Plant growth and production are faced with various biological and abiotic stresses,among which salt stress seriously affects the normal growth and development,quality and yield formation of plants.Plants have evolved morphological structure,physiological and biochemical reactions and genetic basis to adapt to salt stress during the long process of evolution.In terms of morphological structure,the leaves of salt-tolerant plants have waxy layer and lower stomatal density than those of salt-sensitive plants,and salt glands,microhairs,salt vesicles,and casparian strip have salt secretion or blocking functions.In terms of physiological activity regulation,on the one hand,salt-tolerant plants have high enzymatic and non-enzymatic antioxidant substances,such as SOD,CAT,phenolic substances,on the other hand,salt-tolerant plants have a high content of osmoregulatory substances,or can synthesize osmoregulatory substances under salt stress,including soluble proteins and sugars of organic substances and inorganic ions.In terms of molecular mechanism,SOS pathway is the most clearly studied ion regulation pathway,which maintains intracellular Na⁺/K⁺ balance through the synergistic action of SOS1,SOS2 and SOS3.In addition,plant hormones and carbon metabolism pathways also play an important role in the process of plant salt tolerance.This paper summarizes the research progress of salt-tolerant plants,and discusses the potential research focus and direction of salt-tolerant plants in terms of morphological structure,physiological basis,genetic molecular basis and transgenic methods in response to salt stress,which will help researchers quickly find the breakthrough point,gradually improve the mechanism system of salt-tolerant plants,and accelerate the efficient utilization of salt-tolerant plants.

This study aimed to clarify the regulatory mechanism of exogenous glycine betaine(GB)on the antioxidant and photosynthetic systems of maize seedling leaves under combined heat and drought stress(TD),providing a theoretical basis for alleviating crop stress under extreme environments.Using the maize variety Xianyu 335 as experimental material,different concentrations of GB(0,50,100,200,and 400 mmol/L)were applied to the leaves at the three-leaf-one-heart stage.After 24 hours,combined stress was simulated in a climate chamber with high temperature(day/night temperature of 40 ℃/28 ℃)and 20% PEG-6000 to induce moderate drought,exploring the regulatory effects of GB on the antioxidant system and photosynthesis of maize seedlings.The results showed that 100 mmol/L GB significantly promoted plant growth.Compared with the TD treatment,plant height,leaf area,shoot dry weight,and root dry weight increased by 27.48%,27.45%,28.33%,and 78.26%,respectively,while the root-to-shoot ratio increased by 14.91 percentage points.On the 5th day after stress,100 mmol/L GB significantly enhanced antioxidant enzyme activities,with superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT)activities increasing by 69.09%,69.02%,and 41.81%,respectively.Simultaneously,the contents of malondialdehyde(MDA),superoxide anion($\mathrm{O}^{\bar{.}}_{2}$),and hydrogen peroxide(H₂O₂)decreased by 21.92%,6.50%,and 25.33%,respectively.Furthermore,soluble sugar(SS)and soluble protein(SP)contents increased by 31.69% and 18.98%.Photosynthetic characterization analysis indicated that GB effectively improved the lamellar system structure of chloroplast grana and stroma thylakoids,thereby significantly increasing the SPAD value under combined stress and alleviating damage to the photosystem Ⅱ(PSⅡ)reaction center.This was manifested by a decrease in minimal fluorescence(F0)and increases in variable fluorescence(Fv)and maximum fluorescence(Fm).Additionally,by mitigating the stomatal and non-stomatal limitations caused by combined stress,GB treatment significantly enhanced photosynthetic performance,increasing the net photosynthetic rate(Pn)by 24.14% on the 5th day after stress.In conclusion,under combined heat and drought stress,exogenous GB can protect the photosynthetic system by enhancing antioxidant enzyme activities and osmotic adjustment capacity,thereby alleviating stress damage and promoting the growth of maize seedlings.

This study investigated the impacts of drought on the agronomic,physiological,and biochemical characteristics of peanuts developed a classification methodology for drought resistance,screened the varieties of peanut with drought resistant.Agronomic traits of 27 peanut germplasms under drought stress were measured 30 days after sowing,and drought resistance was graded by correlation analysis,principal component analysis,cluster analysis,and membership function method.Drought-resistant peanut JNH3,intermediate L231,and drought-sensitive L236 were selected for determination of physiological and biochemical indexes and microstructure observation,and different drought-resistant peanut germplasms were identified.The results showed that after drought treatment,the decrease in main stem height ranged from 2.26% to 34.06%,the length of first branches decreased from 1.11% to 57.20%,the main stem base coarse decreased from 1.54% to 38.36%,and the root-shoot ratio decreased from 65.01% to 92.83% under different environments.According to the comprehensive weighted membership function,peanut materials were grouped into three types:drought-resistant,intermediate,and drought-sensitive.Among them, the above-mentioned traits of the intermediate type and the drought-sensitive type peanuts reached a significant level compared with the control. Under drought stress,ROS in functional leaves of peanut increased,and different expressions of ROS were found by NBT and DAB staining,among which NBT and DAB staining were JNH3,L231,and L236 from light to deep,conforming to the classification of drought resistance type.Compared with the control,the POD activity of JNH3,L231,and L236 increased by 42.71%,26.04% and 20.59% respectively,among different varieties,and CAT activity trend was consistent with the above.The SOD activity of JNH3,L231,and L236 increased by 48.01%,63.49% and 73.15% respectively,among different varieties,and the MDA activity trend was consistent with the above.The proline content of JNH3,L231,and L236 was increased by 1.1,1.07 and 1.03 times,and the soluble sugar content of JNH3,L231,and L236 was increased by 44.06%,31.54%,and 38.62% respectively,among different varieties.Under drought stress,peanut root growth was limited,the total root length and total root area were significantly reduced,the root tip cells were partially necrosis,and the degrees were shallow to deep in JNH3,L231,and L236 respectively.

The effects of different degrees of drought stress on antioxidant enzyme activity, malondialdehyde(MDA)content,photosynthetic characteristics,and yield composition of wheat were investigated to provide a theoretical basis and technical support for optimizing water-saving production of wheat.From 2023 to 2025,four soil water gradients of heavy drought(I-hd),moderate drought(I-md),mild drought(I-fd)and suitable water content(I-sm)were set up in the Longkou Experimental Station of Shandong Academy of Agricultural Sciences.The antioxidant enzyme activity,MDA content,photosynthetic characteristics and grain yield composition of wheat under different drought stress were systematically analyzed.The results showed that compared with moderate and heavy drought,mild drought and suitable water were beneficial to optimize spike number,grain number per spike and 1000-grain weight,thus significantly increasing grain yield,and the average grain yield in two years increased by 11.1%—51.0%.The activities of antioxidant enzymes such as superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT)were significantly increased at each growth stage under mild drought and suitable water,and the MDA content in leaves was significantly decreased at each growth stage,which played an important role in reducing the degree of cell membrane lipid oxidation and delaying plant senescence.The leaf area index(LAI),chlorophyll relative value(SPAD value)and net photosynthetic rate(Pn)of leaves at booting,flowering and mid-filling stages were maintained at a high level under mild drought and suitable water conditions,which provided a physiological basis for the improvement of photosynthetic rate,while the above indices were significantly reduced during the whole growth period under moderate and severe drought conditions.The results of correlation analysis showed that the activities of antioxidant enzymes(SOD,POD,CAT)were significantly negatively correlated with MDA content,and significantly positively correlated with photosynthetic characteristics(LAI,SPAD,Pn)and yield components(spike number,grain number per spike,1000-grain weight),which provided physiological guarantee for maintaining higher photosynthetic capacity.In summary,both mild drought and suitable water significantly increase the activities of antioxidant enzymes such as SOD,POD,and CAT in leaves at each growth stage,reduce the content of harmful substances such as MDA,and optimize LAI and SPAD values to improve the photosynthetic rate of leaves.The final grain yield increased by 11.1%—51.0%.However,there was no significant difference in grain yield,antioxidant enzyme activity and photosynthetic characteristics between mild drought and suitable water.Therefore,it is concluded that under mild drought conditions,high and stable yield of wheat can be achieved by optimizing photosynthetic characteristics and leaf antioxidant capacity,which provides a reliable practical approach for water-saving crop production.

To clarify the effects of drought stress and cultivars on the net photosynthetic rate(Pn),the activities of photosynthetic enzymes in flag leaf in the afternoon(FLA)during grain filling stage and grain yield of winter wheat,a pond culture experiment with four water levels and two winter wheat cultivars was conducted under the condition of rainproof pond cultivation in 2019—2021.The four water treatments included severe drought(W1),moderate drought(W2),mild drought(W3),and suitable water supply(W4).The Pn,and the activities of Rubisco,RCA,PEPC,ATPase and PPDK in flag leaf from 14:00 to 16:00 during the early(EGFS)and medium(MGFS)grain filling stage,and the grain yield at maturity of strong drought resistance cultivar Jinmai 47(JM47)and weak drought resistance cultivar Yanzhan 4110(YZ4110)were investigated.Drought stress decreased the FLA Pn and activities of most photosynthetic enzymes,and the grain yield of wheat.The decrease of these indexes increased with drought stress degree,but the effects were different among varieties and years.Compared with W4,the FLA Pn of JM47 under W1,W2 and W3 decreased by 33.6%—40.6%,12.0%—30.5% and 5.0%—13.5%,as well as YZ4110 decreased by 44.0%—52.0%,22.5%—38.1% and 11.5%—20.5%,respectively.Compared with W4,the FLA Rubisco activity decreased during EGFS but increased during MGFS for JM47,while it decreased by 13.3%—25.6%,7.1%—14.0% and 11.2%—11.6% for YZ4110,respectively,under W1,W2 and W3.Compared with W4,the FLA RCA activity significantly decreased under most drought treatments during EGFS,while increased under W2 and W3 for JM47 and decreased under W1 and W2 for YZ4110 during MGFS.Compared with W4,the FLA ATPase activity of JM47decreased under W1 but increased under W3,while that of YZ4110 decreased under W1,W2 and W3 by 19.3%—48.7%,7.2%—24.2% and 0.1%—8.9%,respectively.The FLA PEPC activity under different treatments varied with growing seasons and varieties.Compared with W4,the FLA PPDK activities of JM47 and YZ4110 under W1 were decreased by 12.4%—18.8% and 16.7%—18.2%.Compared with YZ4110,in most conditions,the FLA Pn and photosynthetic enzyme activities of JM47 had no significant difference under suitable water supply(W4),but increased under drought treatments(W1,W2 and W3).The results of correlation analysis showed that yield,FLA Pn were significantly positively correlated to FLA ATPase activity during EGFS and MGFS,as well as FLA PEPC activity during EGFS.Thus,increasing the FLA ATPase and PEPC activities during the grain filling period is conducive to the increase of FLA Pn and grain yield of wheat.

In order to alleviate the continuous cropping obstacle of millet,provide a reference for optimizing millet planting mode,millet continuous cropping(Si)was named as control(CK),millet-corn(Si-Zm),millet-potato-corn(Si-St-Zm),millet-corn-soybean(Si-Zm-Gm)and millet-soybean-potato(Si-Gm-St)were used to analyze the effects of different rotation patterns on the physiological indicators,photosynthetic characteristics,agronomic characters,yield and downy mildew incidence rate during the critical millet growth periods.The results showed that compared with CK,in the Si-St-Zm,Si-Zm-Gm and Si-Gm-St rotation patterns,the activeness of superoxide dismutase,peroxidase and polyphenol oxidase in millet flag leaves were significantly increased,with the largest increases of 45.55%,41.55% and 109.09%,respectively.In the Si-Zm-Gm and Si-Gm-St rotation patterns,millet plant height,stem thickness,root length and root branch number were significantly increased,with the largest increases of 30.48%,30.50%,31.76% and 13.79%, respectively.In addition,compared with CK,under the Si-Gm-St rotation system,the H₂O₂ and MDA content in the millet flag leaves were significantly decreased,with the maximum reductions of 18.78% and 47.29%, respectively;and the stomatal conductance,net photosynthetic rate,transpiration rate and relative chlorophyll content were significantly improved by 31.94%-101.43%,35.74%-234.00%,16.44%-46.97% and 24.15%-66.16%,respectively;with millet ear length,1000-grain weight and yield increased by 14.90%,17.09% and 10.58%,respectively;and millet downy mildew incidence rate significantly reduced by 12.33%.In short,compared with CK,the Si-Gm-St rotation system significantly increased the activeness of SOD,POD and PPO,and improved photosynthetic efficiency in millet flag leaves,meanwhile,the millet yield and disease resistance enhanced.Therefore,compared with Si-Zm,Si-St-Zm and Si-Zm-Gm rotation patterns,Si-Gm-St rotation system has the best effect on alleviating continuous cropping obstacles,which can provide a reference for optimizing millet planting system.

In order to reveal the response characteristics of potato growth,development,and photosynthetic traits to different water gradients during the critical growth period in semi-arid regions,this study conducted simulated experiments involving waterlogging (soil moisture maintained at 85% field capacity)and drought stress (drought initiated when soil moisture reached 65% field capacity)to investigate various growth traits and photosynthetic parameters of potatoes.The results showed that the plant height and biomass accumulation of potatoes under waterlogging were not different from those under normal irrigation.The plant height growth and biomass accumulation of potato under drought stress were significantly decreased.Meanwhile,the photosynthetic characteristics of potato leaves were significantly decreased under drought stress,including a 43% reduction in net photosynthetic rate and a 55% reduction in stomatal conductance.There was no significant difference in photosynthetic characteristics(except for stomatal conductance)between waterlogging treatment and normal irrigation treatment.Drought stress and waterlogging treatment decreased the photosynthetic capacity and light energy utilization of potato leaves to different degrees.Among them,under waterlogging conditions,the growth and development of potato leaves were more easily inhibited when exposed to strong light,and the activity of potato leaves was reduced.The growth and development of potato leaves were more easily inhibited when exposed to weak light under drought conditions,but the activity of potato leaves was not reduced.Comprehensive analysis showed that potato was more susceptible to drought stress in tuber expansion stage in semi-arid region,followed by longer waterlogging duration affecting potato growth and development.

This study investigated the effects of arbuscular mycorrhizal fungi(AMF)inoculation on the physiological characteristics and the accumulation of active components in the medicinal tree peony Paeonia ostii Fengdan under drought stress,with the aim of providing a theoretical basis for utilizing AMF to enhance the drought resistance and medicinal quality of this species.Using P.ostii seedlings as experimental material,four treatments were established:well-watered control(CK),drought stress(DR),AMF inoculation under well-watered conditions(AMCK),and AMF inoculation under drought stress(AMDR).Indicators related to plant redox homeostasis(including superoxide dismutase(SOD)activity,proline and soluble sugar content),photosynthetic characteristics(including photosynthetic pigment content,gas exchange parameters,and chlorophyll fluorescence parameters),and the content of active components(such as total flavonoids,paeonol,and paeoniflorin)in the root bark were measured.The results showed that drought stress induced significant accumulation of malondialdehyde(MDA)and reactive oxygen species(ROS),with increases of 33.53% and 50.04%, respectively,while photosynthetic performance was markedly inhibited.This was specifically evidenced by significant decreases in net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),maximum photochemical efficiency(Fv/Fm),and photosynthetic performance index(PIabs).AMF inoculation effectively alleviated these adverse effects.It was found that inoculation not only significantly increased SOD activity by 6.36% and elevated the contents of osmoregulatory substances (soluble proteins, soluble sugars, and proline) by 23.72%, 53.31%, and 14.70%, respectively,but also reduced ROS levels,thereby enhancing cell membrane stability.A significant recovery was also observed in photosynthetic pigment content and photosynthetic and chlorophyll fluorescence parameters(Pn,Gs,Tr,Fv/Fm,and PIabs).Furthermore,under drought stress conditions,AMF inoculation further promoted the accumulation of secondary metabolites in the root bark,including total flavonoids,paeonol,and paeoniflorin,with increases of 18.67%, 11.39%, and 5.17%, respectively, compared with the DR treatment.In conclusion,it is demonstrated that AMF can effectively mitigate the physiological damage caused by drought stress in P.ostii by enhancing its antioxidant capacity,promoting the accumulation of osmoregulatory substances,and improving photosynthetic performance.Simultaneously,AMF boosts the content of secondary metabolites in the root bark.

In order to investigate the physiological regulation mechanism of exogenous H₂O₂ on the cotton seedlings under NaCl stress,the cotton variety Xinluzao 48 was used as the test material in an outdoor potting method.Two-factor random combinations of salt stress (NaCl,concentration gradients of 0,100,200 mmol/L) and H₂O₂ (concentration gradients of 0,0.005,0.010,0.020,0.050 mmol/L) were set,to study the change rule of fresh weight,dry weight,chlorophyll content,chlorophyll fluorescence parameters,photosynthetic gas parameters,antioxidant enzyme activities and osmotic regulation system of cotton seedlings.The results showed that exogenous H₂O₂ effectively alleviated the inhibitory effect of salt stress on the growth of cotton seedlings,increased chlorophyll content,photosynthetic gas parameters and chlorophyll fluorescence parameters of cotton seedlings,maintained the normal operation of photosynthesis of cotton seedlings and ensured the accumulation of dry matter.Meanwhile,exogenous H₂O₂ could increase the activity of antioxidant enzymes (POD,APX,CAT),accelerated the removal of ROS from cotton seedlings.Exogenous H₂O₂ reduced the electrolyte leakage rate,MDA content,the content of osmoregulation substances such as pro,free amino acid and SS,and improved the salt resistance of cotton seedlings.Among all treatment,0.020 mmol/L exogenous H₂O₂ had the best effect in alleviating the salt stress suffered by cotton seedlings.In summary,exogenous H₂O₂ improves the adaptation of cotton seedlings to salt stress by improving photosynthetic performance,keeping stable photosynthesis in cotton seedlings,and maintaining the dynamic balance between ROS production and elimination in cotton seedlings.

In order to explore the effective methods for the identification of drought tolerance of foxtail millet during the entire growth period,select the identification indices of drought tolerance of foxtail millet,and speed up the process of drought tolerance breeding of foxtail millet,a field experiment was conducted using a randomized incomplete block design(alpha-lattice design)and repeated thrice in 2019—2020. Each experiment consisted of 30 foxtail millet genotypes treated under drought stress(DS)and normal water supply(CK). The agronomic traits and drought tolerance coefficient(DC)of the genotypes were assessed during the entire growth period. Combined analysis of variance showed that soil water environment had significant effects on 1000-grain weight,and extremely significant effects on the other indices. Genotype had significant effects on spike weight and grain weight per plant,and extremely significant effects on the other indices. Besides,the interaction between genotype and soil water environment extremely significantly affected the growth traits of foxtail millet,but not yield traits(except 1000-grain weight). Under drought stress,the characteristic value of each index decreased in varying degrees compared with CK,and the sensitivity of each index to drought stress was different. The results of t test showed that the effect of drought stress was significant(except 1000-grain weight). GGE biplot explained 71.15% of the total variation of data.The drought tolerance coefficient of each index was correlated in different degrees,in which the drought tolerance coefficients of plant height,spike length,stem and leaf dry weight and top second leaf area were significant positive correlation,and that of spike weight per plant,grain weight per plant,kernels per spike and yield were also significant positive correlation. The drought tolerance of foxtail millet could be reflected by different agronomic traits. According to the distance from ideal drought-tolerant varieties and ideal drought-tolerant evaluation indices,the drought tolerance and evaluation indices of foxtail millet materials were ranked. Taixuan 26,Chaogu 62,Chaogu 13 and other materials had strong drought resistance,plant height and spike weight per plant could be used as indices for drought tolerance identification in foxtail millet. GGE biplot provided an objective and effective new visual identification method for the breeding of drought resistant foxtail millet varieties.

To investigate the effects of long-term fertilization on yield formation and its physiological regulation mechanisms in double cropping late rice,it utilized a long-term fertilization experiment(initiated in 1981)in red paddy soils of Jinxian.Four typical treatments were selected:no fertilization(CK),single application of nitrogen-phosphorus-potassium(NPK),double dose of NPK(HNPK),and combined organic-inorganic fertilization(NPKM).Comparisons were made on double cropping late rice yield,dry matter accumulation,chlorophyll dynamics,and differential gene expression in leaves at fullheading and filling stages in the 42nd year of long-term fertilization.Results showed that long-term fertilization resulted in yields ranked as NPKM>HNPK>NPK>CK,with HNPK and NPKM treatments significantly surpassing NPK,showing increases of 29.63% and 57.18% respectively.Compared with NPK,both NPKM and HNPK significantly improved yield components:effective panicles,grains per panicle,and grain density increased by 16.98%—46.42%,8.68%—15.26%,3.69%—7.37%,respectively.Regarding dry matter accumulation,NPKM and HNPK significantly enhanced dry matter weight at all growth stages and promoted translocation of stem-leaf dry matter to panicles from filling to maturity.The contents of chlorophyll in NPKM and HNPK treatments were significantly higher than those in CK and NPK treatments at all stages,and NPKM delayed the decay of chlorophyll from filling stage to maturity stage.Correlation analysis revealed significant positive relationships between yield and dry matter accumulation from tillering to heading(△DM1)and filling to maturity(△DM3),while showed extremely negative correlation with chlorophyll reduction from grain filling to maturity(△S3).Transcriptome analysis demonstrated that long-term fertilization significantly affected gene expression in leaves during fullheading and filling stages,with differentially expressed genes primarily enriched in photosynthesis,carbon/nitrogen metabolism,signal transduction,and stress-related pathways.In conclusion,long-term fertilization regulates gene expression and combined organic-inorganic fertilization improved yield components,enhanced early-stage dry matter accumulation,promoted assimilate translocation from vegetative organs to panicles during grain filling,maintain higher chlorophyll levels,and delayed leaf senescence post-grain filling.This comprehensive mechanism achieves yield enhancement through strengthening source(enhancing photosynthetic capacity),expanding sink(increasing dry matter storage),and facilitating flow(promoting assimilate transport).

To investigate the effect of exogenous melatonin (MT) on salt tolerance of soybean seedlings,and to screen the appropriate application concentration under different salt stress.The soybean variety Tianyou-2986 was used as the test material,and 3 salt concentrations (low salt S₃:3 g/L,medium salt S₅:5 g/L,high salt S₇:7 g/L ) and 6 MT concentrations were set(M₀:0 μmol/L,M₁:25 μmol/L,M₂:50 μmol/L,M₃:75 μmol/L,M₄:100 μmol/L,M₅:150 μmol/L),the morphological parameters,biomass,antioxidant enzyme activity and osmoregulatory substance content of soybean seedlings were analyzed.With the increase of salt stress,the root morphological parameters,biomass,root-shoot ratio,antioxidant enzyme activity and osmoregulatory substance content of soybean seedlings decreased,while the malondialdehyde content increased.Under low salt (S₃) and medium salt (S₅) stress,The number of total length,lateral roots,SOD and POD of 50 μmol/L MT were increased by 52.30%,19.98%,74.10%,40.03% (low salt) and 68.52%,19.24%,81.72% and 37.42% (medium salt),respectively.Under high stress (S₇),75 μmol/L MT increased by 71.17%,19.11%,80.79% and 27.01%,respectively.Under salt stress,exogenous 25—100 μmol/L MT promoted soybean seedling growth and improved salt tolerance to different degrees.The overall evaluation of the affiliation function showed that 50 μmol/L MT was the most effective in alleviating salt damage under low and medium salt stress,and the suitable concentration of MT was 75 μmol/L under high salt stress,and the main reason for the alleviation of salt damage in soybean seedlings was that MT increased the activities of antioxidant enzymes and osmoregulatory substance content,and reduced the content of malondialdehyde,which could alleviate oxidative and osmotic stresses of soybeans under salt stress.

To select the suitable sorghum varieties for brewing in Qitai County,and provide reference for breeding and generalization of the new sorghum varieties in Xinjiang,20 new sorghum varieties were introduced from other provinces and their growth periods,agronomic traits and yields were compared to identify the highest and stable yield of each variety in 2020-2022.And the nutritional qualities such as grain starch,lysine,tannin,soluble total sugar,crude protein,crude ash and crude fiber were measured.The results showed that the growth period,agronomic traits,yields and nutritional composition were different between varieties and planting years.The average growth periods of 20 varieties were 84-146 days and plant heights ranged from 68.44 to 250.46 cm.The two species,Longza 18 and Longza 20,belonged to extremely early maturing and short varieties.The 13 short stem varieties with plant heights of less than 150 cm were identified as suitable for mechanized cultivation,such as Fengza 4,Liaonuo 11,Jiza 124,Jiza 127,Liaoza 37,Liaonian 3,Jiniang 3,Jinza 34,Jinnuo 3,Tongza 108,Jinza 109,Chiza 106 and Jinnuoliang 5.Hongyingzi was the only late-maturing high-stem variety.The yield ranged at 4 364.32-13 779.84 kg/ha,Jinza 109 had the highest yield while Shenza 5 had the lowest yield.There were differences in grain quality among different varieties;Liaoza 10 had the highest starch content of 759.93 g/kg while Jinza 34 had the lowest tannin content of 1.81 g/kg.In summary,based on the characteristics of growth period,agronomic traits,yield and quality,the tested short-stem and mid-mature variety Jinza 109 showed the highest yield,best stability and best comprehensive performance,which can be planted and popularized as the preferred variety suitable for mechanized cultivation in the Qitai area.

To reveal the mechanism of drought resistance of different resistant rice during germination period,Rice drought-sensitive materials(Calrose,Jingning 10,Shanxing 86)and drought resistance materials(Farry,Songjing 3,Ningjing 36)were studied on the effects of simulated drought stress(15% PEG-6000)on the growth index,physiological indexes and corresponding gene expression of different rice seeds.The results showed that under normal conditions,there were no significant differences in the expression levels of growth indicators and stress-related genes between drought-sensitive and drought-resistant cultivars.However,changes in physiological indicators were shown that there were no significant differences in the activities of superoxide dismutase(SOD) and peroxidase(POD),the contents of soluble sugar(SS) and hydrogen peroxide(H₂O₂) among different genotypes.The contents of malondialdehyde(MDA) and superoxide anion($\mathrm{O}_{2}^{\bar{.}}$) in the drought-sensitive cultivar Shanxing 86 were significantly higher than those in other materials,and the contents of catalase(CAT),proline(Pro) and soluble protein(SP) of drought resistant Ningjing 36 were significantly higher than those of other materials as well.Under drought stress,the relative germination potential(RGP),relative bud length(RSL),germination drought resistance index(GDRI)and vitality index(VI)of germinating seeds increased by 0.03—0.07 percentage,0.32—0.39 percentage,0.12—0.18 percentage and 92.41%—108.39%,respectively;MDA and reactive oxygen species($\mathrm{O}_{2}^{\bar{.}}$,H₂O₂) contents in germinating seeds of drought-resistant cultivars decreased by 2.54%—61.64%,19.60%—46.30% and 35.61%—62.02% respectively compared with drought-sensitive cultivars.The contents of osmotic regulating substances(Pro,SS,SP) increased by 5.93%—18.29%,1.08%—7.97% and 3.47%—6.03% respectively.The activities of antioxidant enzymes(SOD,POD, CAT) were increased by 17.29%—33.12%,15.24%—76.06% and 14.68%—18.61% respectively.The relative expression levels of OsP5CS,antioxidant enzyme synthesis genes (OsALM1, OsPOX1, OsCATC) were up-regulated by 2.66%—182.31% and 57.14%—513.27%,0.38%—109.06% and 63.39%—184.25% respectively.Comprehensive analysis showed that drought stress inhibited the germination of rice seeds and affected the physiological characteristics of seeds and the expression of corresponding genes during germination.Under drought stress,vigor index(VI),peroxidase(POD)and peroxidase synthesis gene(OsPOX1)are the key indicators affecting rice seed germination,whether it is drought-resistant or drought-sensitive materials.In addition to the above indicators,soluble protein(SP),proline synthesis gene(OsP5CS)and catalase gene(OsCATC)are other key indicators affecting drought-resistant materials.Relative shoot length(RSL),hydrogen peroxide(H₂O₂)and superoxide dismutase gene(OsALM1)are other key indicators affecting drought-sensitive materials.

In order to explore the effects of saline-alkali stress on the physiological and molecular mechanism of Brassica napus L.,using Huayouza 62 as experimental material.The seedlings of Brassica napus L.were treated with different concentrations of compound salt,compound alkali and compound saline-alkali solution.Physiological indexes such as seed germination rate,chlorophyll content,proline content,soluble sugar content and antioxidant enzyme activity in Brassica napus L.leaves were determined.The accumulation of betaine in rape leaves was determined by high performance liquid chromatography(HPLC).The key enzyme gene choline monooxygenase gene(CMO)in betaine synthesis pathway was analyzed by qRT-PCR technique.The results showed that the degree of damage to seed germination in artificially simulated saline-alkali solution of different concentrations was compound saline-alkali>alkali>salt.Low concentration saline-alkali solution promoted chlorophyll formation in rape leaves,while high concentration saline-alkali solution inhibited chlorophyll formation,saline-alkali stress significantly increased the contents of proline and soluble sugar,and the contents of proline and soluble sugar in high saline-alkali solution(YJ75,saline-alkali 75 mmol/L)for 21 d were 65.99 and 5.21 times higher than those in the control group,respectively,and the content of malondialdehyde was increased by saline-alkali stress.Saline-alkali stress significantly increased the activity of peroxidase(POD).Compared with the control group,the content of POD in high saline-alkali solution(YJ75)increased by 2.26 times after 21 d,and the content of POD reached the highest value on the 14th day after treatment with compound salt and compound alkali,however, the activity changes of superoxide dismutase (SOD) and catalase (CAT) were not obvious, and the role of species in the process of saline-alkali stress was low.Saline-alkali stress significantly increased the expression of key enzyme gene CMO,thus regulating the accumulation of betaine.In summary,the damage degree of saline-alkali stress to Brassica napus L. was compound saline-alkali > alkali > salt.Under high saline-alkali stress,Brassica napus would accumulate a large amount of betaine to reduce the damage.

In order to study the synergistic regulation characteristics of plant growth regulators on canopy-root traits of spring maize and to further reveal the lodging resistant mechanism of the plants,in 2021—2022,with the maize varieties Dika 159(DK159)and Xianyu 335(XY335)as experimental materials,at two planting densities of 75 000,90 000 plants/ha,plant growth regulator treatment (PGR) and water control (CK) were set up to analyze and compare the canopy structure,stem basel internode characters,root morphological characteristics and physicochemical properties of root bleeding sap under different treatments.The results showed that PGR had regulatory effects on both the maize canopy and roots.After PGR treatment,plant height,ear height and center of gravity height decreased,the mean leaf tilt angle above ear increased,light transmittance of ear layer increased by 23.59% on average,light transmittance of basel layer increased by 18.60% on average,and stem quality of basal internode was significantly improved.At the same time,the total root number,root length and root dry weight of PGR treatment increased,the root width at 10 cm below the surface increased,the root bleeding sap flow and nutrient flow increased,and the root morphological characteristics and transport capacity were obviously optimized.The flow of CTK and IAA in the root bleeding sap increased,while the flow of GA decreased.PGR effectively reduced the occurrence of stem lodging and root lodging through the synergistic regulation of canopy and root system,the field lodging rate of maize decreased from 13.43% to 6.47%,and the average yield of maize increased by 16.10%,thus achieving stable and high yield.

In order to explore the photosynthetic physiological response mechanisms of three summer maize varieties (Xundan 20, Jinbei 288 and Dika 667) which were commonly cultivated in arid and semi-arid areas to drought stress, these three varieties were treated under different drought stresses (including non-drought treatment (CK), light drought (LD) and heavy drought (HD)). Responses of net photosynthetic rate to light intensity (Pn-PAR) and net photosynthetic rate to intercellular CO₂ concentration (A-Ci) were estimated by the portable photosynthesis system Li-6400, and responses of chlorophyll fluorescence parameters to light intensity were measured by portable modulation chlorophyll fluorescence meter MINI-PAM, respectively. The results were as follows. As for all these three varieties, the response modes of Pn and stomatal conductance (Gs) to PAR were similar among these three maize varieties, and the responses of Pn to Gs shifted to left along the drought stress gradient. The initial chemical efficiency (CE) and photosynthetic capacity (Amax) were significantly lower under heavy drought treatment than under the other two treatments for each of the three varieties. Compared with the results under CK treatment, the non-photochemical quenching coefficient (qN) and the quantum yield of the regulatory energy dissipation (Y (NPQ)) were lower and the quantum yield of non-regulated energy dissipation (Y(NO)) was higher under LD or HD treatment for the two varieties of Jundan 20 and Dika 667; and the photochemical quenching coefficient (qP) was lower under HD treatment for the variety of Jinbei 288. Compared with the results under CK treatment, the maximum net photosynthetic rate (Pmax) and initial quantum efficiency (AQY) were a little higher under LD treatment for the variety of Jinbei 288. Compared with the other two varieties, the Pmax and AQY showed higher tolerance to drought stress by keeping relatively lower qQ and lower Y(NO) for the variety of Jinbei 288, and these results not only showed the greater tolerance of Jinbei288 to drought stress, but also provided reference for the screening of crop varieties for drought tolerance.

In order to study the effects of continuous drought treatment in whole growth period on cotton growing development and final yield,in this experiment,pot-culture method was taken and Xinluzao 19hao,Xinluzao 27hao and Xinluzao 54hao as materials,the treatments were light and moderate drought stress,then measured morphological indexes,physiological indexes and photosynthetic parameters at seedling stage,bud stage,blooming stage and boll opening stage,and investigated yield components at harvest time.Results showed:cotton height and stem diameter decreased with the strengthen of drought stress; The content of reactive oxygen species and antioxidant enzyme activities were great difference at different growth stage,correlation analysis showed that there were significant or extremely significant correlation between active oxygen content and antioxidant enzyme activity,indicted that antioxidant enzymes activity changed regularly with the content of reactive oxygen species,so as to eliminate the excessive oxygen species in vivo and prevent the damage of reactive oxygen species; The photosynthesis of cotton at bud stage decreased with the strengthen of drought stress,but increased at boll opening stage,except Xinluzao 27hao which possibly due to persistent drought treatment caused the different developmental stage of cotton at later growth stage; Drought stress reduced the yield per plant and fiber length of Xinluzao 27hao and Xinluzao 54hao,light drought stress had little effect on single boll weight,even played a role in promoting; There were four indexes of cotton at blooming stage had significant correlation with yield per plant,indicted that cotton blooming stage might be the key period which easy to be affected by environment and determined the final yield.

In order to explore the relationship between soluble sugar content and grain starch content of spring barley,Mengpi 3 and Mengpi 5 were used as test materials,and four density treatments of 3.75,4.50,5.25,6.00 million plants/ha were set.The dynamic changes of soluble sugar and starch content in leaves,stems and grains during grain filling of barley under different planting densities were studied from 2018 to 2019.Its effect on the formation of grain starch components was analyzed.The results showed that the soluble sugar content in leaves,stems and grains of 2 years and 2 varieties showed a unimodal curve with the grain filling process,and the peak value appeared on 21 days after anthesis.With the increase of planting density,the soluble sugar content in leaves,stems and grains was increased first and then decreased,with the increase of planting density,and the peak value was 5.25 million plants/ha treatment.The contents of total starch,amylose and amylopectin in grains of 2 varieties in 2 years increased gradually with the filling process,increased first and then decreased with the increase of planting density,and the peak value was 5.25 million plants/ha treatment.Correlation analysis showed that there was a very significant positive correlation between the soluble sugar content of leaves,stems and grains at each filling stage and the starch component content of grains at maturity;the path analysis showed that the soluble sugar content of leaves,stems and grains at 21 days.After anthesis had the greatest effect on the total starch content of grains at maturity,and the path coefficients reached 1.002 3,0.580 4 and 0.745 5,respectively.The soluble sugar contents of leaves,stems and grains at 35 days after anthesis and 7 days after anthesis were the most affected on amylose content,and the path coefficients were 0.776 6,0.469 7 and 0.715 6,respectively.The soluble sugar content of leaves at 21 days after anthesis,stems at 7 days after anthesis and grains at 14 days after anthesis had the greatest effect on the amylopectin content of grains at maturity.The path coefficients were 1.046 9,0.638 2 and 0.775 6,respectively.5.25 million plants/ha was the most suitable planting density to increase the content of starch components in barley grains.The soluble sugar content of stem and grain at the beginning of grain filling 7 d after anthesis is of great significance to improve the yield and quality of barley.

In order to clarify the effects of drought stress on the photosynthetic characteristics in flag leaf in the afternoon during grain filling stage and grain yield of winter wheat with different drought resistance,an experiment with two winter wheat cultivars and four water levels was conducted under the condition of rainproof pond cultivation in 2018—2019 and 2019—2020.The two winter wheat cultivars were Jinmai 47(JM47,strong drought resistance)and Yanzhan 4110(YZ4110,weak drought resistance).The four water treatments included severe drought(W1:65% MFC(maximum field water capacity)before sowing + 45%—55% MFC after jointing),moderate drought(W2:75% MFC before sowing + 55%—65% MFC after jointing),mild drought(W3:75% MFC before sowing+65%—75% MFC after jointing),suitable water supply(W4:75%MFC before sowing+75%—85% MFC after jointing).The net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO₂ concentration(Ci),transpiration rate(Tr),instantaneous water use efficiency(IWUE),maximum photochemical efficiency of PS Ⅱ (Fv/Fm)and actual photochemical efficiency of PS Ⅱ(ΦPS Ⅱ)in flag leaf from 14:00 to 16:00 during the early,medium and medium-late grain filling stage and the grain yield and its components at maturity were investigated.The results showed that both water and cultivars had significant effects on the photosynthetic and fluorescence characteristics in flag leaf in the afternoon during the grain filling stage and the grain yield at maturity of winter wheat.From the two-year average,compared with W4,the Pn,Gs and ΦPSⅡ in flag leaf in the afternoon during the grain filling stage under drought stress(W1,W2 and W3)respectively decreased by 2.07%—68.92%,-3.23%—50.00% and -1.89%—30.19% in JM47,and decreased by 7.71%—80.19%,11.11%—59.26% and 0—73.47% in YZ4110;the flag leaf Tr values in the afternoon during the medium grain filling stage in JM47 and YZ4110 respectively decreased by 6.30%—32.87% and 6.49%—41.74%,and the flag leaf Fv/Fm values in the afternoon during the medium-late grain filling stage decreased by 1.20%—18.52% and 2.50%—30.00%.In general,for all the above indexes,the decreasing amplitude for the same index was JM47<YZ4110.Compared with YZ4110,the Pn,Gs,ΦPSⅡ and Fv/Fm in flag leaf in the afternoon during the grain filling stage under drought stress(W1,W2 and W3)of JM47 respectively increased by 0.86%—64.89%,8.33%—36.36%,1.96%—184.62% and 1.25%—17.86%,and the grain yields of JM47 were respectively increased by 28.91%,8.06% and 5.40%.Except for IWUE,the flag leaf photosynthetic parameters in the afternoon during the grain filling stage were significantly and extremely significant correlated with grain yield,but the correlation indexes varied with variety and grain filling stage.For JM47,the correlation indexes between the grain yield and flag leaf photosynthetic parameters were highest for Pn,Gs and Fv/Fm during the medium-late grain filling stage,for ΦPSⅡ during the medium grain filling stage,and for Tr during the early grain filling stage.For YZ4110,the correlation indexes were highest for Pn,Gs and Tr during the early grain filling stage,for ΦPSⅡ during the medium grain filling stage and for Fv/Fm during the medium-late grain filling stage.In summary,drought stress decreased the photosynthetic function of flag leaf in the afternoon during grain filling stage and thus decreased the grain yield of winter wheat,the strong drought resistance variety could maintain better flag leaf photosynthetic characteristics in the afternoon during the grain the filling stage under drought stress condition,and significantly improved the ΦPSⅡ of flag leaf in the afternoon during the medium grain filling stage and the Pn,Gs and Fv/Fm of flag leaf in the afternoon during the medium-late grain filling stage,thereby increasing the grain yield.

The effects of sowing date on the yield and yield components of winter wheat,and the response characteristics of growth and development and plant type structure to accumulated temperature were studied in order to clarify the growth characteristics and reasonable plant type structure of wheat adapting to climate change.From autumn 2017 to summer 2019,field trials were conducted in Gaocheng,Hebei Province.Five sowing dates were set,September 25,October 5,October 15,October 25 and November 4.The results showed that the yield of wheat was higher sown from October 5 to 15 than other treatments,and the accumulated temperature before winter was 410-549 ℃.When accumulated temperature before winter was suitable,spike number was high and grain number per spike was moderate.When the accumulated temperature was as high as 733 ℃,the number of invalid tillers was more,the effective tiller rate was lower,and spike number was lower.When the accumulated temperature was insufficient to 279 ℃,the spike number and grain number per spike decreased.Accumulated temperature had a significant effect on growth and development indicators.Under the condition of high and stable yield,the individual index of wheat before winter was put forward:the number of main stem and tillers per plant was 2.3,the number of secondary roots was 2.5,the number of leaves of main stem was 4.1,and the spike differentiation of over winter was single edge stage.The accumulated temperature had an obvious effect on the plant structure of wheat.Delay with sowing date,the flag leaf became longer and wider,the leaf area increased,and the leaf from the top third to the top fifth became narrower and the leaf area decreased.Delay with sowing date,stem diameter of the base increased,the stem length of the top first to top second increased and length of the top third to top fifth decreased,and plant height decreased significantly.According to the equation of yield and accumulated temperature before winter,it was recommended that the suitable sowing time of wheat was October 8 to 14 under high and stable yield conditions,and the accumulated temperature range before winter was 433-541 ℃.Under late sowing conditions,the plant type structure was more reasonable,the growth and development of the plant were moderate before winter,the flag leaf was smaller and its stem length was shorter,and the leaf from the top third to the top fifth from the top was larger and their stem was slightly longer.

In order to study the effect of drought stress on physiological characteristics of grafting flue-cured tobacco,using KRK26 as scion, KRK26,K326 and Anyan 2 as rootstock,analysing and discussing root morphology, plant morphology and physiological indexes of resistance in pot culture under different treatment. The results indicated that under drought stress conditions at early period, the relative content of chlorophyll (SPAD readings) decreased, while the content of proline, superoxide dismutase (SOD) activities, catalase (CAT) activities and peroxidase (POD) activities in flue-cured tobacco demonstrated an increasing trend. The root length,surface area,plant height,stem girth, node spacing and LAI of the grafted tobacco plants showed a decreasing trend,the content of proline continued to increase in both grafted seedlings and non-grafted seedlings with the aggravation of drought stress when tobacco leaves were turning to mature, whereas, the SPAD readings, SOD activities, CAT activities and POD activities all demonstrated a decreasing trend. The speed of decreasing in different root grafted was slower than that in own root grafted. Compared with KRK26/K326 and KRK26/KRK26, KRK26/Anyan 2 had greater parameters under drought stress, but the SPAD readings did not have significant difference. All the results showed that less damage was made to KRK26/Anyan 2 than KRK26/K326 and KRK26/KRK26 under drought stress, and KRK26/KRK26 suffered the most serious damage. According to correlation analysis, there was a certain correlation between morphological indexes and resistance indexes of grafting flue-cured tobacco. In conclusion, there were obvious differences among grafted tobacco in physiological characteristics, and there response to soil drought. The order of drought resistance was KRK26/Anyan 2, KRK26/K326 and KRK26/KRK26 in turn from strong to weak, based on the main root morphology,plant morphology,physiological characteristics under drought stress.

To clarify the effects of different tillage methods on soil moisture dynamics changes and maize yield under the condition of straw return to field in the black soil area along the foothills of Daxing'anling,based on six consecutive years of tillage positioning experiments,this study analyzed the effects of seven types of tillage methods,namely,full-crushing and deep-tillage (SCD),full-crushing and shallow-tillage (SSS),full-crushing and deep-tillage (SCS),full-crushing and re-harrowing (SCR),full-crushing and rotary tillage (STR),full-crushing and no-tillage (NTS),and conventional tillage without returning straw to the field (CK)on soil moisture characteristics,water consumption,water use efficiency,and agronomic traits and yield of maize in the 0—60 cm soil layer at different growth stages of maize in each treatment.The results showed a bimodal pattern of soil quality moisture content in 2022 and 2023.0—10 cm soil layer soil quality moisture content was significantly higher than that of CK,and the NTS treatment had the highest soil quality moisture content in several periods.10—20 cm soil layer soil quality moisture content was lower than that of CK in the SSS and NTS treatments at the jointing stage,and soil quality moisture content was higher than that of CK in the 20—40 cm and 40—60 cm soil layers in 2022 and 2023 for all the treatments.In 2022 and 2023,maize plant height in all treatments except NTS treatment was significantly higher than CK at different growth stages.The SCD treatment was the tallest and the NTS treatment was the shortest at mature stage.Leaf area index (LAI) varied little among treatments at seedling stage of maize,STR treatment had the highest LAI after the jointing stage,and all treatments had significantly higher LAI than NTS treatment at the big trumpet stage.Dry matter accumulation in all treatments except for the SCS,NTS treatment was significantly higher than in CK,and dry matter accumulation was highest in the SCD treatment and lowest in the NTS treatment at mature stage.All tillage treatments increased maize yield and water use efficiency compared with CK,but the SCD treatment was significantly higher than CK.Comprehensive analysis of the indexes showed that the two tillage methods of full-crushing and deep-tillage and full-crushing and shallow-tillage were favorable to improve soil structure,maize yield and water use efficiency in the black soil area along the foothills of Daxing'anling.

To study the physiological effects of different degrees of drought on soybean cultivars in different development periods. Two soybean cultivars with different drought resistances were taken as the experiment materials to study the effects of drought stress on the resistance index and physiological characteristics of soybean in different growth periods, and to explore the physiological mechanism of soybean response to different drought intensities at different developing stages in pot culture. Four treatments were set up:continuous mild drought stress (T1), continuous moderate drought stress(T2), drought stress in full seed stage (T3) and without drought stress(CK). The results showed that under drought stress, the chlorophyll contents of both soybean cultivars increased, and Jindazaochun 2 was more obvious at early stage, but it was less than that of Jinda 74 at grain-filling stage. Under continuous mild drought stress and continuous moderate drought stress, the MDA content of Jindazaochun 2 at different growth stages significantly increased, while the POD and MDA contents of Jinda 74 significantly increased under continuous moderate drought stress. At the branching stage, the content of reducing sugar in Jinda 74 decreased significantly during moderate drought. In the Granulation stage, the reducing sugar content of soybean leaves in Jindazaochun 2 was significantly increased, Jinda 74 was only reduced under drought treatment in the Granulation stage. At flowering stage, reducing sugar content reduced in Jindazaochun 2, but increased significantly in Jinda 74. It was found that drought had a great influence on reducing the plant height, node number, stem diameter of both cultivars. The decrease in plant height and stem diameter of Jinda 74 was more obvious. The resistance of Jinda 74 to drought was higher than that of Jindazaochun 2, which was related to the reduction of plant height and water consumption under continuous drought conditions. The results will provide a basis for comprehensive understanding of the soybean resistance to drought stress.

Tremendous impact of drought on agricultural production,research drought stress on physiological and yield,will provide the basis for soybean production in arid areas.In this paper,the use of plastic storage box drought stress test were studied photosynthetic physiology,leaf osmotic adjustment and antioxidant enzyme composition and biomass yield on the soil water into arid(45%-55% of the maximum water holding capacity of soil field) two horizontal and humid(80%-100% field soil water holding capacity,CK).The results showed that drought stress soybean net photosynthetic rate,stomatal conductance and transpiration rate decreased significantly,water use efficiency increased;drought stress on leaf peroxidase(POD) and superoxide dismutase(SOD) no significant effect on the content;malondialdehyde(MDA) content increased by 25.00% to reach a significant level;the amount of reducing sugars and total soluble sugars increased by 47.09% and 47.16%,respectively.Drought stress on soybean plant height,node number,stem diameter,aboveground biomass,yield decreased significantly.Under drought stress,soybean stomatal conductance decreased significantly,severely affected the supply of CO₂,reducing the net photosynthetic rate,so that the decline in soybean photosynthetic metabolism.Plant material can be adjusted to maintain the moisture permeation through the cell.Although soybeans can maintain cell moisture through osmotic adjustment substances,drought still inhibits normal plant growth and decreases soybean biomass and yield.

In order to understand the dynamic rules of sugars, starch, protein and trace elements of different types of wheat during grain filling stage under drought stress, and to identify the difference of nutriment between drought and irrigation in the process of grain-filling by high-yield wheat, high-quality wheat and water-saving wheat, the wheat varieties of Jimai 325, Jimai 418 and Jimai 323 in the North of Huang-Huai Region were used as experimental materials. The plants heading and flowering on the same day were selected for marking, and the grains of each variety were taken every 6 days after 7-31 days after anthesis. The effects of drought during grain filling on the contents of total soluble sugar, sucrose, glucose, fructose, protein, Fe, Zn, Mn, Cu, amylose and amylopectin accumulation, starch accumulation rate and the activities of key enzymes in starch synthesis were studied. The results showed that the content of sucrose and glucose in wheat grains was significantly decreased under drought stress, and the effect on fructose content was relatively small, and the sucrose and fructose of high-yielding variety Jimai 325 were less affected by drought in the filling process. Drought stress decreased the content of amylopectin and total starch in wheat grains, but had relatively little effect on the content of amylose. The effect of drought stress on starch content of high-yield and high-quality varieties was significantly greater than that of drought-tolerant variety Jimai 418. The activity of starch synthase was increased in the early and middle stages of filling stage under drought stress, and decreased rapidly in the middle and late stages compared with irrigation control. The content and accumulation of four mineral elements in wheat grains were Mg>Fe>Zn>Mn. With the progress of grain filling, the content of trace elements showed a downward trend. The accumulation of Fe, Zn and Mg in grains of Jimai 325 was higher. The difference of nutrient accumulation in grain filling process of different types of wheat under drought conditions were studied to provide theoretical data and reference basis for optimizing cultivation measures and realizing high quality, high yield and water saving of special wheat.

In order to explore a fast and efficient way to screen drought-resistant varieties of winter wheat, and to select drought-resistant winter wheat varieties. Six winter wheat varieties, Yannong 999, Taimai 1918, Jimai 22, Jimai 23, Taishan 27 and Shiluan 02-1 were used in this study. Normal water treatment(75% relative soil water content), mild drought treatment(55% relative soil water content) and moderate drought treatment(40% relative soil water content) were arranged to explore the chlorophyll fluorescence parameters, biomass, root-shoot ratio, SPAD, superoxide dismutase(SOD) activity, malondialdehyde(MDA) content and their correlations. Results showed that, compared with other varieties, under drought stress, Taimai 1918 obtained the highest drought resistance coefficient(DTC). The smallest reduction of root to shoot ratio, SPAD value, photosystem Ⅱ maximum photosynthetic efficiency(Fv/Fm), photosystem Ⅱ actual photosynthesis efficiency(φPSⅡ), relative electron transfer rate(ETR), SOD, and the largest increasing in non-photochemical quenching(NPQ) and minimal increasing in MDA content were observed in Taimai 1918. The order of drought resistance of 6 winter wheat varieties was Taimai 1918 > Yannong 999 > Jimai 22 > Jimai 23 > Taishan 27 > Shiluan 02-1. The chlorophyll fluorescence parameters were significantly correlated with drought resistance coefficient, SOD activity and MDA content. Sum up, the drought resistance in Taimai 1918 was strongest, and chlorophyll fluorescence parameters can be used for screening drought-resistant winter wheat varieties at seedling stage.

In order to identify the differences in source-sink relationships among different types of barley and the main source-sink indexes affecting yield,four barley materials with large leaf area differences,GP6,GKP7,GK6 and C2-1,were selected to study the differences in photosynthetic characteristics,dry matter,soluble carbohydrates,and filling characteristics and their relationships with yield in 7—28 d after anthesis.The results showed that the length-to-width ratio of flag leaves of GK6 and GKP7 was lower than that of GK6 and C2-1,while the chlorophyll content,photosynthetic rate and soluble sugar of flag leaves and penultimate leaves were higher.The chlorophyll content of flag leaves and penultimate leaves of GKP7 decreased the most,while the decrease of GK6 and C2-1 was smaller.During the early stage of grain filling,the dry weight of leaves and stem sheaths in GK6 was the highest,but the dry matter decreased the most during the filling process.The dry weight of GP6 and GKP7 was lower than that of GK6 and higher than that of C2-1,but the decrease was relatively small throughout the filling period;the grain rapid weight gain time of GP6 and GKP7 was 7—21 d longer than that of GK6 and C2-1(7—14 d),and the average filling rate(R) and time of maximum filling rate(Tmax)of GP6 was the highest,and the soluble sugar content of stem sheath and grain was lower than that of C2-1 at the early filling stage,which was higher than that of other materials.GKP7 filling active periods(D) and maximum filling rate(Rmax)were the highest,soluble sugar content in stem sheath was lower than GP6 and C2-1 at the early grout stage,and higher than other varieties at the later grout stage of leaf and stem sheath.The soluble sugar content in all organs of GK6 was low,and the soluble sugar content in stem sheath and grains was the highest at the early stage of C2-1 filling,but the content decreased rapidly at 7—14 d and was lower at the later stage of filling.The number of thousand grains weight and yield of GK6 and GKP7 were significantly higher than those of GK6 and C2-1,and the sink capacity of GK6 and C2-1 was smaller.Grain weight per spike/leaf area was GKP7>GP6>C2-1>GK6.Correlation analysis showed that the ratio of flag leaf length to width was negatively correlated with yield,and the stem sheath and leaf dry weight,leaf soluble sugar content,number of grains per spike,grain weight per spike/leaf area were positively correlated with yield at maturity.The chlorophyll content and photosynthetic rate at 7 d after anthesis,the grain dry weight at 14—28 d after anthesis,R and Rmax were positively correlated with yield.In summary,GKP7 has the most reasonable source-sink relationship,with GP6 ranking second,C2-1 source and sink are small,and GK6 source is large and sink is small.The ratio of flag leaf length to width,chlorophyll content and photosynthetic rate at the beginning of filling,grain dry weight,maximum filling rate and average filling rate can be used as the main indexes for high yield breeding.

To study the effects of salt stress on growth and physiological characteristics of sorghum at different growth stages(elongation, flowering, and maturity), two sorghum varieties with different salt tolerances, Gaoliangzhe(salt tolerance) and Henong No.16(salt sensitive), were planted at four salt treatment levels(CK:0 g/kg, S3:3 g/kg, S5:5 g/kg, S7:7 g/kg). Moreover, the two varieties were compared under different salt treatment levels, plant morphology, root morphology, leaf photosynthetic characteristics and antioxidant enzyme activities at different growth stages. The results showed that with increasing salt treatment concentration, the antioxidant enzyme activity and relative chlorophyll content(SPAD) of the two varieties increased first and then decreased. The antioxidant enzyme activity reached the maximum value under S3 or S5 treatment, and there were significant differences between the maximum and CK. With the increase of salt treatment concentration, the malondialdehyde(MDA) of the two sorghum varieties increased significantly, which S7 treatment was significantly higher than CK. Under the same treatment, the antioxidant enzyme activity of salt-tolerant varieties(Gaoliangzhe) was higher than that of salt-sensitive varieties(Henong No.16), but the content of MDA was lower than that of salt-sensitive varieties. The photosynthetic capacity of the two varieties was significantly affected by salt stress. In elengation, S7 treatment significantly reduced the Pn of Gaoliangzhe, and Ci of the two varieties under S7 treatment was higher than that of CK. Under salt stress, the growth of the sorghum aerial portion and underground portion of sorghum were affected. The basal stem diameter, total length of root, root surface area, number of root tips, and number of root branches for two varieties reached the maximum under S3 treatment. And basal internode length, plant height, total length of root and root volume reached the lowest value under S7 treatment. In addition, grain fat content and grain starch content in two sorghum varieties decreased under salt stress.The grain tannin content was significantly higher than CK in low-salt (S3, 3 g/kg). In general, low-salt can promote the growth of sorghum, while medium-salt (S5, 5 g/kg) and high-salt (S7, 7 g/kg) conditions have a significant inhibitory effect on sorghum growth. And Gaoliangzhe is more salt-tolerant than Henong No.16.

To determine the optimum strip configuration for the intercropping of soybean and maize with different border-row advantages,the field experiments were carried out in two distinct ecological regions,Jian'an District of Xuchang City and Shangshui County of Zhoukou City,Henan Province.The experimental materials included two maize varieties with strong border-row advantage(MC121 and Denghai 3206(DH3206)),and two with weak border-row advantage(Haoyu 16(HY16)and MY73),previously screened,and one soybean variety Jindou 99(JD99).Two strip intercropping patterns were established∶6 rows of soybeans alternating with 4 rows of maize(6S4M)and 4 rows of soybeans alternating with 2 rows of maize(4S2M).Sole cropping of soybeans(CKS)and maize(CKM)were set as the controls.This study investigated the variations in maize agronomic traits,dry shoot weight,yield and its components of each row under different strip patterns,and compared the differences of land equivalent ratio(LER).The results showed that the LER was greater than 1 in 12 of the 16 treatments formed by two strip configurations for four maize varieties in the two ecological regions,and the LER of maize varieties HY16 and MY73 was greater than 1 under each strip configuration at two sites.The LER of MC121 and DH3206,with strong border-row advantage,was higher in strip type of 4S2M than that of 6S4M.In contrast,the LER of HY16,with weak border-row advantage,was higher in strip type of 6S4M than that of 4S2M,while it was opposite for MY73.Under 6S4M planting pattern,stem diameter,canopy light transmittance,chlorophyll a and chlorophyll b contents in ear leaf and leaf below the ear of maize variety DH3206 decreased with the increase of border row order;bottom light transmittance,chlorophyll b content in ear leaf and leaf below the ear of maize variety MC121 decreased with the increase of border row order in two experimental sites.The yield of maize varieties MC121 and DH3206 with strong border-row advantage in Jian'an District and Shangshui County decreased by 23.71%,27.00% and by 20.03%,9.05%,respectively.The dry shoot weight per plant of the edge row-2 at maturity decreased by 15.87%,19.93% and by 13.82%,24.56%,respectively,compared with the edge row-1.In contrast,there was no significant change in yield and dry shoot weight per plant at maturity between the edge row-1 and the edge row-2 of maize varieties with weak border-row advantage.In conclusion,the average LER of varieties with weak border-row advantage is higher than those with strong border-row advantage under the same strip configuration,and maize yield difference between intercropping and monoculture is seriously affected by variety type.Therefore,screening and matching suitable maize varieties is essential for improving the yield and benefit of soybean-maize strip intercropping system.

In order to clarify the drought resistance and drought resistance mechanism of Allium polyrhizum in Inner Mongolia grassland,potted water control method was adopted.Two gradients were set,75% of the maximum field water capacity as the control(CK),and 25% of the soil relative water content under 30 days of drought stress.The root morphology,physiological characteristics and leaf photosynthetic characteristics of Allium polyrhizum from different sources were analyzed under drought stress. The result showed that Allium polyrhizum in Siziwang Banner compared with the Chifeng and Ordos was remaining relatively high root surface area,root volume and root length 0-0.5 mm in diameter. Allium polyrhizum root growth was relatively less affected by drought stress,chloroplasts were relatively stable and strong drought resistance in Siziwang Banner. Drought stress significantly decreased the above ground biomass,below ground biomass and total biomass of Allium polyrhizum in Chifeng and Ordos,but had no significant effects on Siziwang Banner(P>0.05). The Pn,Tr,Gs,Ci and leaves relative water content of Allium polyrhizum seedlings were significantly decreased and the relative permeability of cytoplasmic membrane was markedly increased under the whole drought stress treatment. Drought stress induced stomatal closure of Allium polyrhizum leaves and reduced transpiration to decrease water loss.The root characteristics,relative water content,chlorophyll and photosynthetic characteristics of Allium polyrhizum in different sources were certain differences under the same treatment. In general,the effect of drought stress on Allium polyrhizum in Siziwang Banner was relatively weak,it was indicating stronger drought tolerance.

The purpose of this study was to explore the effects of different drought stress levels on maize growth traits and yield in the semi-arid region of Northeast China, and to lay a theoretical foundation for further research on the physiological mechanism of maize drought resistance.Three kinds of maize varieties with different drought tolerance were selected and five water gradients of normal water supply(CK), light drought(LS), moderate drought(MS), severe drought(SS)and lethal(S)were set at maize jointing, tasselling and filling stages, respectively. The effects of different drought stress on the growth traits and yield related indexes of three maize varieties were comprehensively analyzed. The plant height, ear position and dry matter weight of maize decreased with the increasing of drought degree, but the stem diameter had no significant difference with the increasing of drought degree. The plant height, ear position and dry matter accumulation of maize variety Jinqing 707 was the highest, followed by Nendan 19 and Fudan 16. During tasselling stage, the spike characters of maize changed most obviously under drought stress, and the maize yield was the lowest under severe drought, and no yield under continuous drought.Under the same drought degree, the worse the drought tolerance of maize varieties, the greater the yield reduction. The specific performance of maize yield is Jinqing 707 > Nendan 19 > Fudan 16.A comprehensive analysis of multiple indicators shows that tasselling stage is the key period of water requirement of maize, which is easily affected by drought stress. At the same time, it is pointed out that drought stress or serious degree of drought stress in tasselling stage is the main factor leading to the decrease of maize yield.

Yellow-seeded rapeseed is popular with consumers because of the appearance and good quality of rapeseed oil.However,the unstable separation of progeny traits seriously affects its large-scale application.In order to analyze the internal reasons for the unstable separation of yellow-seeded rapeseed traits,the differences in the internal physiological mechanisms between yellow and black seeds in yellow-seeded rapeseed were explored.Yellow-seeded rapeseed(CK)was used as the material to study the differences in agronomic traits,physiological and biochemical indexes,and seed coat color-related genes between yellow(Y)and black(B)seed plants in the separation offspring.The results showed that the rhizome diameter and plant height of Y were larger than those of CK and B.The plant height of B was significantly different from that of CK and Y,respectively,and the rhizome diameter of B was significantly different from that of Y.The disease index of Y was 1.97,and the disease indexes of CK and B were 2.55 and 3.33,respectively,indicating that Y was superior to CK and B in disease resistance.The content of MDA in Y leaves was the lowest at 9—10 leaf stage,and the POD activity in Y and CK flowers continued to increase at flowering stage,indicating that yellow-seeded rape had strong stress resistance.The expression levels of TT18 and TT8 genes in B and Y at 7—8 leaf stage and 9—10 leaf stage were higher than those in CK,and the expression levels of TT18 gene in B and Y at final flowering stage were significantly lower than those in CK.At 28 days after pollination,the expression of MYB47 gene in Y seed was the highest,which was 5.56 times that of CK and 5.79 times that of B,respectively.The expression of TT8 gene was the highest in Y at 21 days after pollination,which was 3.30,2.29 times that of CK and B,respectively.It showed that yellow-seeded rapeseed had obvious advantages in oil content and stress resistance.Therefore,vigorous development of yellow-seeded rapeseed can provide new ideas for improving the supply of rapeseed oil and solving the safety of edible oil in China.

The effects of tillage depth and organic fertilizer rates on photosynthetic characteristics,yield formation,and economic benefits of wheat were explored to provide a theoretical and technical basis for fluvo-aquic soil or similar soil types.The two-factor split-plot field experiment was conducted in the typical fluvo-aquic soil area of Qihe County,Dezhou City,Shandong Province from 2022 to 2024,where the tillage depth 15-20 cm(D1)and tillage depth 30-35 cm(D2)were assigned to the main plots,and the organic fertilizer rates of 800(L),1 200(M),and 1 600 kg/ha(H)were assigned to the subplots.The photosynthetic characteristics,aboveground dry matter accumulation characteristics and yield composition,in wheat were tested in fluvo-aquic soil under different tillage depths and organic fertilizer rates.Both D2M and D2H treatments were beneficial to improve the yield and yield components of wheat,and the spike number,kernels per spike,1000-grain weight,and grain yield significantly increased by 5.5%-8.5%,3.5%-12.1%,6.7%-13.2% and 6.6%-12.8%,compared with other treatments,respectively.D2M and D2H treatments also stabilized or increased the above-ground dry matter accumulation at jointing,anthesis,and maturity stages by improving the above-ground dry matter accumulation rate at each growth stage,which was 9.0%-22.1%,8.9%-25.8% and 10.7%-24.3% higher than averaged across the two years of other treatments,respectively.Compared with D1,D2 was more conducive to promoting the effect of organic fertilizer on the SPAD of leaves at different growth stages.Under D2M and D2H treatments,higher chlorophyll content could be maintained from the mid- to late-filling stages.Under M and H organic fertilizer application rates,the Pn of leaves at different growth stages of D2 was significantly higher than that of D1.At jointing,booting,flowering,mid-filling,and late-filling stages,on average over the two years,D2M and D2H increased significantly by 12.0% to 16.7%,13.7% to 16.8%,13.8% to 19.7%,20.2% to 25.8%,and 24.6% to 44.8%,respectively,compared with D1M and D1H.Under the same organic fertilizer application rates,the difference in leaf LAI between the two tillage depths gradually increased with the progression of the growth process.D2M and D2H performed best at anthesis and mid-filling stages,increasing by 13.2% to 27.2%,and 13.4% to 29.4%,respectively,compared with other treatments on average over the two years.In conclusion,both D2M and D2H treatments could enhance the photosynthetic characteristics of plants and the above-ground dry matter accumulation ability,thereby optimizing the yield components and achieving the drastically improvement of wheat yield.However,there were no significant differences in the indices between D2M and D2H treatments.Therefore,considering resource conservation,this study suggests that the combination of a tillage depth of 30-35 cm and an organic fertilizer application rate of 1 200 kg/ha can achieve wheat high yielding.

Yield and nitrogen accumulation of maize will decline under soil acidification,but the physiological mechanism is not clear.Field experiment was conducted with four different soil acidity gradients:nautral acid(pH=7,CK),weak acid(pH=6,T1),medium acid(pH=5,T2)and strong acid(pH=4,T3),comparing yield,nitrogen accumulation,grain protein content,nitrogen metabolism-related enzyme activities,gene expression,nitrate nitrogen,ammonium nitrogen,soluble protein,free amino acid content in leaf and stem of maize.The results showed that compared with CK,the yield of T1,T2 and T3 treatments declined by 4.2%,30.7% and 52.3%,respectively.Grain number per spike decreased by 1.8%,28.1% and 42.8%;grain protein content showed a downward trend with T3 treatment significantly reduced by 14.5%.At the big flare stage,with the increase of soil acidity,nitrogen accumulation in leaves showed a downward trend,it was significantly decreased in T2 and T3 treatment by 28.1% and 56.2%,respectively.In stem,the nitrogen accumulation increased firstly and then decreased.Compared with CK,T1 treatment was significantly increased by 33.1%,and T3 treatment significantly decreased by 65.4%.At the big flare stage, the activities of nitrate reductase, glutamate dehydrogenase and glutamate synthase in leaf and stem under T3 treatment were significantly higher than those in CK, while the activities of glutamine synthase in leaf were significantly decreased. The amino acids in stem decreased first and then increased.With the increase of soil acidity,the expressions of ZmGln2 and ZmFd-GOGAT were up-regulated,which promoted the assimilation of {{\mathrm{NH}}_4}^{+} released by photorespiration and {{\mathrm{NH}}_4}^{+} produced by {{\mathrm{NO}}_3}^{-} reduction;the down-regulated expression of ZmGln1.2-ZmGln1.4, ZmNADH-GOGAT2 in leaf and ZmNADH-GOGAT1 in stem decreased the assimilation of {{\mathrm{NH}}_4}^{+} released by catabolism.By up-regulating or down-regulating the expression of relevant genes,maize could promote the production of more free amino acids and soluble proteins during nitrogen metabolism to resist acidification stress,but also reduced the nitrogen accumulation,resulting in lower yield and grain protein content.

The aims were to study the effect of maize straw returning on soil fertility and productivity under wheat-maize rotation system in North China,and to explore the best way and suitable amount of maize straw returning.From 2021 to 2023,a field split-plot experiment was conducted in Quzhou County,Hebei Province to compare the effects of different maize straw returning methods and amounts on wheat growth,yield composition and soil organic matter content.There were two treatments in the main area,which were cutting and crushing.The sub-area was the amount of straw returning to the field,4 levels,which were 0,0.5,1.0,and 1.5 times of the amount of maize straw in the year.The results showed that compared with straw crushing,the yield of wheat increased by 4.3% under straw cutting treatment,the number of spikes increased by 7.6%,and the harvest index increased by 1.4%,with all significant difference in 2023.The N content of wheat straw was significantly increased by 0.04 percentage points,the N and P uptake of wheat aboveground were significantly increased by 10.8% and 14.3%,respectively(2022),but the K content of wheat straw was significantly reduced by 0.13 percentage points(2023).Cutting treatment could significantly promote the growth of wheat before and after winter,and the NDVI value at jointing stage significantly increased by 11.9%(2022).Soil pH increased by 0.22 units(2023).With the increase of maize straw returning amount,wheat yield and NDVI value at jointing stage showed parabolic model of first increased and then decreased,the N,P and K absorption of above ground wheat showed a significant downward trend,and soil organic matter showed a continuous significant increase trend.Based on the growth potential and yield of wheat,the suitable returning ratio of straw cutting treatment was 58%—62%,and the suitable returning ratio of crushing treatment was 29%—42%.Under the conditions of this experiment,maize straw cutting returning has obvious advantages in promoting wheat growth,and increasing wheat yield.It can be popularized and applied in wheat-maize rotation areas that 58%—62% maize straw is returned into the soil.

Kales,which are widely cultivated as ornamental plants in wintertime or cold areas,play important roles for urban landscaping.Cold stress which can reduce the ornamental value is one of the most important characters for the improvement and breeding of kales.In order to elucidate the physiological characteristics during low temperature and reveal cold resistance mechanism,several varieties and strains which were bred by our group were used as research materials.The relative electrical conductivity (REC) under different low temperature treatment,semi-lethal temperature (LT₅₀) of different accessions,as well as the osmoregulation substances contents and antioxidant enzymes activities under different temperature treatment were analyzed.It was showed that the REC of kale leaves increased rapidly when temperature under -5℃,and reached maximum values at about -10℃.The TL₅₀ values of kale accessions were -10.3——13.7℃.The TL₅₀s of red types were lower than white types,as well as round and leatherleaf types were lower than wrinkle types.These results were consistent with field cold resistance performances of the varieties.Changing characteristics of the detected osmoregulation substances and antioxidant enzyme activities were different under different temperature treatments.These physiological indexes reached maximum values at -5℃ or -8℃ and decreased at lower temperature,except soluble sugar which reached maximum value at -10℃.The principal component analysis revealed that LT₅₀ value,soluble sugar and free proline contents were main components causing cold resistance variations among different varieties.These results will provide theoretical basis for the establishment of kale cold resistance evaluation system,and lay foundation for the development of new varieties with excellent cold resistance.

In order to clarify whether existed autophagy phenomenon in sugar beet under salt stress and its relationship with plant salt-resistant physiological characteristics, the self-phage occurrence, reactive oxygen species content, osmosis regulating substance content and their relationship under different salt gradients were studied with salt-resistant sugar beet variety LS2004 and salt-sensitive sugar beet variety KWS7125 as experimental materials. The results showed that salt stress could induce autophagy in sugar beet seedlings. Autophagy was involved in the defense process of sugar beet seedlings against salt stress. The specific manifestation was that autophagy increased with the increase of salt concentration. Under the salt stress condition of 300 mmol/L, LS2004 had the strongest autophagy and the largest number of autophagosomes, which was 1.22 times that of KWS7125. The hydrogen peroxide content of KWS7125 and LS2004 reached the peak under the treatment of 200 mmol/L, which were increased by 40.06% and 41.54% respectively compared with that of the control. Under each treatment, the superoxide anion content and relative electrical conductivity of KWS7125 were higher than those of LS2004. The soluble protein content, proline content and total soluble sugar content of LS2004 firstly increased and then decreased with the increase of salt concentration, but there were differences in change rules with KWS7125. In summary, autophagy existed in sugar beet seedlings under salt stress, and the comprehensive effect of autophagy, alleviating oxidative damage, and osmotic adjustment substance content could be used by sugar beet seedlings to improve the salt tolerance of sugar beet.

The paper studied the effects of carbonization temperature on biochar yield and the physicochemical properties from wheat-straw improved the application of wheat-straw biochar,in order to further expound the mechanism of action of wheat straw biochar.The effects of different carbonization temperatures(100,200,300,400,500,600,700,800℃)on wheat-straw biochar yield and the physicochemical properties (porosity condition,the content of total carbon and inorganic carbon,CEC content,oxygen-containing functional group,pH and FTIR) were studied through mionectic carbonization with the heating rate of 20℃/min. Fourier transform infrared spectrometer was used to obtain infrared spectra and the reasons for the changes of biochar physicochemical properties were analyzed.The wheat-straw of low temperature carbonization was acidic,after 400℃,was alkaline. The degree of wheat straw biochar carbonized increased with the increased of carbonization temperature, and the yield decreased from 91.32% to 18.52% in 100-400℃. In the carbonization process,the wheat-straw biochar porosity increased,the structure was loose. Pore size,specific surface area and specific pore volume showed first increased and then decreased trend,and all reached the maximum at 400℃,were 6.675 m²/g,13.992 nm,0.015 cm³/g respectively.In 200-400℃,the content of organic carbon was high. The content of CEC was maintained at a high level in 400-800℃,between 69.13-84.35 cmol/kg.The analysis of infrared spectrum and surface oxygen functional groups showed that,with the increase of pyrolysis temperature,the degree of aromatization of wheat-straw biochar increased,and the structure became more stable. The carbonization temperature of wheat-straw is more ideal at about 400℃.

This study explored the effects of full-width uniform seeding on the canopy light energy utilization characteristics,dry matter accumulation and transport of winter wheat in saline-alkali land,and clarified the physiological mechanism of high yield and high efficiency,to provide theoretical and practical basis for the promotion of full-width uniform seeding of winter wheat in the Yellow River Delta.In the growing season of winter wheat from 2022 to 2024,Jingyou 368 wheat variety was used as the material,and two seeding patterns of full-width uniform seeding and conventional drill seeding were set up.The differences of yield,dry matter accumulation,dry matter transport,canopy photosynthetically active radiation interception amount and radiation use efficiency under different seeding patterns were analyzed,and the correlation analysis was carried out.The results showed that the yield and spike number of wheat under full width uniform seeding were higher than those under conventional drilling seeding.The full-width uniform seeding achieved extremely significant increases of 18.35% and 46.97% from 2022 to 2023,and 18.71% and 47.21% from 2023 to 2024,respectively.Under the full-width uniform seeding,the wheat stem & tillers number was higher than that under the conventional drilling seeding.From 2022 to 2023,full-width uniform seeding significantly increased the tiller number by 58.83%.From 2023 to 2024,full-width uniform seeding extremely significantly increased the tiller number by 57.30%.The dry matter accumulation of wheat at anthesis stage,dry matter accumulation at maturity stage and dry matter translocation of vegetative organs before anthesis under full-width uniform seeding were higher than those under conventional drilling seeding.From 2022 to 2023,full-width uniform seeding achieved extremely significant increases of 75.78%,41.70% and 109.69%,respectively,and from 2023 to 2024,full-width uniform seeding achieved extremely significant increases of 71.23%,40.81% and 98.07%,respectively.The leaf area index,canopy photosynthetic active radiation interception and radiation use efficiency of wheat under full-width uniform seeding were higher than those of conventional drilling seeding.The full-width uniform seeding in 2022—2023 achieved extremely significant increases of 58.36%,4.11% and 47.17%,respectively,and the full-width uniform seeding in 2023—2024 achieved extremely significant increases of 59.78%,4.11% and 44.00%,respectively.In summary,the full-width uniform seeding of wheat in saline-alkali land improves the canopy light energy utilization performance and tiller productivity by shaping a reasonable population structure and improving the seedbed environment,which is conducive to the formation of plant photosynthetic products and the increase of spike number per unit area,and ultimately achieves high yield of wheat.Therefore,full width uniform seeding is a better seeding pattern for stable and high yield of winter wheat in saline-alkali land of the Yellow River Delta.