Composition for resisting waterlogging, strengthening seedlings and stabilizing yield of wheat as well as application and use method of composition

Abstract

The invention relates to the technical field of wheat stain resistance. The invention provides a composition for resisting waterlogging, strengthening seedlings and stabilizing yield of wheat as well as application and a use method of the composition. The composition comprises the following components: S-abscisic acid, paclobutrazol-mepiquat chloride and a humic acid-containing micro-element fertilizer. The combined pesticide provided by the invention can improve the root volume, surface area and dry weight, effectively relieve the influence of waterlogging on root growth, promote the occurrence rate of first tillering of wheat, promote the growth of leaves and tillering and improve the tillering quality. The photosynthetic ability, chlorophyll fluorescence ability, oxidation metabolism resistance and carbon and nitrogen metabolism of the main stem and the first tiller are enhanced. And finally, the improvement of the quality of early-stage stem tiller groups can be promoted, tillering and ear formation are promoted, and the yield is increased.

Description

Technical Field

[0001] The invention relates to the technical field of wheat waterlogging resistance, and in particular to a composition for wheat waterlogging resistance, strong seedlings and stable yield, and an application and use method thereof. Background Art

[0002] As the main planting method in the region, the wheat-rice model has the advantages of high annual benefits, high yield potential, and easy mechanized planting, which is of great significance to ensuring food production security. In recent years, the promotion of rice varieties with long growth periods has gradually delayed harvesting, and the tight connection between stubbles has led to short field drying time and wet and sticky soil. Due to climate change, autumn rains flooded the wheat-growing areas from September to November, and the paddy field flooding, soil sedimentation and consolidation, and mechanical rolling all destroyed the soil aggregate structure, resulting in water accumulation in the field during the appropriate sowing period of wheat and difficulty in infiltration, resulting in serious waterlogging problems. After encountering waterlogging, wheat seedlings showed delayed growth, yellowing and wilting of leaves, and a reduction of more than 30% in tillering, resulting in a 10% to 15% reduction in yield. Waterlogging reduces the oxygen concentration in the rhizosphere, aggravates anaerobic respiration of the root system, inhibits cell division and ion exchange, reduces the water absorption capacity of the root system, hinders plant transpiration, and reduces the nitrogen absorption capacity, causing chlorophyll atrophy and reduced stomatal density in the mesophyll, which is not conducive to leaf photosynthesis. The chloroplast membrane system is an important place for light energy absorption, transmission and conversion. Adverse stress will hinder the photochemical reaction of electrons, produce a large amount of reactive oxygen, trigger cell membrane lipid peroxidation, damage the chloroplast membrane structure and accelerate hydrolysis. Waterlogging will also lead to a decrease in the openness of the reaction center PSII, and reduce the actual photochemical efficiency (ΦPSII) and the maximum photochemical efficiency (Fv / Fm).

[0003] Therefore, studying measures to supplement wheat roots with nutrition, promote photosynthesis, and ensure tillering and ear formation is of great significance for cultivating strong seedlings that are resistant to waterlogging and achieving stable production and increased income. Summary of the invention

[0004] The purpose of the present invention is to provide a composition for wheat waterlogging resistance, strong seedlings and stable yield, and its application and use method, so as to increase root volume, surface area and dry weight, and effectively alleviate the influence of waterlogging on root growth.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The invention provides a composition for wheat waterlogging resistance, strong seedlings and stable yield, comprising the following components: S-inducing factor, paclobutrazol-methylpiperidin and micro-fertilizer containing humic acid.

[0007] Preferably, the mass ratio of S-inducing factor, paclobutrazol·methylpiperidin and humic acid-containing micro-fertilizer in the composition is 4-6:230-270:90-110.

[0008] Preferably, the specification of the paclobutrazol·mepirac is 30% paclobutrazol·mepirac, in which the content of paclobutrazol is 23-27% and the content of mepirac is 3-7%.

[0009] Preferably, the humic acid-containing micro-fertilizer contains the following components in concentrations: 35-45 g / L humic acid, 90-110 g / L nitrogen, 90-110 g / L phosphorus, and 140-160 g / L potassium.

[0010] The invention also provides application of the composition in wheat waterlogging resistance, seedling strengthening or yield stabilization.

[0011] The present invention also provides a method for using the composition, comprising the following steps:

[0012] (1) mixing the composition with water to obtain a liquid medicine;

[0013] (2) Spray the solution onto wheat in two batches.

[0014] Preferably, the concentration of S-inducing factor in the liquid medicine in step (1) is 4-6 mg / kg, the concentration of paclobutrazol-methylpiperidin is 280-320 mg / kg, and the concentration of humic acid-containing micro-fertilizer is 90-110 mg / kg.

[0015] Preferably, the first spraying time of the liquid medicine in step (2) is when the wheat has three leaves and one heart, and the second spraying time is 12 to 16 days after the first spraying.

[0016] Preferably, the single spraying amount of the liquid in step (2) is 280-320 kg / hm 2 .

[0017] The present invention provides a composition for wheat waterlogging resistance, seedling strengthening and stable yield, and its application and use method, wherein the composition comprises the following components: S-inducing agent, paclobutrazol·methylpiperidin and humic acid-containing micro-fertilizer. The combined agent provided by the present invention can increase root volume, surface area and dry weight, effectively alleviate the influence of waterlogging on root growth, promote the occurrence rate of the first tiller of wheat, promote the growth of leaves and tillers and improve the quality of tillers. Enhance the photosynthetic capacity, chlorophyll fluorescence capacity, antioxidant metabolism and carbon and nitrogen metabolism of the main stem and the first tiller. Finally, it can promote the improvement of the quality of the early stem tiller population, promote tillering into ears and increase yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the change of precipitation and relative soil water content after sowing;

[0019] Figure 2is the effect of spraying the agent on the interception and absorption capacity of light energy, where ABS / RC is the absorption flux per unit reaction center (RC), φPo is the maximum quantum yield of primary photochemistry, ψo is the probability of capturing excitons and transporting electrons to transport chains other than QA-, φEo is the quantum yield of electron transport, RC / CSo is the density of reduced PSII reaction centers, PI abs is an absorption-based performance index, and PICS is a unit cross-sectional absorption performance index (application of rapid chlorophyll fluorescence induced kinetic analysis in photosynthesis research);

[0020] Figure 3 The effect of spraying of pesticides on fluorescence parameters;

[0021] Figure 4 The effect of spraying the pesticide on the light response ability;

[0022] Figure 5 The effect of spraying the pesticide on the sugar content of stem and tiller leaves;

[0023] Figure 6 The effect of spraying the pesticide on the nitrogen content of stem and tiller leaves;

[0024] Figure 7 The effect of spraying pesticides on leaf membrane permeability;

[0025] Figure 8 The effect of spraying the pesticide on the antioxidant enzyme activity of leaves;

[0026] Fig. 9 The spraying of the pesticide affects the fruit set at each ear position of the main stem and tillers. DETAILED DESCRIPTION

[0027] The invention provides a composition for wheat waterlogging resistance, strong seedlings and stable yield, comprising the following components: S-inducing factor, paclobutrazol-methylpiperidin and micro-fertilizer containing humic acid.

[0028] In the present invention, the mass ratio of S-inducing factor, paclobutrazol·methylpiperidin and humic acid-containing micro-fertilizer in the composition is preferably 4-6:280-320:90-110, and more preferably 5:300:100.

[0029] In the present invention, the specification of paclobutrazol·mepirac is preferably 30% paclobutrazol·mepirac, and the content of paclobutrazol in the 30% paclobutrazol·mepirac is preferably 23-27%, more preferably 25%, and the content of mepirac is preferably 3-7%, more preferably 5%.

[0030] In the present invention, the humic acid-containing micro-fertilizer preferably contains the following concentrations of components: 35-45 g / L humic acid, 90-110 g / L nitrogen, 90-110 g / L phosphorus, and 140-160 g / L potassium, and more preferably: 40 g / L humic acid, 100 g / L nitrogen, 100 g / L phosphorus, and 150 g / L potassium.

[0031] In the present invention, the concentration of nitrogen is measured as nitrogen element, the concentration of phosphorus is measured as P2O5, and the concentration of potassium is measured as K2O.

[0032] The invention also provides application of the composition in wheat waterlogging resistance, seedling strengthening or yield stabilization.

[0033] The present invention also provides a method for using the composition, comprising the following steps:

[0034] (1) mixing the composition with water to obtain a liquid medicine;

[0035] (2) Spray the solution onto wheat in two batches.

[0036] In the present invention, the concentration of S-inducing factor in the liquid medicine in step (1) is preferably 4-6 mg / kg, more preferably 5 mg / kg, the concentration of paclobutrazol-methylpiperidin is preferably 280-320 mg / kg, more preferably 300 mg / kg, and the concentration of humic acid-containing micro-fertilizer is preferably 90-110 mg / kg, more preferably 100 mg / kg.

[0037] In the present invention, the first spraying time of the liquid medicine in step (2) is preferably when the wheat has three leaves and one heart, and the second spraying time is preferably 12 to 16 days after the first spraying, and more preferably 14 days.

[0038] In the present invention, the single spraying amount of the liquid in step (2) is preferably 280 to 320 kg / hm 2 , more preferably 300kg / hm 2 .

[0039] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0040] Example 1 Materials and Methods

[0041] 1. Overview of the test site

[0042] The experiment was conducted in Yuanxing Township, Dayi County, Chengdu City (30°58′N, 103°53′E) from 2022 to 2024. The soil of the test site is loam, and the soil nutrients at 0-20cm are: organic matter 38.91, 47.84g / kg, total nitrogen 2.06, 2.42g / kg, alkaline nitrogen 269.64, 195.05mg / kg, total phosphorus 0.23, 0.38g / kg, available phosphorus 17.24, 12.91mg / kg, total potassium 14.73, 10.66g / kg, available potassium 249.63, 240.20mg / kg, precipitation during the wheat growing season 324.6, 382.6mm, average daily temperature 13.5, 13.7℃. In this experiment, the dynamics of soil moisture content at 0-20cm from sowing to jointing stage (70d after sowing) are as follows Figure 1 As shown in the figure, the relative soil moisture content was above 90% within 20 days after wheat sowing, which met the waterlogging standard according to (GB / T 32752-2016).

[0043] 2. Test materials and experimental design

[0044] The wheat used for the test was Shumai 1963, which was bred by Sichuan Agricultural University. The pesticides were provided by Sichuan Runer Technology Co., Ltd., and their names and dosages were S-ABA 5 mg / kg, 30% paclobutrazol mepiquat (PM) 300 mg / kg, humic acid water-soluble fertilizer (HA) 100 mg / kg, and sprayed at 300 kg / hm 2 Application. Among them, the main components of humic acid water-soluble fertilizer are humic acid 40g / L, nitrogen (N) 100g / L, phosphorus (P2O5) 100g / L, potassium (K2O) 150g / L.

[0045] The experiment adopted a single-factor randomized block design. From 2022 to 2023, the experiment had five kinds of pesticide treatments, namely S-ABA, PM, HA, S+P+H (S-ABA+PM+HA), and spraying of clean water CK was set as a control. From 2023 to 2024, the S+P+H combination was subdivided on the basis of the first year's treatment, and three new combination treatments were added, namely S+P (S-ABA+PM), S+H (S-ABA+HA), and P+H (P+H). Each treatment was set up with 3 replications, and the pesticide was sprayed when the wheat was three leaves and one heart, and then sprayed again after 14 days. The experimental base fertilizer used was 15-15-15 compound fertilizer 750kg / hm 2 , topdressing with common urea (N 46.0%) 145kg / hm 2 Wheat was sown in holes, with a row spacing of 20 cm and a hole spacing of 10 cm. Six seeds were sown in each hole, and the area of ​​the plot was 12 m 2 The basic seedling is 2×10 6 plant / hm 2 .

[0046] 3. Measurement items and methods

[0047] (1) Determination of relative soil moisture content

[0048] The five-point sampling method was used. Sampling was carried out on the day of sowing and every 10 days after sowing. Sampling was carried out in the 0-10 cm and 10-20 cm soil layers. The soil was collected with a ring knife, dried and the relative moisture content of the soil was calculated.

[0049] Relative water content: (W1-W3) / (W2-W3)×100%

[0050] Among them, W1 is the weight of the ring knife and soil after the ring knife takes the soil, W2 is the weight of the ring knife, and W3 is the weight of the ring knife and soil after drying.

[0051] (2) Root growth survey

[0052] At the jointing stage, 15 plants and their roots were dug from each plot. The roots were cleaned and scanned using Epson Expression10000XL. The scanned images were analyzed using Win RHIZO root analysis system to calculate the total root length, root volume and root surface area. The plants and the scanned roots were dried and weighed to calculate the root-crown ratio.

[0053] Root-to-crown ratio = total weight of underground roots / total weight of aboveground stems and leaves

[0054] (3) Investigation on the quality of stem and tiller growth at the seedling stage

[0055] At the three-leaf stage, 20 wheat plants were uniformly taken from each plot, and the main stems of another 20 wheat plants were marked in the plot. After 7 days, the first tiller was marked. At the jointing stage, 15 wheat plants were taken from each plot, and the leaf age, length, and stem diameter of the main stem (O), the first tiller (T1), and the remaining tillers (T2) were measured. 0.1 g of the flat leaves at the top of the main stem and tiller of the samples at the three-leaf stage (t1) and jointing stage (t2) were weighed and placed in 10 mL of acetone-ethanol mixture (1:1, V / V) for 7 days. The absorbance of the extract was measured at 645 nm and 663 nm wavelengths to calculate the chlorophyll a, b and total content. The remaining leaves and stems of the plant were withered at 105°C for 30 minutes, dried at 85°C to constant weight, and then weighed. The leaf area index and leaf area ratio at the jointing stage, as well as the group growth rate, relative growth rate, growth function (G value), and seedling index from the three-leaf stage to the jointing stage were calculated.

[0056] Chl a(mg / g)=(12.7×A663-2.69×A645)×V / w / 1000

[0057] Chl b(mg / g)=(22.9×A645-4.68×A663)×V / w / 1000

[0058] Total chlorophyll (mg / g) = (20.2×A645+8.02×A663)×V / w / 1000

[0059] Leaf dry weight ratio (LWR) = LW / W

[0060] Leaf area index (LAI) = total leaf area / S

[0061] Relative growth rate (RGR, mg / g / d) = (lnW2-InW1) / (t2-t1)1000

[0062] Net assimilation rate (NAR, mg / m 2 / d)=(lnL2-InL1)·(W2-W1) / (L2-L1)-(t2-t1)1000

[0063] Growth function (G value) = (W2-W1) / (t2-t1)

[0064] Seedling strength index (SSI) = (stem diameter / plant height + root dry mass / aboveground dry mass) × whole plant dry mass.

[0065] Wherein, V is the volume of chlorophyll extract (if it is a diluted solution, it needs to be converted), w is the fresh weight of the material, W, L, Lw are the plant dry weight, leaf area and leaf dry weight, respectively, W1, W2, L1, L2 are the plant dry weight and leaf area at t1 and t2, respectively, and S is the land area.

[0066] (4) Determination of photosynthetic capacity and fluorescence parameters

[0067] At the jointing stage, 5-7 leaves were expanded at the top of the main stem and the first tiller of wheat in each plot. The photosynthetic rate (PN), intercellular CO2 concentration (Ci), stomatal conductance (Gs) and transpiration rate (Tr) were measured using the Li-6800 portable photosynthetic meter from LI-COR Company of the United States between 9:00 and 11:00 in the morning on sunny days. The OJIP fluorescence curve was measured using the Handy PEA+ portable plant efficiency meter to calculate the ABS / RC, ψo, RC / CSo, and use the ultra-portable modulated chlorophyll fluorescence meter MINI-PAM-II to measure the induction curve, light response curve, and determine Fv / Fm, Y(NO), Y(II), Y(NPQ), QL, and NPQ.

[0068] (5) Leaf relative conductivity and malondialdehyde determination

[0069] At the six-leaf and one-heart stage, 15 main stems and the top expanded leaves of the first tiller were selected from each plot. The leaves were rinsed with tap water to remove surface dirt and then rinsed twice with deionized water. The surface moisture of the leaves was absorbed with clean gauze, and then 20 leaf discs were punched with a hole puncher. The discs were soaked for 24 hours and the conductivity of the solution was measured, recorded as R1. Then a small beaker was placed in a boiling water bath and heated for 10 minutes. After cooling to room temperature, the conductivity of the solution was measured again, recorded as R2.

[0070] Relative conductivity = R1 / R2×100%.

[0071] Thiobarbituric acid method was used to determine the MDA content in tiller nodes and leaves at jointing stage.

[0072] (6) Leaf antioxidant enzyme assay

[0073] The expanded leaves at the top of the first tiller and the main stem at the six-leaf and one-heart stage were taken, and the superoxide dismutase (SOD) was determined by the NBT (nitroblue tetrazolium) photoreduction method, the peroxidase (POD) was determined by the guaiacol method, the catalase (CAT) was determined by the ultraviolet absorption method, and the ascorbate peroxidase was determined by the ultraviolet absorption method with reference to Faiza (APX).

[0074] (7) Investigation of stem tillering dynamics

[0075] In each plot, two representative rows of sample points with a length of 0.8 m were framed to investigate the number of tillers at the seedling stage, the rapid tillering stage, the jointing stage, the booting stage, the flowering stage and the maturity stage. According to the tillering occurrence law, the direction of the effective ear 9 o'clock in the maturity stage was extended in the opposite direction to the intersection point formed in the tillering stage to make the "effective tillering critical point". According to the tillering dynamics, the effective tillering occurrence rate (TER1), the ineffective tillering occurrence rate (TER2), the tillering death rate (TDR), the tillering capacity per plant (TC), the number of ears per plant (FTP), and the ear formation rate (TSR) were calculated respectively. The calculation formulas for each parameter are as follows:

[0076] TER1 = (number of tillers at the critical point of effective tillering - basic seedlings) / time interval

[0077] TER2 = (maximum tiller number - effective tillering critical point tiller number) / time interval

[0078] TDR = (maximum number of tillers - effective ears) / time interval

[0079] TC = (maximum number of tillers - basic seedlings) / basic seedlings

[0080] FTP=Effective ear / Basic seedling

[0081] TSR = effective ear / maximum tiller number × 100%

[0082] (8) Fruiting characteristics and yield

[0083] Wheat maturity survey 0.8m in each plot 2 The number of tillers in the fixed sampling point was 30 main stems and their tillers were selected to investigate the fruiting situation of each ear position, and the number of fruiting spikelets, sterile spikelets, and grains per ear were calculated. 2 After threshing and drying, the thousand-grain weight and actual yield (13% moisture content) of the group were determined.

[0084] 4. Data processing

[0085] Excel 2010 software was used to organize the experimental data, DPS7.05 and spass 26.0 software were used for variance analysis, principal component analysis and comprehensive score, the LSD method was used for multiple comparisons, and origin 2021 software was used for drawing.

[0086] Results and Analysis

[0087] 1. Effect of spraying combined pesticides on wheat seedling growth

[0088] (1) Effects of spraying combined pesticides on wheat root growth

[0089] As can be seen from Table 1, spraying S-ABA in the two growing seasons increased root dry weight by 36.0% and 47.2%, increased root length by 38.5% and 47.2%, increased root surface area by 33.2% and 44.9%, increased root volume by 22.7% and 51.9%, and increased root-to-crown ratio by 47.2% and 21.4% compared with CK. Spraying PM increased root dry weight by 33.9% and 54.0%, increased root length by 30.8% and 75.0%, increased root volume by 70.5% and 23.1%, and increased root-to-crown ratio by 34.0% and 14.3% compared with CK. Spraying HA showed a decreasing trend in root volume and root-to-crown ratio, while spraying S+P+H increased root dry weight by 30.2% and 32.0%, increased root length by 19.2% and 30.5%, and increased root volume by 22.7% and 26.9% compared with CK.

[0090] Spraying PM in the 2022-2023 growing season significantly increased the root surface area compared with CK, and spraying S+P+H significantly increased the root-crown ratio. Spraying S+P in the 2023-2024 growing season significantly reduced the root-crown ratio compared with CK, and spraying S+H increased root dry weight by 36.0%, root length by 16.7%, root surface area by 14.3%, and root volume by 21.2% compared with CK, and reduced the root-crown ratio by 14.3%. Spraying P+H increased root dry weight by 22.0%, root length by 33.3%, and root surface area by 20.9% compared with CK.

[0091] In summary, after wheat suffered from waterlogging at the seedling stage, spraying S-ABA, PM and their combination S+P at the three-leaf stage can effectively promote the accumulation of root assimilates and the increase of secondary roots, and improve the root-crown ratio. Although spraying HA significantly improved the growth of the aboveground part, the root volume and root-crown ratio were significantly reduced, which was not conducive to subsequent growth. The above-mentioned drug combinations S+H and S+P+H can effectively combine the above advantages, achieve the effect of "controlling the upper part and promoting the lower part", increase the root volume, surface area and dry weight, and effectively alleviate the impact of waterlogging on root growth.

[0092] Table 1 Effects of pesticide spraying on wheat root growth

[0093]

[0094] Note: CK (clear water), S-ABA (S-absorbent), PM (paclobutrazol·methylpiperidin), HA (water-soluble fertilizer containing humic acid), S+P (S-absorbent + paclobutrazol·methylpiperidin), S+H (S-absorbent + water-soluble fertilizer containing humic acid), P+H (paclobutrazol·methylpiperidin + water-soluble fertilizer containing humic acid), S+P+H (absorbent + paclobutrazol·methylpiperidin + water-soluble fertilizer containing humic acid) Different letters indicate significant differences (P < 0.05), and the same is true for the table below.

[0095] (2) Effects of spraying combined pesticides on wheat tiller growth

[0096] As can be seen from Table 2, spraying HA and S+P+H in both growing seasons can increase the leaf age, stem tiller length and stem diameter of the main stem and T1 compared with CK. Spraying S-ABA in the 2022-2023 growing season significantly reduced the leaf age, length and T1 length of the main stem compared with CK, but increased the leaf age, stem diameter and main stem diameter of T1. Spraying PM significantly reduced the leaf age of the main stem compared with CK, and significantly increased the stem diameter of the main stem and T1.

[0097] Spraying S-ABA in the 2023-2024 growing season increased the stem length of T2 by 33.3% compared with CK, and the stem thickness of the main stem, T1, and T2 increased by 28.6%, 16.7%, and 19.2%, respectively. Spraying PM significantly increased the leaf age and main stem thickness of T1 compared with CK. Spraying the combination of the two, S+P, significantly increased the leaf age, length, and main stem thickness of T1. Spraying S+H and P+H significantly increased the leaf age of T1, the length and stem thickness of the main stem and T1.

[0098] In summary, spraying HA can significantly promote the growth of the aboveground part and increase the length and diameter of the tillers. Spraying S-ABA and PM showed a decrease in the length of the tillers and promoted the increase in the diameter of the main stem and T1 tillers, but the combination of the two, S+P, did not significantly improve the diameter of the stem. The combination of S-ABA, PM and HA, S+H and P+H, increased the leaf age and stem diameter of the T1 tillers more than the application of each alone, which helped the T1 tillers to become ears. The combination of the three, S+P+H, has the effect of improving the quality of the T1 tillers, and can also reduce the length of the main stem and T1, and promote the assimilation of more tillers.

[0099] Table 2 Effects of pesticide combination on wheat tiller quality at jointing stage

[0100]

[0101]

[0102] (3) Effect of spraying combined pesticides on wheat growth rate

[0103] From the growth of wheat from the three-leaf stage to the jointing stage, it can be seen in Table 3 that the relative growth rate of tillers and the net assimilation rate of leaves after spraying HA in the two growing seasons were significantly higher than those of CK, and the G value increased by 26.7% and 46.7%. After spraying S-ABA, the growth rate and net assimilation rate of the aboveground tillers were not significantly higher than those of CK, but its promotion effect on the underground part made its seedling index higher. Spraying PM had the largest increase in relative growth rate compared with CK among the three single-application agents, which was 24.0% and 11.3%. Among the combination agents, the interaction between the two growth retardants S+P caused a significant decrease in the growth rate of wheat, but the other combinations showed a promoting effect. P+H had the largest increase in leaf assimilation rate and G value compared with CK, which was 16.1% and 40%, and the seedling index of S+H and S+P+H was the largest compared with CK, which was 38.0% and 44.2%, which also significantly increased the relative growth rate of tillers.

[0104] In summary, spraying S-ABA promotes underground growth, and PM and HA promote aboveground growth, which are both helpful for seedling cultivation. There is an interaction effect between the drug combinations. The S+P interaction inhibits growth, while S+H and P+H are affected by HA to promote growth rate and increase the seedling index. The combination of the three, S+P+H, breaks the side effects of the interaction between the two retardants S+P, and better improves the group quality and leaf assimilation capacity.

[0105] Table 3 Effect of pesticide spraying on wheat growth rate

[0106]

[0107] Note: CK (clear water), S-ABA (S-absorbent), PM (paclobutrazol-methylpiperidone), HA (water-soluble fertilizer containing humic acid), S+P (S-absorbent + paclobutrazol-methylpiperidone), S+H (S-absorbent + water-soluble fertilizer containing humic acid), P+H (paclobutrazol-methylpiperidone + water-soluble fertilizer containing humic acid), S+P+H (absorbent + paclobutrazol-methylpiperidone + water-soluble fertilizer containing humic acid) different letters indicate significant differences (P < 0.05).

[0108] 2. Effects of spraying combined pesticides on photosynthesis of stems and tillers

[0109] (1) Effects of spraying combined pesticides on wheat leaf growth

[0110] From Table 4, spraying HA and S+P+H in both growing seasons can significantly increase the leaf area index, the chlorophyll a content and the total chlorophyll content of the main stem compared with CK. Spraying S-ABA and HA significantly increased the leaf dry weight ratio of tillers compared with CK, and spraying PM increased the chlorophyll b content of the main stem compared with CK. The waterlogging was more serious in the 2022-2023 growing season, with fewer wheat tillers, slower leaf development, and a low overall leaf area index. Spraying S-ABA and PM increased the leaf area ratio by 81.1% and 42.2% compared with CK, and the chlorophyll a content of the main stem leaves by 9.6% and 5%. Spraying S-ABA increased the total chlorophyll content of the main stem leaves by 7.8% compared with CK.

[0111] In the 2023-2024 growing season, spraying S-ABA and PM increased the leaf area index by 30.7% and 51.8% compared with CK, the total chlorophyll content of the main stem leaves increased by 14.7% and 12.9%, and the dry weight ratio of tiller leaves increased by 11.3% and 18.9%. Spraying the combination of S+P increased the dry weight of tiller leaves by 20.8% compared with CK. Spraying S+H significantly increased the leaf area index and leaf area ratio compared with spraying only S-ABA and HA, increasing by 49.1% and 12.0% compared with CK.

[0112] In summary, by comparing the leaf growth during the jointing stage, it can be seen that spraying PM and HA promoted leaf growth, HA increased the mass proportion of tillering leaves, and S-ABA and HA significantly increased the chlorophyll content. The combined agent S+P+H increased LAI, LWR and total chlorophyll content to a greater extent, which is speculated to be due to the interaction between the agents. S-ABA and PM can effectively delay the phenomenon that HA promotes vigorous growth of the aboveground part and insufficient root growth, and promote leaf growth and root growth more than stems, "controlling the upper part and promoting the lower part" to improve the quality of the stem tiller group.

[0113] Table 4 Effects of pesticide spraying on the growth of wheat leaves before jointing

[0114]

[0115]

[0116] (2) Effects of spraying combined pesticides on photosynthesis of wheat leaves

[0117] From Table 5, spraying S-ABA and PM significantly increased the intercellular carbon dioxide concentration of the main stem and tiller compared with CK, the stomatal conductance of the main stem increased by 29.0% and 38.7%, and the stomatal conductance of the tiller increased by 43.7% and 75%. Spraying PM increased the transpiration rate of the main stem and tiller by 28.9% and 91.9% compared with CK, and the photosynthetic rate of the main stem and tiller increased by 58.3% and 52.7%. Spraying the combination of the two, S+P, increased the photosynthetic rate, stomatal conductance, and transpiration rate of the main stem more than S-ABA and PM alone. Spraying HA increased the photosynthetic rate of the main stem and tiller by 59.32% and 49.3% compared with CK, and the intercellular carbon dioxide concentration of the main stem increased significantly, and the stomatal conductance and transpiration rate of the main stem and tiller increased significantly. S+H increased the stomatal conductance and transpiration rate of tillers more than the application of S-ABA and HA alone.

[0118] In summary, spraying PM and HA increased the photosynthetic rate of stems and tillers, spraying PM helped to open the stomata of the main stem and tillers, and the combination of the two, P+H, failed to further improve the photosynthetic capacity but improved the transpiration capacity. The combination of S-ABA and HA effectively promoted the improvement of the photosynthetic capacity of tillers. The combination of three agents, S+P+H, effectively combined the advantages of each agent and improved the photosynthetic capacity of the plant.

[0119] Table 5 Effects of pesticide spraying on photosynthesis of wheat at jointing stage

[0120]

[0121] (3) Effects of spraying combined pesticides on chlorophyll fluorescence of stems and tillers

[0122] Depend on Figure 2 After spraying HA, the interception and absorption performance of chlorophyll in the main stem of wheat for light energy was greatly improved compared with CK. S+H and S+P+H showed significant differences in ψo, Compared with CK, the interception and absorption performance of tillers after spraying PM was improved. The interaction P+H with HA was improved more. S+P+H had advantages in improving energy interception and absorption, and improved the light energy utilization capacity of chlorophyll.

[0123] from Figure 3It can be seen that spraying S-ABA significantly increased the main stem Fv / Fm and Y(II) compared with CK, and reduced the main stem Y(NO) by 13.9% compared with CK. Spraying PM significantly increased the main stem and tiller Y(II) by 23.5% and 13.9%, increased QL by 40.4% and 50.39%, and reduced Y(NO) by 20.5% and 54.9%. The combination of S+P had a higher effect on the main stem and tiller Y(II) than the single application. Spraying HA increased the main stem Y(II) by 29.4% compared with CK, increased the main stem and tiller NPQ by 101.0% and 36.3%, reduced the main stem and tiller Y(NO) by 18.3% and 36.8%, and increased Y(NPO) by 35.9% and 76.2%. Its combination with S-ABA, S+H, increased Y(II) of the main stem and tiller by more than 20% compared with the single application, increased QL by more than 49.1% compared with the single application, and reduced Y(NO) by more than 38.4% compared with the single application. The combination of P+H has an advantage in promoting the improvement of NPQ of the main stem and tiller, which is 37.7% and 50.4% higher than CK. The combination of the three, S+P+H, can balance the efficacy of each agent and has an advantage in improving Y(NPQ) of the main stem and tiller, which is 33.2% and 48.3% higher than CK.

[0124] In summary, S-ABA effectively improved the photosynthetic capacity of the main stem and reduced light damage. PM and HA promoted the improvement of QL of the main stem and had significant mutual synergy. The application of the three alone and their combination S+H, P+H, and S+P+H all contributed to the increase of light energy utilization of stems and tillers. Y(NPQ) is considered an important indicator of stress resistance. Spraying PM and HA significantly improved the light protection ability of tillers, HA significantly improved the light protection ability of the main stem, and P+H and S+P+H had the greatest improvement in the light protection ability of stems and tillers. Y(NO) reflects the damage to the light system under adversity. PM and HA significantly reduced the degree of damage to the stem and tiller tube system, S-ABA significantly reduced the damage to tillers, S+H had the greatest reduction in the damage to the stem and tiller light system, and S+P+H also showed a significant reduction.

[0125] (4) Effects of spraying combined pesticides on the light response ability of stem tillers

[0126] Depend on Figure 4The ETR change trend of the main stem showed the effect of S+H, P+H>S+P>S+P+H>S-ABA, PM>CK, HA. The co-application of HA with S-ABA and PM can enhance the potential maximum electron transfer efficiency of the main stem leaves. The ETR change trend of tillers showed the effect of S+P, S+H>PM>S+P+H, S-ABA, PM, HA>CK. Spraying S+H is more conducive to the utilization of light by leaves. α, as the initial slope of the light curve, reflects the efficiency of light utilization by leaves. The main stem sprayed with S+H, P+H, and S+P+H increased by 9.0%, 14.1%, 17.1%, and 16.1% compared with CK, and tillers increased by 30.2%, 25.0%, and 27.9%. IK reflects the tolerance of wheat to strong light. After spraying S+H and P+H, the tolerance of the main stem increased by 45.0% and 51.3% compared with CK, and the tillering increased by 28.1% and 29.1%. In summary, spraying S+H significantly improved the light energy utilization rate of stems and tillers. Although it decreased after adding PM, it was still significantly improved compared with CK.

[0127] 3. Effects of spraying combined pesticides on sugar and nitrogen metabolism in stem and tiller leaves

[0128] (1) Effects of spraying combined pesticides on sugar content in stem and tiller leaves

[0129] like Figure 5 As shown in the results, spraying S-ABA increased the soluble sugar and sucrose content of the main stem by 37.0% and 93.8% compared with CK, and increased the sucrose content of tillers by 41.0%. Spraying PM increased the soluble sugar content of the main stem and tillers by 28.8% compared with CK, and the sucrose content showed a decreasing trend. Spraying the combination of the two, S+P, increased the sucrose content of the main stem by 12.0% compared with CK. Spraying HA increased the soluble sugar and sucrose content of the main stem by 27.2% and 14.2% compared with CK, and increased the content of the two in tillers by 35.8% and 7.0%. The combination of S+H increased the soluble sugar content of the main stem and the sucrose content of tillers by 13.4% and 38.8% compared with the single application. The effect of S+P+H on increasing the soluble sugar and sucrose content of the main stem and tillers was similar to that of S+H, but it increased the sucrose content of the main stem by 15.2% compared with S+H. In summary, spraying S-ABA can effectively promote the accumulation of soluble sugar and sucrose in stem and tiller leaves, while PM and HA have a greater effect on increasing the soluble sugar in main stem leaves. The interactions of S+H and S+P+H are more effective in increasing the sucrose content in stem and tiller leaves than single application.

[0130] (2) Effect of spraying combined pesticides on nitrogen content of stem and tiller leaves

[0131] Depend on Figure 6As shown in the results, spraying S-ABA significantly increased the content of soluble protein and free amino acids in the main stem by 18.2% and 21.5% compared with CK, and tillering increased by 47.8% and 33.7%. Spraying HA promoted the content of soluble protein and free amino acids in the main stem and tiller by 14.7% and 51.1% compared with CK, and tillering increased by 69.1% and 112.0%. Spraying PM and HA increased proline in the main stem by 47.9% and 17.3%, and total nitrogen content by 10.6% and 24.4%, and the total nitrogen content of tillers increased significantly compared with CK. Spraying P+H significantly increased the soluble protein in the main stem and tiller compared with CK, and the effect of increasing free amino acids increased by 7% compared with single application. The improvement effect of S+P+H was similar to that of P+H, and it was more conducive to the accumulation of nitrogen metabolites in stems and tillers than CK. In summary, spraying S-ABA and HA can promote the increase of soluble protein and free amino acid contents in stem and tiller leaves, spraying PM and HA can help increase the proline and total nitrogen contents in stem and tiller. The interactions of P+H and S+P+H effectively combine the above advantages, narrow the gap in nitrogen metabolism between stem and tiller and improve the quality of tillering.

[0132] 4. Effect of spraying combined pesticides on the antioxidant capacity of stem and tiller leaves

[0133] (1) Effects of spraying combined pesticides on membrane damage of stem and tiller leaves

[0134] Depend on Figure 7 As shown, spraying S-ABA reduced the relative conductivity of the main stem leaves by 32.0% and the MDA content of the main stem and tiller leaves by 39.9% and 52.4% compared with CK, and spraying PM reduced the MDA content of tiller leaves by 17.8% compared with CK. Spraying the combination of the two, S+P, can reduce the relative conductivity and MDA content of the main stem by 21.8% and 15.5% compared with CK. Spraying HA significantly increased the relative conductivity of tillers and the MDA content of the main stem compared with CK. Spraying the combination of S-ABA and HA, S+H, can also significantly increase the leaf conductivity of the main stem and tiller. Spraying P+H reduced the relative conductivity of the main stem leaves by 27.9% and the MDA content by 18.5% compared with CK. Spraying the combination of three agents, S+P+H, reduced the relative conductivity of the main stem leaves by 32.4% compared with CK, and reduced the MDA content of the main stem and tiller by 25.2% and 38.3%. In summary, S-ABA, PM and their combination S+P can all help reduce leaf membrane damage. Although HA has a tendency to promote membrane damage, its combination with S-ABA and PM can still reduce membrane permeability, help protect the normal functioning of leaf tissues and organs, and reduce the hindrance of waterlogging to wheat growth.

[0135] (2) Effects of spraying combined pesticides on antioxidant enzyme activities in wheat leaves ( Figure 8 )

[0136] The process of plants removing active oxygen and alleviating membrane damage is often the conversion of O 2-It is converted into H2O2, and then CAT, APX and POD are responsible for clearing the converted H2O2. Spraying S-ABA and HA increased the SOD enzyme activity of the main stem by 8.0% and 13.9% compared with CK, and increased the SOD enzyme activity of tillers by 15.2% and 7.4%, effectively improving the conversion capacity of reactive oxygen. The mutual combination of the two, S+H, increased the SOD enzyme activity of the main stem and tiller leaves by 18.5% and 10.7% compared with CK, and performed better. PM helps to improve the activity of enzymes that have a scavenging effect, and significantly increases the POD and APX activities of the main stem leaves compared with CK. The interaction of PM and S-ABA, S+P, increased the SOD enzyme activity of the main stem and tillers by 13.1% and 13.0% compared with CK, and increased the POD activity by 77.7% and 53.0%. Spraying HA significantly increased the SOD activity of the main stem and tiller by 14.0% and 7.44% compared with CK, increased the POD activity by 78.9% and 52.9%, and increased the CAT activity of the main stem leaves by 41.4%. Spraying the combination of HA and S-ABA S+H increased the SOD activity of the main stem and tiller by 18.5% and 10.7% compared with CK, increased the POD activity by 87.2% and 52.4%, and increased the APX activity of the main stem by 70.3% compared with CK. Its combination with PM P+H increased the APX and CAT activities of the main stem by 86.8% and 41.0%. The three-agent combination S+P+H effectively combined the advantages of the three agents, increasing the SOD activity of the main stem and tiller leaves by 9.0% and 9.7%, the POD activity by 84.5% and 37.9%, and the APX and CAT activities of the main stem by 72.4% and 30.3%. In summary, spraying S-ABA, HA and their combination S+H can effectively increase the activity of H2O2 converting enzyme SOD in stem and tiller leaves, and the combined spraying has a higher increase. Spraying PM and P+H can effectively increase the activities of scavenging enzymes such as APX, POD, and CAT in the main stem leaves. Spraying HA can increase the activities of SOD, POD, and CAT in stem and tiller leaves. The effect of S+P+H co-application is similar to that of P+H, but the increase in POD activity in stem and tiller is higher.

[0137] 5. PCA analysis of the effect of spraying combined agents on improving photosynthesis and stress resistance of stem tillers

[0138] As can be seen from Tables 6 and 7, the effect of spraying the pesticide alone on the photosynthesis of the main stem is PM>HA>S-ABA, and the tillering is PM>S-ABA>HA. The effect of spraying the pesticide alone on the stress resistance of the main stem is S-ABA>PM>HA, and the tillering is S-ABA>HA>PM. The photosynthesis of the main stem is S+P+H>S+H>P+H>S+P when sprayed in combination, and the effect on tillering is S+H>S+P+H>P+H>S+P. The stress resistance of the main stem is S+H>S+P+H>P+H>S+P when sprayed in combination, and the effect on tillering is S+P+H>S+H>P+H>S+P.

[0139] In summary, spraying PM alone can help improve the photosynthetic capacity of wheat stems and tillers, and spraying S-ABA alone can help enhance the stress resistance of stems and tillers. However, the combination of the two, S+P, has a poor improvement effect and needs to be combined with HA, that is, S+P+H, to significantly improve the photosynthetic and stress resistance capabilities. The combination S+H also shows advantages.

[0140] Table 6 Comprehensive ranking of the effects of spraying combined pesticides on improving the photosynthetic capacity of stems and tillers

[0141]

[0142] Table 7 Comprehensive ranking of the effects of spraying combined pesticides on improving the stress resistance of stem tillers

[0143]

[0144] 6. Effect of spraying combined pesticides on wheat tillering and ear formation

[0145] (1) Effects of spraying combined pesticides on changes in wheat tiller population

[0146] Table 8 shows that spraying S+P+H significantly increased the number of stem tillers. In 2022-2023, which was severely waterlogged, and 2023-2024, which was less waterlogged, the tillering capacity per plant increased by 28.2% and 7.9%, the number of spikes increased by 14.4% and 18.0%, and the effective tillering rate increased by 16.5% and 72.5% compared with CK. The performance of spraying PM was different in the two years. Although the number of tillers was large in 2022-2023, the ability to form spikes was poor. In 2023-2024, the number of spikes increased on the basis of high tillering capacity per plant. S-ABA had a significant effect on delaying growth in 2023-2024, which reduced the tillering capacity per plant compared with CK but ensured the increase of tillering quality and effective spikes. Spraying HA increased the number of spikelets by 10.3% and 9.8% in two growing seasons compared with CK, and the effective tillering rate increased by 19.9% ​​and 36.7%. The S+H applied together with S-ABA increased the number of spikelets more than the single application, which was 14.3% higher than CK.

[0147] In summary, spraying PM increased the tillering capacity of individual plants, while S-ABA and HA increased the ear formation rate. The combination of S+P and S+H had a higher effect on increasing the number of ears. Spraying HA promoted the occurrence rate of effective tillers and reduced the tiller extinction rate. S+P+H balanced the advantages of the above agents and improved the tillering-ear formation ability.

[0148] Table 8 Effects of pesticide spraying on the occurrence and disappearance of wheat tillering

[0149]

[0150] (2) Effects of spraying combined pesticides on wheat tillering characteristics

[0151] As can be seen from Table 9, spraying HA in the two growing seasons increased the main stem ear weight by 24.2% and 17.8% compared with CK, increased the number of tillering spikelets by 21.5% and 11.5%, and reduced the number of sterile spikelets on the main stem by 34.4% and 13.6%. Spraying PM reduced the number of sterile spikelets on tillers by 44.9% and 7.9% compared with CK. Spraying S+P+H effectively increased the main stem and tillering ear weight compared with CK, and increased the number of tillering spikelets by more than 1.7. Spraying S-ABA in the 2022-2023 growing season significantly reduced the number of sterile spikelets on the main stem and tillers compared with CK. In the 2023-2024 growing season, spraying S-ABA increased the main stem and tiller ear weight by 11.1% and 23.6% compared with CK. Spraying S+P, P+H, and S+H also increased the main stem and tiller ear weight. Among them, S+H promoted the increase in the number of main stem and tiller spikelets compared with CK. Fig. 9 , the agent improves the fruit setting ability mainly for the grain setting at the base and upper part of the ear. S-ABA, HA and S+P+H mainly increase the final number of grains per ear by improving the fruit setting ability of the grains in the upper part of the main stem, while S+P+H also has a certain improvement ability in the middle and lower parts. In summary, spraying HA and S+P+H can promote the increase of the weight of the main stem and tillering ears, the number of fruiting spikelets, and improve the fruit setting ability of the stem tillers.

[0152] Table 9 Effects of combined application of plant regulators and humic acid on wheat fruiting characteristics

[0153]

[0154] 7. Effect of spraying combination pesticides on yield

[0155] Spraying S+P+H, HA, and S-ABA in 2022-2023 significantly increased yields, with Shumai 1963 yields increasing by 26.3%, 24.4%, and 13.3% compared with CK. Spraying S-ABA significantly increased the number of tillers, but there was no significant difference in the number of tillers per ear and the thousand-grain weight compared with CK. Spraying PM can significantly increase the number of tillers and the number of grains per ear to increase the tillering contribution rate.

[0156] In 2023-2024, spraying HA, PM, and S-ABA increased effective tillering by 35.1, 34.1, and 20.4% compared with CK, the number of grains per ear on the main stem increased by 3.2, 2.6, and 0.7 grains, the number of grains per ear on the tiller increased by 2.9, 6.2, and 5.8 grains, and the contribution rate of tillering yield increased significantly. The actual yield increased by 17.2, 15.4, and 7.4% compared with CK. The effective tillering of the treatments with the application of the drugs increased significantly compared with CK. The number of grains per ear on the tiller stems of the two treatments S+H and P+H containing HA increased significantly. The thousand-grain weight of S+P and S+P+H was lower than that of CK, but the contribution rate of tillering yield was still 15.6 and 9.5% higher than that of CK. The actual yield of S+P+H and S+H increased by 27.8 and 22.0% compared with CK.

[0157] In summary, the biggest factor limiting yield increase is still the effective ear. Only by increasing the number of effective tillers can the tiller contribution rate be increased to a greater extent. Spraying HA and the combinations of S+H and S+P+H have greater advantages in improving the quality of the main stem and tillers and increasing the tiller yield contribution rate. Among them, S+P+H has the best stable yield effect in two growing seasons.

[0158] Table 10 Effects of foliar fertilizer on yield traits of wheat with different spike types

[0159]

[0160]

[0161] in conclusion

[0162] After wheat encounters waterlogging at the seedling stage, spraying PM alone can improve the photosynthetic capacity of the main stem and the first tiller of wheat, and spraying S-ABA alone can help promote root growth and improve stress resistance, but the combination of the two, S+P, has the disadvantage of slowing growth. The combination of HA, which supplements nutrition and improves growth rate, can complement each other in reducing root damage, promoting aboveground growth, promoting photosynthesis, and improving stress resistance, and has a better effect than the single application of the agent, thereby promoting the occurrence rate of tillers and improving the quality of ear formation, which is conducive to the cultivation of strong seedlings under the stress of waterlogging at the seedling stage and ensuring the increase of ears and stable yield.

[0163] As can be seen from the above embodiments, the present invention provides a composition for wheat waterlogging resistance, strong seedlings, and stable yield, and its application and use method, the composition comprising the following components: S-inducing factor, paclobutrazol·methylpiperidin and humic acid-containing micro-fertilizer. The combined agent provided by the present invention can increase root volume, surface area and dry weight, effectively alleviate the impact of waterlogging on root growth, promote the occurrence rate of the first tiller of wheat, promote the growth of leaves and tillers and improve the quality of tillers. Enhance the photosynthetic capacity, chlorophyll fluorescence capacity, antioxidant metabolism, and carbon and nitrogen metabolism of the main stem and the first tiller. Ultimately, it can promote the improvement of the quality of the early stem tiller population, promote tillering into ears and increase yield.

[0164] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A composition for wheat waterlogging resistance, seedling strengthening and yield stabilization, characterized in that: The invention comprises the following components: S-inducing factor, paclobutrazol·methylpiperidin and micro-fertilizer containing humic acid.

2. The composition according to claim 1, characterized in that The mass ratio of S-inducing factor, paclobutrazol·methylpiperidin and humic acid-containing micro-fertilizer in the composition is 4-6:280-320:90-110.

3. The composition according to claim 1, characterized in that The specification of the paclobutrazol·mepirac is 30% paclobutrazol·mepirac, in which the content of paclobutrazol is 23-27% and the content of mepirac is 3-7%.

4. The composition according to claim 1, characterized in that The humic acid-containing micro-fertilizer contains the following components in concentrations: 35-45 g / L humic acid, 90-110 g / L nitrogen, 90-110 g / L phosphorus, and 140-160 g / L potassium.

5. Use of the composition according to any one of claims 1 to 4 for wheat waterlogging resistance, seedling strengthening or yield stabilization.

6. The method for using the composition according to any one of claims 1 to 4, characterized in that: The steps include: (1) mixing the composition according to any one of claims 1 to 4 with water to obtain a liquid medicine; (2) Spray the solution onto wheat in two batches.

7. The method of use according to claim 6, characterized in that: The concentration of S-inducing factor in the liquid medicine in step (1) is 4-6 mg / kg, the concentration of paclobutrazol-methylpiperidin is 280-320 mg / kg, and the concentration of humic acid-containing micro-fertilizer is 90-110 mg / kg.

8. The method of use according to claim 6, characterized in that: The first spraying time of the liquid medicine in step (2) is when the wheat has three leaves and one heart, and the second spraying time is 12 to 16 days after the first spraying.

9. The method of use according to claim 6, characterized in that: The single spraying amount of the liquid in step (2) is 280-320 kg / hm 2 .

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