Composition for wheat waterlogging resistance, seedling strengthening and yield stability, and application and use method thereof

Abstract

The present invention relates to the technical field of wheat waterlogging resistance. The present invention provides a composition for wheat waterlogging resistance, strong seedlings and stable yield, and its application and use method, wherein the composition comprises the following components: S-inducer, 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. It can 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 and tiller population, promote tillering into ears and increase yield.

Description

Technical Field

[0001] The present 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] The rice-wheat (winter wheat-rice) model, the dominant cropping method in the region, offers advantages such as high year-round profitability, high yield potential, and ease of mechanization, making it crucial for ensuring food security. In recent years, the promotion of long-growing rice varieties has led to delayed harvests, resulting in shorter drying times and moist, sticky soils. Climate change has also impacted wheat-growing regions, with frequent autumn rains from September to November. Furthermore, flooding during the rice season, soil subsidence and consolidation, and mechanical compaction have disrupted soil aggregate structure, leading to waterlogging and impeded infiltration during the wheat planting period. Waterlogging can cause delayed growth, yellowing and wilting of leaves, and a reduction in tillering of over 30%, resulting in a 10-15% yield reduction. Waterlogging reduces rhizosphere oxygen concentration, intensifying root anaerobic respiration, inhibiting cell division and ion exchange. This reduced root water uptake hinders transpiration, and reduced nitrogen absorption leads to a decrease in chlorophyll content and stomatal density in the mesophyll, hindering leaf photosynthesis. The chloroplast membrane system is a crucial site for the absorption, transmission, and conversion of light energy. Adverse environmental stress can hinder the photochemical reactions of electrons, generating large amounts of reactive oxygen species that trigger lipid peroxidation in the cell membrane, damaging the chloroplast membrane structure and accelerating hydrolysis. Waterlogging can also reduce the openness of the PSII reaction center, lowering both the actual photochemical efficiency (ΦPSII) and the maximum photochemical efficiency (Fv / Fm).

[0003] Therefore, studying measures to supplement wheat nutrition outside the roots, 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, seedling strengthening and yield stability, and its application and use method, so as to increase root volume, surface area and dry weight, and effectively alleviate the impact 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 resisting waterlogging, strengthening seedlings and stabilizing yield of wheat, comprising the following components: S-inducing agent, paclobutrazol-methylpiperidin and a micro-fertilizer containing humic acid.

[0007] Preferably, the mass ratio of S-inducing agent, 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-1-one is 30% paclobutrazol·mepirac-1-one, wherein the content of paclobutrazol in the 30% paclobutrazol·mepirac-1-one is 23-27%, and the content of mepirac-1-one 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 present 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 the wheat twice.

[0014] Preferably, the concentration of S-inducible 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 / hm2. 2 .

[0017] The present invention provides a composition for resisting waterlogging, strengthening seedlings, and stabilizing yield in wheat, as well as its application and use method. The composition comprises the following components: S-inducer, paclobutrazol-methylpiperidin, and a humic acid-containing micronutrient fertilizer. The combination provided by the present invention can increase root volume, surface area, and dry weight, effectively alleviating the effects of waterlogging on root growth, promoting the rate of first tiller formation in wheat, and promoting leaf and tiller growth to improve tiller quality. It also enhances the photosynthetic capacity, chlorophyll fluorescence, antioxidant metabolism, and carbon and nitrogen metabolism of the main stem and first tiller. Ultimately, it can improve the quality of the early stem and tiller population, promote tiller formation 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 pesticide spraying on light energy interception and absorption capacity, 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 an absorption performance index per unit cross section (application of rapid chlorophyll fluorescence induced kinetics analysis in photosynthesis research);

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

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

[0022] Figure 5 The effect of spraying the pesticide on the sugar content of stems and 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 pesticide spraying on leaf membrane permeability;

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

[0026] Figure 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 resisting waterlogging, strengthening seedlings and stabilizing yield of wheat, comprising the following components: S-inducing agent, paclobutrazol-methylpiperidin and a micro-fertilizer containing humic acid.

[0028] In the present invention, the mass ratio of S-inducing agent, paclobutrazol·mepiquat 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 components in concentrations: 35-45 g / L of humic acid, 90-110 g / L of nitrogen, 90-110 g / L of phosphorus, and 140-160 g / L of potassium, and more preferably: 40 g / L of humic acid, 100 g / L of nitrogen, 100 g / L of phosphorus, and 150 g / L of potassium.

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

[0032] The present 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 medicinal solution;

[0035] (2) Spray the solution onto the wheat twice.

[0036] In the present invention, the concentration of S-inducing agent 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 time for the first spraying of the liquid medicine in step (2) is preferably the three-leaf and one-heart stage of wheat, and the time for the second spraying 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 / hm2. 2 , more preferably 300kg / hm 2 .

[0039] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection 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 experimental 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 was 324.6, 382.6mm, and the average daily temperature was 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 variety used for the test was Shumai 1963, bred at Sichuan Agricultural University. The pesticides were provided by Sichuan Runer Technology Co., Ltd. Their names and dosages were: S-ABA 5 mg / kg, 30% paclobutrazol mepiquat (PM) 300 mg / kg, and humic acid water-soluble fertilizer (HA) 100 mg / kg, sprayed at 300 kg / hm2. 2 Among them, the main components of the humic acid water-soluble fertilizer are humic acid 40g / L, nitrogen (N) 100g / L, phosphorus (P2O5) 100g / L, and potassium (K2O) 150g / L.

[0045] The experiment adopted a single-factor randomized block design. From 2022 to 2023, the experiment had five 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 replicates. The pesticide was sprayed when the wheat was three leaves and one heart, and sprayed again after 14 days. The experimental soil fertilizer used was 15-15-15 compound fertilizer 750kg / hm2. 2 , topdressing with ordinary 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 plot area was 12 m2. 2 The basic seedlings are 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, with sampling 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 excavated from each plot. The roots were cleaned and scanned using an Epson Expression 10000XL. The scanned images were analyzed using the Win RHIZO root analysis system to calculate total root length, root volume, and root surface area. The plants and scanned roots were then dried and weighed to calculate the root-to-shoot ratio.

[0053] Root-to-shoot ratio = total weight of underground roots / total weight of above-ground stems and leaves

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

[0055] At the three-leaf stage, 20 uniform wheat plants were collected from each plot. Another 20 main stems were marked in the plot. Seven days later, the first tillers were marked. At the jointing stage, 15 wheat plants were collected from each plot. The leaf age, length, and stem diameter of the main stem (O), first tiller (T1), and remaining tillers (T2) were measured. 0.1 g of flat leaves from the main stem and tiller tips of the samples at the three-leaf stage (t1) and jointing stage (t2) were weighed and extracted in 10 mL of a 1:1, v / v acetone-ethanol mixture for 7 days. The absorbance of the extract was measured at 645 nm and 663 nm, and the chlorophyll a, b, and total content were calculated. The remaining leaves and stems of the plants were withered at 105°C for 30 min, 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-lnW1) / (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 at the top of the main stem and the first tiller of wheat were marked in each plot. The photosynthetic rate (PN), intercellular CO2 concentration (Ci), stomatal conductance (Gs) and transpiration rate (Tr) were measured using a 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 a Handy PEA+ portable plant efficiency meter. The ABS / RC ratio, ψo, RC / CSo, and the induction curve and light response curve were measured using the ultra-portable modulated chlorophyll fluorescence instrument MINI-PAM-II, and the Fv / Fm, Y(NO), Y(II), Y(NPQ), QL, and NPQ were determined.

[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. Then, 20 leaf discs were punched out with a hole puncher and soaked for 24 hours. The conductivity of the solution was measured and 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 and recorded as R2.

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

[0071] The MDA content in tiller nodes and leaves at jointing stage was determined by thiobarbituric acid method.

[0072] (6) Leaf antioxidant enzyme assay

[0073] The expanded leaves at the top of the first tiller and the main stem of 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 UV absorption method, and the ascorbate peroxidase was determined by the Faiza (APX) UV absorption method.

[0074] (7) Investigation of stem and tiller dynamics

[0075] In each plot, two representative rows of sampling points with a length of 0.8 m were framed, and the number of tillers was investigated 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 pattern, the effective tillering critical point was determined by extending the direction from the 9-point direction of the effective ear at maturity to the intersection point at the tillering stage. 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 according to the tillering dynamics. 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 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 of each plot 0.8m 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 measured.

[0084] 4. Data processing

[0085] Excel 2010 software was used to organize the experimental data, and DPS7.05 and spas 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. Effects of spraying combined pesticides on wheat seedling growth

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

[0089] Table 1 shows that, over the two growing seasons, spraying S-ABA increased root dry weight by 36.0% and 47.2%, root length by 38.5% and 47.2%, root surface area by 33.2% and 44.9%, root volume by 22.7% and 51.9%, and root-to-shoot ratio by 47.2% and 21.4%. Spraying PM increased root dry weight by 33.9% and 54.0%, root length by 30.8% and 75.0%, root volume by 70.5% and 23.1%, and root-to-shoot ratio by 34.0% and 14.3%. Spraying HA decreased root volume and root-to-shoot ratio, while spraying S+P+H increased root dry weight by 30.2% and 32.0%, root length by 19.2% and 30.5%, and root volume by 22.7% and 26.9%.

[0090] Spraying PM during the 2022-2023 growing season significantly increased root surface area compared with CK, while spraying S+P+H significantly increased the root-to-shoot ratio. Spraying S+P during the 2023-2024 growing season significantly decreased the root-to-shoot ratio compared with CK. 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%, while decreasing the root-to-shoot 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 waterlogging at the seedling stage, spraying S-ABA, PM, and their combination S+P at the three-leaf stage effectively promoted root assimilate accumulation and secondary root production, improving the root-to-shoot ratio. While spraying HA significantly boosted aboveground growth, it significantly reduced root volume and the root-to-shoot ratio, hindering subsequent growth. The aforementioned combinations, S+H and S+P+H, effectively combined these advantages to achieve a "control-the-top" and "promote-the-bottom" effect, increasing root volume, surface area, and dry weight, effectively mitigating the effects 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·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), different letters indicate significant differences, the same is true for the table below.

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

[0096] Table 2 shows that spraying HA and S+P+H increased the leaf age, tiller length, and stem diameter of the main stem and T1 compared to CK in both growing seasons. Spraying S-ABA in the 2022-2023 growing season significantly reduced the leaf age and length of the main stem, as well as T1 length, but increased T1 leaf age, stem diameter, and main stem diameter. Spraying PM significantly reduced the leaf age of the main stem and significantly increased the stem diameter of the main stem and T1 compared to CK.

[0097] During the 2023-2024 growing season, spraying S-ABA increased T2 stem length by 33.3% compared to CK, and increased stem diameters of the main stem, T1, and T2 by 28.6%, 16.7%, and 19.2%, respectively. Spraying PM significantly increased T1 leaf age and main stem diameter compared to CK. The combination of S+P significantly increased T1 leaf age, length, and main stem diameter. Spraying S+H and P+H significantly increased T1 leaf age, main stem, and T1 length and diameter.

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

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

[0100]

[0101]

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

[0103] Table 3 shows the growth of wheat from the three-leaf stage to the jointing stage. Spraying HA significantly increased the relative growth rate of tillers and the net assimilation rate of leaves compared to CK in both growing seasons, with G values ​​increasing by 26.7% and 46.7%. Spraying S-ABA did not significantly increase the growth rate and net assimilation rate of aboveground tillers compared to CK, but its stimulating effect on the belowground part resulted in a higher seedling index. Spraying PM had the greatest increase in relative growth rate among the three single-application pesticides, at 24.0% and 11.3% compared to CK. Among the combinations, the interaction between the two growth retardants S+P significantly decreased wheat growth rate, but all other combinations showed a stimulating effect. P+H had the greatest increase in leaf assimilation rate and G value compared to CK, at 16.1% and 40% respectively. S+H and S+P+H also significantly increased the seedling index compared to CK, at 38.0% and 44.2%, respectively. They also significantly increased the relative growth rate of tillers.

[0104] In summary, spraying S-ABA promotes underground growth, while PM and HA promote aboveground growth, both contributing to strong seedling cultivation. There is an interaction between the agent combinations: S+P inhibits growth, while S+H and P+H, influenced by HA, promote growth rate and increase the seedling index. The three-agent combination, S+P+H, overcomes the side effects of the interaction between the two retardants S+P, further improving colony quality and leaf assimilation capacity.

[0105] Table 3 Effects 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 stem and tiller photosynthesis

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

[0110] Table 4 shows that spraying HA and S+P+H significantly increased leaf area index, main stem chlorophyll a content, and total chlorophyll content compared to CK in both growing seasons. Spraying S-ABA and HA significantly increased tiller leaf dry weight ratio compared to CK, while spraying PM increased main stem chlorophyll b content compared to CK. Waterlogging was more severe during the 2022-2023 growing season, resulting in fewer tillers, slower leaf development, and a lower overall leaf area index. However, spraying S-ABA and PM increased leaf area ratio by 81.1% and 42.2% compared to CK, and chlorophyll a content in main stem leaves by 9.6% and 5%. Spraying S-ABA increased total chlorophyll content in main stem leaves by 7.8% compared to CK.

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

[0112] In summary, by comparing leaf growth during the jointing stage, it can be seen that spraying PM and HA promoted leaf growth, HA increased the proportion of tiller leaf mass, and S-ABA and HA significantly improved chlorophyll content. The combination of S+P+H showed greater increases in LAI, LWR, and total chlorophyll content. This is presumably due to the interaction between the agents. S-ABA and PM can effectively delay the phenomenon of HA promoting vigorous growth of aboveground parts while insufficient root growth, promoting leaf growth and root growth relative to stems, thereby improving the quality of the stem and tiller population by "controlling the above and promoting the below."

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

[0114]

[0115]

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

[0117] Table 5 shows that spraying S-ABA and PM significantly increased intercellular CO2 concentrations in the main stem and tillers compared to CK. Stomatal conductance in the main stem increased by 29.0% and 38.7%, respectively, and stomatal conductance in the tillers increased by 43.7% and 75%. Spraying PM increased the transpiration rate in the main stem and tillers by 28.9% and 91.9%, respectively, and the photosynthetic rate in the main stem and tillers by 58.3% and 52.7%, respectively, compared to CK. Spraying the combination of S-ABA and PM significantly increased the photosynthetic rate, stomatal conductance, and transpiration rate in the main stem compared to S-ABA or PM alone. Spraying HA significantly increased the photosynthetic rate in the main stem and tillers by 59.32% and 49.3%, respectively, compared to CK. It also significantly increased intercellular CO2 concentration in the main stem, and significantly increased stomatal conductance and transpiration rate in the main stem and tillers. Spraying S-ABA and HA significantly increased stomatal conductance and transpiration rate in tillers compared to applying S-ABA or HA alone.

[0118] In summary, spraying PM and HA increased the photosynthetic rate of stems and tillers. Spraying PM helped open stomata in the main stem and tillers. The combination of PM and HA, while not leading to a further increase in photosynthetic capacity, did improve transpiration. The combined application of S-ABA and HA effectively promoted photosynthetic capacity in tillers. The three-agent combination, S+P+H, effectively combined the advantages of each agent to enhance plant photosynthetic capacity.

[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 was greatly improved compared with CK. The results of S+H and S+P+H were in ψo, Compared with CK, PM spraying improved the interception and absorption performance of tillers. The P+H interaction with HA was more improved. S+P+H had advantages in improving energy interception and absorption, and improved the light energy utilization capacity of chlorophyll.

[0123] from Figure 3As can be seen, spraying S-ABA significantly increased the Fv / Fm and Y(II) of the main stem compared to CK, while reducing Y(NO) of the main stem by 13.9% compared to CK. Spraying PM significantly increased Y(II) of the main stem and tillers 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 greater effect on increasing Y(II) of the main stem and tillers than either application alone. Spraying HA increased Y(II) of the main stem by 29.4%, increased NPQ of the main stem and tillers by 101.0% and 36.3%, reduced Y(NO) of the main stem and tillers by 18.3% and 36.8%, and increased Y(NPO) by 35.9% and 76.2%. The combination of S-ABA (S+H) and the active ingredient (S-ABA) increased Y(II) in the stem and tillers by over 20% compared to either application alone, increased QL by over 49.1%, and decreased Y(NO) by over 38.4% compared to either application alone. The combination of P+H significantly improved NPQ in the stem and tillers, increasing them by 37.7% and 50.4% respectively compared to CK. The three-ingredient combination (S+P+H) balanced the efficacy of each agent and significantly improved Y(NPQ) in the stem and tillers, increasing them by 33.2% and 48.3% respectively compared to CK.

[0124] In summary, S-ABA effectively enhanced the photosynthetic capacity of the main stem and reduced light damage. PM and HA promoted the improvement of QL in the main stem and had a significant synergistic effect. The application of the three alone and in their combinations (S+H, P+H, and S+P+H) all contributed to an increase in light energy utilization efficiency in the stems and tillers. Y (NPQ) is considered an important indicator of stress resistance. Spraying PM and HA significantly enhanced the photoprotection capacity of tillers, while HA significantly improved the photoprotection capacity of the main stem. P+H and S+P+H had the greatest effect on the photoprotection capacity of tillers. Y (NO) reflects the damage to the photosystem under stress. PM and HA significantly reduced the extent of damage to the stem and tiller vascular system, while S-ABA significantly reduced tiller damage. S+H had the greatest effect on reducing photoprotection damage in stems and tillers, and S+P+H also showed a significant reduction.

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

[0126] Depend on Figure 4The ETR trend for the main stem showed the following: S+H, P+H > S+P > S+P+H > S-ABA, PM > CK, HA. The combined application of HA with S-ABA and PM enhanced the potential maximum electron transfer efficiency of the main stem leaves. The ETR trend for tillers showed the following: S+P, S+H > PM > S+P+H, S-ABA, PM, HA > CK. Spraying S+H further enhanced leaf light utilization. α, the initial slope of the light curve, reflects the leaf light utilization efficiency. Compared to CK, main stem ETR increased by 9.0%, 14.1%, 17.1%, and 16.1% when spraying S+H, P+H, and S+P+H, respectively, and tillering ETR increased by 30.2%, 25.0%, and 27.9%, respectively. IK reflects wheat's tolerance to strong light. Spraying S+H and P+H increased the main stem's tolerance by 45.0% and 51.3% compared to CK, and tillering increased by 28.1% and 29.1% respectively. In summary, spraying S+H significantly improved light energy utilization efficiency in stems and tillers. Although it decreased after adding PM, it still significantly increased compared to CK.

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

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

[0129] like Figure 5 As shown, spraying S-ABA increased soluble sugar and sucrose content in the main stem by 37.0% and 93.8% compared to CK, and increased sucrose content in tillers by 41.0%. Spraying PM increased soluble sugar content in the main stem and tillers by 28.8% compared to CK, with a decreasing trend in sucrose content. Spraying the combination of S-ABA and PM increased sucrose content in the main stem by 12.0% compared to CK. Spraying HA increased soluble sugar and sucrose content in the main stem by 27.2% and 14.2% compared to CK, and increased both content in tillers by 35.8% and 7.0%. The combination of S-ABA and PM increased soluble sugar and sucrose content in the main stem by 13.4% and 38.8% compared to either application alone. The combination of S-ABA and PM increased soluble sugar and sucrose content in the main stem and tillers by similar amounts as S-ABA and PM, but increased sucrose content in the main stem by 15.2% compared to S-ABA and PM. 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 interaction of S+H and S+P+H is more effective in increasing the sucrose content in stem and tiller leaves than single application.

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

[0131] Depend on Figure 6As shown, spraying S-ABA significantly increased soluble protein and free amino acid content in the main stem by 18.2% and 21.5% compared to CK, and tillering by 47.8% and 33.7%. Spraying HA increased soluble protein and free amino acid content in the main stem and tiller by 14.7% and 51.1% compared to CK, and tillering by 69.1% and 112.0%. Spraying PM and HA increased proline content in the main stem by 47.9% and 17.3%, respectively, and total nitrogen content by 10.6% and 24.4%, respectively, with total nitrogen content in tillers significantly increasing compared to CK. Spraying P+H significantly increased soluble protein in the main stem and tillers compared to CK, and increased free amino acid content by 7% compared to either application alone. The effects of S+P+H were similar to those of P+H, and it also enhanced nitrogen metabolite accumulation in the stem and tiller compared to CK. In summary, spraying S-ABA and HA can promote the increase of soluble protein and free amino acid content in stems and tillers and leaves, spraying PM and HA can help increase the proline and total nitrogen content in stems and tillers. The P+H and S+P+H interactions effectively combine the above advantages, narrow the nitrogen metabolism gap between stems and tillers and improve tillering quality.

[0132] 4. Effect of spraying combined pesticides on the antioxidant capacity of stems and 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 electrical 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% respectively, compared to CK. Spraying PM reduced the MDA content of tiller leaves by 17.8% compared to CK. Spraying the combination of S-ABA and PM reduced the relative electrical conductivity of the main stem by 21.8% and MDA content by 15.5% respectively, compared to CK. Spraying HA significantly increased the relative electrical conductivity of tillers and the MDA content of the main stem compared to CK. Spraying the combination of S-ABA and HA, S+H, also significantly increased the electrical conductivity of the main stem and tiller leaves. Spraying P+H reduced the relative electrical conductivity of the main stem leaves by 27.9% and the MDA content by 18.5% compared to CK. Spraying the combination of S-ABA, PM, and PM reduced the relative electrical conductivity of the main stem leaves by 32.4% and the MDA content of the main stem and tiller leaves by 25.2% and 38.3% respectively, compared to CK. In summary, S-ABA, PM and their combination S+P all help to 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 obstacles to wheat growth caused by waterlogging.

[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 SOD enzymes into 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 increased 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 tiller by 13.1% and 13.0% compared with CK, and increased the POD activity by 77.7% and 53.0%. Spraying HA significantly increased SOD activity in the main stem and tillers by 14.0% and 7.44% compared to CK, POD activity by 78.9% and 52.9%, and CAT activity in the main stem leaves by 41.4%. The combination of HA and S-ABA (S+H) increased SOD activity in the main stem and tillers by 18.5% and 10.7% compared to CK, POD activity by 87.2% and 52.4%, and APX activity in the main stem by 70.3% compared to CK. The combination of HA and PM (P+H) increased APX and CAT activities in the main stem by 86.8% and 41.0%. The three-agent combination (S+P+H) effectively combined the advantages of all three agents, increasing SOD activity in the main stem and tiller leaves by 9.0% and 9.7%, POD activity by 84.5% and 37.9%, and APX and CAT activities in 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 combination spraying has a higher improvement. Spraying PM and P+H can effectively increase the activities of scavenging enzymes such as APX, POD, and CAT in the main stem leaves, while spraying HA can increase the activities of SOD, POD, and CAT in stem and tiller leaves. The effect of co-application of S+P+H is similar to that of P+H, but the improvement of POD activity in stem and tiller is higher.

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

[0138] As can be seen from Tables 6 and 7, the effect of spraying the pesticide alone on improving the photosynthesis of the main stem was PM>HA>S-ABA, and on tillering it was PM>S-ABA>HA. The effect of spraying the pesticide alone on improving the stress resistance of the main stem was S-ABA>PM>HA, and on tillering it was S-ABA>HA>PM. The effect of combined spraying on improving the photosynthesis of the main stem was S+P+H>S+H>P+H>S+P, and on tillering it was S+H>S+P+H>P+H>S+P. The effect of combined spraying on improving the stress resistance of the main stem was S+H>S+P+H>P+H>S+P, and on tillering it was 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 S+P has a poor improvement effect and needs to be applied in combination with HA, that is, S+P+H to significantly improve the photosynthetic and stress resistance. The combination S+H also shows advantages.

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

[0141]

[0142] Table 7 Comprehensive ranking of the effects of spraying combination pesticides on improving the stress resistance of stems and tillers

[0143]

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

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

[0146] Table 8 shows that spraying S+P+H significantly increased the number of stem tillers. In the severely waterlogged 2022-2023 and less waterlogged 2023-2024 years, the tillering capacity per plant increased by 28.2% and 7.9%, respectively, compared to the control (CK) treatment. The number of ears increased by 14.4% and 18.0%, respectively, and the effective tillering rate increased by 16.5% and 72.5%, respectively. Spraying PM showed different results between the two years. While the number of tillers increased in 2022-2023, ear formation was poor. In 2023-2024, the number of ears increased despite high tillering capacity per plant. S-ABA significantly slowed growth in 2023-2024, reducing tillering capacity per plant compared to the CK treatment while maintaining tiller quality and promoting an increase in effective ears. Spraying HA increased the number of ears by 10.3% and 9.8% over the two growing seasons compared to CK, and the effective tillering rate increased by 19.9% ​​and 36.7%. The combined application of S+H with S-ABA increased the number of ears even more than either application alone, increasing it by 14.3% compared to CK.

[0147] In summary, PM spraying increased tillering capacity per plant, while S-ABA and HA increased ear formation. The combinations of S+P and S+H were even more effective in increasing ear formation. HA spraying promoted the rate of effective tillering and reduced the rate of tiller extinction. S+P+H balanced the advantages of the above agents, improving tillering and ear formation.

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

[0149]

[0150] (2) Effects of spraying combination pesticides on wheat stem tillering and fruiting characteristics

[0151] As shown in Table 9, spraying HA during the two growing seasons increased main stem spike weight by 24.2% and 17.8% compared to CK, increased the number of tiller-bearing 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 to CK. Spraying S+P+H effectively increased main stem and tiller spike weight and increased the number of tiller-bearing 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 to 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 spikelets in the main stem and tillering compared with CK. Figure 9 The agents that improve seed set primarily target the base and upper portion of the ear. S-ABA, HA, and S+P+H primarily increase the final number of grains per ear by improving the seed set of the upper portion of the main stem, while S+P+H also has a certain improvement in the middle and lower portions. In summary, spraying HA and S+P+H can increase the weight of the main stem and tillering ears, increase the number of fruiting spikelets, and improve the seed set of stems and 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 significantly increased yield in 2022-2023, with Shumai 1963 yielding 26.3%, 24.4%, and 13.3% higher than CK. Spraying S-ABA significantly increased tiller number, but there were no significant differences in tiller number and 1000-grain weight compared to CK. Spraying PM significantly increased tiller number and grain number per spike, thereby increasing the tiller 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 spike on the main stem increased by 3.2, 2.6, and 0.7 grains, and the number of grains per spike on the tiller increased by 2.9, 6.2, and 5.8 grains, and the contribution rate of tiller yield was significantly improved. The actual yield increased by 17.2, 15.4, and 7.4% compared with CK. The effective tillering of the treatments with combined application of pesticides increased significantly compared with CK. The number of grains per spike on the stem tiller of the two treatments containing HA, S+H and P+H, increased significantly. The thousand-grain weight of S+P and S+P+H was lower than that of CK, but the contribution rate of tiller yield was still increased by 15.6 and 9.5% compared with 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 maximized. Spraying HA and the combinations of S+H and S+P+H have greater advantages in improving the main stem and tiller quality 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] When wheat is damaged by waterlogging during the seedling stage, spraying PM alone can improve the photosynthetic capacity of the main stem and first tiller. Spraying S-ABA alone helps promote root growth and enhance stress resistance, but the combination of the two, S+P, has the disadvantage of slowing growth. However, the combination of S+P+H, which supplements nutrients and increases growth rate, complements the advantages of HA in reducing root damage, promoting aboveground growth, boosting photosynthesis, and enhancing stress resistance, producing superior results compared to applying either agent alone. This boosts the rate of tillering and improves ear quality, facilitating the cultivation of strong seedlings under waterlogging stress and ensuring increased ear volume and stable yields.

[0163] As can be seen from the above examples, the present invention provides a composition for wheat waterlogging resistance, seedling growth, and stable yield, as well as its application and use method, the composition comprising the following components: S-inducer, paclobutrazol-methylpiperidin, and a humic acid-containing micro-fertilizer. The combination 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 leaf and tiller growth, and improve tiller quality. It enhances 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 and 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 principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A composition for wheat waterlogging resistance, strong seedlings and stable yield, characterized in that: The invention comprises the following components: S-inducing agent, paclobutrazol·methylpiperidin and micro-fertilizer containing humic acid; The mass ratio of S-inducible, paclobutrazol·mepiquat and humic acid-containing micro-fertilizer in the composition is 4-6:280-320:90-110; The humic acid-containing micronutrient fertilizer contains the following components in concentrations: 35-45 g / L of humic acid, 90-110 g / L of nitrogen, 90-110 g / L of phosphorus, and 140-160 g / L of potassium; The specification of the paclobutrazol·mepirac-1-chloride is 30% paclobutrazol·mepirac-1-chloride, in which the content of paclobutrazol is 23-27% and the content of mepirac-1-chloride is 3-7%.

2. Use of the composition according to claim 1 in wheat waterlogging resistance, seedling strengthening or yield stabilization.

3. The method for using the composition according to claim 1, wherein: The steps include: (1) Mixing the composition according to claim 1 with water to obtain a liquid medicine; (2) Spray the solution onto the wheat in two batches.

4. The method of use according to claim 3, characterized in that: The concentration of S-inducible 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.

5. The method of use according to claim 4, 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.

6. The method of use according to claim 4, characterized in that: The single spraying amount of the liquid in step (2) is 280~320kg / hm 2 .

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