Method for regulating physiological indexes of cupressus funebris seedlings

Abstract

The application discloses a method for regulating physiological indexes of Cunninghamia lanceolata seedlings and belongs to the technical field of plant growth promotion. ‑2 ·s ‑1 The application uses natural light with illumination intensity of 5%-68% or blue light, red light, 1:1 L red / far red light, 1:2 L red / far red light, far red light with illumination intensity of 40 μmol·m ‑2 ·s ‑1 The Cunninghamia lanceolata seedlings are irradiated by blue light, red light, 1:1 L red / far red light, 1:2 L red / far red light and far red light with illumination intensity. The results show that the activity of leaf carbohydrate metabolism enzymes is reduced, the overall growth is slowed down, and the dry biomass accumulation is reduced under low illumination intensity. Compared with white light, the blue light reduces the dry biomass accumulation of the Cunninghamia lanceolata seedlings. The far red light and the increase of the proportion of the far red light are beneficial to the elongation of the Cunninghamia lanceolata seedling height, and the dry biomass accumulation is increased.

Description

Technical Field

[0001] This invention belongs to the field of plant growth promotion technology, and more specifically, relates to a method for regulating the physiological indicators of Chinese fir seedlings. Background Technology

[0002] Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) is an important fast-growing afforestation species in southern my country, playing a vital role in meeting timber demand and maintaining ecological security. However, the long-term excessive pursuit of short-term economic benefits has led to a series of ecological problems in Chinese fir plantations, including soil degradation, low ecosystem service functions, and poor vegetation regeneration, directly impacting their sustainable management. With the rapid development of modern multifunctional forestry, afforestation has shifted from being primarily focused on timber production to primarily serving forest ecological functions. Research on the ecological processes and functions of plantations, such as natural regeneration, is increasingly attracting academic attention, and the ability of plantations to regenerate naturally is crucial for achieving sustainable management. Chinese fir plantations have poor natural seed regeneration capacity, and existing research indicates that seed source is not the main limiting factor affecting regeneration. Southern China has abundant rainfall and suitable temperatures, so water and temperature are also not major factors affecting regeneration. However, the high canopy closure and abundant ferns in Chinese fir plantations, resulting in insufficient understory light, are likely the main reasons for obstacles to seedling survival and sapling establishment.

[0003] Plants can detect subtle changes in light conditions and initiate morphological and physiological changes necessary for survival in specific habitats. Morphological and growth plasticity are important strategies for plant adaptation to the environment, influenced not only by light intensity but also by light quality, including different wavelengths and proportions of light. Plants can respond to environmental changes and resource competition by regulating the allocation of biomass between aboveground and belowground tissues, ensuring the maximization of the absorption of limited resources. Different light environments lead to different biomass allocations in various plant organs. According to optimal allocation theory, when light becomes the primary limiting factor, plants tend to allocate more resources to their aboveground parts. [50-51] In strong light, plants allocate more biomass to light-harvesting tissues, increasing the light-receiving area, which reduces the root-to-shoot ratio. Conversely, under intense light, plants reduce resource input to the above-ground parts, decreasing leaf area to effectively avoid photoinhibition caused by excessive light absorption. Simultaneously, to alleviate the high transpiration rate under strong light, they increase the proportion of biomass allocated to the roots, promoting root growth to acquire more water. Light quality also plays a crucial role in regulating plant biomass accumulation and allocation.

[53] Because red light wavelengths perfectly match the absorption peaks of chlorophyll and phytochromes, and because red light promotes cell division and expansion, it can promote biomass accumulation and increase leaf area. Other studies have found that blue light also plays a significant role in promoting leaf expansion, increasing leaf area, and increasing biomass accumulation; however, some studies have reported that blue light inhibits cell division and expansion, leading to a decrease in leaf area. Therefore, studying the physiological and metabolic responses of Chinese fir seedlings to different light environments is of great significance for revealing the understory regeneration barriers in Chinese fir. Summary of the Invention

[0004] In view of the above-mentioned problems in the existing technology, the technical problem to be solved by the present invention is to provide a method for regulating the physiological indicators of Chinese fir seedlings, so as to facilitate the early management of Chinese fir plantations.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A method for regulating the physiological indicators of Chinese fir seedlings involves adjusting the light intensity and / or controlling the light quality of the seedlings to regulate their physiological indicators. The light intensity is controlled within a range not exceeding 90,000 Lux, and the light quality includes white light, blue light, red light, 1:1L red / far-red light, 1:2L red / far-red light, and far-red light. The physiological indicators include nitrogen content, phosphorus content, nitrogen-to-phosphorus ratio, potassium content, calcium content, magnesium content, manganese content, gibberellin content, and starch content. Content, soluble sugar content, non-total structural carbon content, soluble starch content, ribulose diphosphate carboxylase / oxygenase activity, fructose-1,6-bisphosphatase activity, sucrose phosphate synthase activity, adenosine diphosphate glucose pyrophosphatase activity, phosphoenolpyruvate carboxylase activity, carbon content, carbon-nitrogen ratio, carbon-phosphorus ratio, cytokinin content, abscisic acid content, auxin content, root activity, root biomass, stem biomass, leaf biomass, total biomass, and root biomass ratio.

[0007] Within a light intensity range not exceeding 90,000 Lux, increasing the light intensity can increase the starch content, soluble sugar content, total non-structural carbon content, ribulose diphosphate carboxylase / oxygenase activity, sucrose phosphoryl synthase activity, phosphoenolpyruvate carboxylase activity, adenosine diphosphate glucose pyrophosphorylase activity, carbon content, and cytokinin content of Chinese fir seedlings.

[0008] Within a light intensity range not exceeding 90,000 Lux, the content of nitrogen, phosphorus, potassium, calcium, magnesium, manganese, gibberellin, and abscisic acid can be increased by reducing the light intensity.

[0009] When the light intensity is 400 μmol·m -2 ·s -1 Adjust to 40 μmol·m -2·s -1 Within the specified range, blue light or 1:1L red / far-red light irradiation was used to promote the root vitality of Chinese fir seedlings.

[0010] When the light intensity is 40 μmol·m -2 ·s -1 Adjust to 400 μmol·m -2 ·s -1 Within the specified range, white light, blue light, red light, a 1:1 red / far-red light ratio, a 1:2 red / far-red light ratio, or far-red light can be used to promote the increase of root biomass, root biomass ratio, stem biomass, and leaf biomass in Chinese fir seedlings.

[0011] At 400 μmol·m -2 ·s -1 Under light intensity, controlling the light quality to change from white light to blue light can promote an increase in the stem biomass ratio and leaf biomass ratio of Chinese fir seedlings.

[0012] At 40 μmol·m -2 ·s -1 Under light intensity, controlling the light quality to change from white light to red light, or 1:1 red / far-red light, or 1:2 red / far-red light, or far-red light can promote the accumulation and distribution ratio of stem biomass in Chinese fir seedlings.

[0013] At 40 μmol·m -2 ·s -1 Under light intensity, controlling the light quality from white light to 1:1 red / far-red light, 1:2 red / far-red light, or far-red light can promote an increase in leaf biomass in Chinese fir seedlings.

[0014] At 400 μmol·m -2 ·s -1 Under light intensity, controlling the light quality from white light to red light, or 1:1 red / far-red light, or 1:2 red / far-red light, or far-red light can promote the increase of total biomass and root-to-shoot ratio in Chinese fir seedlings.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] This invention uses natural light with an intensity of 5%-68% or 400 μmol·m⁻². -2 ·s -1 Light intensity of blue light, red light, 1:1L red / far-red light, 1:2L red / far-red light, far-red light, or 40 μmol·m -2 ·s -1Chinese fir seedlings were treated with blue light, red light, 1:1 L red / far-red light, 1:2 L red / far-red light, and far-red light. The results showed that low light intensity reduced the activity of carbohydrate metabolism enzymes in the leaves, slowed overall growth, and decreased dry biomass accumulation. Compared with white light, blue light reduced the dry biomass accumulation of Chinese fir seedlings. Far-red light and an increased proportion of far-red light promoted seedling height elongation and increased dry biomass accumulation. Attached Figure Description

[0017] Figure 1 Figure showing the non-structural carbon content of Chinese fir leaves under different light intensities;

[0018] Figure 2 The graph shows the activity of carbohydrate metabolism enzymes in Chinese fir leaves under different light intensities.

[0019] Figure 3 Figure 1 shows the C, N, and P content of Chinese fir leaves under different light intensities;

[0020] Figure 4 Figures showing the K, Ca, Mg, and Mn contents of Chinese fir leaves under different light intensities;

[0021] Figure 5 Figure showing the endogenous hormone content in Chinese fir leaves under different light intensities;

[0022] Figure 6 Root vitality diagram of Chinese fir seedlings under different light conditions;

[0023] Figure 7 Diagram showing the biomass accumulation and distribution of Chinese fir seedlings under different light conditions. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to specific embodiments. Unless otherwise specified, the technical means used in the following embodiments are all conventional means well known to those skilled in the art.

[0025] Example 1

[0026] 1. This invention was conducted in a flat, open nursery area of ​​the Shunchang County State-owned Forest Farm in Fujian Province. Full sunlight was used as the control (no shading treatment). The other four light intensity gradients were constructed by erecting square iron frames (each side 1.8 meters long) and covering them with black nylon netting of different pinhole sizes. On sunny, cloudless days, at 12:00 noon each day for seven consecutive days, the light conditions under each treatment were measured using a photometer (HiPoint HP350, Taiwan, China). Based on the measurement results, the light transmittance of each shaded netted enclosure was found to be 68%, 27%, 12%, and 5% of full sunlight, respectively, referred to below as 68% light intensity, 27% light intensity, 12% light intensity, and 5% light intensity. Simultaneously, a handheld spectrometer (HP350) was used to measure the red / far-red light intensity under each treatment (see Table 2-1). The shaded netted enclosures were distributed parallel to the sun's daily movement trajectory to minimize the spatiotemporal variation of solar radiation. They were enclosed on all sides, but the bottom line was 15 cm above the ground to maintain air circulation. Four replicates were set up for the same light intensity gradient (i.e., four shaded net chambers were built for the same light intensity gradient). During the experiment, a temperature and humidity recorder (RHD-07C, Hebei, China) was installed under each treatment to continuously monitor the atmospheric temperature and humidity. The instrument automatically counted once every 20 minutes. All data measured during the experiment were sorted and analyzed to obtain the average air humidity and atmospheric temperature under each light intensity treatment, as shown in Table 1.

[0027] Table 1 Environmental conditions under different light intensities

[0028]

[0029] Note: Data are expressed as mean ± standard error. Different lowercase letters indicate significant differences between different light intensities (p<0.05).

[0030] The experimental seedlings were one-year-old clonal Chinese fir seedlings (Yang-061 variety), purchased in May 2020 from Yangkou State-owned Forest Farm, Shunchang County, Fujian Province. The seedlings were transplanted into pots (30cm inner diameter, 32cm height) filled with local red mountain soil. The soil organic matter content was 4.03±0.39 mg·g. -1Seedlings were acclimatized in a greenhouse at the experimental site for one month, with one seedling planted in each pot. After acclimatization, 120 relatively uniform and well-developed Chinese fir seedlings were selected, with an average height of 33.14±3.43 cm and an average ground diameter of 4.70±0.57 mm, and randomly divided into 5 groups. Each group was treated with the same light intensity gradient, with 4 replicates per light intensity gradient and 6 seedlings per replicate. The selected seedlings were then randomly placed under different light intensity gradients. To ensure that seedlings under each treatment received similar light conditions and that there was no mutual shading between adjacent plants, a distance of 40 cm was maintained between adjacent plants, and the pots were systematically rotated weekly. No fertilizer was applied during the experiment, but weeds were regularly removed from the experimental field, and the soil was watered 2-3 times per week to maintain soil moisture. The light intensity experiment lasted for 4 months, ending in October 2020.

[0031] 2. The anthrone colorimetric method was used to determine the soluble sugar (SS) and starch (S) content in leaves. One seedling was randomly selected from each replicate of different treatments, and normal leaves of the same height and location were picked, washed with distilled water, and blotted dry with filter paper. 0.2 g of fresh leaves (with veins removed) were weighed, ground, and 5 mL of distilled water was added. The mixture was then subjected to a boiling water bath for 30 min, repeated twice. After cooling and centrifugation, the supernatant was collected in a 25 mL volumetric flask and diluted to volume. This solution was used for the determination of soluble sugar content. Then, the solid residue after soluble sugar extraction was dried, and perchloric acid was added to extract starch. The absorbance of the extract at 630 nm was measured using a UV-Vis spectrophotometer (UV-2800, Shimadzu, Japan). The soluble sugar and starch contents were calculated based on the glucose standard curve. The total non-structural carbon (TNC) content was the sum of the soluble sugar and starch contents.

[0032] The results are as follows Figure 1 As shown, with decreasing light intensity, the starch content, soluble sugar content, and total non-structural carbon content in leaves all decreased significantly, reaching their lowest levels at 5% light intensity, at 54.31%, 38.46%, and 44.27% respectively under full light. Figure 1 (A~C). This indicates that strong light treatment is beneficial for carbon accumulation in the leaves of Chinese fir seedlings, increasing the content of total non-structural carbon and its components. The soluble sugar / starch ratio generally decreases with decreasing light intensity, with higher ratios under full light and 68% light intensity, while lower ratios are found under 27%, 12%, and 5% light intensity. Figure 1 D).

[0033] 3. Key enzymes of the Calvin cycle in leaves were selected: ribulose-1,6-bisphosphatase / oxygenase (Rubisco) and fructose-1,6-bisphosphatase (FBPase). Enzyme activities of sugar metabolism-related enzymes, including sucrose phosphate synthase (SPS), adenosine diphosphate glucose pyrophosphorylase (AGPase), and phosphoenolpyruvate carboxylase (PEPC), were measured. Enzyme activity was determined using a chemical reagent kit (Suzhou Keming Biotechnology Co., Ltd., Suzhou, China), following the manufacturer's instructions. Enzyme extraction was performed according to the manufacturer's specifications. The enzyme solution was then transferred to a microplate and the absorbance was measured at 340 nm using a microplate reader (Bio-Tek ELX800, Bio-Tek Instruments Inc., Winooski, VT, USA). Finally, the enzyme activity was calculated using the formula provided in the instructions.

[0034] The results are as follows Figure 2 As shown, with decreasing light intensity, the activity of ribulose diphosphate carboxylase / oxygenase in leaves significantly decreased. Figure 2 A) The activity of fructose-1,6-bisphosphatase initially increased significantly, reaching its maximum at 68% light intensity, at 562.95 ± 35.95 nmol·min⁻¹. -1 g -1 Subsequently, the activity decreased significantly, reaching its lowest levels at 12% and 5% light intensities, at only 19.24% and 19.25% of that at 68% light intensities. Figure 2 B). Compared with full light treatment, the reduction in light intensity significantly decreased the activity of sucrose phosphate synthase in leaves, reaching its lowest levels at 12% and 5% light intensities, at 30.87% and 31.64% of that under full light, respectively. Figure 2 C). The activity of adenosine diphosphate glucose pyrophosphorylase generally showed a decreasing trend with decreasing light intensity. The decrease was small and not significant at full light, 68%, 27%, and 12% light intensities, but it decreased significantly at 5% light intensity. Figure 2 D). Phosphoenolpyruvate carboxylase activity decreased significantly with decreasing light intensity, decreasing by 15.65%, 68.94%, 88.88%, and 85.11% respectively compared to full light exposure. Figure 2 E).

[0035] 4. After drying and weighing, the root, stem, and leaf samples of the seedlings were ground and sieved (1mm aperture) and stored for testing. Carbon and nitrogen contents were determined using a CN elemental analyzer (VARIO MAX CN, Elementary, Germany) via the dry-burning method. Phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and manganese (Mn) contents were first prepared by double-acid digestion of the samples using an ultra-high pressure microwave digestion system (Multiwave ECO, Anton Paar, Austria). After dilution, the concentrations of each element were determined using an inductively coupled plasma optical emission spectrometer (ICP-OES, Optima 8000, PerkinElmer), and the content of each nutrient element was calculated using formulas.

[0036] The results are as follows Figure 3 As shown, the C content in leaves decreased significantly with decreasing light intensity. Figure 3 A). Leaf nitrogen (N) content increased significantly with decreasing light intensity. Compared with full sunlight, leaf N content increased by 18.23%, 42.42%, and 98.79% under 27%, 12%, and 5% light intensities, respectively. Figure 3 B). The trend of P content in leaves was similar to that of N content, with higher P content observed under low light intensity. Compared to full light treatment, the increases were smaller and not significant at 68% and 27% light intensities, while significant increases were observed at 12% and 5% light intensities, with increases of 30.34% and 80.74%, respectively. Figure 3 C). As light intensity decreases, the carbon-to-nitrogen ratio generally shows a downward trend, reaching its lowest point at 5% light intensity, at only 48.84% of that at full illumination. Figure 3 D). The carbon-to-phosphorus ratio decreases significantly with decreasing light intensity, reaching its minimum at 5% light intensity. Figure 3 E). Changes in light intensity had no significant effect on the nitrogen-to-phosphorus ratio (NPK) of Chinese fir seedling leaves; the NPK ratio was relatively higher under low light intensity. Figure 3 F).

[0037] The results are as follows Figure 4 As shown, the contents of K, Ca, Mg, and Mn all increased significantly with decreasing light intensity. Compared to full sunlight, the K content in leaves increased by 22.54%, 52.05%, 91.30%, and 134.34% under different light intensities, respectively. Figure 4 A), the Ca content increased by 14.73%, 26.34%, 129.99%, and 149.17%, respectively. Figure 4 B). At 68% light intensity, the leaf Mg content did not differ significantly from the full-light treatment. It increased significantly starting at 27% light intensity, reaching a peak at 5% light intensity, and was significantly higher than other treatments, being 1.640 times that of the full-light treatment. Figure 4C). The Mn content in leaves increased significantly with decreasing light intensity, reaching its highest level at 5% light intensity, an increase of 56.50% compared to the full-light treatment. Figure 4 D).

[0038] 5. Refer to Cao Gang

[163] The method used was to determine the contents of cytokinin (ZA), abscisic acid (ABA), gibberellin (GA3), and auxin (indoleacetic acid, IAA) in the leaves of Chinese fir seedlings using a RIGOL L3000 high performance liquid chromatograph.

[0039] The results are as follows Figure 5 As shown, the cytokinin content in leaves decreased significantly with decreasing light intensity, reaching its lowest level at 5% light intensity, a decrease of 57.34% compared to full light intensity. Figure 5 A). As light intensity decreases, the content of abscisic acid in leaves first decreases and then increases, reaching its lowest level at 27% light intensity, which is only 28.73% of that under full light. Figure 5 B). The gibberellin content in leaves initially decreased slightly and then increased significantly, reaching its highest level under 5% light intensity. Figure 5 C). There was no significant difference in auxin content in the leaves of Chinese fir seedlings among different treatments, but compared with full light treatment, the auxin content in the leaves of other treatments was decreased. Figure 5 D).

[0040] Example 2

[0041] 1. The experiment was conducted in the experimental greenhouse of Fujian Agriculture and Forestry University (26°4′30″~26°6′00″N, 119°13′30″~119°14′30″E). Based on the previous research results, two light intensity gradients (400 μmol·m⁻¹) were selected. -2 ·s -1 and 40 μmol·m -2 ·s -1 Six light quality treatments were set for each light intensity gradient: blue light (BL, 450–455 nm), red light (RL, 650–660 nm), 1:1 red / far-red light (1:1L), 1:2 red / far-red light (1:2L), far-red light (FrL, 715–735 nm), and white light (WL, 450–570 nm) as controls. Among them, 1:1 red / far-red light (1:1L) and 1:2 red / far-red light (1:2L) were achieved by evenly arranging red and far-red LED beads in a proportional manner.

[0042] All treatments were conducted in separate growth chambers (90cm × 100cm × 100cm cube-shaped steel frame structures). The different growth chambers were separated by a non-reflective, opaque black film to prevent light pollution. Each growth chamber was equipped with an upward airflow distribution system to control the temperature and ensure air circulation. Two LED light panels, each 40cm × 80cm in size, were horizontally mounted above each growth chamber. The vertical distance between the top of the seedling canopy and the LED light panels was maintained at 20cm. PPFD was measured at the top of the seedlings, and the brightness of the LED light panels was adjusted to maintain a value of 400 μmol·m⁻². -2 ·s -1 and 40 μmol·m -2 ·s -1 During the experiment, the distance between the LED light panels and the seedling canopy was adjusted in a timely manner according to the growth of the Chinese fir seedlings. All LED light panels were controlled by an automatic timer calibrator, providing 12 hours of light per day (from 6:00 to 18:00).

[0043] In April 2021, one-year-old clonal Chinese fir seedlings (Yang-061) were purchased from the nursery of Yangkou State-owned Forest Farm, Shunchang County, Fujian Province. The seedlings were transplanted into pots filled with a mixture of peat moss and vermiculite (volume ratio 2:1), with one seedling planted in each pot. The seedlings were then placed in an experimental greenhouse for one month. After the seedlings had recovered, 72 relatively uniformly grown and well-developed Chinese fir seedlings (average height 31.55±5.32 cm, average diameter at breast height 3.69±0.31 mm) were selected and randomly divided into 12 groups. These groups were then placed in growing chambers with different light environments for another three months. Each treatment consisted of six seedlings, with each pot considered a replicate. The seedlings were randomly placed, ensuring they were exposed to the same light conditions, were independent of each other, and did not shade each other. To avoid light heterogeneity, the pots were adjusted weekly. No fertilizer was applied during the experiment; only regular weeding and watering 2-3 times per week were performed to maintain soil moisture.

[0044] 2. Root activity (RV) was determined using the TTC method: 0.5 g of fresh root tip tissue was fully immersed in 10 ml of a solution of 0.4% TTC and phosphate buffer (1 / 15 mol·L⁻¹). -1 Add equal volumes of the solution (pH=7.0) to a container, seal the container with plastic wrap, and incubate in the dark at 37°C for 2 hours. Then, use a pipette to draw 1 mol·L⁻¹ of the solution. -12 ml of H2SO4 solution was added to stop the reaction. For the control group, H2SO4 solution was added first, followed by root tip tissue, with all other procedures maintained. After stopping the reaction, the roots were removed with tweezers, dried with filter paper, and then ground with ethyl acetate and a small amount of quartz sand for extraction. After multiple washes with ethyl acetate, the extract was transferred to a 10 ml volumetric flask and diluted to volume. The absorbance of the extract at 485 nm was measured, and root activity was calculated using the formula.

[238] .

[0045] The results are as follows Figure 6 As shown, the root activity of *Cunninghamia lanceolata* seedlings decreased significantly with decreasing light intensity, but the response to changes in light quality differed under different light intensities. Compared to white light, 400 μmol·m -2 ·s -1 Under different light intensities, blue light, 1:1 red / far-red light, and far-red light treatments resulted in lower root activity in *Cunninghamia lanceolata* seedlings, while 40 μmol·m⁻¹ light treatment showed lower root activity. -2 ·s -1 Root activity was enhanced under blue light and 1:1 red / far-red light, while root activity was relatively low under red light, 1:2 red / far-red light, and far-red light treatments.

[0046] 3. All seedlings were harvested and separated into roots, stems, and leaves. Each seedling was placed in an envelope, labeled, and placed in an oven at 105℃ for 30 minutes to blanch. The temperature was then adjusted to 80℃ and dried to constant weight. The dry biomass of each part (root biomass RB, stem biomass SB, leaf biomass LB, g) was then measured. Based on the final data, the total biomass (TB, g), the biomass ratios of each part (root biomass ratio RMR, stem biomass ratio SMR, leaf biomass ratio LMR), and the root-to-shoot ratio (R:S) were calculated.

[0047] With decreasing light intensity, the root biomass and root biomass ratio of Chinese fir seedlings decreased significantly under all light quality conditions. Figure 7 A).

[0048] As light intensity decreased, the stem biomass of *Cunninghamia lanceolata* seedlings decreased significantly. At 400 μmol·m⁻², the stem biomass of *Cunninghamia lanceolata* seedlings decreased significantly. -2 ·s -1 Under varying light intensity, changes in light quality had no significant effect on the stem biomass of *Cunninghamia lanceolata* seedlings (p = 0.222), but a significant effect on the stem biomass ratio. Under blue light, the stem biomass of *Cunninghamia lanceolata* seedlings decreased, while the stem biomass ratio significantly increased and was higher than under other light qualities. At 40 μmol·m⁻², the stem biomass of *Cunninghamia lanceolata* seedlings decreased. -2 ·s -1 Under different light intensities, except for a decrease in stem biomass accumulation and allocation ratio under red light, *Cunninghamia lanceolata* seedlings showed greater stem biomass accumulation and allocation ratio under other light qualities. Under different light intensities, *Cunninghamia lanceolata* seedlings grown under far-red light exhibited the highest stem biomass and stem biomass ratio, and the stem biomass accumulation and allocation ratio increased with increasing proportion of far-red light. Figure 7B).

[0049] With decreasing light intensity, the leaf biomass of *Cunninghamia lanceolata* seedlings decreased significantly, while the leaf biomass ratio increased significantly. At 400 μmol·m⁻², the leaf biomass ratio was significantly higher. -2 ·s -1 Under varying light intensity, changes in light quality had no significant effect on the leaf biomass of *Cunninghamia lanceolata* seedlings (p = 0.302), but a significant effect on the leaf biomass ratio. Compared to white light, the leaf biomass ratio of *Cunninghamia lanceolata* seedlings was lower under all light qualities except for a slight increase under blue light. At 40 μmol·m⁻¹ -2 ·s -1 Under different light intensities and light qualities, there was no significant difference in leaf biomass of *Cunninghamia lanceolata* seedlings (p = 0.099). Compared with white light, leaf biomass decreased under blue and red light, while leaf biomass was higher under 1:1 red / far-red, 1:2 red / far-red, and far-red light, and decreased with increasing proportion of far-red light. Figure 7 C).

[0050] With decreasing light intensity, the total biomass and root-to-shoot ratio of *Cunninghamia lanceolata* seedlings decreased significantly. At 400 μmol·m⁻², the total biomass and root-to-shoot ratio of *Cunninghamia lanceolata* seedlings also decreased. -2 ·s -1 Under varying light intensity, changes in light quality had no significant effect on the total biomass of seedlings (p = 0.056). Compared to white light, the total biomass and root-to-shoot ratio of *Cunninghamia lanceolata* seedlings decreased under blue light, while the total biomass and root-to-shoot ratio were higher under other light qualities. At 40 μmol·m⁻², the total biomass and root-to-shoot ratio of *Cunninghamia lanceolata* seedlings decreased. -2 ·s -1 Under light intensity, the total biomass and root-to-shoot ratio of Chinese fir seedlings were relatively low under blue and red light, with the lowest root-to-shoot ratio observed under the 1:2 red / far-red light treatment. Figure 7 D).

[0051] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A method for regulating the physiological indexes of Cunninghamia lanceolata seedlings, characterized in that, By adjusting light intensity and controlling light quality irradiation treatment of Chinese fir seedlings, the physiological indexes of Chinese fir seedlings are regulated; the light intensity is changed in the range from 400 μmol·m -2 ·s -1 to 40 μmol·m -2 ·s -1 , the light quality includes white light, blue light, red light, 1:1 L red / far red light, 1:2 L red / far red light, far red light, and the physiological indexes are root activity, root biomass, stem biomass, leaf biomass, total biomass, root biomass ratio and root / shoot ratio. At light intensity from 400 μmol·m -2 ·s -1 - 40 μmol·m -2 ·s -1 , the use of blue light or 1:1 L red / far red light irradiation achieved the promotion of the root activity of Chinese fir seedlings; At light intensity from 40 μmol·m -2 ·s -1 -400 μmol·m -2 ·s -1 , white light or blue light or red light or 1:1 red / far-red light or 1:2 red / far-red light or far-red light was used to achieve the promotion of root biomass, root biomass ratio, stem biomass, and leaf biomass of Chinese fir seedlings.

2. The method for regulating the physiological indexes of Cunninghamia lanceolata seedlings according to claim 1, characterized in that, At 400 μmol·m -2 ·s -1 Under the light intensity, the light quality was controlled from white light to blue light, which promoted the increase of the stem biomass ratio and leaf biomass ratio of Chinese fir seedlings.

3. The method for regulating the physiological indexes of Cunninghamia lanceolata seedlings according to claim 1, characterized in that, At 40 μmol·m -2 ·s -1 Under the light intensity, the light quality was controlled to change from white light to red light or 1:1 red / far-red light or 1:2 red / far-red light or far-red light, to achieve the promotion of the accumulation of Chinese fir seedling stem biomass and the increase of the distribution ratio.

4. The method for regulating the physiological indexes of Cunninghamia lanceolata seedlings according to claim 1, characterized in that, At 40 μmol·m -2 ·s -1 Under the light intensity, the light quality was controlled to change from white light to 1:1 red / far-red light or 1:2 red / far-red light or far-red light, to promote the increase of Chinese fir seedling leaf biomass.

5. The method for regulating the physiological indexes of Cunninghamia lanceolata seedlings according to claim 1, characterized in that, At 400 μmol·m -2 ·s -1 Under the light intensity, the light quality was controlled to change from white light to red light or 1:1 red / far-red light or 1:2 red / far-red light or far-red light, to achieve the promotion of total biomass and root / shoot ratio of Chinese fir seedlings.

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