Laser light source and method for increasing content of vitamin C in protected cucumber

Abstract

The invention provides a laser light source and a method for improving the content of vitamin C. The method comprises the steps that red and blue lasers in equal proportion are adopted for supplementing light to the cucumber protected with light, and the illumination intensity of the red and blue lasers reaching top leaves is controlled to be 1-2.0 micromoles * m <-2 > * s <-1 >; the photosynthetic rate of cucumber leaves irradiated by the laser provided by the invention is 30.5 [mu] mol.m <-2 >. S <-1 >, and the photosynthetic rate of the leaves is increased by 13.4%; the vitamin C content of cucumbers is set to be 9.23 mg / 100g, and compared with the vitamin C content of cucumbers which are not irradiated, the vitamin C content of the cucumbers is increased by 32.4%.

Description

Technical Field

[0001] This invention belongs to the field of facility vegetable production technology, specifically relating to a laser light source and a method for increasing the vitamin C content in facility cucumbers using a laser light source. Background Technology

[0002] Cucumber (Cucumis sativus L.) is one of my country's major greenhouse vegetable crops, widely cultivated in northern China's winter and spring solar greenhouses to meet the year-round market demand for fresh vegetables. However, during this period, light intensity is generally weak, and the use of multiple layers of covering in greenhouses for insulation further reduces the light transmittance of the film, thus affecting the photosynthetic efficiency of cucumber leaves. At the same time, the enclosed environment inside the greenhouse leads to poor air circulation, preventing the timely replenishment of CO2 consumed by photosynthesis, resulting in a significant decrease in CO2 concentration. The growing environment for greenhouse cucumbers also presents several factors unfavorable to vitamin C (VC) synthesis.

[0003] The synthesis of vitamin C in plants mainly depends on the L-galactose pathway, also known as the Smirnoff-Wheeler pathway. The starting point of this main pathway is glucose, and L-galactose, as the characteristic intermediate of this pathway, is converted from glucose through the conversion of pentose phosphate. Glucose is produced through photosynthesis in leaves. Low light and low CO2 conditions inhibit photosynthesis and reduce the supply of glucose, the starting material of the L-galactose pathway, thus limiting the synthesis of vitamin C at its source.

[0004] For the cultivation of greenhouse cucumbers, common improvement measures include opening the greenhouse for ventilation to introduce external CO2, artificially applying CO2, and increasing light intensity through supplemental lighting, thereby improving the photosynthetic rate and CO2 assimilation efficiency, and indirectly promoting vitamin C accumulation. However, these methods have significant limitations in practical applications: first, when the outside temperature is low, opening the greenhouse for ventilation can easily cause the temperature inside the greenhouse to drop, affecting the normal growth and development of cucumbers; second, simply changing environmental factors fails to simultaneously regulate the enzyme systems related to CO2 absorption and fixation in cucumber leaves (such as Rubisco), so CO2 assimilation efficiency may not be effectively improved, and vitamin C content may not necessarily increase. Summary of the Invention

[0005] To address the technical challenge of increasing the vitamin C content in greenhouse cucumbers using traditional methods, this invention provides a low-power laser irradiation method that uses a certain ratio of red and blue lasers to irradiate the leaves of greenhouse cucumbers, thereby increasing the vitamin C content in the cucumbers.

[0006] The first objective of this invention is to provide a laser light source, which is a red-blue laser hybrid light source, wherein the intensity ratio of red light to blue light in the hybrid light source is 1:1, and the intensity of the hybrid light source reaching the tip leaf is 1-2.0 μmol·m⁻¹. -2 ·s -1 .

[0007] The second objective of this invention is to provide a use of a laser light source for increasing the vitamin C content in greenhouse cucumbers. Specifically, the laser light source is a mixed light source with a red light to blue light intensity ratio of 1:1, and the light intensity of the mixed light source reaching the top leaves is 1-2.0 μmol·m⁻¹. -2 ·s -1 .

[0008] The third objective of this invention is to provide a method for increasing the vitamin C content in greenhouse cucumbers. This method involves supplementing the greenhouse cucumbers with a laser light source, specifically a red-blue laser, and controlling the light intensity of the red-blue laser reaching the terminal leaves to be 1-2.0 μmol·m⁻¹. -2 ·s -1 .

[0009] In some preferred embodiments, the intensity ratio of red light to blue light in the red-blue laser is 3:1 to 1:3.

[0010] In some more preferred embodiments, the intensity ratio of the red light to the blue light is 2:1 to 1:2.

[0011] In some of the most preferred embodiments, the ratio of the intensity of the red light to the intensity of the blue light is 1:1.

[0012] In some more specific embodiments, red and blue lasers are used to supplement the lighting of greenhouse cucumbers in spring or autumn. The greenhouse cucumbers are planted in single rows with a plant spacing of 25 cm and a row spacing of 1.6 m. Eight laser supplementary lights are evenly installed in a 40m greenhouse; the laser supplementary lights are about 2m away from the top of the cucumbers. Furthermore, the laser fill light has a power of 13 W; Furthermore, the laser fill light is used from 8:00 to 18:00 daily. Specifically, the intensity of the red and blue laser light reaching the top of the plant is 1-2.0 μmol·m. -2 ·s -1 The blue light peak is 449 nm, and the red light peak is 663 nm.

[0013] In some specific embodiments of the present invention, the method for increasing the vitamin C content in greenhouse cucumbers includes the following steps: 1) Plant in a single row with a plant spacing of 25 cm and a row spacing of 1.6 m; 16 Eight 13W laser supplement lights are evenly installed in a 40m greenhouse; the laser supplement lights are red and blue laser lights, and the intensity ratio of red light to blue light of the laser supplement lights is 3:1-1:3. 2) In spring and autumn, supplemental lighting should be provided to greenhouse cucumbers from 8:00 to 18:00 daily, with the red and blue laser light intensity reaching the top of the plant at 1-2.0 μmol·m⁻². -2 ·s -1 The optimal red and blue laser intensity reaching the plant tip is approximately 1.36 μmol·m⁻¹. -2 ·s -1 ; 3) Provide reasonable nutrient supply, plant management, water and fertilizer management and pest and disease control measures for greenhouse cucumbers until the harvest season.

[0014] In some preferred embodiments, the ratio of red light to blue light intensity of the laser fill light lamp in 1) above is 2:1 to 1:2; More preferably, the ratio of red light to blue light intensity of the laser fill light in 1) above is 1:1.

[0015] The beneficial effects of this invention are: 1) The invention uses a new type of low-energy light source for supplemental lighting. Compared with traditional supplemental lighting sources, the light source used in this invention has very low energy consumption while increasing the vitamin C content of cucumbers in greenhouses. It is a new type of low-energy supplemental lighting source for greenhouse fruits and vegetables. 2) Irradiating cucumber leaves with a laser light source upregulated the gene (CsaV3_2G030320) encoding carbonic anhydrase (carbonic anhydrase helps increase the CO2 concentration in chloroplasts, thereby increasing the carboxylation rate of ribulose diphosphate carboxylase). The relative expression level increased by 78.7%, leading to an increase in the amount of carbonic anhydrase protein in the chloroplasts. This increased carbonic anhydrase significantly accelerated the conversion of CO2 to HCO3-. - The conversion directly increases the carboxylation rate of ribulose diphosphate carboxylase, and by inhibiting photorespiration, it increases the glucose content, the final product of photosynthesis. Sufficient glucose accelerates vitamin C synthesis; the photosynthetic rate of leaves not exposed to laser irradiation is 26.9 μmol·m⁻¹. -2 ·s -1 The photosynthetic rate of cucumber leaves irradiated with the laser described in this application was 30.5 μmol·m⁻¹. -2 ·s -1 The photosynthetic rate of the leaves increased by 13.4%; the vitamin C content of cucumbers irradiated with the laser of this application was 9.23 mg / 100g, while the vitamin C content of unirradiated cucumbers was 6.97 mg / 100g, an increase of 32.4%. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the embodiments, but this is not intended to limit the present invention. Any equivalent substitutions made in the art based on the disclosure of the present invention shall fall within the protection scope of the present invention.

[0017] Example 1 Experimental materials: The North China type cucumber "Chuancui 13" was used as the experimental material.

[0018] Experimental design: The experiment was conducted in spring. Cucumbers were planted using coconut coir strips, with a plant spacing of 25 cm and a row spacing of 1.6 m, in single rows. 16 Eight laser lights are evenly installed in the 40m greenhouse.

[0019] The laser supplemental lighting lamp (CXL1-X0220-0603, Zhejiang Changxin Optoelectronic Technology Co., Ltd.) had a power of 13 W. Two parallel experimental groups were set up: a laser supplemental lighting group (T) and a control group without supplemental lighting (CK). Both red and blue light levels were set to 6, meaning the red-to-blue laser intensity ratio was 1:1. The lamp was positioned approximately 2 m from the cucumber plant tip, and the light intensity reaching the plant tip was approximately 1.36 μmol·m⁻¹. -2 ·s -1 The blue light peak is at 449 nm, and the red light peak is at 663 nm. Supplemental lighting was initiated during the early fruiting stage of the plants, with laser supplemental lighting occurring daily from 8:00 AM to 6:00 PM. Both the laser-supplied group (T) and the unsupplied control group (CK) consisted of 20 cucumber plants each. Both groups were located in the same greenhouse and received the same cucumber nutrient supply, plant management, water and fertilizer management, and pest and disease control measures.

[0020] Experimental results: During the cucumber harvesting period, the vitamin C content of cucumbers was measured after harvesting. The content of the laser-supplemented group was 9.23 mg / 100g, while the content of the unsupplemented control group was 6.97 mg / 100g. The vitamin C content increased by 32.4% after laser supplementation.

[0021] The photosynthetic rate of cucumber leaves in different experimental groups was measured using a LI-6800 photosynthesis measurement system. The photosynthetic rate of cucumber leaves in the laser-supplemented group (T) was 30.5 μmol·m⁻¹. -2 ·s -1 The photosynthetic rate of cucumber leaves in the control group (CK) without supplemental lighting was 26.9 μmol·m⁻¹. -2 ·s -1 .

[0022] Example 2 Experimental materials: The North China type cucumber "Chuancui 13" was used as the experimental material.

[0023] Experimental design: The experiment was conducted in spring. Cucumbers were planted using coconut coir strips, with a plant spacing of 25 cm and a row spacing of 1.6 m, in single rows. 16 Eight laser lights are evenly installed in the 40m greenhouse.

[0024] The laser supplemental lighting lamp (CXL1-X0220-0603, Zhejiang Changxin Optoelectronic Technology Co., Ltd.) had a power of 13 W. Three parallel experimental groups were set up: group T1 (red-blue ratio 1:1), group T2 (red-blue ratio 3:1), and group T3 (red-blue ratio 1:3). In group T1, both red and blue light levels were set to 6, resulting in a 1:1 ratio. In group T2, red and blue light levels were set to 9 and 3, respectively, resulting in a 3:1 ratio. In group T3, red and blue light levels were set to 3 and 9, respectively, resulting in a 1:3 ratio. At a distance of approximately 2 m from the cucumber plant tip, the light intensity reaching the plant tip was approximately 1.36 μmol·m⁻¹. -2 ·s -1 The blue light peak is at 449 nm, and the red light peak is at 663 nm. Supplemental lighting was started in the early fruiting stage of the plants, with laser supplemental lighting from 8:00 to 18:00 daily. Each group consisted of 20 cucumber plants; the three experimental groups of cucumbers were located in the same greenhouse and were subjected to the same cucumber nutrient supply, plant management, water and fertilizer management, and pest and disease control measures.

[0025] Experimental results: During the cucumber harvesting season, cucumbers were picked and their vitamin C content was measured. The vitamin C content of group T1 was 8.93 mg / 100g, group T2 was 7.22 mg / 100g, and group T3 was 7.47 mg / 100g.

[0026] Example 3 Experimental materials: The North China type cucumber "Chuancui 13" was used as the experimental material.

[0027] Experimental design: The experiment was conducted in spring. Cucumbers were planted using coconut coir strips, with a plant spacing of 25 cm and a row spacing of 1.6 m, in single rows. 16 Eight laser lights are evenly installed in the 40m greenhouse.

[0028] The laser supplemental lighting lamp (CXL1-X0220-0603, Zhejiang Changxin Optoelectronic Technology Co., Ltd.) had a power of 13 W. The experiment included four groups: laser supplemental lighting group T1 (red-blue ratio 1:1, red and blue light levels 2), laser supplemental lighting group T2 (red-blue ratio 1:1, red and blue light levels 6), laser supplemental lighting group T3 (red-blue ratio 1:1, red and blue light levels 9), and CK (no supplemental lighting). At a distance of approximately 2 m from the cucumber plant tip, the light intensity at the plant tip (T1) was approximately 0.65 μmol·m⁻¹. -2 ·s -1T2 is approximately 1.36 μmol·m -2 ·s -1 T3 is approximately 2.14 μmol·m -2 ·s -1 The blue light peak is at 449 nm, and the red light peak is at 663 nm. Supplemental lighting began in the early fruiting stage of the plants, with laser supplemental lighting from 8:00 AM to 6:00 PM daily. Each group consisted of 20 cucumber plants. Both the laser-supplied and control groups were located in the same greenhouse and received the same cucumber nutrient supply, plant management, water and fertilizer management, and pest and disease control measures.

[0029] Experimental results: During the cucumber harvesting season, cucumbers were picked and their vitamin C content was measured. The vitamin C content was 6.59 mg / 100g in group T1 (red-blue light ratio 1:1, red and blue light levels 2 for both groups), 8.78 mg / 100g in group T2 (red-blue light ratio 1:1, red and blue light levels 6 for both groups), 6.42 mg / 100g in group T3 (red-blue light ratio 1:1, red and blue light levels 9 for both groups), and 6.46 mg / 100g in group CK.

[0030] The photosynthetic rate of cucumber leaves in different experimental groups was measured using a LI-6800 photosynthesis measurement system. The photosynthetic rate of cucumber leaves in group T1 was 25.7 μmol·m⁻¹. -2 ·s -1 The photosynthetic rate of cucumber leaves in group T2 was 29.8 μmol·m⁻¹. -2 ·s -1 The photosynthetic rate of cucumber leaves in group T3 was 25.1 μmol·m⁻¹. -2 ·s -1 The CK group had a cucumber leaf photosynthetic rate of 24.7 μmol·m⁻¹. -2 ·s -1 .

[0031] Example 4 Experimental materials: The North China type cucumber "Chuancui 13" was used as the experimental material.

[0032] Experimental design: The experiment was conducted in autumn. Cucumbers were planted using coconut coir strips, with a plant spacing of 25 cm and a row spacing of 1.6 m, in single-row planting. 16 Eight laser lights are evenly installed in the 40m greenhouse.

[0033] The laser supplemental lighting lamp (CXL1-X0220-0603, Zhejiang Changxin Optoelectronics Technology Co., Ltd.) had a power of 13 W. Two parallel groups were set up in the experiment: a laser supplemental lighting group (T) and a control group (CK). Both red and blue light levels were set to 6, and the lamp was positioned approximately 2 m from the top of the cucumber plant. The light intensity reaching the top of the plant was approximately 1.36 μmol·m⁻¹. -2 ·s -1The blue light peak is at 449 nm, and the red light peak is at 663 nm. Supplemental lighting began in the early fruiting stage of the plants, with laser supplemental lighting from 8:00 AM to 6:00 PM daily. Each group consisted of 20 cucumber plants. Both the laser-supplied and control groups were located in the same greenhouse and received the same cucumber nutrient supply, plant management, water and fertilizer management, and pest and disease control measures.

[0034] Experimental results: During the cucumber production period, cucumbers were harvested and their vitamin C content was measured. The vitamin C content of cucumbers in group T was 4.41 mg / 100g, and the vitamin C content of cucumbers in group CK was 3.09 mg / 100g. The vitamin C content increased by 42.7% after supplemental lighting.

[0035] The net photosynthetic rate of different experimental groups was measured using the LI-6800 photosynthesis measurement system. The photosynthetic rate of cucumber leaves in group T was 14.84 μmol·m⁻¹. -2 ·s -1 The photosynthetic rate of cucumber leaves in the CK group was 10.89 μmol·m⁻¹. -2 ·s -1 .

[0036] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications to the technical solutions of the present invention made by those skilled in the art without departing from the spirit of the invention are permissible.

Claims

1. A laser light source, characterized in that: The laser source is a red-blue laser hybrid source, with a red to blue light intensity ratio of 1:

1. The light intensity reaching the top leaves of the plant from this hybrid source is 1-2.0 μmol·m⁻¹. -2 ·s -1 .

2. A method for increasing the vitamin C content in greenhouse cucumbers, characterized in that, The method involves supplementing the lighting of greenhouse cucumbers with a laser light source, specifically a red-blue laser, with the light intensity reaching the top leaves being 1-2.0 μmol·m⁻². -2 ·s -1 The intensity ratio of red light to blue light is 1:

1.

3. The method according to claim 2, characterized in that, The method involves supplementing the greenhouse cucumbers with red and blue laser light in spring or autumn. The greenhouse cucumbers are planted in single rows with a plant spacing of 25cm and a row spacing of 1.6m. Eight laser supplementary lights are evenly installed in a 40m greenhouse; the laser supplementary lights are about 2m away from the top of the cucumbers.

4. The method according to claim 3, characterized in that, The laser fill light has a power of 13W.

5. The method according to claim 3 or 4, characterized in that, The laser fill light is used from 8:00 to 18:00 every day.

6. The method according to claim 5, characterized in that, The intensity of the red and blue laser light reaching the top of the plant is 1-2.0 μmol·m. -2 ·s -1 The blue light peak is 449 nm, and the red light peak is 663 nm.

7. The method according to claim 2, characterized in that, The method includes the following steps: 1) Plant in a single row with a plant spacing of 25 cm and a row spacing of 1.6 m; 16 Eight 13W laser supplement lights are evenly installed in a 40m greenhouse; the laser supplement lights are red and blue laser lights, and the ratio of the intensity of the red light to the intensity of the blue light of the laser supplement lights is 1:

1. 2) In spring and autumn, supplemental lighting should be provided to the greenhouse cucumbers from 8:00 to 18:00 daily, with the red and blue laser light intensity reaching the top of the plant at 1-2.0 μmol·m⁻¹. -2 ·s -1 ; 3) Provide reasonable nutrient supply, plant management, water and fertilizer management and pest and disease control measures for greenhouse cucumbers until the harvest season.

8. The use of the laser light source as described in claim 1 in increasing the vitamin C content in greenhouse cucumbers.