To investigate the effects of row spacing and chlormequat chloride application on lodging resistance and yield performance of foxtail millet in Southeastern Shanxi,a two-factor randomized block design was employed,utilizing Jingu 21 as the experimental material.The experimental design included three row spacing levels(30,40,and 50 cm,designated as D30,D40,and D50,respectively)and three chlormequat chloride treatment regimes:spraying with water only(CK),single application at the six-leaf stage(T1),and sequential applications at both the six-and eight-leaf stages(T2).This resulted in a total of nine treatment combinations.The study evaluated the impacts of these treatments on stem morphological characteristics,lodging incidence,grain yield,and its component traits.Results showed that chlormequat chloride application under varying row spacing conditions significantly improved stem breaking resistance while significantly reducing plant height,center-of-gravity height,and field lodging rate.The D40+T2 treatment exhibited the highest stem breaking resistance(94.59 N)and concurrently achieved the lowest values for plant height(161.53 cm),center-of-gravity height(80.3 cm),and lodging rate(16.31%).In terms of yield,as row spacing increased,the yield of CK,T1,and T2 treatments all showed a decreasing trend.Among them,the D30+T1 treatment achieved the highest yield of 4 923.83 kg/ha.Correlation analysis indicated that under different row spacing and chlormequat treatments,millet yield was mostly positively correlated with plant height and panicle traits,while consistently negatively correlated with lodging rate.This demonstrates that optimizing row spacing and chlormequat application can effectively regulate key agronomic traits.In conclusion,optimizing row spacing along with appropriate chlormequat treatment can effectively minimize the risk of lodging while maintaining yield.The D30+T1 treatment demonstrated superior overall performance and is therefore recommended for broader adoption in foxtail millet cultivation in Southeastern Shanxi.

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 fully utilize the effect of foliar fertilizer on increasing soybean yield,an experiment was conducted to study the effects of foliar fertilizer application frequency and timing on soybean growth,photosynthesis,yield and grain quality.The results showed that F1 (spraying at the beginning of flowering stage)was more beneficial than F2 (spraying at the beginning of pod stage)and F3(spraying at the beginning of filling stage)for increasing fresh leaf weight per plant,dry leaf weight per plant,fresh root weight,dry root weight,fresh root weight growth rate,dry root weight growth rate and dry matter accumulation rate of population,and spraying foliar fertilizer twice F4 (initial of flowering stage+initial of pod stage),F5 (initial of flowering stage+initial of filling stage),F6 (initial of pod stage+initial of filling stage)in improving the above indexes were better than spraying foliar fertilizer once F1,F2,and F3.Spraying foliar fertilizer once F2 was the most beneficial for increasing chlorophyll content and photosynthetic rate,while F1 had the highest canopy photosynthetically active radiation;spraying foliar fertilizer twice F4 had the highest values of chlorophyll content,photosynthetic rate and canopy photosynthetically active radiation,compared to F1,F2,and F3,F4 significantly increased chlorophyll content and canopy photosynthetically active radiation at filling stage by 8.22%,7.08%,9.89% and 9.25%,13.36%,16.78%,respectively.Compared to spraying foliar fertilizer once,spraying foliar fertilizer twice significantly increased the dry weight of soybean population,and compared to CK,spraying foliar fertilizer once and twice could enhance yield by 82.34—327.86 kg/ha and 318.91—463.98 kg/ha,respectively.Although spraying foliar fertilizer twice was more beneficial for increasing the protein content of soybean grain when compared to spraying foliar fertilizer once,the effect was insignificant,spraying foliar fertilizer at the initial of flowering stage+initial of pod stage was the most effective way to increase protein content.Overall,spraying foliar fertilizer once at the beginning of the flowering period was the most beneficial for improving soybean growth,photosynthetic characteristics and yield,while spraying at the beginning of the pod stage was the most beneficial for improving protein content,and spraying foliar fertilizer twice at the beginning of flowering stage+beginning of the pod stage had the best effect.

This study aimed to investigate the effects of acidic soil on the growth metabolism and photosynthesis of Hainan green sweet orange (Citrus sinensis L.)and to elucidate its antioxidant regulatory mechanisms under acid stress.A pot experiment was conducted to analyze the physiological metabolic changes,antioxidant responses,and expression patterns of key antioxidant enzyme regulatory genes in green sweet orange under acid stress.The results showed that the plant height growth,leaf area and fresh weight of green sweet orange plants decreased significantly under a strongly acidic soil environment,with the most serious effect of pH 3.5 treatment;the weakly acidic(pH 6.5)soil could promote the growth of plants,which manifested as positive growth in the amount of each growth index.Strong acid treatment significantly impaired photosynthesis and normal growth metabolism of green sweet orange leaves,manifested as negative growth in transpiration rate(Tr)and stomatal conductance(Gs)were significantly reduced.Superoxide dismutase(SOD)and phenylalanine ammonia-lyase(PAL)activities increased by 6.60-fold and 5.90-fold at 24 h post-treatment under pH 3.5.The malondialdehyde(MDA)content in leaves treated with pH 3.5 increased by 6.47-fold compared to the initial time point(0 h),significantly higher than that under pH 6.5.Principal component analysis(PCA)and redundancy analysis(RDA)revealed a significant negative correlation between enzyme activity and physiological-biochemical indices(R²=0.82).Gene expression analysis demonstrated that CsSOD and CsPAL reached peak levels at 24,48 h post-stress respectively and remained upregulated within 72 h,showing 2.33-fold and 2.64-fold increases compared to 0 h,respectively.In summary,strongly acidic soil inhibits the growth and development of green sweet orange by reducing photosynthetic pigment content and metabolic efficiency.SOD and PAL serve as key antioxidant enzymes in response to acid stress,with CsSOD and CsPAL genes dynamically regulating enzymatic activity to mitigate stress.

To identify the suitable sowing date and planting density for the synergistic improvement of yield and quality of strong gluten wheat,the strong gluten wheat variety Kexing 3302 was used as the experimental material.Two sowing dates(October 18(S1)and October 28(S2))and five densities(basic seedlings of 180×10⁴ plants/ha(D180),225×10⁴ plants/ha(D225),270×10⁴ plants/ha(D270),315×10⁴ plants/ha(D315),and 375×10⁴ plants/ha(D375))were set.Field experiments were conducted in 2021—2023 to investigate the effects of sowing date and density on physiological indicators,yield,and quality of wheat plants.The results showed that the relative chlorophyll content(SPAD)of wheat leaves generally decreased with the increase of planting density,and reached its maximum at most growth stages under low-density treatment.With the delay of the sowing date,the relative chlorophyll content of leaves showed an upward trend,with S1 sowing date being lower than S2.As planting density increased,the normalized difference vegetation index(NDVI)generally showed an upward trend,and the NDVI value at S2 sowing date was significantly lower than that at S1 sowing date.The number of spikes and grain yield decreased with the delay of the planting density,but increased with the increase of planting density,with the highest yield under D375 treatment.With the delay of the sowing date,both protein content and wet gluten content generally showed a slight downward trend,but the grain protein content of all treatments was above 13.5%.The total starch content of wheat grains generally decreased with the increase of density at S1 sowing date,but increased with the increase of density at S2 sowing date.In addition,the peak viscosity,trough viscosity,final viscosity,and breakdown value generally increased with the increase of density under the two sowing dates.Parameters such as dough stability time and water absorption rate did not exhibit obvious regular pattern under different sowing dates and planting density,but all met the standards for strong gluten wheat.In summary,at sowing date S1,the planting density of Kexing 3302 at 315×10⁴—375×10⁴ plants/ha can achieve high quality and high yield.

Bindao 8(BD8),Bindao 10(BD10)and Bindao 18(BD18)are a series of new rice varieties with high yield and resistance,which were newly bred by Institute of Coastal Agriculture,Hebei Academy of Agriculture and Forestry Sciences,all showing the characteristics of bent ear large grain leaf under the rice.Under high-yield cultivation conditions,the yield exceeds 12.5 t/ha.This study used BD8,BD10 and BD18 as materials,compares them with their parents Jinyuan 89(JY89)and Kenyu 60(KY60),and the control variety Yanfeng 47(YF47),analyzes the yield composition,dry matter accumulation,and photosynthetic characteristics,and the mechanism underlying its high-yield.The results showed that the average yield of the Bindao varieties was 12.61-13.06 t/ha,which was 15.51% higher than that of YF47;the above-ground dry matter accumulation was 19.74-20.56 t/ha,which was significantly higher than the control by 16.45%;the yield reservoir capacity was increased by 14.5%-15.2% compared to the parents and the control;the thousand-grain weight was 28-30 g,which was 16.57% higher than that of YF47.After heading,the leaf area index of the Bindao varieties showed a trend of steady increase and slow decline,the photosynthetic potential was 356.83-378.58 (m²·d)/m²,which was 50.17% higher than that of YF47;the total chlorophyll content during the wax ripening period was high by 49.42%,and the net assimilation rate was 2.62-2.78 g/(m²·d),ensuring the material production during the later growth period.The apparent transfer rate of non-structural carbohydrates in the stem sheath was 39.26%-43.24%,and the efficient output during the early and mid-grain filling period could fill the reservoir capacity,with a grain setting rate exceeding 93%.In summary,the Bindao varieties achieve ultra-high yields through the synergistic effects of "large reservoir capacity+strong source supply smooth transportation",providing theoretical support for high-yield breeding of Japonica rice in North China.

To provide scientific evidence for assessing the ecological risks of carboxylated multi-walled carbon ranotubes(MWCNTs-COOH)and their combined pollution with lead(Pb)and Cadmium(Cd),the present study employed a hydroponic culture system to investigate the effects of individual MWCNTs-COOH(2.5,5.0 and 10.0 mg/L)and their combination with 5 μmol/L Cd+20 μmol/L Pb(Cd+Pb)on several indicators of carbon and nitrogen metabolism in rice seedlings,and the findings provide a scientific basis assessment for the ecological risks of the combined pollution of MWCNTs-COOH and Cd+Pb.The results showed that,2.5 mg/L MWCNTs-COOH increased chlorophyll content and net photosynthetic rate(Pn),and enhanced the contents of soluble sugar,starch,free amino acid and soluble protein,as well as the activities of nitrate reductase(NR),glutamine synthase(GS)and glutamate synthase(GOGAT),but significantly decreased the activity of glutamate dehydrogenase(GDH).Whereas,10.0 mg/L MWCNTs-COOH evidently suppressed the growth of rice root and stem.Meanwhile,such treatment significantly reduced chlorophyll content and Pn,decreased soluble sugar and starch content,but induced NR activity accompanied by the decline in GS,GOGAT and GDH activities.After joint treatments,compared with the Cd+Pb group,the 2.5 mg/L MWCNTs-COOH combined group showed no significant changes in root and shoot length,net photosynthetic rate,as well as the contents of chlorophyll,soluble sugar,starch,and also the activities of GS and GOGAT.However,significant increases were observed in NR and GDH enzyme activities.In contrast,the 10.0 mg/L MWCNTs-COOH combined group exhibited evident decreases in all the mentioned parameters in comparison to the Cd+Pb group,except for NR activity which showed an obvious increase.The above results indicated that low concentration of MWCNTs-COOH promoted carbon and nitrogen metabolism in rice leaves,whereas high concentration of MWCNTs-COOH inhibited carbon and nitrogen metabolism.Furthermore,low concentration of MWCNTs-COOH combined with Cd+Pb showed a synergistic effect,which facilitated nitrogen metabolism of rice,but posed no apparent impact on carbon metabolism.However,high concentration of MWCNTs-COOH combined with Cd+Pb exhibited an antagonistic effect,which restrained rice growth,reduced the generation of photosynthates,and thus markedly inhibited carbon and nitrogen metabolism.In addition,MWCNTs-COOH either alone or in combination with Cd+Pb caused the increase in free amino acid and soluble protein contents,which was helpful for rice seedlings to resist adverse stress.

This study was carried out to understand the effect of different light quality treatment on the growth,photosynthesis and antioxidant enzyme activities of tomato seedlings in artificial light plant factory.The trial was conducted at a light intensity of 200 μmol/(m²·s),with blue LED light(B)as control.Green light(G),red light(R),far red light(Fr),or ultraviolet light(UV)with consistent light intensity was added on the basis of blue light to clarify the growth,photosynthetic and antioxidant enzyme activities of tomato seedlings under different light quality combinations.The results showed that compared with control,the height of tomato seedlings under B+Fr treatment was significantly improved,increased by 34.54%.B+R treatment significantly increased the stem diameter and dry and fresh weight of tomato seedlings by 39.27%,25.58% and 22.20%,respectively compared with B.The intercellular CO₂ concentration and stomatal conductance(Gs)of tomato seedlings under B+G treatment were higher than other treatments.Besides,B+R treated seedlings had the highest effective photochemical quantum yield of PS Ⅱ,the actual photochemical quantum yield of PSⅡ and the photochemical quenching coefficient,increased by 4.30%,0.97% and 1.87%,respectively compared with the control.Furthermore,B+G,B+R treatment significantly increased the antioxidant enzymes activity,and significantly decreased the content of malondialdehyde(MDA),reactive oxygen species and hydrogen peroxide in tomato seedlings.Thereinto,MDA content of B+R treated seedlings was 50.64% lower than B treatment,while SOD,POD and APX activities were 15.44%,25.00% and 21.65% higher than B treatment,respectively.Taken together,B+R treatment was not only conducive to the cultivation of strong tomato seedlings,but also helped improving PSⅡ activity of leaves,thus enhancing photosynthetic performance.Meanwhile,B+R light treatment could also maintain a high level of antioxidant enzyme activity in tomato plants and improved the antioxidant capacity of tomato plants.

In order to investigate the effects of salt stress on the growth,development and quality of facility cucumbers,salt treatment was carried out on Zhongnong 126 cucumber in the multi-storey glass greenhouse of Vegetable Research Center of Beijing Academy of Agriculture and Forestry Sciences from 2023 to 2024.Four treatments of 0(control),25,50 and 100 mmol/L NaCl were added into the nutrient solution to analyze the effects of different concentrations of NaCl treatment on growth and development,photosynthetic characteristics,antioxidant enzyme activity,fruit quality and yield of cucumber.The results showed that with the increase of NaCl concentration,cucumber plant height decreased,stem diameter had no significant difference,and leaf area decreased.Leaf photosynthetic pigment content,Net photosynthetic rate(Pn), stomatal conductance(Gs), transpiration rate(Tr), maximum photochemical efficiency(Fv/Fm),photochemical quenching coefficient(qP)decreased gradually. Intercellular CO₂ concentration(Ci)gradually increased; Non-photochemical quenching coefficient(NPQ) increased first and then decreased, and was highest under T2 treatment. The activities of Superoxide dismutase(SOD), peroxidase(POD), catalase(CAT)increased and then decreased.Except SOD,the activities of POD and CAT were the highest at 25 mmol/L NaCl concentration,which were 38.73% and 95.18% higher than CK,respectively.The content of H₂O₂ increased gradually.With the increase of NaCl concentration,the melon length shortened and the melon head pointed,and the fruit deformity rate increased.The vitamin C content increased first and then decreased, and it performed best under T1 treatment, which was significantly better than the control group. There was no significant difference in soluble solid content among different treatments.Salt treatment significantly reduced the yield of cucumber by 38.89%-81.35% compared with control.Based on the comprehensive evaluation of yield and quality,it is suggested that Zhongnong 126 cucumber should be treated with 25 mmol/L NaCl,which can significantly improve fruit quality.Subsequent research will focus on optimizing cultivation techniques,improving plant salt tolerance while ensuring quality,achieving yield improvement,and providing technical support for high-quality cucumber production.

Malus sieversii M.Roem.exhibits exceptionally high genetic diversity,and the red-fresh apple is considered a variety within this species.It investigated the antioxidant activity of red-fresh apple fruits during ripening and postharvest storage,as well as the changing trends in antioxidant enzyme activities,aiming to provide a reference for the exploitation and utilization of M.sieversii and the selection and breeding of functional apples.Using Huashuo as a control,the contents of total phenols,total flavonoids,and free radical scavenging capacity in four red-fresh apple varieties were studied,along with the activity trends of related antioxidant enzymes during storage.The results showed that the total phenol and total flavonoid contents in the four red-fresh apple resource fruits ranged from 1.42-3.12 mg/g and 19.36-64.81 μg/g,respectively,which were significantly higher than those of the control Huashuo,with Ke showing extremely significant differences.The free radical scavenging capacity was higher than that of the control group,but the difference was not statistically significant.A significant positive correlation was observed between total phenols and total flavonoids,as well as between total phenols and 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt(ABTS),and between total flavonoids and ABTS.Throughout the storage period,the activities of polyphenol oxidase,superoxide dismutase,and catalase in Ke were higher than those in the other varieties.Ke can be used as a functional apple parent material for breeding offspring with high antioxidant capacity,thereby facilitating the development and utilization of germplasm resources in M.sieversii.

The purpose is to analysis the fruit quality and fruit cracking characteristics of Xinjiang self-bred grape varieties under the application of plant growth regulator.The table grapes Xinyu and Xinya bred by research institute of grapes and melons of Xinjiang uygur autonomous region were selected as experimental materials,and 5 mg/L GA₃+5 mg/L 6-BA were sprayed at the veraison period,setting the veraison period and spraying once(T1),twice(T2),three times(T3)every 14 days.The optimal spraying scheme was screened out by measuring the basic indexes of grape fruit quality and fruit cracking rate.The contents of grape skin cell wall components(pectin,protopectin,cellulose,hemicellulose)and the activities of PG,PEP,PL,CE were determined by ELISA kit,and the relative expression of PG,PEP,PL,CE genes were detected by Real-time Quantitative PCR.At the T3 treatment,the content of fructose and glucose components increased significantly,the content of tartaric acid and malic acid decreased significantly,the solid-acid ratio increased significantly,and the fruit cracking rate decreased by 40.7,24.0 percentage points respectively.Compared with the control group from the late verasion to the harvest period,the activities of PG,PEP,PL and CE metabolism-related enzymes and the expression levels of corresponding related genes decreased,and the content of pectin,protopectin,cellulose and hemicellulose cell wall components increased,thus affecting the fruit cracking rate.In conclusion,the fruit quality was improved by spraying of GA₃+6-BA three times after veraison period,at the stage of 100% colored berries,inhibited the enzyme activities PG,PME,PL by reducing PG,PL gene expression,then enhanced the production of protopectin,at the stage of 100% colored berries and the harvest period,inhibited the enzyme activities CE by reducing CE gene expression,then enhanced the production of hemicellulose.While the content of protopectin and hemicellulose increase stabilized the cell wall structure,enhanced the mechanical properties of peel and reduced the fruit cracking rate.

In order to investigate the differences of phenolic substances in wine grape berries and wines at different harvesting periods,three maturity levels (23,25 and 27 °Brix) were set as harvesting periods for Beimei wine grape berries in the eastern foothills of the Helan Mountains in Ningxia,and the basic physical and chemical indexes and phenolic substance contents of berries and wines were analyzed by transcriptome sequencing.Physicochemical indexes and phenolic content were measured,and transcriptome sequencing analysis was performed on the fruit at 23 and 25 °Brix.The results showed that the 100-grape weight and titratable acid content of Beimei fruits decreased with the prolongation of the harvesting period,while the total soluble sugar,tannin,anthocyanin,total phenol content and sugar-acid ratio showed an increasing trend,with significant differences in different periods.The alcoholic content,total phenol and tannin content of wines also increased with the prolongation of harvest period,and the titratable acid,volatile acid and anthocyanin content varied with different periods.Acid,volatile acid and anthocyanin content did not change much;the phenolic acid and flavonol content of grape berries and wine showed an overall increasing trend with the prolongation of the harvest period,and the flavanol content fluctuated and changed,which was the main phenolics,reaching the maximum value at T2 and W2.Transcriptomic analysis revealed 1 316 DEGs,including 598 upregulated and 718 downregulated genes.KEGG pathway analysis revealed that the differentially expressed genes (DEGs) were primarily enriched in four pathways associated with phenolic compound biosynthesis,which are flavonoid biosynthesis,phenylalanine metabolism,phenylpropanoid biosynthesis and flavonoid and flavonol biosynthesis,among which PAL and CHS were the main differentially expressed genes.In summary,as the harvest period extends,the quality of grape fruit and wine improves,the content of phenolic compounds increases,and the expression of PAL and CHS was up-regulated,providing a theoretical basis and foundation for the selection of raw materials for brewing different types of wine and the mining of genes related to phenolic synthesis.

By studying the quality and antioxidant capacity of strawberries irrigated with hydrogen-rich water(H)and ordinary water(CK),the influence of hydrogen-rich water on improving strawberry quality and prolonging strawberry preservation period was revealed,which provided a reasonable basis for effectively reducing the use of chemical fertilizers and pesticides and improving strawberry taste quality and food safety.Taking Jijiu and Yuzhu strawberries as materials,the roots of strawberries were irrigated with hydrogen-rich water and ordinary water respectively.The contents of soluble solids,titratable acid,fructose,glucose,sucrose,vitamin C and the activities of protective enzymes superoxide dismutase(SOD)and catalase(CAT)were measured,the morphological characteristics of roots and leaves,chlorophyll content and photosynthetic rate of leaves were measured respectively.The results showed that the contents of soluble solids,titratable acid,sucrose and vitamin C in strawberry fruit treated with hydrogen-rich water were significantly higher than those treated with ordinary water,and random forest analysis showed that titratable acid,sucrose and vitamin C were the main factors affecting the soluble solids of strawberry.The length,volume,surface area,diameter,root tip number,leaf length,width,leaf area,chlorophyll and photosynthetic rate of strawberry treated with hydrogen-rich water were significantly higher than those treated with ordinary water.The activities of CAT and SOD in strawberries stored at 25 ℃ were significantly higher than those at 4 ℃,and the activities of enzymes in strawberries treated with hydrogen-rich water were significantly higher than those in ordinary water treatment.With the extension of strawberry storage time,the activity of CAT first increased and then decreased,and reached the highest on the third day,while the activity of SOD did not change significantly with the extension of storage time.The above results showed that hydrogen-rich water can improve the taste and quality of strawberries,prolong the fresh-keeping period and shelf life of strawberries,and achieve the purpose of improving quality and increasing efficiency.

To explore the physiological and biochemical characteristics of cut peony under NaCl stress,the flower branches of the cut peony variety Shirley Temple with the first level of flowering series as the test material were treated with different concentrations of NaCl(0,0.2%,0.4%,0.6%)by hydroponics method.The phenotype changes of the flower branches were observed,and the corresponding physiological and biochemical reactions were measured by DAB and NBT staining,so as to understand the salt tolerance potential of the cut peony Shirley.To explore the salt tolerance mechanism of cut flower peony.The results showed that there was no significant change in branch phenotype of peony Xiulan under 0.2% salt stress,the leaf became slightly yellowed and curled under 0.4% salt stress,and the leaf curled and wrinkled under 0.6% salt stress.Under salt stress,leaf water content and chlorophyll content decreased significantly with the increase of salt concentration.Electrolyte permeability and proline content were significantly increased.The accumulation of reactive oxygen species($\mathrm{O}^{\bar{.}}_{2}$ and H₂O₂)and the activity of various antioxidant enzymes were significantly up-regulated under high concentration salt stress.In summary,0.2% salt stress had little effect on Xiulan,but 0.4% and above salt concentration exceeded the tolerance range of Xiulan.The cut peony Xiulan can cope with salt stress mainly by increasing the content of osmoregulatory substances and antioxidant enzymes.

A field experiment was conducted from 2023 to 2024 to investigate the response of silage yield in different types of summer maize varieties to various planting patterns.Two varieties,Cangyu 338(CY338,a low-density tolerant variety)and Nongda 372(ND372,a density-tolerant variety),were selected as experimental materials.Four planting patterns were established,including conventional mode(CT),1∶1∶2 mode(1∶1∶2),double plant mode(DP),and 40+80 mode(40+80).Results showed that the dry weight(dry yield)of maize plants and whole ears increased gradually,while the fresh weight(fresh yield)declined during the maize growth period.Significant differences in dry and fresh weight,as well as yield,were observed among the different planting patterns.The dry and fresh weight showed as follows:CT>40+80>1∶1∶2>DP,however,higher plant yield was achieved under DP and 1∶1∶2 patterns.The highest whole ear yield was obtained under CT in 2023 and DP in 2024,followed by the 1∶1∶2 pattern.Additionally,there were significant annual variations in whole ear yield.Dry and fresh weight per plant and whole ear of CY338 were higher than those of ND372,whereas the yield exhibited the opposite trend.A similar changing trend was observed across different years.The response of dry and fresh weight per plant and whole ear to planting patterns indicated that CT resulted in the highest values,while DP yielded the lowest.Except for the dry and fresh weight per plant of ND372 in 2023 under other planting patterns,the 40+80 pattern generally produced higher dry and fresh weights compared to the 1∶1∶2 pattern.In contrast to dry and fresh weight,variety yield exhibited significant variations.The lowest yield for both plant and whole ear was observed under the 40+80 pattern.However,plant yield under the DP and 1∶1∶2 patterns exceeded that of other patterns.Notably,the DP pattern achieved the highest yield,except for ND372 in 2023,which experienced higher precipitation during the experiment.For CY338 in 2024,a year with less precipitation,the DP pattern yielded the highest whole ear production,followed by the 1∶1∶2 pattern,while other varieties showed the highest yield under the CT pattern.In conclusion,planting patterns significantly influence plant and ear characteristics.Corn varieties with high-density tolerance can achieve increased plant and whole ear silage yields.The DP pattern is particularly effective for enhancing plant silage yield(with the 1∶1∶2 pattern being suitable for density-tolerant varieties in rainy years),while the CT pattern is more effective for whole ear silage yield(with the DP pattern being advantageous for low-density-tolerant varieties in the years with less rainfall).

It is of great significance to study the effects of brackish water sprinkler irrigation on the growth and yield of summer maize to alleviate the shortage of fresh water resources,promote the utilization of unconventional water resources and guarantee the production of summer maize.Field trial was conducted for two consecutive years in the central plain area of the Heilonggang Basin,Hebei Province.It aimed to investigate the effects of three sprinkler irrigation treatments(fresh water,2 g/L brackish water,and 3 g/L brackish water)on root distribution,photosynthetic performance,and grain yield in summer maize.Results showed that the average dry root weight density of 0-60 cm soil layer in the whole growth period of 2 g/L brackish water sprinkler irrigation was reduced by 7%-9% than fresh water irrigation but with no significant difference,and the average root dry weight density of 3 g/L brackish water sprinkler irrigation was significantly reduced by 19%-26%.Compared with fresh water irrigation,the 2,3 g/L brackish water sprinkler irrigation both had adverse effects on the photosynthetic characteristics of leaves,especially the 3 g/L brackish water sprinkler irrigation,the net photosynthetic rate,stomatal conductance and light use efficiency were significantly reduced by 29%-37%,40%-49% and 29%-35%,respectively,which seriously affected the photosynthetic capacity of the leaves.In 2020,the leaf area index of 2 g/L brackish water sprinkler irrigation was reduced by 15% compared with that of fresh water sprinkler irrigation but with no significant difference,and the leaf area index of 3 g/L brackish water sprinkler irrigation was significantly reduced by 28%.In 2021,there was no significant difference in leaf area index between different treatments during the whole growing period.There was no significant difference in plant height between different treatments during the whole growth period of two years.2 g/L brackish water sprinkler irrigation had no significant effect on yield of summer maize in both years,and the yield of 3 g/L brackish water sprinkler irrigation was significantly reduced by 9% in 2020.No significant differences were observed in ear count,kernel number per ear,or 100-grain weight across the irrigation treatments.In summary,the salinity of brackish water sprinkler irrigation less than 2 g/L can guarantee the growth and yield of summer maize in this area.

It is important for agricultural production to study the spatial and temporal distribution of winter wheat drought in Hebei Province.Based on the meteorological observation data of 119 national meteorological stations in Hebei Province during the growing period of winter wheat from 1991 to 2021,based on the national standard of"Meteorological Drought Grade"(GB/T 20481-2017),we calculated the meteorological drought composite index(MCI)and analyzed the spatial and temporal distribution characteristics of winter wheat drought in Hebei Province in recent 30 years.The results showed that:the frequency of drought decreased gradually with the drought grade from light drought to extreme drought.The average frequency of light drought occurrence in different growth stages of winter wheat in Hebei Province ranges from 22.1% to 22.5%.The average frequency of medium drought occurrence ranges from 11.7% to 14.5%.The average frequency of heavy drought occurrence ranges from 3.6% to 5.5%.The average frequency of extreme drought occurrence ranges from 0.4% to 1.0%.During the whole growth period,the areas with relatively high frequency of occurrence of medium drought and above were mainly distributed in most parts of Hengshui,west and south of Cangzhou,east of Xingtai,and east of Handan,and the frequency of occurrence was more than 20.25%.From 1991 to 2021,the drought intensity and range of winter wheat in Hebei Province showed a significant decreasing trend in the middle and later stages of growth.

It aims to evaluate the storage tolerance of 20 popular wheat varieties from the Huang-Huai wheat region under natural aging conditions and classify them,thereby providing a theoretical basis for the breeding and selection of storage-tolerant wheat varieties.The experiment involved natural aging treatments of 12 and 24 months,with seeds harvested 3 months prior serving as the control.Measurements included seed vigor,seed coat characteristics(color and cell membrane integrity),and physiological and biochemical indicators(soluble sugar,gluten protein,starch content,antioxidant enzyme activity,and malondialdehyde content).The results indicated that as aging time increased,seed vigor of all varieties significantly declined.Germination rate and germination potential decreased by 2.17-10.79 percentage points and 2.80-23.39 percentage points,respectively,after 12 months,and further declined by 15.95-25.88 percentage points and 14.93-41.44 percentage points after 24 months.The hue,saturation,and intensity of seed coat color decreased,while electrical conductivity increased,indicating gradual damage to the seed coat cell membrane.Among the physiological and biochemical indicators,except for malondialdehyde,soluble sugar,protein,starch content,and antioxidant enzyme activity all showed a declining trend,with greater declines observed after 24 months compared to 12 months.Total starch content exhibited the most significant decrease,declining by 6.43-32.13 percentage points and 21.02-44.95 percentage points after 12 and 24 months,respectively.Based on indicators such as germination rate,seed coat color,electrical conductivity,soluble sugar,and antioxidant enzyme activity,the 20 wheat varieties were classified into storage-tolerant,moderately storage-tolerant,and non-storage-tolerant types.Among them,Annong 0711,Luohan 19,and Xinmai 26 demonstrated strong storage tolerance.The findings provide parental materials,evaluation criteria,and theoretical references for the breeding of storage-tolerant wheat varieties.

Waterlogging stress severely impacts soybean production.To investigate the effects of waterlogging stress on soybean growth and development and elucidate its response mechanisms,this study employed four soybean germplasms cultivated in the Huaibei region as experimental materials.Through simulated waterlogging treatment at the V2 stages,combined with yield analysis,physiological indices,and transcriptomic profiling,the study explores the waterlogging tolerance mechanisms in soybean.The results demonstrated that waterlogging stress significantly reduced dry matter accumulation and nitrogen uptake efficiency in the waterlogging-sensitive cultivar Xudou 18,resulting in a yield loss of 30.23%.In contrast,the waterlogging-tolerant cultivar Huaidou 13 exhibited stronger adaptability with only a 16.77% yield loss,attributed to stabilized root nitrogen absorption and maintained root dry matter accumulation.Transcriptomic analysis revealed that differentially expressed genes(DEGs)in Huaidou 13 under waterlogging stress were significantly enriched in pathways that related to the biosynthesis of secondary metabolites,photosynthetic systems,and antioxidant activity.Conversely,DEGs in Xudou 18 were predominantly associated with hormone transduction,photosynthesis,and peroxisome-related pathways.A total of 148 genotype-specific DEGs were identified between cultivars with contrasting waterlogging tolerance,primarily enriched in photosynthesis,secondary metabolite biosynthesis,and fatty acid metabolism.Identified transcription factors included members of the AP2/ERF-ERF,C3H,ARR-B,NAC,and WRKY families.In summary,transcription factors or genes in secondary metabolic pathways that may be related to waterlogging tolerance were screened.

Drought during the grain filling period can seriously affect the later growth and development of foxtail millet plants,as well as the morphogenesis,yield,and quality of grains.To analyze the effects of drought during the grain filling period on the later growth and development of foxtail millet,as well as the morphogenesis of grains,and to provide a theoretical research basis for the molecular mechanism of foxtail millet starch regulation in response to drought stress,it investigated the effects of different degrees of drought during the grain filling period on the agronomic and grain quality traits of foxtail millet using Jingu 21 as the material.Simultaneously,Real-time Quantitative PCR was used to analyze the response of key genes SiAGPase1(Glucose pyrophosphorylase)and SiSSS1(Starch synthase)to drought during starch synthesis.The results showed that drought had significant effects on fresh weight per plant,fresh weight per root,fresh weight per panicle,panicle weight,grain weight per spike,grain weight per thousand grains,main stem diameter,subpanicle internode length,chlorophyll content,seed setting rate,spike code density and other agronomic characters.The more severe the stress,the greater the degree of reduction.The analysis of grain composition showed that drought can reduce the content of fat,crude protein,peak viscosity and final viscosity.The more severe the stress,the greater the reduction degree.Gene expression analysis showed that the expression levels of SiAGPase1 and SiSSS1 changed sharply during the grain filling period under drought stress.The results revealed that SiAGPase1 and SiSSS1 played an active role in regulating the balance between starch decomposition and starch accumulation in grains under drought stress in order to adapt to plant response to drought stress.

To explore the disparities in overwintering rates and yields between Brassica napus L.and Brassica rapa L.in the cold and arid regions of the north,as well as to examine the correlation between diverse agronomic traits,yield,and cold resistance-enhancing traits,it utilized 45 B.napus L.and 22 B.rapa L.varieties as subjects.It conducted a statistical analysis of their overwintering rates,average yields and agronomic traits.It also studied seeding density experiments with B.napus L.and B.rapa L.varieties that exhibited similar yield levels,compared root traits between B.napus L.and B.rapa L..The results indicated that among the 67 varieties tested,the average overwintering rate of B.rapa L.(97.59%) was significantly higher than that of B.napus L.(65.87%).The average yield potential of B.napus L.was higher than that of B.rapa L..For B.rapa L.,which was capable of stable overwintering,increasing the seeding density significantly elevated the number of effective plants but did not augment the average yield.Conversely,for B.napus L.,its lower overwintering rate constrained the increase in the number of effective plants,thereby limiting the average yield.B.napus L.with a high overwintering rate exhibited agronomic traits such as higher branching positions and angular density,fewer secondary branches,total branches,and effective siliques per plant after overwintering.Comparison of root traits between B.napus L.and B.rapa L.showed that enlarged root systems,short hypocotyls,and growth points positioned below the ground surface were advantageous traits contributing to the robust cold resistance of B.rapa L..It proposes that breeding density-tolerance B.napus L.with root traits akin to those of B.rapa L.and with growth points situated below the ground surface represents a pivotal breeding direction for enhancing the overwintering rate of B.napus L.,fostering increased rapeseed yield,and ensuring oil supply stability.

The study aimed to examine the differences in physiological responses to NaCl between these two sweet cherry scion-rootstock combinations,explore the physiological mechanisms governing how different sweet cherry scion-rootstock combinations respond to salt stress,and provide a basis for screening salt-tolerant rootstocks and cultivating sweet cherries in saline-alkali soils.One-year-old plants of the sweet cherry cultivar Meizao(M) grafted onto Gisela 6 (G6) and Colt (KT) rootstocks were used as experimental materials.A pot culture experiment was conducted to simulate NaCl stress,with determinations made on the contents of osmotic adjustment substances,activities of antioxidant enzymes,and photosynthetic gas exchange parameters.The results showed that NaCl treatment promoted the accumulation of osmotic adjustment substances such as soluble sugar,soluble protein,and proline in the leaves of the two sweet cherry scion-rootstock combinations.With the increase in NaCl treatment concentration,the soluble sugar content of M/G6 increased first and then decreased,while that of M/KT continued to increase.Under the 150 mmol/L NaCl treatment,the increase in proline content of M/KT (6.11 times) was significantly higher than that of M/G6 (1.74 times).The contents of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) increased with the increase in NaCl treatment concentration.However,the peroxidase (POD) activity of M/G6 reached its peak at 100 mmol/L,which was significantly higher than that of M/KT.With the increase in NaCl treatment concentration,the net photosynthetic rate (Pn) and stomatal conductance (Gs) of the leaves of the two sweet cherry scion-rootstock combinations gradually decreased,while the intercellular CO₂ concentration (Ci) gradually increased.Non-stomatal limitation was the main factor for the decrease in Pn of the leaves of the two scion-rootstock combinations.M/G6 showed better salt tolerance under moderate salt stress (100 mmol/L),alleviating oxidative damage by relying on the accumulation of soluble sugar and the enhancement of POD activity.M/KT maintained osmotic balance through the accumulation of proline and the increase in SOD activity under high salt stress (150 mmol/L).Based on comprehensive evaluation,in actual production,M/KT can be considered as a reference option for slightly saline soil,and M/G6 is recommended for moderately saline soil.

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

In order to explore the effects of different canopy light environments on apple mesophyll conductance and its key parameters and photosynthetic biochemical parameters,the open-center Fuji apple trees were used as experimental materials.The canopy light environment,photosynthetic biochemical parameters and leaf tissue structure of apple trees were measured after thinning,and the apple trees without thinning were used as controls(CK).Results showed that,the peak and mean value of daily maximum and averaged photosynthetically active radiation(PAR)increased by 23%,166%,and 43%,123%,respectively.Compared to the CK,product of light absorption coefficient and light energy partitioning ratio(α·β)and dark respiration rate under light(R_d)of treatment increased by 84.62%,56.00% respectively,while apparent CO₂ compensation point(C_i^*)value decreased by 6.67%.The average value of mesophyll conductance(g_m)calculated by quantitative α·β value was 9.89% higher than that of the CK,and the maximum and average values of mesophyll conductance(g_m')calculated by empirical α·β value(0.425)were 20.65%,39.38% higher than those of the CK,respectively.The g_m ' of the treatment and the CK was higher than that of the g_m,and the g_m' of the treatment and the CK was 54.33%,21.67% higher than the average value of the g_m,respectively.V_cmax derived from P_n-C_i(neglecting mesophyll conductance),P_n-C_c'(using empirical α·β)and P_n-C_c(using quantified α·β)response curves demonstrated significant differences(V_cmax-Ci and V_cmax-Cc' underestimated by 40.59%,19.85% in comparison with V_cmax-Cc in treatment,respectively),and treatment was significantly higher than CK(V_cmax-Ci,V_cmax-Cc' and V_cmax-Cc increased by 11.21%,5.85%,10.69%,respectively);J_max and V_tpu were similar to V_cmax.The anatomical structures of leaves showed that the mean values of palisade tissue(PT)thickness and spongy tissue(ST)thickness of thinning treatment significantly increased respectively by 43.95%,43.31%,in comparison with those of the CK.The area and perimeter of PT and ST in thinning treatment were respectively 43.60% and 310.86% with 34.73% and 115.82% higher than those in CK.In summary,after thinning treatment,the light condition of apple canopy was improved,the leaf structure was changed,and the photosynthetic efficiency of the plant was improved.

This study aimed to investigate the impacts of three exogenous amino acids on the growth and development of tomato seedlings under high-temperature stress.Tomato seedlings were selected as the study material.The normal temperature treatment with clean water at 25 ℃/18 ℃(day/night)and the high-temperature treatment with clean water at 40 ℃/30 ℃(day/night)served as control and heat groups,respectively.Under high-temperature,tomato seedlings were sprayed with 5 mmol/L γ-aminobutyric acid(GABA),0.2 mmol/L 5-aminolevulinic acid(ALA),and 5 mmol/L Proline(Pro)on the leaves once every seven days for two times.Growth parameters,antioxidant enzyme activities,and physiological parameters were determined.The results indicated that the plant height,stem diameter,and biomass accumulation of tomato seedlings was significantly reduced under high temperature.Compared with heat treatment,spraying GABA,ALA,and Pro significantly enhanced the plant height and stem thickness of tomato seedlings,promoted root development,increased biomass accumulation and relative growth rate under high-temperature.Moreover,the chlorophyll content and net photosynthetic rate of tomato seedlings declined remarkably.The chlorophyll content in the ALA treatment was higher than that in other treatments,while the net photosynthetic rate in the GABA treatment was the optimal.Compared with heat treatment,spraying GABA and ALA significantly augmented the activities of superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT).High-temperature stress substantially elevated the relative electrical conductivity(REC)and malondialdehyde(MDA)content of leaves.Meanwhile,the leaves treated with Pro exhibited the lowest REC and MDA content,nearly returning to the level of control treatment.The outcomes of cluster and principal component analyses revealed that the GABA and ALA treatments mainly enhanced the photosynthetic rate and promoted plant growth by coordinately regulating the chlorophyll content and antioxidant enzyme activities of tomato seedlings,thereby strengthening the capacity to resist high-temperature stress.In contrast,Pro treatment effectively regulated the leaf's osmotic pressure by reducing leaf relative conductivity and MDA content.

To address issues such as shallow soil layers,upward movement of the plowpan,and soil salinization in the saline-alkali soils of the West Liaohe Plain,field trials were conducted in Huatugula Town,Horqin Zouyi Middle Banner,Tongliao City,Inner Mongolia Autonomous Region,from 2020 to 2021.Two tillage methods(traditional rotary tillage and powder ridge plowing),two irrigation quotas(2 100,2 700 m³/ha),and mulching and shallow burial measures were set up,resulting in six experimental treatments:2 100 m³/ha irrigation quota+traditional rotary tillage+shallow burial(CK×NM),2 100 m³/ha irrigation quota+traditional rotary tillage+mulching(CK×DM),2 100 m³/ha irrigation quota+powder ridge plowing+shallow burial(FA×NM),2 100 m³/ha irrigation quota+powder ridge plowing+mulching(FA×DM),2 700 m³/ha irrigation quota+powder ridge plowing+shallow burial(FB×NM),2 700 m³/ha irrigation quota+powder ridge plowing+mulching(FB×DM).The effects of powder ridge plowing and mulching treatments on soil properties,structure,saline and alkaline content,and maize yield in the 0—40 cm soil layer under different irrigation quotas were analyzed. The result showed that compared to the CK×NM treatment, in the 0—40 cm soil layer, the soil bulk density decreased by 8.4%—22.9%, the total soil porosity increased by 4.9—14.8 percentage points, and the soil three-phase ratio R value decreased by 34.6%—88.2% under powder ridge plowing + mulching treatment,among them, the bulk density, total porosity, and three-phase ratio R value of the soil treated with FB×DM treatment were significantly reduced by 20.0%,-13.1 percentage points, and 88.2%, respectively;soil moisture content after sowing increased by 5.5—12.1 percentage points in the 20—40 cm soil layer, soil hardness increased by 33.4%—397.5% in the 7.5—17.5 cm soil layer,among them, the soil moisture content, hardness of the FB×DM treatment increased significantly by 12.1 percentage points, 214.3%,respectively;CO₂ flux of the FB×DM treatment increased significantly by 496.4%.Compared to the CK×NM treatment, the powder ridge plowing+mulching treatment reduced the soil pH value, total alkalinity, electrical conductivity, and total salt content in the 0—40 cm soil layer, with reduction rates of 0.7%—10.9%, 2.5%—67.5%, 24.3%—68.7%, and 10.3%—81.0%, respectively. Among them, the soil pH value, total alkalinity, electrical conductivity, and total salt content of the FB×DM-treated soil were significantly reduced by 10.9%, 48.2%, 59.2%, and 80.0%, respectively.Maize germination rate, ear fresh weight, and yield were increased by 13.2—20.1 percentage points,52.5%—68.2%, and 22.4%—45.5%, respectively,among them, the germination rate, ear fresh weight, and yield of the FB×DM treatment were significantly increased by 20.1 percentage points,68.2%, and 45.5%, respectively, compared to the CK×NM treatment. Considering the comprehensive improvement effects and maize yield, it is concluded that the 2 700 m³/ha irrigation quota+powder ridge plowing+mulching(FB×DM) is a more suitable cultivation mode for saline and alkaline land in the West Liaohe Plain.

To investigate the effects of delayed sowing on the growth,development,grain yield and quality of wheat,Yunong 907(YN907)and Yunong 922(YN922),two new high yield and high quality wheat varieties,were selected as experimental materials.Three sowing dates were established:October 22nd(S1,the conventional sowing date),October 31st(S2,delayed sowing by 9 days),and November 9th(S3,delayed sowing by 18 days).The study investigated the effects of delayed sowing on the phenological stages,grain yield and flour quality of wheat,and analyzed the relationship between temperature characteristics and wheat yield,and quality under delayed sowing conditions.The results indicated that compared with the conventional sowing date, the full growth period of YN907 and YN922 was shortened with the delay of sowing date in both years. The accumulated temperature before winter and the average daily temperature before heading decreased with the delay of sowing date, while the average daily temperature and effective accumulated temperature after heading increased. The effective accumulated temperature of the full growth period showed a downward trend. The effective accumulated temperature of the full growth period of YN907 and YN922 in S3 treatment was 243.95,222.10 ℃·d lower than that in S1 treatment in 2022—2023, and 136.30,189.40 ℃·d lower in 2023—2024, respectively. The yield and its components decreased with the delay of sowing, with a yield reduction of 6.45% to 17.26%. Compared with the conventional sowing date, the wet gluten content and protein content increased under the delayed sowing conditions.Under the background of climate warming and the scale-up of the agricultural operation,the sowing date of wheat can be adjusted to adapt to the temperature change.YN907 and YN922 had the highest yield on October 22nd.Delaying the sowing date to October 31st could maintain the higher yield level and increase the grain protein content.When the sowing date continues to be postponed,the grain protein content will be significantly increased but the yield will be significantly decreased.

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

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

The aim of this study was to investigate the relationship between calcium uptake,indoleacetic acid(IAA)and organic acid metabolism during the development and ripening of Cerasus humilis fruits,in order to provide a basis for further research and applications of Cerasus humilis.The high calcium and low calcium Cerasus humilis fruits from Inner Mongolia were taken as the experimental materials.Samples were taken at different stages of fruit development and ripening,including the young fruit stage(S1),hard kernel stage(S2),coloring and enlargement stage(S3),hard ripening stage(S4),and fully ripe stage(S5),this study investigated the changes of calcium uptake capacity,IAA,and organic acid metabolism,and carried out correlation analysis.The results indicated that the uptake capacity of water-soluble calcium continuously increased throughout the development and ripening of Cerasus humilis fruits,with a marked rise in uptake activity,uptake rate,and uptake amount at the fully ripe stage;the uptake capacity of calcium pectin was higher from the young fruit stage to hard kernel stage but declined in the later stages of fruit development,with a significant reduction in uptake activity,uptake rate,and uptake amount at the fully ripe stage;the uptake capacity for active calcium and total calcium followed trends similar to those observed for calcium pectin.During fruit development and ripening,the IAA content in Cerasus humilis fruits showed a pattern of initially increasing and then decreasing,with significantly higher levels during the the young fruit stage and hard kernel stage compared to other stages.The activity of NAD-MDH,as well as malic acid content and organic acid total content,generally increased,peaking at the hard ripening stage.The activity of NADP-ME declined overall,while citric acid content increased initially and then decreased,reaching its highest point at the hard kernel stage.Correlation analysis revealed varying degrees of correlation between IAA content,organic acid metabolism indicators,and the uptake capacity of different calcium forms in high-calcium and low-calcium Cerasus humilis fruits.Specifically,IAA content was positively correlated with the uptake capacity of total calcium;the activity of NAD-MDH,malic acid content,and organic acid total content was negatively correlated with total calcium uptake capacity;while the activity of NADP-ME and citric acid content was positively correlated with total calcium uptake capacity.During the development and ripening of Cerasus humilis fruits,calcium uptake is associated with IAA content and organic acid metabolism.High levels of IAA and citric acid contents during the early stages of fruit development significantly promote calcium uptake,whereas enhanced malic acid synthesis and metabolism in the later stages of fruit development inhibits calcium uptake.

To improve the growth,yield,and quality of cantaloupe under extreme high temperature weather in Turpan,Xinjiang,the effects of spraying prohexadione-calcium(PCa)on the physiological growth of cantaloupe under high temperature stress were investigated,distilled water(CK)and PCa with concentrations of 20(PCa1),50(PCa2),100(PCa3),150 mg/L(PCa4)were sprayed on cantaloupe leaves.Through comprehensive analysis of indicators such as photosynthesis,reactive oxygen species content,antioxidant enzymes,antioxidant substances,vine length,stem thickness,yield,and quality of cantaloupe under high temperature stress,the optimal concentration of PCa suitable for foliar spraying of cantaloupe in the region was found.The results showed that as the concentration of PCa increased,the chlorophyll a,chlorophyll b, $\mathrm{O}_{2}^{-}$,H₂O₂,and stem diameter of cantaloupe gradually increased at different stages,with increases of 9.25%-36.29%,4.25%-49.92%,21.45%-334.55%,5.36%-109.41%,and 2.33%-20.69% compared to CK,respectively;and MDA gradually decreased,with a decrease of 7.37%-48.83% compared to CK,respectively.Spraying PCa increased photosynthesis and reactive oxygen species in cantaloupe under high temperature stress,reducing the damage of high temperature to cantaloupe biofilm.PCa1,PCa2,and PCa3 treatments increased the levels of soluble protein,soluble sugar,PRO,SOD,POD,AsA,GSH,yield,soluble solids content,and soluble sugar content of the fruit in cantaloupe under high temperature stress compared to CK.Among the three treatments,PCa2 treatment showed better performance in terms of various indicators.Spraying PCa at an appropriate concentration significantly improved the osmotic regulation substances,antioxidant enzymes,antioxidant substances,and yield and quality of cantaloupe under high temperature stress,enhanced its heat resistance,and achieved increased yield and quality of cantaloupe.Although PCa4 treatment increased the yield of cantaloupe,it reduced the content of soluble solids and soluble sugars in the fruit.High concentrations of PCa delayed the growth of cantaloupe and affected its quality at harvest.Therefore,PCa2 treatment in production is the best treatment to achieve heat resistance,yield increase,and quality improvement of cantaloupe under high temperature stress.It is recommended that the optimal concentration for spraying PCa in this area is 50 mg/L.

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

In order to investigate the effects of different mulching measures on soil moisture and heat status and yield of winter wheat in northwest dry area,winter wheat Kangzhuang 974 was used as test material.From September 2022 to July 2023,three different coverage treatments including wheat straw strip covering three rows(M3),four rows(M4)and five rows(M5)and plastic film covering(PM)treatment were set up in the experimental base of Gansu Agricultural University,The open field(CK)was used as the control.The results showed that:compared with CK,the soil water storage of 0—200 cm during the whole growth period of winter wheat was significantly increased by mulch,the average increase of straw strip mulch was 13.22%,the increase range was M3>M4>M5,and the PM increased by 19.65%.The soil moisture increasing effect of mulch increased gradually with the progress of growth stage,and the maximum increase was 37.53—87.76 mm at maturity stage.It decreased with the deepening of soil layer,and the increase of 0—20 cm was the largest,ranging from 5.10—9.48 mm.Mulching significantly reduced the total water consumption and total water consumption intensity during the whole growth period,and the influence of mulching on water consumption and total water consumption intensity during the later growth period was most obvious.Compared with CK,wheat straw strip mulching significantly reduced the soil temperature of 0—25 cm during the whole growth period by 1.60—2.70 ℃,and M3 treatment had the largest decrease.The maximum decrease occurred at the grouting stage(3.67 ℃),and the maximum decrease between soil layers(3.01 ℃)occurred at 5 cm.Compared with CK,PM significantly increased the soil temperature from 0 to 25 cm during the whole growth period by 1.50 ℃,and the overwintering period and 5 cm had the largest increase,which were 2.20,1.79 ℃,respectively.The temperature of straw mulch increased at 7:00 at wintering stage,jointing stage and ripening stage,and the temperature increased and decreased at other times.PM temperature increased at all time except at 14:00 in grouting stage and ripening stage.Compared with CK, the yield and water use efficiency of M5 and PM were increased by 8.67%, 26.49% and 0.96, 2.94 kg/(ha·mm), panicle number was the most significant factor(CV=17.67%).Yield was significantly positively correlated with spike number(r=0.754^**),WUE(r=0.891^**)and soil temperature(r=0.723^**),and significantly positively correlated with grain number per spike(r=0.522^*).Banded mulching of wheat stalk can achieve both ecological and economic benefits,and M5 is more conducive to the formation of yield.

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

In order to study the effects of different fertilization treatments on the growth and development of aromatic rice,the present experiment was conducted with Qingxiangyou 19 xiang as the experimental material,and five fertilization treatments were designed,broadcasting compound fertilizer(T1),6 cm deep application of compound fertilizer(T2),broadcasting urea(T3),6 cm deep application of urea(T4),and no fertilizer applied treatment(T5),to explore the impacts of different fertilizer applications on the yield,quality,aroma,photosynthetic efficiency,and several other physiological properties of aromatic rice.The results of the experiment showed that the different fertilizer treatments had significant effects on the yield and quality of aromatic rice.The yields of aromatic rice were significantly higher in the deep-fertilization treatments(T2 and T4)than broadcasting-fertilization treatments(T1 and T3).In addition,the yield of aromatic rice was 19.61%,20.03%,39.57% and 32.28% higher than T5 treatment under T2 and T4 treatments in 2022 and 2023,respectively.In terms of net leaf photosynthetic rate,deep fertilization treatments significantly increased the net photosynthetic efficiency of aroma rice leaves by 25.69%,15.95%,17.83% and 11.28% under T2 and T4 treatments in 2022 and 2023,respectively,compared with T5 treatment.Moreover,2-acetyl-1-pyrroline(2-AP)content,2-AP synthesis-related precursor contents,and major enzyme activities were increased in aromatic rice under the deep fertilization treatments.Compared to the T5 treatment,the 2-AP content was significantly increased in the T2 treatments,reaching 161.31,180.17 μg/kg in 2022 and 2023,respectively.Furthermore,a significant increase in precursor content and major enzyme activities were also observed under deep fertilization treatments.The contents of proline,pyrrolidine-5-carboxylic acid and 1-pyrrolidine were increased by 9.90%,10.08%,4.38% and 8.13%,8.26%,6.06% under T2 treatment in 2022 and 2023,respectively.The activities of pyrrolidine-5-carboxylic acid synthetase and proline dehydrogenase activities were enhanced by 8.72%,27.79%,5.52% and 30.91% under the T2 treatment in 2022 and 2023,respectively.In conclusion,the deep fertilization treatment was able to significantly increase the yield,quality,net photosynthetic rate of leaves and promote the biosynthesis of 2-AP in aromatic rice.

Explore the effects of amino acid type water-soluble fertilizer on chlorophyll content and proportion of celery,and the regulation of gene expression related to chlorophyll metabolism,which provides a theoretical basis for the rational application of amino acid type water-soluble fertilizer foliar fertilizer in the production of high-quality pigment-rich celery.The celery variety Ningqin 1 was sprayed with different concentrations of amino acid type water-soluble fertilizer,the contents of chlorophyll a,chlorophyll b and total chlorophyll in leaf blades and petioles were determined and analyzed,and the relative expression levels of genes related to chlorophyll metabolism were determined by fluorescence quantitative PCR(RT-qPCR).The effects of amino acid type water-soluble fertilizer on chlorophyll accumulation and relative expression levels of related genes were related to the treatment concentration and leaf location.Treatment with 500 μL/L amino acid type water-soluble fertilizer increased the contents of chlorophyll a,chlorophyll b and total chlorophyll in leaf blades and petioles,and decreased the ratio of chlorophyll a/b in petioles.The expression of chlorophyll synthesis-related genes(AgHEMA,AgHEMB,AgCHLM,AgPOR and AgCAO)was induced,and the expression levels of degradation related genes(AgPAO and AgPPH)were significantly down-regulated.Treatment with 1 000 μL/L amino acid type water-soluble fertilizer inhibited chlorophyll accumulation to a certain extent,increased chlorophyll a/b ratio in leaf blades,and significantly down-regulated the expression levels of genes related to chlorophyll synthesis and chlorophyll degradation AgPPH.The suitable concentration of amino acid type water-soluble fertilizer foliar fertilizer can improve the chlorophyll content of celery at seeding stage by regulating the expression level of genes related to chlorophyll metabolism.

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 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.

To reveal the mechanism of drought resistance rice in booting stage,six single chromosome segments substitution lines (SSSLs) constructed from Oryza meridionalis and O.glumaepatula and their recipient parent Huajingxian 74 (HJX74) were used as experimental materials for potted drought treatment.Six biochemical indexes during 0,5,10 days of drought treatment and 5 days of rewatering and 11 agronomic traits after setting stage were measured,and the drought tolerance of 7 materials was comprehensivly evaluated by correlation analysis and principal component analysis.The result showed that under drought stress,there were extremely significant difference in agronomic traits among the 7 materials.There were extremely significant difference between M78-1 and HJX74 in relative panicle length,relative empty grain number and relative grain number per panicle,and there was extremely significant difference between M148 and HJX74 in relative dented grain number,there were extremely significant differences between M107 and HJX74 in relative panicle length and relative number of secondary branches; six drought-tolerant QTLs were identified at booting stage,including qRPL1-1,qRPL2-1,qRNSB2-1,qRNDG11-1,qRNEG1-1,qRGNP1-1,which were distributed on chromosomes 1,2,and 11.The superoxide dismutase (SOD) activity and peroxidase(POD) activity increased by 3.76%—18.20% and 31.88%—100.00% after 5 days of drought,while malondialdehyde (MDA)concentration decreased by 41.07%—81.65%.After 10 days of drought,SOD activity and POD activity decreased by 9.20%—48.53% and 44.74%—79.79%,while malondialdehyde (MDA)concentration was extremely significantly higher than that on the 5th day of drought.Osmoregulatory substances such as proline,soluble sugar and soluble protein continued to increase at the 5 d and 10 d drought treatment stages,and the biochemical indexes basically returned to normal level after 5 days of rewater.The comprehensive analysis revealed that the eigenvector and contribution rates of relative seed setting rate,POD activity and proline were the largest,indicating that these three indexes could better represent the drought tolerance of rice at booting stage.In conclusion,drought stress can affect agronomic traits and biochemical indexes of rice at booting stage,and rice can regulate its metabolic process in response to drought stress.

In order to explore the difference in starch composition content and the change of rice digestion rate in rice lines. In this study, the contents of amylose (AC), total starch (TS), rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS)in 126 indica rice strains were analyzed by enzyme digestion method in vitro. And then detected the digestion rate of the cooked rice and estimated the glycemic index (eGI) of 18 rice lines with significant differences in AC,SDS and RS. The results indicated that the starch contents of these lines differ greatly, AC was 4.29%—25.58% with an average of 10.43%, TS was 71.69%—82.45% with an average of 77.73%, RDS was 43.31%—57.47% with an average of 50.07%, SDS was 18.96%—32.56% with an average of 25.26%, and RS was 0.59%—4.87%with an average of 2.39%. There was a certain correlation between eGI values and starch content in different rice lines. The eGI values of high AC were significantly lower than low AC, but it was also found that the eGI values of Diangu 2030 with low AC and Dianpan 3429 with low SDS were also low. The eGI values of high SDS were lower than low SDS, but there were also cases where the eGI values of low SDS were also low. The eGI value of high RS was significantly lower than low RS. The rice digestion rate was fast and the sugar release was the highest of all the rice stains within 30 min after the meal, which continued to decrease after 60 min. The eGI values of the lines with high AC, SDS or RS content were generally lower than those with low starch content. The grain digestion rates were different among the tested rice lines, and it suggested that the digestion rates of rice grain could be affected by other factors except the AC, SDS and RS. These results can offer valuable references for the development of low-GI rice varieties.

In order to investigate the effect of exogenous 24-epibrassinolide(EBR)on the physiological characteristics of Lycium barbarum seedlings under salt stress,Ningxia L. barbarum Ningqi 7 was used as the experimental material.Five treatments were set up,namely 0 mmol/L NaCl+distilled water spray(CK),150 mmol/L NaCl+distilled water spray(N0 treatment),150 mmol/L NaCl+0.005 mg/L EBR(T1 treatment),150 mmol/L NaCl+0.050 mg/L EBR(T2 treatment),and 150 mmol/L NaCl+0.500 mg/L EBR(T3 treatment).The seedling plant height,basal diameter,aboveground and underground biomass,chlorophyll content,photosynthetic parameters,antioxidant enzyme activity and the content of osmoregulatory were measured on the 7th day,14th day,and 21st day respectively.The results showed that compared with N0 treatment,T1,T2,T3 treatments significantly increased the plant height,basal diameter,aboveground and underground biomass,photosynthetic pigments in leaves,net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), superoxide dismutase (SOD), peroxidase (POD), catalase(CAT)activities,as well as the content of osmoregulatory in L.barbarum seedlings,intercellular CO₂ concentration (Ci) and malondialdehyde (MDA) content significantly decreased,T2 treatment had the best effect.On the 21st day of salt stress,compared to the N0 treatment,the plant height,basal diameter,aboveground and underground biomass of L.barbarum seedlings increased by 23.63%,15.45%,17.70%,and 47.06%,the content of Chlorophyll a,Chlorophyll b,and Chlorophyll a+b increased by 10.68%,12.31%,and 6.57%,respectively;Pn,Tr,and Gs increased by 55.53%,27.83%,and 9.76%,respectively;the Ci value decreased by 14.42%;the activities of SOD,POD,and CAT increased by 13.23%,20.10%,and 9.31%,respectively;the MDA content decreased by 35.28%;the proline content,soluble sugar content,and soluble protein content increased by 45.17%,86.54%,and 57.00%,respectively.In summary,an appropriate concentration of exogenous 24-epibrassinolide can promote the growth of L.barbarum seedlings under salt stress,improve the photosynthetic capacity and antioxidant enzyme activity of L.barbarum seedlings,increase the content of osmoregulatory substances,alleviate the damage of salt stress to L.barbarum seedlings,and enhance the salt tolerance of L.barbarum seedlings.Among them,exogenous 0.050 mg/L EBR has the best effect.

To clarity the response of phenols in different organs of L.ruthenicum Murr.to soil salinization.The stems of annual(F₁),biennial(F₂),triennial(F₃)and wild(Q₁),mild(Q₂),moderate(Q₃),and severe(Q₄)salinized soil were used as experimental materials.The quality of L.ruthenicum was evaluated by principal component analysis.It showed that there were significant differences in each index of L.ruthenicum under different treatments.Among the fruits,the content of wild Q₁ calcium and flavonoids(1.623 g/L,73.963 mg/g)was the highest,the content of total phenol,anthocyanin and procyanidins in Q₄ was the highest(2.049 mg/g,151.836 mg/L,286.167 mg/g),in the shoot,calcium content(4.167 g/L)in Q₂ was the highest,the total phenol content of Q₃(0.491 mg/g)was the highest,the content of flavonoids,anthocyanins and procyanidins in Q₄ was the highest(25.704 mg/g,2.463 mg/L,10.208 mg/g),in leaves,the content of calcium and flavonoids(5.469 g/L,34.593 mg/g)was the highest in Q₁,the content of total phenols and procyanidins(0.943 mg/g,21.00 mg/g)was the highest in Q₄,the content of anthocyanin in Q₂ was the highest(2.880 mg/L);among the annual branchs,the calcium content(2.561 g/L)was the highest in F₁,the contents of total phenols,anthocyanins and procyanidins(0.409 mg/g,0.163 mg/L,8.858 mg/g)in F₂ were the highest,the content of flavonoids(34.593 mg/g)in F₃ was the highest.There was a correlation between soil salinity and various indicators. It is significantly positively correlated with the fruit calcium, and extremely significantly positively correlated with the frui flavone and the leaf calcium. The fruit calcium was significantly positively correlated with the leaf calcium, extremely significantly positively correlated with the fruit flavone, significantly negatively correlated with the fruit anthocyanin and the branch flavone, extremely significantly negatively correlated with the fruit proanthocyanidin.

In order to investigate the effects of reactive oxygen species(ROS)on the growth and antioxidant system of sweetpotato under potassium deficiency stress,and further reveal the defense mechanism of ROS regulation in sweetpotato under potassium deficiency stress.This study selected two sweetpotato varieties,Xushu32(low potassium tolerant)and Ningzi 1(low potassium sensitive),as experimental materials.The experiment was conducted in an artificial climate chamber using hydroponic cultivation to ensure consistent environmental conditions.After pretreatment with exogenous H₂O₂ and diphenyl chloroiodate(DPI),ROS inhibitor,the sweetpotato seedlings were subjected to potassium deficiency treatment.The changes in relative H₂O₂ content,antioxidant gene expression levels,and enzyme activity indicators in sweetpotato roots at different time points after potassium deficiency treatment were measured.The morphological characteristics of sweetpotato were recorded to explore the effects of ROS signaling on the growth of sweetpotato seedlings under potassium deficiency stress.The results showed that under potassium deficiency treatment,the biomass of sweetpotato decreased and leaf color lightened.The relative concentration of ROS in sweetpotato seedling roots showed the highest fluorescence intensity on the 14th day.The expression levels of antioxidant-related genes in sweetpotato roots generally increased,with a more significant increase in expression levels after H₂O₂ pretreatment.Compared with-K treatment,both H₂O₂ and DPI pretreatment could enhance the activity of antioxidant enzymes in sweetpotato leaves,and different enzyme activities showed different trends within 21 days of potassium deficiency treatment.There were varietal differences in the effects of different treatments.The experimental results showed that H₂O₂ could act as a stress signaling molecule to increase the expression level of antioxidant genes and the enzymatic activities of APX,SOD and POD in sweetpotato seedlings,thus scavenging excess ROS and effectively alleviating the inhibition of growth of sweetpotato seedlings by potassium deficiency stress.And DPI could inhibit the production of endogenous H₂O₂,maintain the antioxidant enzyme activity,protect the ROS enzymatic scavenging system of sweetpotato seedlings and avoid oxidative damage to tissues.

In order to investigate the optimal application period of allantoin,Sweet Research No.8 was used as the experimental material in saline soil located in Wuma Village,Shangjia Town,Zhaodong City,Heilongjiang Province.Six treatments were established:spraying with a mass concentration of 0.1 mmol/L allantoin at the seedling stage(M),leaf tufts rapid growth stage(Y),tuber expansion stage(K),seedling stage + leaf tufts rapid growth stage(MY),and seedling stage + leaf tufts rapid growth stage + tuber expansion stage(MYK),and a control group was sprayed with water(CK).The effects of allantoin spraying on the photosynthetic characteristics,antioxidant enzyme activities and tuber yield indexes of sugar beet were determined at different periods.The results showed that the chlorophyll content of allantoin treatment increased compared with that of CK,and with the MY treatment being 27.8%,12.4%,21.8%,and 32.2% higher than the MY treatment in all periods;the stomatal conductance of allantoin sprayed treatments,RuBP enzyme activity,transpiration rate,photochemical quenching capacity,actual photosynthetic efficiency,and antioxidant enzyme activity were all differently enhanced compared with that of CK;the nonoptical quenching capacity,malondialdehyde content,and intercellular CO₂ concentration were lower than CK,with the MY treatment having the best effect,and there was no significant difference between the MYK and MY treatments.Compared with the CK treatment,the yield of MY-treated tubers increased by 26.6%,and the sugar yield increased by 21.3% percentage points.In summary,spraying allantoin in the seedling + leaf cluster growth period can effectively alleviate the harm caused by saline stress to sugar beet,thus improving sugar beet yield,and providing a theoretical basis for exogenous allantoin to improve saline-alkali tolerance of sugar beet.

In order to investigate the impact of different environments on the symbiotic nodulation ability of soybean-rhizobia and to screen suitable culture conditions for symbiotic nodulation,this study established 10 treatments based on 4 environmental factors(culture temperatures:22,26,30 ℃;culture substrates:vermiculite,vermiculiteand nutrient soil;inoculation periods:0 day post-inoculation,inoculation at 10 days;final bacterial concentration:OD₆₀₀=0.5,OD₆₀₀=0.9,OD₆₀₀=1.3),resulting in 36 different culture conditions.Five nodulation-related phenotypes of soybean-rhizobia were measured under these conditions,including the number of nodules per plant,nodule dry weight per plant,nodule size,SPAD of leaf growth at 10 and 24 days post-inoculation(DPI).Principal component analysis,fuzzy mathematics membership function method,and cluster analysis were employed to comprehensively evaluate and classify the symbiotic nodulation ability of soybean-rhizobia under different conditions.A comprehensive evaluation system for the nodulation ability of soybean-rhizobia was established,and the optimal culture conditions were selected based on the comprehensive evaluation index D value.The results showed that culture temperature was the primary environmental factor influencing the symbiotic nodulation of soybean-rhizobia.The maximum values of the number of nodules per plant,nodule dry weight per plant,nodule size,SPAD of leaf growth at 10 and 24 days post-inocubion corresponded to culture temperatures of 30,26,26,30 and 26 ℃,respectively,under,different culture conditions.Under the culture conditions set,the optimal culture temperature for the symbiotic nodulation of soybean-rhizobia was 26 ℃.Multivariate linear regression analysis and grey relational analysis based on the comprehensive evaluation index D value indicated that nodule dry weight and nodule size had a strong correlation with the symbiotic nodulation ability of soybean-rhizobia,serving as important reference indicators for nodulation ability identification.The results of this study established a comprehensive evaluation system for the symbiotic nodulation ability of soybean-rhizobia,providing a theoretical basis for selecting phenotypes and culture conditions for nodulation ability identification.

Calcium-dependent protein kinases(CPK)are a class of protein kinases that respond to calcium signals and participate in regulating the polar growth of pollen tubes,which is crucial for plant reproduction and is precisely controlled by calcium signals and the cytoskeleton.To reveal the function of CPK in the polar growth of pollen tubes in Arabidopsis,bioinformatics methods were used to analyze the expression patterns and evolutionary relationships of CPK family members,and constitutively active(CA)and dominant-negative(DN)CPK17 mutants were constructed.Based on gene gun technology,we observed the phenotypic changes of CA-CPK17 and DN-CPK17 overexpressing pollen tubes,compared the effects of high and low calcium stress on the growth of CPK17 and CA-CPK17 overexpressing pollen tubes,and analyzed the co-expression of CPK17 and its homologous protein CPK34.Additionally,the protein interaction network of CPK17 was predicted,and some of the interacting proteins were validated.The results showed that there were seven pollen-specifically expressed CPKs in Arabidopsis thaliana.Among them,CPK17 and CPK34 had a high similarity (93%),and were highly expressed in mature pollen,and low or no expression in other tissues.Overexpression of CPK17 had no significant effect on pollen tube growth,while CA-CPK17 caused depolarized growth and tip swelling of pollen tubes,and DN-CPK17 had no obvious effect.Overexpression of CPK34 also caused similar defects in pollen tube growth,and co-overexpression of CPK17 and CPK34 aggravated the defects.Calcium stress experiments showed that overexpressing CPK17 pollen tubes were insensitive to low calcium conditions,but sensitive to high calcium conditions.While pollen tubes overexpressing CA-CPK17(lacking the regulatory domain)were insensitive to both high and low calcium conditions.The predicted interacting proteins of CPK17 were mainly ROP negative regulators,but yeast two-hybrid experiments failed to confirm the interaction.These results indicated that the C-terminal regulatory domain of CPK17 plays an important role in the response to calcium signals.CPK17 and CPK34 have synergistic effects on pollen tube growth,possibly by regulating calcium influx and affecting intracellular calcium gradient.

The pollen tube is one of the important structures for plant sexual reproduction,and its growth requires precise coordination of intracellular and extracellular signals.Calcium ions(Ca²⁺)as an important second messenger play a crucial role in various stages of pollen tube growth.Ca²⁺ enters the cytoplasm through ion channels from the external environment or internal calcium stores,and is then transported out of the cell by calcium pumps and exchangers to maintain the dynamic balance of calcium ions.The coordinated regulation of calcium ion influx and efflux is the key to the establishment and maintenance of calcium ion signaling.Calcium-dependent protein kinases(CPKs)and calcineurin B-like proteins(CBLs)are two important classes of calcium-sensing proteins,which can perceive changes in intracellular calcium concentrations and regulate the polar growth of pollen tubes by phosphorylating downstream target proteins.Specifically,the CBL-CIPK signaling pathway may participate in the regulation of ion balance and vacuolar dynamics,while the CPK signaling pathway may affect the turgor pressure,growth rate and direction of the pollen tube by regulating water channels,nitric oxide synthesis,and ion channels.These calcium signaling molecules have complex regulatory relationships with the small G protein ROP1 and its downstream pathways.In summary,this review summarizes the critical role of calcium signaling in pollen tube growth,and elaborates on the regulatory mechanisms of the CPK and CBL-CIPK signaling pathways,providing important references for in-depth understanding of the molecular mechanisms underlying pollen tube polar growth.

Vernalization is a unique and necessary physiological stage in the growth and development of winter wheat,which determines the ecological adaptability and yield of winter wheat.This paper briefly summarizes the production and application value of vernalization of winter wheat.By summarizing and analyzing the structure and function of the key genes TaVRN1,TaVRN2 and TaVRN3 in wheat vernalization and their regulatory networks,it is believed that the study of epigenetic regulation of TaVRN1 is the core work of wheat vernalization mechanism analysis.Combined with the existing research on the expression regulation of TaVRN1,the causes of the difference in vernalization demand of wheat,the mechanism of long-term low temperature perception in winter,the research progress of overwintering memory and overwintering memory reset after vernalization,and the effect of vernalization on the regulation of cold tolerance,spikelet development,tillering and other agronomic traits of wheat were mainly introduced.In addition,this study summarizes the unsolved scientific problems in vernalization,and discusses the future research direction of wheat vernalization,which provides reference suggestions for the research of high yield and rapid breeding of wheat.

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

Cd-sensitive wheat CM28 was used as the research object to investigate the effects of spraying exogenous glycine on its physiological and biochemical processes under different concentrations of cadmium stress.The plant height and root length,above-ground transport coefficient and enrichment coefficient of cadmium,chlorophyll content and malondialdehyde(MDA)content,and the enzyme activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)of CM28 under different treatments were determined.The expression levels of PEPC genes in roots and leaves under different treatments were analyzed by qRT-PCR.The results showed that under 30 μmol/L Cd stress,the spraying of exogenous glycine led to a decrease in the above-ground dry and fresh weights,a decrease in the total-chlorophyll content,and an increase in the MDA content of CM28,indicating that plants were affected by more reactive oxygen species.Under 50 μmol/L cadmium stress,glycine could effectively alleviate the negative effects of cadmium on CM28,resulting in an increase in the total-chlorophyll content,an increase in the above-ground dry and fresh weights,and a decrease in MDA content,suggesting that the plant was affected by reactive oxygen species to a greater extent.The antioxidant enzyme activity of CM28 increased with the increase of cadmium concentration,and the spraying of exogenous glycine could enhance the activity of antioxidant enzymes and alleviate the effect of cadmium on the whole.The expression of PEPC genes in roots increased overall with the rise of cadmium concentration,indicating that PEPC played an important role in the process of plant root resistance to stress,and the spraying of exogenous glycine can also effectively alleviate the cadmium stress on CM28 and reduce the expression of PEPC genes on the whole.In summary,cadmium stress negatively affects the physiological and biochemical processes of CM28,and the spraying exogenous glycine can alleviate the effects.