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.

OFP is a class of plant-specific transcription factors that play important roles in the regulation of plant organ morphogenesis and response to abiotic stresses.In order to study the characterization of soybean OFP transcription factor family members and their roles in drought stress and salt stress,bioinformatics methods were applied to identify and analyze soybean OFP family members.The results showed that:a total of 41 GmOFPs,named GmOFP-1—GmOFP-41,were identified in soybean;these genes were unevenly distributed on 19 chromosomes of soybean,encoding 152—414 amino acids;subcellular localization predicted that soybean OFP proteins were mainly localized in nucleus,chloroplasts,and mitochondria;a total of 10 conserved motifs were identified in soybean OFP proteins,conservative Motifs 1 and 2 were present in all OFP members.Phylogenetic analysis classified soybean and Arabidopsis OFP proteins into five subfamilies ClassⅠ—Class V,of which soybean OFP family genes were mainly distributed in ClassⅠ and Class Ⅲ.The collinearity analysis revealed that 75 pairs of genes in the soybean genome had collinearity,four pairs of genes had tandem duplications,and only two genes,GmOFP-2 and GmOFP-39,did not have collinearity,which indicated that gene fragment duplication was the main reason for the increase in the number of soybean OFP family members.The expression patterns of GmOFP gene family members under drought stress and salt stress treatments were analyzed by qRT-PCR,and the results showed that,compared with the control,16 members out of 41 GmOFP genes exhibited significant differences in gene expression levels after drought treatments,with significant up-regulation of the expression of GmOFP-15,GmOFP-17,and GmOFP-32,while the GmOFP-4,GmOFP-5,GmOFP-6,GmOFP-9,GmOFP-12,GmOFP-21,GmOFP-23,GmOFP-25,GmOFP-26,GmOFP-27,GmOFP-38,GmOFP-39,and GmOFP-40 were significantly down-regulated after drought treatment.Eight members of GmOFPs showed significant differences in gene expression levels after salt treatment,among which GmOFP-7,GmOFP-14,GmOFP-31,GmOFP-32,GmOFP-36,and GmOFP-40 were significantly up-regulated,and GmOFP-1 and GmOFP-15 were significantly down-regulated.The above results suggest that the soybean OFP gene family may have important functions in response to drought stress and salt stress.

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.

The aim was to elucidate the effects of different foliar fertilizer nitrogen application amounts on nitrogen accumulation,translocation,and utilization in maize.This experiment was conducted in 2021—2022 using a randomized block design,with maize variety Lihe 1 as the research object.No fertilization treatment (CK),conventional root fertilization treatment (CF),foliar nitrogen reduction treatment of 20% (LF1),foliar conventional nitrogen application treatment (LF2),and foliar nitrogen increase treatment of 20% (LF3) were set up to analyze the differences in nitrogen accumulation,translocation,and utilization of maize under different nitrogen fertilizer application amounts,no fertilization and conventional root fertilization.The results showed that the nitrogen accumulation in maize stems and leaves showed a trend of first increasing and then decreasing with the advancement of the growth stage,reaching the maximum value at the tasseling and silking stage.The nitrogen accumulation per plant gradually increased with the advancement of the growth stage and reached its maximum value at mature stage,the nitrogen accumulation per plant was highest in the LF2 treatment.The proportion of nitrogen distribution in leaves was highest before the silking stage;after the silking stage,the proportion of nitrogen distribution in grains gradually increased,reaching its peak at mature stage.The CK had the lowest proportion of nitrogen accumulation in grains,while the LF1 treatment had the highest proportion of nitrogen distribution in grains in 2021,and the LF3 treatment had the highest proportion of nitrogen distribution in grains in 2022.The nitrogen transport rate and the contribution rate of nitrogen transport to grains first increased and then decreased with the increase of nitrogen application amounts,the nitrogen harvest index and nitrogen utilization efficiency decreased with the increase of nitrogen application amounts;in 2021 and 2022,the nitrogen utilization efficiency of LF1 treatment,LF2 treatment,and LF3 treatment was higher than that of CF treatment,and the nitrogen utilization efficiency of LF1 treatment was the highest.The nitrogen absorption efficiency of foliar nitrogen application treatment for two years was higher than that of CF treatment.There were no significant differences in ear length,ear thickness,and ear row number among the treatments.CK had the longest bald tip length,and the row number and hundred grain weight of each nitrogen application treatment were higher than those of CK.CF treatment had the highest biological yield,while LF1 treatment had the highest grain yield and harvest index.The grain yield of each treatment was significantly higher than CK,and the harvest index decreased with increasing nitrogen application amounts.Therefore,maize can achieve better growth effects under LF1 foliar nitrogen application in the central and western regions of Inner Mongolia.

To explore the effects of nitrogen application rate on nitrogen uptake and translocation characteristics,nitrogen use efficiency,and the formation mechanisms of yield and quality in soft wheat under weak light stress during the after anthesis stage,under pot conditions,the soft wheat variety Quanmai 725(QM725)was used as the material,and the ¹⁵N tracer method was used.Two nitrogen rates were set in the experiment,namely N1(N 120 kg/ha),N2(N 180 kg/ha),and two shading treatments were set at the wheat filling stage(7-35 d after anthesis)under each nitrogen application rate,namely CK(no shading),SH(30% shading).The relationship between nitrogen application rate and grain yield and quality of soft wheat under weak light after anthesis was analyzed,and the effects of different nitrogen application rates on nitrogen accumulation,transport,grain yield and quality of soft wheat under weak light after anthesis were studied.The results showed that compared with the control,under the conditions of N1 and N2,the nitrogen accumulation of plants at flowering stage and vegetative organs at maturity stage was significantly reduced by weak light treatment after anthesis,and the proportion of nitrogen from fertiliser was significantly higher than that from soil nitrogen,while the proportion of nitrogen accumulation in grains at maturity stage from soil nitrogen was significantly higher than that from fertiliser nitrogen.Under the same nitrogen application rate,the proportion of basal nitrogen fertiliser was greater than that of topdressing nitrogen fertiliser.Under the same weak light treatment conditions,compared with N1,N2 increased the accumulation of fertiliser nitrogen at flowering stage,the accumulation of total nitrogen and fertiliser nitrogen at maturity stage,and the accumulation of total nitrogen,fertiliser nitrogen and soil nitrogen at maturity stage.Under N1 and N2 treatments,the nitrogen harvest index,nitrogen harvest index,nitrogen production efficiency,grain number per spike,1000-grain weight and grain yield of wheat decreased significantly with the decrease of light intensity after anthesis.The content and accumulation of protein and starch in soft wheat grains increased significantly with the increase of nitrogen fertilizer.However,under the same nitrogen application rate,weak light stress reduced the starch content,protein and starch accumulation in grains.Weak light stress after anthesis significantly affected the nitrogen accumulation of soft wheat plants,reduced the transport efficiency of storage substances from vegetative organs to grains after anthesis,resulting in a decrease in the contribution rate of vegetative organs to grains,which was not conducive to the overall nitrogen transport efficiency of plants.With the increase of nitrogen application rate,the nitrogen harvest index,nitrogen harvest index,nitrogen production efficiency and nitrogen use efficiency of wheat were significantly improved.Under the same nitrogen application rate of N1 and N2,after anthesis weak light stress significantly reduced the accumulation of protein and starch in soft wheat grains,which in turn affected the formation of grain weight,resulting in a decrease in yield.

The ubiquitination pathway is one of the key signaling pathways in response to drought stress.In order to clarify the biological function of E3 ubiquitin ligase TaSINA101 gene in response to drought stress,the TaSINA61,TaSINA101 and TaSINA105 genes were cloned from JM47,an excellent drought-resistant wheat cultivar,and their sequence characteristics were analyzed by bioinformatics methods,and the expression levels of the three genes in wheat roots and leaves were detected by qRT-PCR under PEG-6000,NaCl,low temperature and ABA treatments.The heterologous expression of TaSINA101 in transgenic rice was used to analyze the biological function of TaSINA101 in response to drought stress.The results showed that the TaSINA61,TaSINA101 and TaSINA105 genes contained one intron and two exons,and the encoded proteins were composed of 282 amino acids.The qRT-PCR expression analysis showed that the expression of these three genes was induced by various abiotic stresses such as drought stress in roots and leaves.Phenotypic analysis of TaSINA101 transgenic rice under drought stress showed that the leaf fresh weight and dry weight, maximum root length, average root diameter and leaf relative water content of transgenic rice lines OE-1, OE-2 and OE-3 were significantly lower than those of wild type,while the relative conductivity of leaves of transgenic rice lines OE-1 and OE-2 was significantly higher than that of wild type.Therefore,TaSINA101 negatively regulates drought stress tolerance in rice.This study provides a basis for in-depth analysis of the biological function of TaSINA101 gene in wheat.

To clarify the regulatory effect of nitrogen(N)fertilizer reduction and postponing on the productivity of wheat-maize double cropping system in Huang-Huai-Hai Plain.The annual N fertilizer experiment of summer maize and winter wheat was established of four N application systems:annual N fertilizer application 400 kg/ha of traditional farmer treatment(F₄₀₀),10% reduction of annual N fertilizer(FN),20% reduction of annual N fertilizer(FH),and 30% reduction of annual N fertilizer(FL)from 2020 to 2023 at Jiyang Experimental Base of the Shandong Academy of Agricultural Sciences in Jinan.The grain yield,aboveground N accumulation characteristics,N use efficiency,and the nitrate residue after harvest in the 0—200 cm soil layer of wheat-maize double cropping system were tested,in order to provide the theoretical basis for further optimization of N fertilizer management in Huang-Huai-Hai Plain.The results indicated that N fertilizer postponing was optimized the grain yield of summer maize and winter wheat under the condition of N reduction,and the averaged across the three years,FL significantly increased by 9.2%—18.1%,13.5%—20.5%,and 11.1%—19.1%,respectively,compared with F₄₀₀ and FN.N fertilizer postponing improved the N accumulation rate,and promoted aboveground N accumulation at wheat-maize different growth stages,and the averaged across the three years,FL significantly increased plant N accumulation by 5.7%—12.3% and 5.0%—12.8% under silking and maturity,respectively,compared with F₄₀₀,FN,and FH,as well as 8.2%—17.2% in grain N accumulation.For winter wheat,FL and FH treatments were significantly higher than F₄₀₀ and FN at jointing,anthesis,and maturity,and the averaged across the three years,FL and FH significantly increased by 23.4%—28.1%,20.7%—26.3%,and 12.6%—20.8%,respectively,compared with F₄₀₀,FN and FH,at the same time the grain N accumulation under FL significantly increased by 16.4%,15.0% and 5.8%,respectively,compared with F₄₀₀ and FN.N fertilizer postponing optimized the N use efficiency of wheat-maize double crop system,the averaged across the three years,FL significantly increased N uptake efficiency by 4.8%—57.7% and 32.0%—72.4% of summer maize and winter wheat,respectively,compared with F₄₀₀,FN,and FH;and FL significantly increased N partial factor productivity by 68.8% and 40.4% in summer maize,respectively,compared with F₄₀₀ and FN,as well as by 38.4%—71.8% in winter wheat compared with F₄₀₀,FN,and FH.At harvest of summer maize and winter wheat,the soil nitrate residue was mainly enrichment in the 0—40 cm soil layer under four N application systems,the averaged across the three years,accounted for 40.0%,38.9%,44.9%,42.5% and 37.3%,36.9%,46.7%,38.3% of the 0—200 cm soil layer,respectively.In addition,the obvious accumulated effects in 0—200 cm soil layer nitrate residue under F₄₀₀ and FN treatments at harvest of summer maize and winter wheat,but there was the relative balance was achieved under FL and FH treatments.In conclusion,a 30% reduction of annual N fertilizer by N fertilizer postponing could optimize plant N accumulation characteristics and realized synergistic improve grain yield and N use efficiency.Therefore,FL treatment was an optimal N application system for realizing the collaborative target of high-yield,high-efficiency,and environment-friendly of wheat-maize double cropping system in Huang-Huai-Hai Plain.

To clarify the effects of different nitrogen forms combined with magnesium fertilization on potato in the northern foothills of Yinshan Mountains,a field experiment was conducted in Hohhot,Inner Mongolia.The experiment included two nitrogen forms(nitrate nitrogen and ammonium nitrogen)and two magnesium application rates(0,45 kg/ha),resulting in four treatments.The impacts of these treatments on potato yield and its components,dry matter,nitrogen,magnesium,and potassium contents,their accumulation,and nitrogen use efficiency throughout the growth period were analyzed.The results showed that,compared with the application of nitrate nitrogen alone,the combined application of nitrate nitrogen and magnesium significantly increased potato leaf dry matter(21.24%—75.60%)and tuber dry matter(22.04%—62.36%)from tuber initiation stage to harvest stage,as well as whole-plant dry matter(32.54%—70.28%)from seedling stage to harvest stage.It also enhanced nitrogen accumulation(44.01%—69.84%)in tuber initiation stage,starch accumulation stage and harvest stage,whole-plant magnesium accumulation(37.66%—84.21%)during the entire growth period,whole-plant potassium accumulation (24.30%—54.95%) from tuber initiation stage to harvest stage, nitrogen uptake efficiency (30.77%—66.67%) during the entire growth period,and partial factor productivity of nitrogen fertilizer at harvest stage(35.13%).Correlation analysis indicated that potato dry matter,whole-plant nitrogen,magnesium,and potassium accumulation were significantly positively correlated with nitrogen uptake efficiency during the entire growth period(r was all greater than 0.78).At harvest stage,whole-plant potassium content showed a highly significant negative correlation with yield(r was -0.78).Principal component analysis further demonstrated that the total variation among treatments during the entire growth period was highly dispersed,indicating significant differences between nitrogen form combined with magnesium fertilization treatments and those without magnesium application.These findings provide a new strategy for improving nitrogen use efficiency and optimizing nitrogen-magnesium management in potato production in the northern foothills of Yinshan Mountains.

Glyphosate is currently the most widely used broad-spectrum herbicide.Cultivating glyphosate tolerant crops will help improve the effectiveness of chemical control on weed in farmlands,reduce the use of pesticide,and simplify preventive and control measures.To fully detect the glyphosate tolerance(GT)loci in wheat,484 germplasm resources from the Huang-huai wheat region were used to identify glyphosate toxicity.Based on the wheat 15K SNP array data,genome-wide association analysis(GWAS)was used to explore QTL related to glyphosate tolerance in wheat.The main results were as follows:the trend of changes in glyphosate tolerance of wheat varieties cultivated in different eras was slow,and the glyphosate tolerance had not significantly improved;three glyphosate tolerant wheat germplasms(including Henong 130,Jimai 782 and Taishan 23)were selected based on the phenotypic identification results of pesticide damage;seven QTL associated with the level of wheat pesticide damage were detected by GWAS,including 19 significant SNPs,distributed on wheat chromosomes 1A(0.00—30.48 Mb),1B(6.57—30.57 Mb),1D(0.00—22.98 Mb),4A(656.09—680.09 Mb),5A(508.19—532.19 Mb),6A(54.56—85.09 Mb),and 6D(12.02—36.02 Mb);the two QTL qGlyT-1A and qGlyT-6A located on wheat chromosomes 1A and 6A were the main effector sites for glyphosate tolerance in wheat,containing a total of 16 genes that may be related to glyphosate tolerance in wheat.

The SiPRR73 gene was cloned from Yangu 11 using RT-PCR technology,and through analyzing tissue-specific expression,responsive features of SiPRR73 to different photoperiods,photo-thermal combinational treatments and five abiotic stress treatments,the regulation mode of photoperiod and temperature on SiPRR73,and the responsive pattern of SiPRR73 to abiotic stresses in foxtail millet were explored. The results showed that totally 2 928 bp cDNA sequence of SiPRR73 was obtained from Yangu 11,which included 2 283 bp CDS region,encoding 760 amino acids. The SiPRR73 proteins of C4 crops including Panicum miliaceum,Panicum hallii,Sorghum bicolor and Zea mays showed relatively close relationship with SiPRR73. The second parietal leaf was the highest expression tissue of SiPRR73,but the expression level at root,stem and panicle tissues was relatively lower. The expression level of SiPRR73 was higher at light period than that at dark period under both short-day and long-day conditions,and during the whole vegetative growth phase,SiPRR73 showed higher expression level under long-day compared to short-day,which indicated that the expression of SiPRR73 was induced by light and controlled by photoperiod. The temperature determined expression peak number of SiPRR73 and the photoperiod determined occurrence time of expression peaks,so temperature and photoperiod participated in regulating of SiPRR73 expression mutually. PEG and low temperature stresses induced SiPRR73 expression totally,NaCl induced SiPRR73 expression at early stress stage,but inhibited it at later stress stage. Fe stress inhibited SiPRR73 expression at early stage,but induced it at later stage. ABA stress caused the close responsive feature of SiPRR73 to NaCl. This study indicated that SiPRR73 showed light-dependent expression feature,and photoperiod and temperature regulated SiPRR73 by interaction pattern,suggesting that SiPRR73 participated in adaptability regulation process to different photo-thermal conditions and might play a certain role in coping with drought,low temperature,ABA,NaCl and Fe stresses in foxtail millet.

Light-harvesting chlorophyll a/b binding proteins are important in plant photosynthesis and abiotic stress response.To study the characteristics of GhLhcb2A1 and its expression patterns and functions in low temperature and drought response in upland cotton,full-length CDS of GhLhcb2A1 gene was cloned from the leaf cDNA of Jimian 262 by PCR.Bioinformatic analysis was conducted to learn the basic characteristics of the gene.The expression patterns and functions in low temperature and drought response were evaluated by qRT-PCR and virus-induced gene silencing.It was shown that the length of GhLhcb2A1 CDS was 798 bp,encoding 265 amino acids.GhLhcb2A1 was highly expressed in leaves and was significantly up-regulated in leaves and roots under low temperature and drought treatment.Compared with the control,its expression maximized at 3 h under low temperature and drought in leaves with 17.42 and 30.03 folds increase respectively,whereas maximized at 6 h under low temperature and 12 h under drought in roots with 11.65 and 65.04 folds respectively.Subcellular localization assay verified that GhLhcb2A1 was expressed in the chloroplasts of cells.Compared with the control plants,GhLhcb2A1 silenced plants showed a more severe phenotype of water loss and dryness under both low temperatures and drought.The accumulated malondialdehyde content in the leaves of the silenced plants was significantly higher than that of the control,while the proline content and superoxide dismutase activity were significantly lower than those of the controls,suggesting that GhLhcb2A1 silenced plant reduced the resistance to low temperature and drought.The above results implied that this gene played a positive role in regulating low temperature and drought response.

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 explore the effects of different irrigation methods and nitrogen fertilizer management on late rice growth,development,yield formation,and nitrogen use efficiency,Y Liangyou 911 was used as test material.Two irrigation methods(W1.flooded irrigation;W2.moistening irrigation) and three nitrogen fertilizer managenments base,tiller,ear and grain fertilizer ratios(N1:5∶3∶2,N2:3∶4∶3 and N3:3∶4∶2∶1) were designed.No fertilization served as the control (CK1.flooded irrigation;CK2.moistening irrigation).Leaf area index,SPAD value of rice leaves,dry matter mass,yield formation and nitrogen use efficiency were determined under each treatment combination.The results showed that compared with W1,the LAI of rice treated with W2 was lower in the early growth stage and higher in the middle and late growth stages.The SPAD value of W1 treatment was higher,but there was no significant difference in SPAD value in the late growth period.Under the same irrigation conditions,compared with N1,N2 and N3 treatments it could delay the decline of LAI and SPAD values in the late growth period of rice.W2 treatment could significantly increase rice dry matter accumulation by 6.61%-16.37% compared with W1 treatment.Under nitrogen fertilizer treatment,the dry matter mass was higher in the early and middle stages of growth with N1,and the dry matter mass was higher in the later stages with N1 and N3.The yield increase of W2 mode was 7.59%-10.47% compared with W1 mode.The yield of W2N3 treatment was 3.24%-14.53% higher than that of other treatment.Although the effective panicle number was lower in W2N3 treatment,other yield components were increased,which resulted in higher yield.During the two years,W2N2 and W2N3 had higher values of total nitrogen accumulation and nitrogen absorption efficiency,W2N3 had higher values of nitrogen agronomic utilization,nitrogen partial productivity and nitrogen harvest index,and W1N3 had the higher value of physiological nitrogen utilization.In conclusion,irrigation methods and nitrogen management significantly affect rice yield and nitrogen uptake and utilization.The W2 (moistening irrigation) coupled with N3 (base fertilizer∶tillering fertilizer∶ear fertilizer∶grain fertilizer=3∶4∶2∶1) nitrogen management method is more conducive to rice dry matter accumulation,yield improvement and efficient use of nitrogen fertilizer,which can not only meet high yield,but also play a role in water saving.It is the best coupling method of water and fertilizer.

Soil nitrogen(N)cycling enzyme activity serves as a crucial indicator for characterizing soil fertility and N transformation.To investigate the effects of long-term application of fertilizers on the soil enzyme activities correlated with N cycling in rhizosphere soil of double-cropping rice fields in southern China,our project was based on a continue 37-year fertilization localization field experiment,including four fertilization treatments:without fertilizer as a control(CK),single fertilizer(MF),rice straw residue and mineral fertilizer(RF),and 30% organic manure and 70% mineral fertilizer(OM).The activities of N cycling enzymes in the rhizosphere soil were measured,and their correlation with soil chemical properties was analyzed.The results were as follows:compared to MF and CK treatments,OM and RF treatments significantly increased the contents of total N(TN),organic carbon(SOC),ammonium N($\mathrm{NH}_{4}^{+}-\mathrm{N}$),nitrate N($\mathrm{NO}_{3}^{-}-\mathrm{N}$)and microbial biomass N(SMBN)in rhizosphere soil,and also increased rice yield.The urease(Ure)and nitrite reductase(NiR)activities of rhizosphere soil in OM and RF treatments were significantly higher than those in MF and CK treatments.The RF treatment significantly increased rhizosphere soil hydroxylamine reductase(HyR)activities compared to the other three treatments,by 21.7%,13.0%,and 8.7%,respectively.This finding shown that OM treatment significantly increased protease(Pro),nitrogenase(Nit),nitrate reductase(NR)and nitrous oxide reductase(Nos)in rhizosphere soil compared to RF,MF and CK treatments.In comparison to MF treatment,OM treatments increased Pro,Nit,NR and Nos activities in rhizosphere soil by 20.0%,26.1%,426.1% and 26.7%,respectively.Nonetheless,the activity of nitric oxide reductase(Nor)on rhizosphere soil was considerably higher in the CK treatment than in MF,RF and OM treatments.Pearson correlation analysis revealed a substantial positive correlation between soil NR,NiR,Nit,Nos,Ure,Pro and soil TN,SOC,$\mathrm{NH}_{4}^{+}-\mathrm{N}$,$\mathrm{NO}_{3}^{-}-\mathrm{N}$,SMBN as well as rice yield.Soil Nor activity was observed to have a significantly negative connection with soil TN,SOC,$\mathrm{NH}_{4}^{+}-\mathrm{N}$,$\mathrm{NO}_{3}^{-}-\mathrm{N}$,SMBN and rice yield.The findings presented above showed that soil chemical properties and yield were substantially related to rhizosphere soil N cycling enzyme activities.Redundancy analysis(RDA)showed that the first order axis could explain 93.34% of the enzyme activity in rhizosphere soil and soil $\mathrm{NO}_{3}^{-}-\mathrm{N}$,TN and SOC contents were the key factors affecting the pattern of rhizosphere soil enzyme activities.Therefore,the long-term application of organic materials such as organic manure and rice straw can enhance soil chemical and biological characteristics,stimulate soil N cycling enzyme activities,and effectively fertilize paddy soils by partially replacing chemical fertilizers.

To clear under the condition of slow release nitrogen fertilizer applying different content of maize development rule of the diurnal change of photosynthetic characteristics and growth,the light response curve was to fit,so as to farming-pastoral zone of spring maize cultivation and nitrogen utilization to provide theoretical basis.This study took Guangde 5 as the research object,and based on the long-term positioning experiment in 2018,the leaves ear position in spinning—tasseling stage of maize were mesured and analyzed under six nitrogen gradient of N 0(N0,CK), 120(N8), 180(N12), 240(N16), 300(N20),360(N24) kg/ha in 2019 and 2020. SPAD value, intercellular carbon dioxide concentration, stomatal conductivity, diurnal variation of net photosynthetic rate, transpiration rate, light response curve and dry matter accumulation rule.The results showed that with the increase of nitrogen fertilizer application, the changes of SPAD value, net photosynthetic rate, transpiration rate and stomatal conduction degree day of maize increased first and then decreased,and N16 treatment was the highest,and intercellular carbon dioxide concentration was the lowest.The changes of net photosynthetic rate,transpiration rate and stomatal conduction degree day showed unimodal curve.The light response curve fitting analysis showed that the maximum net photosynthetic rate of N16 treatment was the highest.In 2019 and 2020,N16 treatments were 37.48%,29.51%,31.85%,18.17%,37.32% and 80.04%,59.73%,50.30%,6.42%,62.51% higher than N0,N8,N12,N20 and N24 treatments,respectively.Dry matter mass accumulation in whole plant and ear were positively correlated with maximum net photosynthetic rate,apparent quantum efficiency and SPAD value.Comprehensive analysis showed that the most suitable nitrogen fertilizer application rate in western Inner Mongolia was 240 kg/ha.

To improve the applicability of biochar in saline-alkali agroecosystem,the effect and microbial mechanism of modified biochar were studied.In a 2-year field experiment,common biochar(4.5 t/ha),nitrogen-rich modified biochar(7.5 t/ha)and phosphorus-rich modified biochar(15.0 t/ha)were added to investigate their impact on crop grain yield,soil physicochemical properties and soil microbial diversity.It had been observed that the addition of biochar enhanced the quality of saline-alkali soil,with nitrogen-rich modified biochar and phosphorus-rich modified biochar demonstrating more notable effects.Biochar could boost crop yield,improve soil structure and reduce soil bulk density in saline-alkali land.The effects of the three biochar types were not consistent.Among them,the application of 15.0 t/ha phosphorus-rich modified biochar showed favorable responses,with grain yield of(8.92±0.12)t/ha,representing a 110% increase compared to the control group.Biochar affected soil microbial diversity.Common biochar increased soil microbial diversity,whereas phosphorus-rich modified biochar decreased it.With the continuous addition of biochar,soil physical and chemical properties could affect the relationship between soil microorganisms and plant structure,weakening their relationships.In this study,the application of 15.0 t/ha phosphorus-rich modified biochar was recommended to improve saline-alkali agroecosystem.

To investigate the responses of different types of wheat to various nitrogen-phosphorus-potassium ratio compound fertilizers in the Huaihe River region,in terms of photosynthetic characteristics,dry matter accumulation and distribution,yield and quality,four wheat varieties(Zhongke 166,Yannong 999,Huaimai 43,Shannong 17)were selected as experimental materials.Two types of compound fertilizers were set up:high-nitrogen compound fertilizer(N-P₂O₅-K₂O=26-13-7)and equal-proportion compound fertilizer(N-P₂O₅-K₂O=18-18-18).The effects of different compound fertilizer treatments on the photosynthetic characteristics,dry matter accumulation and distribution,yield and quality of each wheat variety were analyzed.The results showed that compared with the equal-proportion compound fertilizer,the high-nitrogen compound fertilizer significantly increased the LAI,SPAD value,net photosynthetic rate and photochemical efficiency of the four varieties,delayed leaf senescence,and prolonged photosynthetic time;it also increased the dry matter accumulation at the flowering and maturity stages,optimized the dry matter distribution ratio,and ultimately increased the grain yield by 4.5% to 14.9%,with protein and wet gluten contents increasing by 1.36% to 8.17% and 3.55% to 9.36% respectively.The response of different varieties to the high-nitrogen compound fertilizer varied slightly,with Yannong 999 having the best overall performance,the largest increase in SPAD value and LAI,the highest net photosynthetic rate and yield,the highest dry matter distribution ratio at the maturity stage,and significant quality improvement;Zhongke 166 had the largest yield increase,the highest protein content and wet gluten content;Huaimai 43 had the highest increase in grain dry matter accumulation;Shannong 17 had the weakest response to the high-nitrogen compound fertilizer,but its yield was still 9.3% higher than that of the equal-proportion compound fertilizer.In summary,the high-nitrogen compound fertilizer showed significant advantages in the photosynthetic characteristics,dry matter accumulation and distribution,yield and quality of different types of wheat.Among them,Yannong 999 had the best overall performance.

The aim was to clarify the effects of different nitrogen application levels on soil organic nitrogen fractions and nitrogen use efficiency in maize fields in the central-western region of Inner Mongolia,so as to provide a reference for the scientific management of soil nitrogen and sustainable development of modern agriculture.Six nitrogen application levels were set up,N0(0 kg/ha),N8(120 kg/ha),N12(180 kg/ha),N16(240 kg/ha),N20(300 kg/ha),and N24(360 kg/ha).The dynamic changes with effects of nitrogen application on soil total nitrogen content,particulate organic nitrogen content,light fraction organic nitrogen content and heavy organic nitrogen content,as well as maize yield and nitrogen use efficiency were analyzed at different soil layers at pre-sowing and post-harvest.The results showed that soil total nitrogen,particulate organic nitrogen,light fraction organic nitrogen,and heavy fraction organic nitrogen content decreased with deepening of the soil layer at the same nitrogen application level;soil total nitrogen content at pre-sowing increased with the nitrogen application levels.Soil total nitrogen content in the N16,N20,and N24 treatments was significantly higher than that in the N0,N8,and N12 treatments at post-harvest.Soil particulate organic nitrogen content of N16 treatment was highest in the 0—10 cm,10—20 cm,and 20—40 cm soil layers at pre-sowing,with 0.14,0.13,and 0.09 g/kg,respectively.At post-harvest,N16 treatment had the highest content in the 10—20 cm,20—40 cm,and 40—60 cm soil layers,with 0.19,0.10,and 0.09 g/kg,respectively.The highest increase of soil light fraction organic nitrogen content of 37.27% was in the N16 treatment,and the highest increase of soil heavy fraction organic nitrogen content of 7.35% was in the N24 treatment,followed by the N16 treatment,at 6.84%.The N16 treatment had the highest maize biological yield of 31 443.50 kg/ha;the highest maize economic yield of 18 526.47 kg/ha;and the nitrogen use efficiency decreased with the increase in nitrogen fertilizer application levels,N16 treatment in the nitrogen harvest index was the highest, at 79.20%.In conclusion,the more suitable nitrogen fertilizer application level in the central-western region of Inner Mongolia should be maintained under 240 kg/ha,in order to achieve the best soil nitrogen management ang crop yield.

In order to explore the effect of straw interlayer on soil respiration and the chemical structural stability of organic carbon components during the remediation of saline-alkali soil,two experimental treatments were set up in the alfalfa-planting farmland at the Saline-Alkali Soil Improvement Experimental Demonstration Base in the Agricultural High-Tech Zone of Dongying City,Shandong Province:a straw interlayer treatment (S,with a 5 cm thick straw layer buried at a 35 cm depth) and a control (CK,without an interlayer). Soil respiration characteristics of the different treatments were analyzed,and comprehensive discussions were conducted in conjunction with soil pH,electrical conductivity(EC),organic carbon component content,and chemical structure characteristics of the soil profile.The results showed that:compared with CK,the S treatment significantly increased the soil respiration rate during the alfalfa growth period, with a maximum increase of 79.84%. Furthermore, the S treatment reduced soil EC in the straw interlayer (35—40 cm) and the overlying soil layer (0—35 cm), effectively inhibiting the upward migration of salt. The 40—50 cm soil layer was identified as a critical zone for organic carbon transformation. In this layer, the S treatment significantly increased SOC content (by 16.67%) and highly significantly elevated particulate organic carbon (POC) and dissolved organic carbon (DOC) contents (by 208.07% and 83.41%, respectively) compared with CK. Characterization of the molecular structure of organic carbon in the 40—50 cm layer revealed distinct responses. For DOC, the S treatment reduced the magnitude-weighted averages of unsaturation (by 30.60%) and aromaticity index (by 4.84%) compared with CK, decreasing the proportion of unstable carbon. For POC, the S treatment increased the relative abundances of alkyl C(10.32 percentage points)and O-alkyl C (8.39 percentage points) while reducing carboxyl C (14.24 percentage points), thereby enhancing POC structural stability. However, for bulk SOC, the S treatment decreased the proportions of alkyl C(3.14 percentage points) and aromatic C(3.38 percentage points) while increasing O-alkyl C(5.17 percentage points)and carboxyl C(1.56 percentage points). This shift indicated a decrease in recalcitrant carbon and an increase in labile carbon, resulting in reduced SOC structural stability. Correlation analysis showed that the significant increased in soil respiration was highly significantly and significantly positively correlated with POC and SOC contents in the critical soil layer, respectively. Specifically, the accumulation of O-alkyl C(a labile component) in the chemical structure of SOC reduced the stability of organic carbon,which was the main reason for the increase in soil respiration.In conclusion,incorporating a straw interlayer significantly increased soil respiration in the short term,which was closely related to the reduction in the stability of the organic carbon chemical structure in the key soil layer.Under future "carbon neutrality" strategies,research on the selection of interlayer materials should be considered.

In order to clarify the change rule of photosynthetic characteristics and the best fertilization method in different growth stages of sweet sorghum under different fertilization treatments, the field experiment was conducted to study the stomatal conductance (Gs), intercellular CO₂ concentration (Ci), transpiration rate (Tr), net photosynthetic rate (Pn), chlorophyll (SPAD), water use efficiency (WUE) and yield of New Sorghum No.3 under 8 different fertilization treatments, including CK, NK, NP, PK, NPK, M (organic fertilizer), NPKM and 1.5NPKM.The results showed that the changes of Pn, Gs, WUE and SPAD value in sorghum leaves under different fertilization treatments were the same at different growth stages, showing a trend of first increasing and then decreasing, and peaking at grain filling stage. The variation trend of Tr and Ci from flowering stage to maturity stage decreased first and then increased, and reached the lowest value in grain filling stage. At the same growth stage, the photosynthetic characteristics of different fertilization treatments were different, and the photosynthetic characteristics of leaves were affected by fertilization treatments. The Tr, Gs and Ci values of NPKM fertilization treatment at maturity stage were higher than those of other treatments, which were 3.64 mmol/(m²·s),328 mmol/(m²·s),439 μmol/mol, respectively. The correlation analysis showed that Pn of NPKM treatment at flowering stage was significant positively correlated with Tr and WUE, while Pn of NPK treatment was positively correlated with Gs and Ci. The biological yield of all fertilization treatments was significantly higher than CK, among them the biological yield of NPKM treatment reached 94.81 t/ha. The biological yield of NPKM increased 97.95%, 26.65%, 20.24%, 19.57%, 15.16%,14.98% and 11.74% respectively compared with CK, M, 1.5 NPKM, NK, PK, NPK and NP. Fertilization affects the photosynthetic parameters of the leaves of New Sorghum No.3 and was conducive to increasing yield. Therefore, it is feasible to use high photosynthetic efficiency breeding to improve biological yield. In order to alleviate the obstacle of continuous cropping of sweet sorghum, different proportion of fertilizer should be adopted. In a word, NPKM is the best fertilization mode to improve photosynthetic conditions and maximize yield, so it is preliminarily confirmed that NPKM is the best fertilization mode to promote the growth and development of continuous cropping sorghum in arid area.

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.

Auxin response factor(ARF)is a class of transcription factors with B3 domain,which is a direct molecule regulating auxin response and controlling gene expression.A gene,ZmARF10,which encoded ARF protein and actively participated in drought-rehydration stress response,was previously screened in maize by analyzed transcriptome data.To further research the molecular mechanism of ZmARF10 regulating drought resistance of maize,and also provide a new idea for molecular breeding of drought resistance,the gene was firstly analyzed by bioinformatics software.Secondly,Quantitative Real-time polymerase chain reaction(qRT-PCR)was used to detect the expression pattern of ZmARF10 in different tissues,under high temperature,drought,high salt,ABA and restoring treatments,and in different inbred lines.Finally,the function of ZmARF10 was analyzed using CRISPR/Cas9 technology.The results showed that ZmARF10 was located on chromosome 3 of maize,with a total length of 2 127 bp,and encoded 708 amino acids with a typical B3 domain.The upstream 2 kb region of ATG of this gene contained response elements related to methyl jasmonate,auxin,abscisic acid and low temperature.The phylogenetic tree showed that the protein encoded by the ZmARF10 gene was closely related to sorghum.qRT-PCR results showed that ZmARF10 was a constitutive expression gene,and the expression level of ZmARF10 was the highest in mature corn roots of maize.Under high temperature,drought,high salt and ABA treatments,the expression of this gene was significantly up-regulated,and the up-regulation ratio was up to 8.2 times after drought stress.After drought stress,the expression level of ZmARF10 gene was significantly higher in the drought-resistant inbred line Zheng 36 than that in the drought-sensitive inbred line B73.Investigation of Arabidopsis wild type and ARF10-deficient mutants showed that,compared with wild type,the mutant plants showed leaf wilting and even dry death,roots curled,root branch number decreased,and lateral root growth and development were hindered under drought conditions.Determination of physiological and biochemical indexes showed that the relative water content,chlorophyll content and net photosynthetic rate of the deficient mutants were significantly lower than those of the wild-type plants after drought stress,indicating that the drought resistance of Arabidopsis decreased after ARF10 gene was knocked out.

IQM(IQ-motif containing protein),a plant-specific calmodulin-binding protein,plays crucial roles in plant growth,development,and responses to various stresses.In order to study the characteristics and potential functions of the maize IQM gene family,bioinformatics approaches were used to identify IQM genes in the maize whole genome,and protein properties,phylogenetic relationship,gene structure,chromosome location,gene replication,cis-acting element,tissue-specific expression and expression patterns under various stresses were investigated.A total of 11 ZmIQMs genes were identified in the whole genome of maize,named ZmIQM1 to ZmIQM11 based on their chromosomal locations.ZmIQMs genes could be classified into three subfamilies,with genes within different subfamilies exhibiting similar structures.Segment duplication was found to play a major role in the amplification and evolution of the ZmIQMs gene family.Cis-acting element analysis showed that the promoter region of ZmIQMs gene contained multiple hormone and stress response elements.The expression pattern of ZmIQMs genes was investigated,and it was found that ZmIQMs genes had different expression patterns in different tissues,and the expression levels of several ZmIQMs genes were changed under different abiotic and biotic stresses.qRT-PCR results showed that under drought stress,the expression of ZmIQM3,ZmIQM4 and ZmIQM10 was up-regulated, and ZmIQM3,ZmIQM4,ZmIQM5,ZmIQM10 and ZmIQM11 responded to Cochliobolus heterostrophus infection.The results showed that ZmIQMs genes played an important role in stress response.

In order to explore the effects of mulching measures(such as straw returning and plastic film mulching)on soil aggregates and organic carbon in semi-arid rain-fed agricultural areas.The potato-wheat rotation system in the dryland of Longzhong was used as the research object.The effects of straw stubble mulching(SR),straw strip mulching(SM),plastic film mulching(PM)and open field(CK)on soil organic carbon components(SOC,POC,MAOC),aggregate stability and aggregate carbon contribution rate were systematically analyzed.By evaluating the soil improvement effect of different mulching measures,integrating the intrinsic indicators such as soil organic carbon component dynamics,aggregate stability and crop productivity and water use efficiency data reported in the literature,the optimal mulching mode that can synergistically improve organic carbon and aggregate stability was screened.The results showed that the organic carbon content and aggregate stability of potato and wheat were improved by three mulching measures in potato-wheat rotation,and the effect of SR treatment was the best.Compared with CK treatment,the SOC content of SR and SM treatment increased by 15.38% and 7.78%,and the SOC content of PM treatment did not change significantly.SR and SM treatment increased the POC content in 0—20 cm soil layer by 18.54%,16.62%,and PM decreased the POC content in 0—20 cm soil layer by 3.06%.The overall trend of MAOC increased in each treatment was SR>SM>PM>CK.Compared with CK treatment,SR and SM treatments increased the proportion of MWD,GMD,>2 mm aggregates and SOC content,while PM significantly reduced MWD and GMD.SR increased the SOC enrichment coefficient of>2 mm aggregates by 17.26% in 0—20 cm soil layer,and SR and SM treatments significantly increased the SOC contribution rate of>2 mm aggregates.In summary,under the conditions of this experiment,all three mulching measures can increase soil organic carbon content,and straw stubble mulching returning to the field has the best effect in improving soil organic carbon content and aggregate stability,effectively improving soil fertility.

This study aimed to elucidate the compositional differences and molecular regulatory mechanisms of anthocyanins in kernels of fresh-eating maize with different colors by integrating metabolomic and transcriptomic analyses,thereby providing candidate genes and a theoretical basis for molecular breeding of colored fresh-eating maize.White WN2000,yellow HN,colored CN1,and black HTN188 were used as materials.Metabolomics was employed to identify anthocyanin-related metabolites and screen differential metabolites;transcriptome sequencing was conducted to obtain differentially expressed genes(DEGs).Metabolite gene associations were analyzed through GO annotation and KEGG pathway enrichment,and key structural genes and transcriptional regulators were mined within the anthocyanin biosynthetic pathway.The results showed that 49 anthocyanin-related metabolites were identified in total.Major anthocyanins,including cyanidin,peonidin,and pelargonidin,accumulated significantly in HTN188,indicating stronger pigment deposition.Transcriptome analysis identified 12 557 DEGs,among which structural genes such as F3H,DFR,and UFGT,as well as transcription factors including MYB and bHLH,were significantly up-regulated in varieties with high anthocyanin content.Correlation analysis revealed that the expression level of Zm00001d011438 was significantly and positively correlated with total anthocyanin content,suggesting that it may play a key role in kernel anthocyanin accumulation.Overall,the integrated metabolomic and transcriptomic analyses characterized differences in anthocyanin composition and related gene expression among differently colored fresh-eating maize kernels,and identified structural genes,transcription factors,and the candidate Zm00001d011438 associated with the anthocyanin biosynthetic pathway,providing references for subsequent functional validation and genetic improvement.

In order to provide production advice of high-quality upper tobacco leaves,field experiment was carried out to elucidate the effects of nitrogen application on the growth,development,carbon and nitrogen metabolism of upper leaves of different tobacco varieties.Three treatments,37.5(LN),75.0(MN)and 112.5 kg/ha nitrogen application rate(HN)were conducted with NC89 and Yunyan 87 as the test varieties.The effects of different treatments on the agronomic traits,photosynthetic characteristics,leaf tissue structure,key enzymes activity of carbon and nitrogen metabolism,and chemical composition of the upper leaves of were studied.The results showed that the leaf length,leaf width,leaf area,and leaf dry mass of the upper leaves of both varieties were significantly improved with the increased of nitrogen application rates.At 115 days after transplanting(DAT),the leaf area of NC89 and Yunyan 87 of HN were significantly increased by 63.10% and 68.43% compared to LN,respectively.Increasing nitrogen rate improved the leaf chlorophyll content of NC89,the leaf chlorophyll content of HN was 6.67%—37.50% higher than that of LN,respectively.The leaf net photosynthetic rate was notably improved by increasing nitrogen rate of Yunyan 87,especially at 70 DAT and 80 DAT.The leaf palisade tissue,leaf spongy tissue,and leaf thickness were markedly promoted with the increased nitrogen application rate on 85—115 DAT.The palisade tissue and spongy tissue thickness of LN and MN were almost stable from 95 to 115 DAT,but HN improved by 9.82%—14.08% and 10.72%—13.72% respectively.The leaf carbon content and leaf carbon and nitrogen ratio of both varieties were significantly decreased by reduced nitrogen rate,while leaf nitrogen content significantly increased.The activities of invertase,sucrose phosphate synthase,sucrose synthase,and glutamate synthase of both varieties were increased with the increased nitrogen application rate.HN decreased the amylase activity of Yunyan 87,but increased that of NC89.At 115 DAT,the amylase activity of HN of Yunyan 87 was 27.53% lower than MN,while HN increased amylase activity by 33.86% and 21.74% compared to LN and MN of NC89,respectively.The activity of glutamine synthetase of Yunyan 87 significantly increased with the increased nitrogen application rate,while there was no significant difference among different treatments of NC89.The content of flue-cured tobacco leaf reducing sugar and total sugar were reduced,but the content of nicotine and total nitrogen were improved with increased nitrogen application rate.Under the same nitrogen application rate,the content of flue-cured tobacco leaf nicotine,total nitrogen,and potassium of Yunyan 87 were higher than NC89,while the content of reducing sugar,content of total sugar(except LN),sugar and nicotine ratio,and nitrogen and nicotine ratio were lower than NC89.The effect of nitrogen application rate on upper leaves of tobacco varieties is difference.Increasing nitrogen application rate could promote the growth,development and carbon metabolism,reduce sugar and nicotine ratio and nitrogen and nicotine ratio,and improve the coordination of chemical components of NC89.However,increasing nitrogen application rate could lead to excessive nitrogen metabolism,delay the transformation from nitrogen metabolism to carbon accumulation metabolism,and cause late maturity of Yunyan 87.

To elucidate the mechanisms of cold response and explore superior cold-tolerance gene resources in wheat,this study employed transcriptome sequencing to uncover key regulatory networks underlying wheat cold response,and performed functional validation of the candidate gene TaGGCT18-6A.The results demonstrated that 4 ℃ cold treatments induced 10 893 and 18 784 differentially expressed genes(DEGs)in wheat seedlings after 6 h and 24 h cold treatment,respectively.KEGG analysis revealed significant enrichment of DEGs in pathways including MAPK signaling transduction and glutathione metabolism.A γ-glutamyl cyclotransferase gene TaGGCT18-6A was cloned through screening key genes in glutathione metabolism.This gene had a length of 1 772 bp,encoding 218 amino acids with conserved GGCT-like superfamily and ChaC core domain.Promoter cis-acting element analysis identified stress-responsive elements such as low-temperature-responsive(LTR)and dehydration-responsive (DRE)elements; consistently,expression pattern analysis showed sustained upregulation of TaGGCT18-6A under 4 ℃ cold treatments. Functional validation in transgenic rice revealed that overexpression lines OE#1, OE#2 and OE#3 exhibited significantly enhanced survival rate,plant height,and biomass. Overexpression lines OE#1 and OE#2 exhibited significantly enhanced plant height, while overexpression lines OE#1, OE#2 and OE#3 exhibited significantly reduced relative electrolyte leakage under -4 ℃ freezing treatments.After 4 ℃ treatment,overexpression lines accumulated higher levels of osmolytes(proline and soluble sugars),decreased malondialdehyde(MDA)content,and increased activities of superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT).These findings collectively demonstrated that TaGGCT18-6A enhanced plant cold tolerance by regulating glutathione metabolism to improve antioxidant capacity.This study will provide a theoretical foundation and valuable genetic resources for molecular breeding of cold-tolerant wheat.

In order to clarify the effects of climate change and organic fertilization on soil nitrogen cycling,a soybean field experiment was conducted in Hefei, Anhui from June to November 2023. Field warming was simulated using infrared radiation warming equipment, and two temperature levels(T0:Ambient temperature;T1:Warming)and different fertilization managements(SF:Synthetic fertilization;OF:Organic fertilization),and determined the effects of warming and organic fertilization on nitrification and denitrification processes and their drivers by investigating soil physicochemical properties,the relative contributions of ammonia-oxidizing bacteria(AOB)and archaea(AOA)to the nitrification potential,denitrification capacity and N₂O/(N₂O+N₂)ratio,as well as soil respiration in combination with enzyme activity measurements.The results showed that warming significantly decreased soil moisture(2.3 precentage points),organic carbon(22.7%),total phosphorus(23.8%),N${\mathrm{H}}_{4}^{+}$-N(17.5%),while significantly increased NO₃^--N(52.8%);organic fertilization significantly increased soil moisture,organic carbon,total phosphorus,NH₄⁺-N content by 1.2 percentage points,26.5%,31.3%,17.0%,respectively.Warming increased soil respiration(26.4%),nitrification potential(31.7%),AOB contribution(16.4 percentage points),denitrification capacity(49.1%),N₂O/(N₂O+N₂)ratio(10.5 percentage points).Organic fertilization significantly decreased the nitrification potential, AOA contribution, denitrification capacity, and N₂O/(N₂O+N₂)ratio by 39.3%, 18.2 percentage points, 24.7% and 16.2 percentage points,respectively.Warming and organic fertilization significantly increased urease (S-UE), nitrite reductase (S-NiR), and hydroxylamine reductase(HR)activities.The correlation analyses showed that NO₃^--N content,S-UE,S-NiR,and HR activities were significantly positively correlated with AOB contribution rate and denitrification capacity.Therefore,warming increased soil N${\mathrm{O}}_{3}^{-}$-N content and the activities of S-UE,S-NiR and HR,which in turn increased the nitrification contribution of AOB,denitrification capacity and N₂O/(N₂O+N₂)ratio,leading to an increase in the loss of N₂O;while organic fertilization could increase the soil nutrients and regulate the role of AOA and AOB in the nitrification process,reduce the contribution of AOA,denitrification capacity and N₂O/(N₂O+N₂)ratio,and thus decrease the N₂O loss,consequently,mitigating the adverse effects of warming.

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 role of the BnMLP2 gene in drought tolerance in ramie,the BnMLP2 gene encoding a metallothionein-like protein in ramie was obtained by analyzing ramie transcriptome data using Zhongzhu-1 as the material.The BnMLP2 gene was screened and cloned from the ramie transcriptome data,and bioinformatics analyses were conducted,including sequence alignment,domain prediction,and subcellular localization prediction.Fluorescent Quantitative PCR was used to determine the expression profile of the BnMLP2 gene in different tissues of ramie and to explore its expression changes under drought stress.The BnMLP2 gene was introduced into Arabidopsis thaliana to construct transgenic plants.Under drought stress conditions,phenotypic,physiological,and biochemical differences between transgenic and wild-type Arabidopsis were compared,along with the expression of stress-related genes.The results showed that the open reading frame of the BnMLP2 gene in ramie was 243 bp in length,encoding 80 amino acids.BnMLP2 had the closest amino acid sequence homology to metallothionein(MT)or metallothionein-like protein (MLP) from Malus domestica,both belonging to the metallothionein family; it contained the PFAM01439 domain and belonged to class Ⅱ metallothionein,with a predicted subcellular localization in the cytoplasm.The BnMLP2 gene was expressed in all tissues of ramie,and its expression was significantly induced by drought,especially in stems.Under drought stress,transgenic Arabidopsis overexpressing BnMLP2 exhibited stronger drought tolerance compared to wild-type plants,as evidenced by significantly increased root length and fresh weight,enhanced antioxidant enzyme and γ-glutamylcysteine ligase (γ-GCL) activities,and accumulation of more proline (Pro),glutathione(GSH),glutathione disulfide (GSSG),and phytochelatins (PCs) to regulate intracellular ion homeostasis.The contents of malondialdehyde (MDA)and hydrogen peroxide (H₂O₂)in transgenic lines were significantly lower than in wild-type plants,at 55% and 80% of wild-type levels,respectively.In addition, the content of sodium and potassium ions in transgenic Arabidopsis under drought conditions was 4.4 times and 1.4 times higher than that of the wild type, respectively. Overexpression of BnMLP2 induced increased expression of three stress-related genes,AtMT1a,AtNCED3,and AtWRKY40,with maximum expression levels of 1.5,1.9,and 2.8 times those in wild-type plants,respectively.These results suggest that the BnMLP2 gene enhances the tolerance of Arabidopsis to drought stress.

Soybean P34 protein mainly exists in soybean seeds,and its upstream promoter was likely to regulate the high expression of downstream genes in seeds.In order to further study the tissue expression pattern of soybean P34 protein gene and the regulatory activity of soybean P34 protein gene promoter,qRT-PCR was used to detect the expression of soybean P34 protein gene in soybean tissues.The 5'upstream sequence of soybean P34 protein gene(GmP34P)was cloned.The transcription initiation sites and cis-elements were analyzed by bioinformatics.The expression vector was constructed and the tobacco was transformed by Agrobacterium-mediated leaf disk method to detect GUS expression in transgenic tobacco.The results showed that the expression of P34 protein gene in soybean seeds was significantly higher than that in roots,stems,leaves and flowers.The length of GmP34P sequence obtained by cloning was 1 380 bp.Predictive analysis showed that the transcriptional start site of this sequence was base A at position 1 342,and the sequence contained a variety of cis-acting elements related to high seed expression,such as RY element,Skn-1 motif,2S seed protbanapa,etc.The plant expression vector pCAM-GmP34P containing GUS gene driven by GmP34P promoter was obtained.The positive transgenic plants were screened by hygromycin,PCR and RT-PCR.The results showed that GUS gene expression was extremely significant in transgenic tobacco seeds compared with other tissues by qRT-PCR with positive pCAM-GmP34P transgenic tobacco plants.GUS histochemical staining showed that the GmP34P promoter could regulate the high expression of downstream GUS gene in seeds.

In order to study the tolerance of heterologously overexpressed Atvip1 gene in sorghum to defense saline-alkali stress and the corresponding growth, NaHCO₃:Na₂CO₃ of 5:1 solution with 75 mmol/L and pH 9.63 was used in sorghum at the stage of three leaves and one heart. The root growth index, chlorophyll content, antioxidant enzyme activity and MDA content were measured at 0, 4, 12, 24, 72, and 120 h of stress. The results indicated that the heterologous overexpression of Atvip1 gene could alleviate the damage of saline-alkali stress on the growth of sorghum seedlings, increase the root surface area and root volume, the number of root tips and branches, and also cause the browning of sorghum main roots to appear later and mild symphonys, and the earlier and more lateral roots occurrence. The new leaves could still be normally extended at 72 h and present little effect on the growth of aboveground. Overexpression of Atvip1 gene could increase the activity of O₂^-· resistance, decrease the content of MDA and enhance the activities of antioxidant enzymes in transgenic sorghum roots. SOD, CAT and GR had obvious effects at 4-12 h during the early stage of stress, respectively. All enzymes played roles during the middle of stress at 24-72 h. CAT and GSH-PX played important roles at the later stage of stress at 120 h. On the base of differential transcriptome analysis of saline-alkali stress, COG analysis of differentially expressed genes(DEGs) showed that defense mechanisms accounted for a relatively large proportion during various periods, and 42 DEGs related to antioxidant enzymes were obtained. Heterologous overexpression of Atvip1 gene can improve the resistance of transgenic sorghum to saline-alkali stress by alleviating the effects on photosynthesis, growth and development, reducing the damages of reactive oxygen species and membrane damage.

In order to study the effects of different nitrogen application rates on rice yield,nitrogen uptake and soil fertility,the effects of different nitrogen application levels on rice yield,nitrogen use efficiency and soil tillage fertility in the Yellow River Irrigation Area were studied from 2021 to 2023 using rice variety Fuyuan 4 as the test material.Compared with other treatments,the average yield of 360 kg/ha was 9.4 t/ha,which was 182.94% higher than that of no nitrogen treatment,and 40.72% and 26.34% higher than that of 210,240 kg/ha.From the perspective of yield components,the increase in yield was mainly due to the increase of grain number per spike and the number of effective spikes,and excessive nitrogen application would cause the decrease of 1000-grain weight.The average of the 3-year results showed that the nitrogen use efficiency was up to 26.93% with 240 kg/ha of nitrogen,and the partial productivity of nitrogen fertilizer decreased with the increase of nitrogen application rate.The highest average value of organic matter was 18.60 g/kg after nitrogen application of 210 kg/ha.Compared with the non-nitrogen application treatment,the soil total nitrogen content of each nitrogen application treatment increased by 7.61%—15.67%,and the soil total nitrogen content of the 360 kg/ha nitrogen application treatment decreased with the increase of the experimental year.The total phosphorus content of soil was gradually reduced in the 360 kg/ha nitrogen application treatment,and the total phosphorus content in other nitrogen application treatments was maintained at about 0.85 g/kg.The total potassium content of nitrogen fertilization treatments gradually decreased with the increase of nitrogen application rate,and the total potassium content of the 360 kg/ha nitrogen application treatment decreased by 23.74%,22.16% and 8.85%,respectively,compared with the nitrogen fertilization treatments of 120,210 and 240 kg/ha.Soil available phosphorus increased with the years of the experiment,and the variation range between treatments increased with time.With the increase of nitrogen application rate,soil available phosphorus increased first and then decreased,and the soil available phosphorus of the 240 kg/ha treatment increased significantly in 2023 compared with other treatments.The soil available potassium of each treatment did not change significantly with the test years.By considering crop yield,nitrogen use efficiency and soil fertility,nitrogen application of 240 kg/ha could balance the environment and production requirements.

The transcription factor BnHY5-2 is associated with plant stress resistance.In order to reveal the response of Brassica napus L.transcription factor BnHY5-2 to salt alkali stress in B.napus,the response of BnHY5-2 to light and salt and alkali was analyzed by transient overexpression,qRT-PCR analysis and subcellular localization.The results revealed that under light conditions,the expression level of the BnHY5-2 gene in B.napus leaves and stems was 29.22 and 3.15 fold higher,respectively,compared to dark conditions.The higher sensitivity to light in leaves suggested that they were the primary site for light signal response.Under light conditions,the expression of BnHY5-2 in leaves and stems was significantly downregulated by 53.1% and 31.0%,respectively,when B.napus was planted in Dalian coastal saline-alkali soil;after applying saline-alkali treatment under dark conditions,the expression of BnHY5-2 was downregulated by 48.2% in the stem,while the difference in expression in the leaves was not significant,indicating organ differences,indicating that the leaves had stricter requirements for light conditions.In B.napus leaves with transient overexpression of BnHY5-2,two out of six genes related to saline-alkali stress(BnNAC32 and BnGS)showed upregulation by 1.25,3.28 fold,respectively,while the other four genes(Bnamy,BnAsp,BnNHX7,BnTPS)were downregulated by 24.8%,25.4%,71.0%,and 82.0%,respectively.Meanwhile,the content of the resistance substance betaine in B.napus increased from 0.256 to 0.573 mg/g,indicating an enhancement by 1.24 fold,suggesting that the overexpression of BnHY5-2 gene could improve the saline-alkali tolerance of B.napus.Subcellular localization results showed that the transcription factor BnHY5-2 was localized in the nucleus and regulates the expression of functional genes.Therefore,BnHY5-2 is not only related to light signaling but also participates in the saline-alkali resistance of Brassica napus L.

To investigate the role of calcium-dependent protein kinase (CDPK) in wheat growth and stress response,the TaCDPK17 gene was cloned from common wheat and its sequence structure,expression pattern,and stress resistance function were preliminarily analyzed.The results showed that the length of the TaCDPK17 gene coding region was 1 701 bp, encoding 566 amino acids and possessing typical structural features of the CDPK family, including one conserved serine/threonine kinase domain and four EF hand shaped domains. Evolutionary tree analysis of TaCDPK17 and CDPK17 from 12 other plants showed that TaCDPK17 had high homology with the CDPK17 sequence of gramineous crops,especially Aegilops tauschii and barley.The promoter region of TaCDPK17 gene contained multiple cis regulatory elements related to hormone signaling pathways,light response.Among them, there are more abscisic acid (ABA) responsive elements (ABRE) and methyl jasmonate responsive elements (CGTCA). The expression analysis based on Real-time Fluorescence Quantitative PCR showed that the expression level of TaCDPK17 increased to varying degrees after induced by 100 μmol/L ABA, 100 μmol/L methyl jasmonate, 20% PEG6000, and 250 mmol/L NaCl. Under stress conditions of 2 μmol/L ABA and 100 mmol/L NaCl, the germination rate of Arabidopsis seeds overexpressing TaCDPK17 was significantly higher than that of the wild type. Meanwhile, overexpression of TaCDPK17 alleviated the inhibitory effects of ABA or osmotic stress treatments on seedling root growth. During stomatal closure, transgenic plants overexpressing TaCDPK17 are more sensitive to ABA and exhibit a stronger stomatal closure trend compared to wild-type plants. These results indicated that TaCDPK17 plays an important role in stress response and hormone signaling in wheat.

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.

This study aims to explore the effects of reduced nitrogen application combined with organic fertilizer on soil carbon and nitrogen contents in the 0—60 cm layer of fragrant pear orchards,as well as the yield and quality of Korla fragrant pears,and to propose the optimal rate of reduced nitrogen application and matching ratio of organic fertilizer.Using 10—12-year-old Korla fragrant pear trees as test materials,a 3-year continuous experiment was carried out.The experiment set up a conventional nitrogen application treatment(denoted as N,with 300 kg/ha of nitrogen applied),three reduced nitrogen application treatments(denoted as N1,N2,N3,which reduced nitrogen by 10%,20%,and 30% respectively compared with the conventional nitrogen application treatment),and two organic fertilizer treatments(denoted as OF1 and OF2,with 22 500,33 750 kg/ha of sheep manure applied respectively).These treatments were combined to form six integrated treatments:N1F1,N2F1,N3F1,N1F2,N2F2,and N3F2.The soil carbon and nitrogen contents,soil carbon-to-nitrogen ratio(C/N),as well as the yield and quality of Korla fragrant pears were determined.The result showed that N1F1,N1F2,N2F2,and N3F2 treatments significantly increased the contents of total soil carbon,soil organic carbon,soil inorganic carbon,soil microbial biomass carbon(SMBC),soil nitrate nitrogen,and soil ammonium nitrogen in the orchard.They also increased the soil C/N ratio,the contents of soluble sugar and vitamin C in pear fruits,decreased the total acid content in fruits,and had no significant effect on pear yield.The N2F1 treatment significantly promoted the contents of soil nitrate nitrogen and ammonium nitrogen but had no significant effect on pear yield or quality.The N3F1 treatment significantly inhibited the contents of soil carbon fractions and pear yield and reduced the soluble sugar content in fruits.Correlation analysis showed that soil nitrate nitrogen,ammonium nitrogen,organic carbon,inorganic carbon,total nitrogen,total carbon,SMBC,and soil microbial biomass nitrogen(SMBN)were significantly or extremely significantly correlated with pear quality;the soil C/N ratio was significantly or extremely significantly negatively correlated with pear yield and quality.Among these factors,soil organic carbon,total nitrogen,nitrate nitrogen,and ammonium nitrogen had more prominent effects on pear yield and quality.Therefore,in subsequent fertilization management,improving the contents of soil organic carbon,total nitrogen,nitrate nitrogen,and ammonium nitrogen and regulating the soil C/N ratio can better increase the yield and improve the fruit quality of Korla fragrant pears.In the management of 10—12-year-old Korla fragrant pear trees,reducing nitrogen application by 20%—30% on the basis of the conventional nitrogen application rate while applying organic fertilizer at 33 750 kg/ha is beneficial.This measure regulates soil carbon and nitrogen contents,improves pear quality,reduces chemical fertilizer input to alleviate soil pollution,and ensures the health of the soil environment.

In order to further analyze the genetic basis regulating the protein content of super sweet corn stalk,this study used the BLINK model to locate the major SNP loci and predict candidate genes controlling the trait,based on the maize 56K gene chip.The results showed that during the harvest period of super sweet corn,the protein content of stalk ranged from 12.63 to 30.29 g/kg,with an average of 20.76 g/kg,showing a normal distribution.Six significant SNP loci regulating the protein content of super sweet corn stalk were identified by GWAS.These loci were distributed on chromosomes 1,4 and 6,and their contribution rates ranged from 10.07% to 18.17%.Among them,Affx-115330268 on chromosome 6 had the highest contribution rate.A total of 184 candidate genes were detected in the 200 kb confidence interval between the upstream and downstream of the significant association sites,of which 34 were annotated genes,accounting for 18.48%.Through GO functional annotation and KEGG pathway enrichment analysis,candidate genes were mainly involved in biological processes such as biological regulation,cellular processes,and catalytic activity,and were enriched in steroid biosynthesis,tryptophan metabolism,photosynthesis-antenna protein and other pathways.Based on the literature search and comparison,it was found that six key genes (GRMZM2G141473, GRMZM2G007854, GRMZM2G111319, GRMZM2G121024, GRMZM2G010353, GRMZM2G049547) that regulate the protein content of super sweet corn stalk,which are mainly involved in protein and enzyme synthesis.

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.

NRL(NPH3/RPT2-Like)is a type of light-responsive protein unique to plants and plays a vital role in the phototropic signal pathway. To reveal the NRL gene maize genome's characteristics and expression,we analyzed them using bioinformatics methods combined with qRT-PCR technology. The property,structure,evolution of their encoded proteins,and growth period tissue expression and stress expression were analyzed. 31 ZmNRL genes identified were located in nine maize chromosomes,encoding protein amino acids 464-749 aa,which predicted to have chloroplast,nuclear and cytoplasmic locations. According to protein conservation,ZmNRL family was divided into four categories. Their gene structure also presented certain conservation,the most contained four exons. Analysis of the cis-elements of gene promoters revealed a large number of abscisic acids,jasmonic acid,light response,and anti-oxidation elements,among which G-box and Sp1 were two types of light-related elements. The expression of ZmNRL family genes in tissues during the growth period showed a temporal and spatial specificity,and the majority expression level was not high. Only ZmNRL2,ZmNRL4,ZmNRL24,and ZmNRL29 highly expressed. Furthermore,the characteristic modules were produced based on the data of the tissue co-expression genes. And the GO enrichment analysis of a particular leaf growth module containing six ZmNRL genes,mainly associated with the plastid organization biological processes and rRNA binding molecular functions. The expression of ZmNRL5,ZmNRL7,ZmNRL12,and ZmNRL19 genes were analyzed by qRT-PCR under salt,drought,high temperature,and Rhizoctonia solani inoculation treatments. The results showed that ZmNRL12 was significantly up-regulated in maize seedlings treated with high temperature,while ZmNRL5,ZmNRL7 and ZmNRL19 genes were down-regulated in drought,salt and pathogen treatments. In summary,31 ZmNRL genes were identified in the maize genome. They not only had apparent specific tissue expression but also participated in biotic and abiotic stress responses.

To investigate the effects of climate warming and combined application of organic and inorganic fertilizer on soybean growth and yield,field experiments were conducted using infrared radiation warming systems to simulate temperature elevation.The experimental design included two temperature levels(T0:Ambient temperature;T1:Warming by 2.9 ℃)and two fertilization regimes(SF:Sole inorganic fertilizer;OF:Combined organic-inorganic fertilizer),aiming to examine the impacts of warming and fertilization practices on soybean dry matter accumulation,photosynthetic rate,leaf enzyme activities,and yield.Results demonstrated that compared to ambient temperature,warming shortened the pre-flowering and post-flowering growth periods by 3—4 d,5—6 d,respectively.Warming significantly reduced leaf nitrate reductase(NR)and glutamine synthetase(GS)activities during the pod-filling stage,decreased leaf area index(LAI)by 9.0%—13.7%,and suppressed net photosynthetic rate,collectively leading to 4.1%—19.3% reductions in post-flowering plant height and aboveground dry matter accumulation.In contrast,the combined organic-inorganic fertilization enhanced NR and GS activities,improved post-flowering photosynthetic efficiency,promoted plant growth,and increased the aboveground dry matter accumulation by 4.1%—15.3% compared to sole inorganic fertilization,with a significant interaction observed between NR and alanine aminotransferase activities.Yield analysis revealed that warming caused 9.7%—16.6%,13.3%—19.0% declines in pods per plant and grains per plant,respectively,resulting in 13.7%—21.1% yield reductions.Conversely,organic-inorganic fertilization increased grains per plant by 12.5% and pods per plant by 9.9%—10.5%,achieving 7.6%—10.8% yield improvements.Notably,significant positive correlations were detected among LAI,photosynthetic rate,nitrogen metabolism enzyme activities,and final yield.These findings demonstrate that climate warming inhibits post-flowering photosynthetic efficiency and aboveground growth in soybeans,while integrated organic-inorganic fertilization partially mitigates warming-induced yield losses through enhancing enzyme activities and photosynthetic performance,providing critical insights for adaptive agricultural practices under global warming scenarios.

In order to explore the role of RPM1 in sorghum disease resistance,a sorghum SbRPM1 gene was obtained from sorghum smut resistant variety SX44B by homologous cloning method.The bioinformatics analysis results showed that the total length of the cDNA of SbRPM1 gene was 2 802 bp,encoding 933 amino acids,and its protein had a theoretical molecular weight of 106.1 ku and an isoelectric point of 7.11,which was a hydrophilic protein.The SbRPM1 protein had no transmembrane structure,and its subcellular localization was in the cytoplasm.Conservative domain analysis showed that SbRPM1 protein contained RX-CC-like,NB-ARC and LRR domains,and belonged to CNL proteins in the NLRs family.Phylogenetic analysis showed that SbRPM1 protein was most closely related to the RPM1 protein of Miscanthus lutarioriparius.The expression pattern of SbRPM1 gene was detected by Real-time quantitative PCR,and the results showed that the expression of SbRPM1 gene was higher in leaves and inflorescence,followed by roots,and the lowest in stem.The expression of SbRPM1 gene was significantly up-regulated at 24—72 h in disease-resistant varieties after inoculation with Sporisorium reilianum pathogen,suggesting that this gene could be induced by S.reilianum and played an important role in sorghum disease resistance.In this study, the CDS sequence of the SbRPM1 gene was cloned for the first time in sorghum, and the structure, nature and expression of the gene were characterized.

Phytosulfokine receptor(PSKR)plays an important role in promoting plant cell proliferation and is involved in plant response to abiotic stresses.To explore the sequence characteristics and the function of wheat PSKR genes,the cDNA sequences of three homologous genes of TaPSKR1 were cloned from wheat variety Jinmai 47 by homologous cloning technology,named TaPSKR1-6A,TaPSKR1-6B and TaPSKR1-6D because of their locations on chromosome 6A,6B and 6D,respectively.The gene structure,protein physical and chemical properties,cis acting elements,functional domains and evolutionary relationships were analyzed by bioinformatics analysis.The expression patterns of TaPSKR1 genes in different tissues and under different stresses were detected by qRT-PCR.The results showed that TaPSKR1-6A,TaPSKR1-6B and TaPSKR1-6D all contained one exon.The open reading frame(ORF)of the three TaPSKR1 genes were 3 153,3 132,3 156 bp,respectively,which encoded 1 050,1 043 and 1 051 amino acid residues.Bioinformatics analysis showed that TaPSKR1 proteins were located on the cell membrane,containing signal peptide,transmembrane domains,eight LRRs type domains and intracellular kinase domain,which belonged to PSKR gene family.Phylogenetic analysis showed that TaPSKR1 proteins had closely relationship with its related species and rice,which were clustered into the same subgroup.The results of expression analysis showed that TaPSKR1 genes were expressed in roots,stems,leaves and seeds,and the expression levels in roots were the highest.Under drought and salt stress treatments,the expressions of three homologous copies of TaPSKR1 genes were sharply upregulated in leaves,suggesting that TaPSKR1 might play an important regulatory role in wheat defense to abiotic stresses.

The plant NADPH oxidase Rbohs(Respiratory burst oxidase homologs) is the main source of reactive oxygen species (ROS),which participate in various physiological processes such as plant growth,development,stress resistance and plant-microorganism interaction.In order to explore the function and mechanism of Rbohs in symbiotic nitrogen fixation,GmRbohL,a member of soybean Rbohs gene family,was cloned in this study.The gene expression pattern,protein subcellular localization and gene function were studied by molecular biology,cell biology and genetics,respectively.The results revealed that: GmRbohL gene was induced by rhizobia and expressed specifically in soybean roots and nodules.Subcellular localization analysis indicated that the gene-encoded protein GmRbohL was a membrane protein.The plant gene silencing (RNAi) vector of GmRbohL was constructed,and the transgenic hairy roots were obtained by the transformation of soybean hairy root mediated by Agrobacterium rhizogenes K599.Gene silencing of GmRbohL resulted in a significant reduction in the number of nodules of transgenic hairy roots,and the production of ROS was also inhibited. Gene silencing of GmRbohL reduced the infection of rhizobia at the stage of root nodule organogenesis,and the expression level of nodulation marker genes also decreased with the decrease of GmRbohL expression.The root nodule tissue sections showed that gene silencing of GmRbohL significantly reduced the number of symbionts in the infected area of root nodules,and the nitrogenase activity of root nodules also decreased accordingly.The above data indicated that gene silencing of GmRbohL significantly inhibits the symbiotic nodulation process of soybean by reducing the production level of ROS.It is speculated that GmRbohL may play an important positive regulatory role in organogenesis of soybean nodules and regulation of nitrogen fixation function.

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.

Preliminary transcriptomic analysis identified ZmRAV1 as a candidate gene involved in maize's response to drought stress. To further investigate its function, this study cloned the ZmRAV1 gene, conducted bioinformatics analysis of its coding sequence, and overexpressed this gene in Arabidopsis thaliana. The function of ZmRAV1 was validated by assessing the phenotypes and physiological and biochemical indices of the transgenic Arabidopsis lines under drought conditions. The results showed that the ZmRAV1 gene had a total length of 1 176 bp and encoded 389 amino acids.It had the highest proportion of irregular coils in its secondary structure and was a hydrophilic protein that did not contain signal peptides and was non transmembrane.Subcellular localization indicated that the protein was located in the nucleus.ZmRAV1 exhibited high conservation across different species.Phylogenetic analysis indicated that ZmRAV1 shares the closest evolutionary relationship with its homolog in Miscanthus sinensis, showing a high degree of homology. After drought stress treatment,the root length of Arabidopsis thaliana lines overexpressing ZmRAV1 during germination was significantly higher than that of wild-type (WT)lines.In the seedling stage,WT showed withering or even death after drought stress,while the survival rate was lower than that of overexpressing lines.Moreover,the POD and SOD activities of ZmRAV1 overexpressing lines were higher than those of WT after drought treatment,indicating that overexpression of ZmRAV1 gene could enhance Arabidopsis thaliana's resistance to drought stress.

Fusarium head blight(FHB)is a devastating fungal disease that seriously threatens the safety of wheat production.Marker-assisted selection(MAS)and pyramiding of resistance genes represent efficient strategies for FHB-resistant breeding.To establish a high-throughput screening system for FHB resistance genes and enhance wheat resistance in Sichuan Province,we performed genome-wide genotyping using a 100K SNP array on 14 Sichuan wheat varieties(lines)along with three FHB-resistant genetic materials.Based on the reported genetic linkage intervals of major FHB resistance genes(Fhb2,Fhb4,Fhb5),we identified SNPs co-segregating with Fhb5 or linked to Fhb2,Fhb4,and subsequently developed kompetitive allele-specific PCR(KASP)markers.Results showed that the genetic relationship of 17 wheat varieties(lines)could be clustered into two major groups:two northern wheat-derived resistant materials(NMAS070 and NMAS069)formed an independent cluster distinct from the Sichuan varieties(lines)while the remaining 15 varieties(lines)were clustered together and subdivided into two subgroups.Functional gene profiling revealed FHB-resistant parents carried superior resistance loci,whereas agronomic parents harbored favorable alleles for yield and quality traits.Through SNP screening,we identified 8 critical SNPs within the linkage intervals of Fhb2,Fhb4 and the co-segregation region of Fhb5.These SNPs enabled the successful development of 4,2,and 2 high-specificity KASP marker systems for Fhb2,Fhb4 and Fhb5,respectively.Validation experiments confirmed all KASP markers achieved precise genotyping and were effectively implemented in molecular breeding for FHB-resistance.This study established a high-efficiency KASP marker system for Fhb2,Fhb4 and Fhb5,providing a robust technical platform for improving FHB resistance breeding of wheat varieties in Southwest China.

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.

In order to improve the blast resistance of Shuijing 3,an excellent food-flavor rice variety,CRISPR/Cas9 gene editing technology combined with gene chip technology were used to pyramid the R gene Pigm and the non-R gene bsr-d1 into Shuijing 3.Firstly,Bsr-d1 was selected as the target gene to construct a recombinant expression vector using the CRISPR/Cas9 gene editing system,and transformed into the excellent food-flavor rice Shuijing 3 by Agrobacterium-mediated method.The homozygous bsr-d1 mutant lines without T-DNA elements,including five mutation types as T insertion,G insertion,GA deletion,CGCA deletion and CGCAGA deletion,were screened out.The japonica line Jinyu 1 containing a broad-spectrum blast resistance gene Pigm was used as the gene donor parent to cross with the homozygous bsr-d1 mutant lines without transgenic components.The Pigm gene was introduced into bsr-d1 mutant lines by cross,backcross and self-cross combing molecular breeding chip to simultaneously perform Pigm gene and background-assisted selection.The improved lines SJ3-G1,SJ3-G2,SJ3-G3,SJ3-G4,SJ3-G5,which were homozygous for the disease resistance genes(carrying both bsr-d1 and Pigm genes)and whose background recovery rates were all above 96%,were finally obtained.The improved strains of Shuijing 3 displayed enhanced leaf blast resistance compared with the wild type in inoculated identification test using Magnaporthe grisea strain GUY11.After inoculation with M.oryzae,the POD activities in the improved strains of Shuijing 3 were significantly lower than that of the wild-type control,while the H₂O₂ contents were significantly higher than that of the wild-type control.The improved Shuijing 3 lines with blast resistance carrying both bsr-d1 and Pigm genes are obtained by CRISPR/Cas9 gene editing technology combined with gene chip technology.