effect on polysaccharide accumulation in the rhizomes of Polygonatum odoratum. Supplementing with different light sources can increase polysaccharide content by 15%–60%, significantly improving the polysaccharide content and enhancing the medicinal value of Polygonatum odoratum.

[0031] Table 1. Polysaccharide content of Polygonatum sibiricum under different light quality treatments

[0032]

[0033] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted herein.

Claims

1. A method for enhancing the polysaccharide content of Polygonatum multiflorum using an LED light source, characterized in that, The method includes: We provide healthy Polygonatum seedlings free from diseases and pests; The Polygonatum seedlings were treated with a 2:3 combination of red and white light. Light and temperature management: The lighting time is controlled to 12 hours per day, and the indoor temperature is controlled at 25 ± 1℃. The white LED has a wavelength of 453nm, and the red LED has a wavelength of 660nm; the light treatment time is 30-90 days.

2. The method for enhancing the polysaccharide content of Polygonatum odoratum using an LED light source according to claim 1, characterized in that, The light treatment period is 60 days.

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