Light environment and nitrate nitrogen coupled leaf lettuce rapid generation adding method

Abstract

The invention belongs to the technical field of crop cultivation, and discloses a lettuce rapid generation adding method. The method comprises the steps that lettuce seeds are subjected to hydroponic seedling culture until each seedling has two leaves and one core, and then field planting is conducted; the nitrogen concentration is 9.0 mmol / L, the temperature is 25 DEG C, the light intensity is maintained at 200 [mu] mol.m <-2 >. S <-1 > in the first five days, the light period is 16: 8, the light quality red: blue: far-red ratio is 6: 1: 1, the light intensity is adjusted to 320 [mu] mol.m <-2 >. S <-1 > in the sixth day, the light period is 16: 8, the light quality red: blue: far-red ratio is 6: 1: 1, and culture is performed for 15 days; the cultured lettuce plants are placed in low-nitrogen nutrient liquid with the concentration of 1.5 mmol / L to be cultured, the temperature is 25 DEG C, the light intensity is 320 [mu] mol.m <-2 >. S <-1 >, the photoperiod is 20: 4, and the ratio of red light to blue light to far-red light is 6: 1: 1 until the plants bloom; after the plants bloom, adjusting the nitrogen concentration of the low-nitrogen nutrient liquid to the normal nitrogen concentration of 9.0 mmol / L until the seeds are mature. The method promotes rapid flowering and seed setting of lettuce, shortens the breeding period, and accelerates the breeding speed of lettuce.

Description

Technical Field

[0001] The invention relates to the technical field of crop cultivation, and in particular to a method for rapid generation of leaf lettuce by coupling light environment and nitrate nitrogen. Background Art

[0002] Lettuce belongs to the genus Lactuca in the Asteraceae family. The traditional breeding cycle is long, with one generation taking 180-240 days and 5-8 years to breed one variety, which limits the speed of developing new varieties. In order to accelerate the breeding process of crops, predecessors have developed rapid breeding and generation technology, which is a comprehensive technology that promotes rapid flowering and rapid maturity of plants by artificially controlling the light and temperature environment. Since the technology was proposed, it has received great attention from plant scientists. Although predecessors have conducted research on rapid breeding and generation on other crops, there has been no report on rapid generation technology for lettuce breeding.

[0003] In view of this, the present invention is proposed. Summary of the invention

[0004] In order to solve the problems in the background technology, the present invention provides a method for rapid generation of leaf lettuce by coupling light environment and nitrate nitrogen.

[0005] To achieve the above object, the technical solution adopted by the present invention is: A method for rapid generation of leaf lettuce by coupling light environment and nitrate nitrogen, comprising: Lettuce seeds were grown in water until the seedlings had 2 leaves and 1 heart, and then transplanted; The seedlings were planted in a hydroponic tank and cultured in a total nitrogen nutrient solution with a nitrogen concentration of 9.0 mmol / L, a temperature of 25°C, and a light intensity of 200 μmol·m -2 ·s -1 , photoperiod 16:8, light quality red: blue: far red = 6:1:1, light intensity increased to 320 μmol·m -2 ·s -1 , photoperiod 16:8, light quality red: blue: far red = 6:1:1, culture 15 d; The cultured lettuce plants were placed in a low nitrogen nutrient solution with a nitrogen concentration of 1.5 mmol / L, a temperature of 25°C, and a light intensity of 277.8-416.7 μmol·m -2 ·s -1 , photoperiod 20:4, light quality red: blue: far red = 6:1:1, culture until the plants bloom; After the plants bloom, the nitrogen concentration of the low-nitrogen nutrient solution is adjusted to a normal nitrogen concentration of 9.0 mmol / L, and other conditions remain unchanged until the seeds mature.

[0006] Preferably, the method for hydroponic seedling cultivation is as follows: lettuce seeds are soaked and then protected from light for germination, and after the seeds germinate, they are placed in a 200 μmol·m -2 ·s -1 Cultivate under light, photoperiod 16:8, light quality red: blue = 4:1, use full nitrogen nutrient solution after cotyledons unfold, and control pH value at 6.0-6.5.

[0007] Preferably, lettuce seeds are soaked for 4 hours and then sown on a sponge soaked in water, and germinated in a dark environment at 20° C. for about 24 hours.

[0008] Preferably, lettuce seeds are cultured for 14 days until the seedlings have 2 leaves and 1 heart and then transplanted.

[0009] Preferably, the cultured lettuce plants are placed in a low nitrogen nutrient solution with a nitrogen concentration of 1.5 mmol / L, a temperature of 25°C, and a light intensity of 320 μmol·m -2 ·s -1 , photoperiod 20:4, light quality red: blue: far red = 6:1:1, culture until the plants bloom.

[0010] Preferably, the molar concentration of each element in the total nitrogen nutrient solution is, N 9.0mmol / L, P 0.9mmol / L, K5.6mmol / L, Ca 2.9mmol / L, Mg 1.0mmol / L, S 1.0mmol / L, Fe 85.94μmol / L, Mn 0.1mmol / L, B0.1mmol / L, Cu 0.1μmol / L, Zn 29.57μmol / L, Mo 1.05μmol / L.

[0011] Preferably, the molar concentration of each element in the low-nitrogen nutrient solution is, N 1.5mmol / L, P 0.9mmol / L, K5.6mmol / L, Ca 2.9mmol / L, Mg 1.0mmol / L, S1.0mmol / L, Fe 85.94μmol / L, Mn 0.1mmol / L, B0.1mmol / L, Cu 0.1μmol / L, Zn 29.57μmol / L, Mo 1.05μmol / L.

[0012] Preferably, during the cultivation until the plants bloom, the plants are cross-topped after they form heads to promote bolting of the plants.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention promotes rapid flowering and seeding of lettuce through the coordinated management of nitrogen and light, thereby shortening the entire growth period of lettuce, completing the breeding cycle more quickly, shortening the breeding years, and accelerating the lettuce breeding speed. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments.It should be understood that these descriptions are exemplary only, and are not intended to limit the scope of the present invention.In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.Unspecified conditions in the embodiments are carried out according to the conditions of normal conditions or manufacturer recommendations.Reagents used or instruments that do not specify manufacturers are conventional products that can be purchased and obtained commercially.

[0015] The embodiment of the present invention provides a method for rapid generation of leaf lettuce by coupling light environment and nitrate nitrogen, comprising: Lettuce seeds were grown in water until the seedlings had 2 leaves and 1 heart, and then transplanted; The seedlings were planted in a hydroponic tank and cultured in a total nitrogen nutrient solution with a nitrogen concentration of 9.0 mmol / L, a temperature of 25°C, and a light intensity of 200 μmol·m -2 ·s -1 , photoperiod 16:8, light quality red: blue: far red = 6:1:1, light intensity increased to 320 μmol·m -2 ·s -1 , photoperiod 16:8, light quality red: blue: far red = 6:1:1, culture 15 d; The lettuce plants were cultured in a low nitrogen nutrient solution with a nitrogen concentration of 0.8-1.8 mmol / L, a temperature of 25°C, and a light intensity of 320 μmol·m -2 ·s -1 , photoperiod 20:4, light quality red: blue: far red = 6:1:1, culture until the plants bloom; After the plants bloom, the nitrogen concentration of the low-nitrogen nutrient solution is adjusted to a normal nitrogen concentration of 9.0 mmol / L, and other conditions remain unchanged until the seeds mature.

[0016] The method for rapid generation of lettuce in the embodiment of the present invention is divided into four stages: hydroponic seedling cultivation, vegetative growth cultivation, low nitrogen reproductive growth cultivation and seed setting, which correspond to the above four steps respectively.

[0017] During the vegetative growth stage, the light intensity was increased to 320 μmol·m -2 ·s -1 , culturing for 15 days after adjustment means culturing for another 15 days after adjusting the light, that is, culturing for another 15 days starting from the 6th day.

[0018] During the low nitrogen reproductive growth cultivation stage, by reducing the nitrogen level and increasing the daily light integral, the flowering process is promoted through synergistic regulation. If the nitrogen is too low or the light intensity is too strong, the two factors will synergistically cause the plant stress to be too severe, the plant mortality rate will increase or the flowering and seeding will be too few. On the contrary, the growth period will be extended and the effect of shortening the growth period will not be achieved.

[0019] Specifically, the specific light intensity conditions for low nitrogen (0.8-1.8 mmol / L) and light intensity were 277.8-416.7 μmol·m -2 ·s -1 , photoperiod 20:4, light quality red: blue: far-red = 6:1:1, that is, the daily light integral DLI is controlled at 20-30 mol / d.

[0020] During the seedling stage of vegetative growth, the nitrogen and light treatment conditions were as follows: nitrogen concentration was 9.0 mmol / L, and light intensity was maintained at 200 μmol·m -2 ·s -1 , photoperiod 16:8, light quality red: blue: far red = 6:1:1. Starting from the 6th day, nitrogen and light treatment conditions were nitrogen concentration 9.0 mmol / L, light intensity 277.8-416.7 μmol·m -2 ·s -1 , photoperiod 16:8, light quality red:blue:far-red = 6:1:1, cultured for 15 d.

[0021] During the seedling growth stage, the normal nitrogen concentration range ensures rapid vegetative growth of the plants. During this stage, the light intensity should not be too strong and the photoperiod should not be too long. The root system of the plant does not grow during this stage. Excessive light intensity and too long photoperiod will cause light stress and affect vegetative growth.

[0022] The method and effect of rapid generation of lettuce are described in detail below through a number of specific examples. The formulas of the full nitrogen nutrient solution and the low nitrogen nutrient solution in the following examples are shown in Table 1.

[0023] Table 1 .

[0024] Example 1 How to quickly add generations to Zhongsheng No. 1: (1) Seeding and seedling raising After soaking the seeds of Zhongsheng No. 1 for 4 h, they were sown on a sponge soaked in water, covered with a lid, and placed in a dark environment at 20 °C for about 24 h for germination. After the seeds germinated, they were transferred to a 200 μmol·m -2 ·s -1Cultivate under light, photoperiod 16:8, light quality red: blue = 4:1, use full nitrogen nutrient solution (nutrient solution formula element content see Table 1) after cotyledons unfold, pH value controlled at 6.0-6.5. Cultivate for 14 days until seedlings have 2 leaves and 1 heart, then transplant.

[0025] (2) Nutritional growth and cultivation The seedlings of Zhongsheng No. 1 were planted in a hydroponic tank and cultured in a total nitrogen nutrient solution with a nitrogen concentration of 9.0 mmol / L, a temperature of 25°C, and a light intensity of 200 μmol·m -2 ·s -1 , photoperiod 16:8, light quality red: blue: far red = 6:1:1, light intensity modulation 320 μmol·m -2 ·s -1 , photoperiod 16:8, light quality red:blue:far-red = 6:1:1, cultured for 15 d.

[0026] (3) Low nitrogen culture to promote reproductive growth Replace the above two nutrient solutions with low nitrogen nutrient solution, with nitrogen concentration of 1.5 mmol / L, temperature of 25°C, and light intensity of 320 μmol·m -2 ·s -1 , photoperiod 20:4, light quality red: blue: far red = 6:1:1, culture until the plants bloom.

[0027] (4) Seed setting After the Zhongsheng No. 1 plants bloom, adjust the nitrogen concentration of the above 3 low-nitrogen nutrient solutions to the normal nitrogen concentration of 9.0 mmol / L, and keep other conditions unchanged until the seeds mature.

[0028] The above breeding method was used as the "light-nitrogen coordinated breeding" group, and the following control groups were set up at the same time: Conventional open field breeding group: open field cultivation, natural environment.

[0029] Conventional lighting and normal nitrogen breeding group: white light quality during the whole growth period, light intensity 200 μmol·m -2 ·s -1 , photoperiod 16:8; nitrogen concentration during the whole growth period was 9.0 mmol / L.

[0030] Increased light normal nitrogen breeding group: Compared with the "light-nitrogen coordinated breeding" group, the only difference is that in step (3), the low-nitrogen nutrient solution is replaced with a full-nitrogen nutrient solution. Specifically: During the vegetative growth and cultivation stage, the light intensity is maintained at 200 μmol·m -2 ·s -1 The photoperiod was 16:8, and the light intensity was increased to 320 μmol·m -2 ·s -1, photoperiod 16:8, culture 15 days; low nitrogen promoted reproductive growth culture stage to seed maturity stage, light intensity 320 μmol·m -2 ·s -1 , photoperiod 20:4; light quality during the entire growth period (i.e. steps (2) to (4)) red: blue: far-red = 6:1:1; nitrogen concentration during the entire growth period is 9.0 mmol / L.

[0031] Conventional light low nitrogen breeding group: Compared with the “light-nitrogen coordinated breeding” group, the only difference is the white light quality during the whole growth period (i.e., steps (2) to (4)), with a light intensity of 200 μmol·m -2 ·s -1 , photoperiod 16:8. The growth period of Zhongsheng No. 1 under the above different breeding methods was statistically analyzed, and the results are shown in Table 2.

[0032] Table 2 Statistics of the growth period of Zhongsheng No. 1 in different breeding methods .

[0033] Example 2 Method for rapid generation of cabbage lettuce KNV000081: (1) Seeding and seedling raising KNV000081 seeds were soaked for 4 h and then sown on a sponge soaked in water. The seeds were covered with a lid and placed in a dark environment at 20 °C for about 24 h for germination. After germination, the seeds were transferred to a 200 μmol·m -2 ·s -1 Cultivate under light, photoperiod 16:8, light quality red: blue = 4:1, use full nitrogen nutrient solution (nutrient solution formula element content see Table 1) after cotyledons unfold, pH value controlled at 6.0-6.5. Cultivate for 14 days until seedlings have 2 leaves and 1 heart, then transplant.

[0034] (2) Nutritional growth and cultivation The seedlings of KNV000081 were planted in a hydroponic tank and cultured in a total nitrogen nutrient solution with a nitrogen concentration of 9.0 mmol / L, a temperature of 25°C, and a light intensity of 200 μmol·m -2 ·s -1 , photoperiod 16:8, light quality red: blue: far red = 6:1:1, light intensity modulation 320 μmol·m -2 ·s -1 , photoperiod 16:8, light quality red:blue:far-red = 6:1:1, cultured for 15 d.

[0035] (3) Low nitrogen culture to promote reproductive growth Replace the above two nutrient solutions with low nitrogen nutrient solution, with nitrogen concentration of 1.5 mmol / L, temperature of 25°C, and light intensity of 320 μmol·m -2 ·s-1 , photoperiod 20:4, light quality red: blue: far red = 6:1:1, culture until the plant blooms. During the culture period, after the plant forms a ball, the top of the ball is cut crosswise to promote the plant to bolt.

[0036] (4) Seed setting After the KNV000081 plants bloom, adjust the nitrogen concentration of the above 3 low-nitrogen nutrient solutions to the normal nitrogen concentration of 9.0 mmol / L, and keep other conditions unchanged until the seeds mature.

[0037] The above breeding method was used as the "light-nitrogen coordinated breeding" group, and the following control groups were set up at the same time: conventional open field breeding group, conventional light normal nitrogen breeding group, increased light normal nitrogen breeding group, and conventional light low nitrogen breeding group, and the setting method was the same as Example 1.

[0038] The growth period of head lettuce KNV000081 under the above different breeding methods was statistically analyzed, and the results are shown in Table 3.

[0039] Table 3 Statistics of growth period of head lettuce KNV000081 in different breeding methods .

[0040] 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 by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for rapid generation of leaf lettuce by coupling light environment and nitrate nitrogen, characterized in that: Include: Lettuce seeds were grown in water until the seedlings had 2 leaves and 1 heart, and then transplanted; The seedlings were planted in a hydroponic tank and cultured in a total nitrogen nutrient solution with a nitrogen concentration of 9.0 mmol / L, a temperature of 25°C, and a light intensity of 200 μmol·m -2 ·s -1 , photoperiod 16:8, light quality red: blue: far red = 6:1:1, light intensity increased to 320 μmol·m -2 ·s -1 , photoperiod 16:8, light quality red: blue: far red = 6:1:1, culture 15 d; The cultured lettuce plants were placed in a low nitrogen nutrient solution with a nitrogen concentration of 0.8-1.8 mmol / L, a temperature of 25°C, and a light intensity of 277.8-416.7 μmol·m -2 ·s -1 , photoperiod 20:4, light quality red: blue: far red = 6:1:1, culture until the plants bloom; After the plants bloom, the nitrogen concentration of the low-nitrogen nutrient solution is adjusted to a normal nitrogen concentration of 9.0 mmol / L, and other conditions remain unchanged until the seeds mature.

2. The method according to claim 1, characterized in that The method of hydroponic seedling cultivation is as follows: lettuce seeds are soaked and then protected from light for germination. After the seeds germinate, they are placed in a 200 μmol·m -2 ·s -1 Cultivate under light, photoperiod 16:8, light quality red: blue = 4:1, use full nitrogen nutrient solution after cotyledons unfold, and control pH value at 6.0-6.

5.

3. The method according to claim 2, characterized in that Lettuce seeds were soaked for 4 hours and then sown on a sponge soaked in water. They were germinated in a dark environment at 20°C for about 24 hours.

4. The method according to claim 1, characterized in that Lettuce seeds were cultured for 14 days until the seedlings had 2 leaves and 1 heart, and then transplanted.

5. The method according to claim 1, characterized in that The cultured lettuce plants were placed in a low nitrogen nutrient solution with a nitrogen concentration of 1.5 mmol / L, a temperature of 25°C, and a light intensity of 320 μmol·m -2 ·s -1 , photoperiod 20:4, light quality red: blue: far red = 6:1:1, culture until the plants bloom.

6. The method according to claim 1, characterized in that The molar concentrations of each element in the total nitrogen nutrient solution are N 9.0mmol / L, P 0.9mmol / L, K 5.6mmol / L, Ca 2.9mmol / L, Mg 1.0mmol / L, S 1.0mmol / L, Fe 85.94μmol / L, Mn 0.1mmol / L, B 0.1mmol / L, Cu 0.1μmol / L, Zn 29.57μmol / L, and Mo 1.05μmol / L.

7. The method according to claim 1, characterized in that The molar concentrations of each element in the low-nitrogen nutrient solution are: N 1.5mmol / L, P 0.9mmol / L, K 5.6mmol / L, Ca 2.9mmol / L, Mg 1.0mmol / L, S 1.0mmol / L, Fe 85.94μmol / L, Mn 0.1mmol / L, B 0.1mmol / L, Cu 0.1μmol / L, Zn 29.57μmol / L, and Mo 1.05μmol / L.

8. The method according to claim 1, characterized in that During the cultivation period until the plant blooms, the plant will be cut into a cross shape at the top after it forms a head to promote bolting.