Abstract:To investigate the genes associated with the growth-promoting effects of Bacillus subtilis in Rehmannia glutinosa,whole genome sequencing was performed in this study and the genes associated with the growth-promoting effects were discovered through functional annotation.The results showed that the genome size of Bacillus subtilis,an endophytic growth-promoting bacterium of Rehmannia glutinosa,was 4 310 699 bp,with a GC content of 43.44%,and a total of 4 521 predicted coding genes.A total of 3 013,3 354,4 395,206,52,and 212 functional genes were annotated in the clusters of orthologous groups(COG),gene ontology(GO),kyoto encyclopedia of genes and genomes(KEGG),carbohydrate-active enzymes(CAZyme),comprehensive antibiotic resistance database(CARD),and virulence factor database(VFDB),respectively.The annotation results indicated that there were 46 genes related to growth-promoting function,with the majority of these genes involved in phosphorus solubilization,nitrogen fixation,and iron carrier processes.In the meantime,anti-SMASH predicted that a total of 409 genes were enriched into 12 secondary metabolite synthesis gene clusters,with the majority encoding eight repressors,including fengycin,1-carbapen-2-em-3-carboxylic acid,bacillaene,bacilysin,subtilosin A,surfactin,pulcherriminic acid,and bacillibactin.Among these,pulcherriminic acid and bacillibactin had been observed to facilitate the chelation of ferric ions in the surrounding environment.

Abstract:Based on a four-year field positioning experiment,three irrigation methods,including traditional irrigation(TI),sprinkler irrigation(SI)and drip irrigation(DI)were used to explore the effects of irrigation methods on crop photosynthetic characteristics,grain yield and water-nitrogen use efficiency under wheat-peanut rotation system,with no irrigation treatment as control(CK),so as to provide a theoretical basis for promoting the popularization and application of water-saving irrigation technology in wheat-peanut rotation system.The results showed that irrigation methods had significant effects on crop SPAD value,net photosynthetic rate,transpiration rate,yield and its components,water and nitrogen use efficiency under wheat-peanut rotation system,and DI treatment was the highest among all treatments,followed by SI treatment.Under wheat-peanut rotation system,compared with other treatments,net photosynthetic rate,transpiration rate and SPAD value of DI treatment increased by 3.3％—105.4％,5.6％—109.6％and 1.0％—19.4％,respectively;Grain number per spike,1 000-grain weight and grain yield of wheat increased by 6.9％—21.1％,4.6％—39.2％and 9.2％—50.6％,respectively;Number of full pods per plant,100-pod weight,kernel rate and yield of peanut increased by 8.8％—35.5％,2.8％—16.2％,1.7％—5.6％and 4.1％—30.1％,respectively.The annual grain yield,water use efficiency and partial factor productivity of nitrogen of wheat-peanut showed DI＞SI＞TI.Compared with TI treatment,the total yield,water use efficiency and partial factor productivity of nitrogen of wheat-peanut of DI treatment increased by 17.9％,19.5％and 17.9％,respectively,and those of SI treatment increased by 10.1％,14.9％and 10.1％,respectively.In summary,under the condition of this study,drip irrigation is the best irrigation method for increasing yield and efficiency of wheat-peanut,followed by sprinkler irrigation,both of which can achieve the goal of high yield and water and nitrogen use efficiency.

Abstract:To investigate the regulatory effects of different plant growth regulator treatments on the fruit quality of Ilex verticillata'Oosterwijk',2-year-old potted seedlings were utilized as materials.Prohexadione-calcium and mepiquat chloride were mixed in varying concentrations,and their effects were compared with different concentrations of uniconazole and paclobutrazol,along with a control group treated with water.Spraying was conducted on the entire leaf surface during the first fruit enlargement period and ripening stage after fruit setting,followed by sampling upon maturity.Morphological indicators such as fruit length,width,single fruit weight,and moisture content were measured,along with peel chromaticity and fruit hardness.Additionally,pigment contents including chlorophyll,carotenoid,anthocyanin,along with flavonoid content,soluble sugar content,and vitamin C content were determined,for conducting inter-indicator correlation analyses.The effects of each treatment were analyzed using the membership function method.Results indicated that the fruit shape index after treatment with various agents exceeded that of the control,suggesting a trend towards regular and plump fruit shape.The highest single fruit weight was observed under T4 treatment(5％ uniconazole 3.30 g/L),with an average of 0.44 g.The treatment with the highest average moisture content was T3(5％prohexadione-calcium 0.67 g/L+98％mepiquat chloride 0.30 g/L),with a content of 65.73％.All treatments enhanced fruit brightness and color saturation,with the highest L* and a* values observed under T5 treatment(5％uniconazole 2.00 g/L)treatment.However,there was no significant difference in b*values among treatments.The highest carotenoid content was recorded under T1 treatment(5％prohexadione-calcium 2.00 g/L+98％mepiquat chloride 1.00 g/L),at 0.022 mg/g.Treatment T5 showed a significant increase in anthocyanin content compared to the control,reaching 190.57 μg/g.The total flavonoid content of I.verticillata'Oosterwijk'fruits showed an initial increase followed by a decrease with increasing spray concentration of the agents,with the highest soluble sugar content observed under T2 treatment(5％prohexadione-calcium 1.30 g/L+98％mepiquat chloride 0.67 g/L).The highest vitamin C content was observed under T3 treatment,with an increase of 38.34％compared to the control group.The rankings of membership function values for each treatment group were T5＞T2=T7＞T3＞T4＞T6＞T1＞CK,indicating that spraying twice with 5％uniconazole at 2.00 g/L during fruit enlargement and ripening stages resulted in the optimal fruit quality.

Abstract:To clarify the quantitative indicators of fresh tobacco leaf maturity,Zhongyan 100 was used as the experimental material.Mid-stem leaves with SPAD values of 10-15(S10～15),15-20(S15～20),and 20-25(S20～25)were harvested to explore the metabolomics characteristics,as well as the appearance evaluation,physical properties,chemical composition,aroma content,and sensory quality of their post-cured leaves.The results showed that the post-cured leaves of the S15～20 treatment obtained the optimal quality,including better appearance quality,good physical properties,harmonious chemical components,and the highest total amount of neutral aromatic substances,showing high maturity.According to the partial least squares discriminant analysis(PLS-DA),32 mutual differential metabolites were identified between two comparison groups,including L-tryptophan,gamma aminobutyric acid,geranic acid,pyrrole-2-carboxylic acid,trehalose,kojibiose,nicotinate D-ribonucleoside,1-methyladenosine,sphinganine,melibiitol,indole,scopoletin,18-hydroxycorticosterone,25-hydroxycholesterol,and kaempferide,et al.These differential metabolites might be key differential metabolites during the maturation process of tobacco.Then,a total of 48 significantly differential metabolites were identified across the two groups,including 11 amino acids,7 steroids,6 organic acids,6 sugars,3 alcohols,3 nucleotides,2 flavonoids,1 vitamin,and 9 other metabolites.These significantly differential metabolites were primarily enriched in pathways such as amino acid biosynthesis,ABC transporters,arachidonic acid metabolism,lysine degradation,biosynthesis of phenylpropanoids,and butanoate metabolism,which might play important regulatory roles during the maturation of tobacco leaves.

Abstract:In order to explore the effect of tobacco essential oil microcapsules on cigarette paper flavoring,firstly,tobacco essential oil was prepared by water distillation.Then complex coacervation method was employed to prepare tobacco essential oil microcapsules with tobacco essential oil as the core material,chitosan as the wall material,and span-80 as the emulsifier,and the embedding yield was determined.Subsequently,scanning electron microscopy,laser particle size analyzer and infrared spectrum analyzer were used to characterize the physical and chemical properties of microcapsules.Finally,the microcapsules were used to flavor cigarette paper,and the sensory evaluation and smoke composition analysis of the flavored cigarettes were carried out.The results showed that the average particle size of tobacco essential oil microcapsules prepared with chitosan as the wall material and tobacco essential oil as the core material was 221.1 nm,and the embedding yield was 75.3%.The prepared tobacco essential oil microcapsules showed smooth and plump spherical surface through scanning electron microscope.The infrared spectrum analysis of tobacco essential oil,chitosan and tobacco essential oil microcapsules showed that tobacco essential oil was embedded in chitosan by comparing their characteristic absorption peaks.The results of sensory evaluation showed that the flavored cigarettes were significantly improved.When the tobacco essential oil microcapsules and tobacco essential oil were compounded at a volume ratio of 1∶2,the aroma effect was more significant,and the sensory evaluation score could reach 86.6.Compared with the control(ie.cigarettes without flavoring),the contents of nicotine,alcohols,aldehydes,acids,esters and ketones in the smoke components of the cigarettes with compound flavors were increased,and the aroma,taste and strength of cigarettes were improved.

Abstract:To clarify the salt-alkali tolerance characteristics of tiger nut(Cyperus esculentus)at the seedling stage and establish precise evaluation indicators and a relevant mathematical model,18 trait indices including germination rate,plant height,root length,root number,plant biomass,plant water content,chlorophyll content,superoxide dismutase(SOD)activity,and soluble protein content were measured for 66 tiger nut germplasm resources under 5 g/kg mixed salt-alkali stress after 15 days of germination.Comprehensive analytical methods,including correlation analysis,principal component analysis(PCA),membership function,grey relational analysis,and stepwise regression analysis,were employed to assess the stress tolerance performance of different materials and establish an evaluation system.The results showed that the variation in salt-alkali tolerance coefficients among different traits ranged from 9.79%to 58.57%,with the coefficient for root dry mass exhibiting the greatest variability and that for relative water content demonstrating the smallest variability.PCA transformed the 18 original indicators into six principal components,which cumulatively accounted for 86.783%of the total variance.Based on the comprehensive evaluation D-value,the 66 germplasm resources were classified into five tolerance levels:extremely strong,strong,moderate,weak,and sensitive.Classification criteria were defined,identifying two germplasm resources with extremely strong tolerance and 12 salt-sensitive germplasm resources.Cultivars Yu Yousha 2 and Yu Yousha 3 were both classified as strongly salt-alkali tolerant materials.Using stepwise regression analysis,a mathematical model for evaluating salt-alkali tolerance at the seedling stage was established.This model demonstrates that by measuring and calculating the salt-alkali tolerance coefficients of total fresh weight,relative water content,root number,total chlorophyll content,plant height,and SOD activity,the D-value can be estimated using the regression equation to assess the salt-alkali tolerance of tiger nut germplasms at the seedling stage.This study provides essential materials,methodological support,and a robust evaluation framework for subsequent research on salt-alkali stress tolerant mechanisms and breeding of tiger nut varieties.

Abstract:Wild soybean is a close relative of cultivated soybean,which has abundant resistance alleles.In order to screen cadmium-tolerant wild soybean germplasm resources and analyze its molecular mechanism of cadmium-tolerance,205 wild soybean lines from eastern Hebei Province were selected as research materials.A hydroponic experiment was conducted to set up cadmium stress and control(without cadmium stress)with two environmental replicates in November 2022 and July 2023.The shoot fresh weight(SFW),root fresh weight(RFW),plant height(PH),root length(RL)were determined,and root shoot ratio(RSR)of fresh weight,cadmium tolerance coefficient(CTC)corresponding to each trait and cadmium tolerance evaluation value(D value)of each wild soybean strain were calculated.At the same time,genome-wide association analysis(GWAS)was carried out,and then haplotype analysis was performed on significant single nucleotide polymorphism(SNP)on chromosome 15.The results showed that the average value of seedlings traits under cadmium stress were lower than those of the control except for RSR.The results of frequency analysis showed that the CTC in the two environments showed normal distribution and genetic characteristics of quantitative traits.According to D value,13 cadmium-tolerant wild soybean germplasms were screened out.Principal component analysis(PCA)showed that 205 wild soybean lines could be divided into three groups.Linkage disequilibrium(LD)analysis showed that 205 wild soybean natural populations decayed at 100 kb.A total of 195 SNPs significantly associated with cadmium tolerance in wild soybean were detected by GWAS analysis,and a single SNP could explain 1.95％to 25.43％of the phenotypic variation.A total of 591 candidate genes were identified according to the physical location of SNPs,of which 11 candidate genes were repeatedly associated with multiple SNPs,which belonged to pleiotropic effects.More importantly,genes of two metal-tolerant proteins(MTPs)and two heavy metal-associated isoprenylated plant proteins(HIPPs)were identified according to functional annotations.They were L0C114386540(MTP 10-like),LOC114388453(MTP 10-like),LOC114369981(HIPP 36-like)and LOC114381753(HIPP 37-like),laying a foundation for elucidation of the molecular mechanism of the inheritance of cadmium tolerance in wild soybean.Haplotype analysis showed that the average CTC of haplotype 2 on chromosome 15 was the largest,which belonged to the excellent haplotype.This results provide information for analyzing the genetic mechanism of cadmium tolerance in wild soybean and provide important genetic resources for cultivating cadmium-tolerant soybean varieties.

Abstract:In order to screen the microorganisms with good control effect for the control of crop fungal diseases,the disease resistance and nano-selenization of Paenobacillus polymyxa KZJ-1 were studied.The results showed that KZJ-1 bacteriological solution had good inhibition effect on Colletotrichum micotianae,Thanatephorus cucumeris,Thielaviopsis basicola and Phytophthora parasitica,with inhibition rates of 49.78％,53.64％,46.42％and 58.85％,respectively.In addition,the strain KZJ-1 could biosynthesize nano-selenium,and the active solution of nano-selenium with different concentrations had a good inhibitory effect on Phytophthora parasitica,and the inhibitory effect was enhanced with the increase of the concentration of sodium selenite added.At the same time,the pot experiment results showed that KZJ-1 and its nano-selenium active bacterial solution could effectively prevent and control tobacco black shank disease and promote the growth of tobacco plants.The disease index of tobacco black shank disease treated with nano-selenium active bacterial solution was the lowest after 7 days of irrigation,and the control effect reached 90.23％,and the control effect decreased slightly to 83.32％after 14 days,both of which were significantly higher than that of the control.The growth rate of plant height,maximum leaf length and maximum leaf width were 16.21％,31.74％and 33.61％,respectively.It can be seen that the biosynthesis of nano-selenium by strain KZJ-1 enhanced the disease resistance and growth promotion ability of the original strain,and had certain practical application value in production.

Abstract:In order to provide scientific basis for protection,introduction and transplantation of Cercis glabra,the dominant environmental factors which affected the geographical distribution of Cercis glabra and the variation trend of potential suitable areas of Cercis glabra in modern and future periods were researched.Based on the 329 distribution records of Cercis glabra in China,3 topographic variables,19 climate variables in modern times and future climate scenarios of low greenhouse gas emissions(ssp 126),moderate greenhouse gas emissions(ssp245),high greenhouse gas emissions(ssp5 85)in the shared socio-economic pathway(SSP),the dominant environmental factors which affected the geographical distribution of Cercis glabra were analyzed,and then the distribution,area,spatial pattern change,centroid migration trend of potential suitable areas of Cercis glabra were predicted by MaxEnt model and ArcGIS software in modern times and future climate scenarios.The results showed that the most important environmental factors were min temperature of coldest month(Bio6),annual precipitation(Bio12)and mean diurnal range(Bio2)for the distribution of potential suitable areas of Cercis glabra,the optimal ranges were-5.5-5.0 ℃,less than 1 750 mm,7.1-9.8 ℃ respectively.The total potential suitable area of Cercis glabra was 231.46×10 4 km2 in modern times,and mainly distributed in middle-south of East China,most areas of Central China,middle-north of South China,east of Southwest and Northwest China,and the high,moderate,low suitable areas accounted for 24.66％,35.21％and 40.13％respectively.In different periods in future climate scenarios,the spatial distributions of suitable areas are similar to modern times,but the total suitable areas are more than modern times,in the climate scenarios of ssp 126,ssp245,ssp585,the total potential suitable areas will increase by 0.49％,5.02％,4.64％in 2050s(2041-2060),and increase by 2.93％,4.47％,5.45％in 2070s(2061-2080);Under the climate scenarios of ssp245 and ssp585,the newly increased rates of the suitable areas are 0.88-1.82 percentage points higher than those in the same period of ssp 126 in 2050s and 2070s,while the lost rates are comparable or slightly smaller;Generally,the newly increased rate is 4.80％-6.71％,and the lost rate is 3.37％-4.65％,it is mainly reflected in the increase of the moderate suitable areas and the decrease of the high suitable areas;The potential suitable areas of Cercis glabra will migrate northward slightly as a whole,and the migration distances are less than 1 latitude;While its distribution center will move to northwest or southwest less than 300 km,then transfer to the border region in the south of Chongqing,north of Guizhou Province,southeast of Sichuan Province,and the meridional movements are more than latitudinal movements significantly,meanwhile,the movement distances in 2070s are less than 2050s.It showes that in the future,the meridional changes of climate environment are more than latitudinal changes,and the migration distances of the distribution centers will show a reducing trend over time;Under the climate with moderate and high greenhouse gas emissions,the climate environment will be more conducive to expansion of the suitable areas of Cercis glabra.

Abstract:To investigate the effects of Artemisia argyi powder on production performance,nutrient apparent digestibility,antioxidant function and the number of fecal microorganisms of fattening pigs,48"Changbai×Dabai"binary fattening pigs with body weight of 50.0 kg were randomly divided into 4 groups:the control group was fed with basal diet only;the experimental groups were added with 2%,4%and 6%Artemisia argyi powder,which were recorded as AAP-1 group,AAP-2 group and AAP-3 group,respectively.The feeding experiment was conducted from May to July 2024,and the indexes were measured after the end.The results showed that in terms of groduction performance,the final weight of the AAP-2 group and the average daily gain of the three experimental groups were significantly improved.The final weight and average daily gain of the AAP-2 group were 10.26%and 19.10%higher than those of the control group,respectively.At the same time,the feed-weight ratio of the AAP-2 group and the diarrhea rate of the three experimental groups were significantly lower than those in the control group,with feed-weight ratio and diarrhea rate of the AAP-2 group decreased by 12.03%and 23.83%,respectively.In terms of nutrient apparent digestibility,compared with the control group,the apparent digestibility of calcium,crude protein and crude fat in the three experimental groups was significantly increased.Among them,the AAP-2 group showed the greatest improvement,with the digestibility of calcium,crude protein,and crude fat increased by 16.82%,10.14%,and 13.48%,respectively,compared to the control group.In terms of antioxidant function,the activities of catalase,glutathione peroxidase,superoxide dismutase,and total antioxidant capacity in the AAP-2 group were 36.77%,21.13%,20.36%,44.80%higher than those in the control group,respectively.The content of malondialdehyde decreased by 25.70%compared with the control group.In terms of the number of fecal microorganisms,the number of Lactobacillus and Bifidobacterium in the AAP-2 group increased by 19.61%and 11.85%,respectively,compared with the control group,while the number of Escherichia coli and Salmonella decreased by 11.18%and 22.09%,respectively.In summary,the addition of 4%Artemisia argyi powder can improve production performance,increase nutrient apparent digestibility,enhance antioxidant function,and increase the number of beneficial bacteriaand reduce the number of harmful bacteria in feces of fattening pigs.

Abstract:To provide scientific basis and technical support for green prevention and control of rice planthopper occurrence and sustainable production of double-cropping rice in paddy fields,field experiments on early and late rice were carried out at Funong Cooperative in Meihua Village,Xidu Town,Hengyang County,Hunan Province.With Xiangzaoxian 45(early rice)and Taiyou 553(late rice)as materials,four nitrogen application levels[early rice N0(0 kg/ha),N1(120 kg/ha),N2(150 kg/ha)N3(180 kg/ha)and late rice N0(0 kg/ha),N1(150 kg/ha),N2(180 kg/ha)and N3(210 kg/ha)]and two silicon levels[S0(0 kg/ha),S1(150 kg/ha)]were designed for the early and late rice.Under machine-transplanted conditions,field experiments were conducted to explore the effects of combined application of silicon fertilizer under different nitrogen application rates on the occurrence of rice planthoppers and rice yield in double-cropping paddy fields in southern Hunan(Hengyang).The results showed that nitrogen application rate had a significant effect on the occurrence of field rice planthoppers,rice yield and its components.With the increase of nitrogen application rate,the number of field rice planthoppers increased significantly,and the effective panicle number,grains per panicle,1 000-grain weight and yield of rice were significantly improved.Silicon application had a significant effect on the occurrence of field rice planthoppers,significantly reducing the number of field rice planthoppers.The highest insect population reduction rate of early rice could reach 56.81%,and that of late rice could reach 71.59%.The effective panicle number,grains per panicle,1 000-grain weight and yield of silicon-applied rice were all improved,but the difference was not significant.The yield increase range of early rice was 2.32%—11.57%,and that of late rice was 2.83%—9.83%.The interaction effect of nitrogen application rate and silicon application had a significant effect on the occurrence of field rice planthoppers and rice yield.The yields of N3S1,N3S0 and N2S1 were higher in both early and late rice,and there was no significant difference among them,but the number of rice planthoppers in N2S1 treatment was significantly lower than that in N3S1 and N3S0 treatments.Considering the rice yield and the control effect of rice planthoppers,it is appropriate to apply 150 kg/ha nitrogen combined with 150 kg/ha silicon fertilizer for early rice,and 180 kg/ha nitrogen combined with 150 kg/ha silicon fertilizer for late rice in Hengyang area.

Abstract:To investigate the methods for alleviating drought stress in flax and improving its drought resistance,the cultivar Jinya 10 was selected as the experimental material.At the budding stage,three treatments were designed:normal control(CK),drought stress following a spray of clear water(DS),and drought stress after spraying 50 g/ha Na2SeO3(SE).Foliar applications of water and selenium fertilizer were conducted,and after the drought period,various parameters were measured,including photosynthetic indices,chlorophyll fluorescence parameters,H2O2 content,malondialdehyde(MDA)level,antioxidant enzyme activities,osmotic adjustment substance content,nitrogen metabolism-related enzyme activities,yield,and yield components.The results revealed that drought stress at the budding stage significantly impaired plant growth and development,whereas selenium application notably mitigated the detrimental effects of drought on flax.The grain yield under the SE treatment was significantly higher,with an increase of 16.43%compared to the DS treatment,primarily due to a substantial rise in the number of capsules per plant and seeds per capsule.Exogenous selenium treatment substantially improved the net photosynthetic rate(Pn),stomatal conductance(Gs),and transpiration rate(Tr)in flax leaves under drought stress,while also increased chlorophyll content.Additionally,the maximum photochemical efficiency(Fv/Fm)and the actual photochemical efficiency of PSⅡ(ΦPSⅡ)were significantly enhanced.Selenium fertilizer also considerably enhanced the activities of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),nitrate reductase(NR),glutamine synthetase(GS),and glutamate dehydrogenase(GDH)under drought stress,with activity increases ranging from 11.19%to 20.57%.It also significantly reduced the non-photochemical quenching coefficient(NPQ),H2O2,and MDA content.Therefore,foliar application of 50 g/ha selenium fertilizer effectively alleviated the negative effects of drought stress during the budding stage on flax growth and yield by enhancing photosynthetic efficiency,optimizing chlorophyll fluorescence parameters,boosting the activity of antioxidant enzymes and nitrogen metabolism related enzymes,and decreasing reactive oxygen species and MDA levels.

Abstract:The high Zn efficiency variety Zhengdan 958(ZD958)and Zn no-sensitive variety Longping 638(LP638)were used as materials.The field plot experiment was conducted with three N rates[225 kg/ha(HN),180 kg/ha(MN)and 90 kg/ha(LN)]and two foliar Zn treatments[no Zn(F0),spraying Zn of 1∶1 at jointing stage and flare opening stage(F1)],and the effects of N and Zn application on the filling characteristics of grains at different positions and their relationship with grain yield of different Zn efficiency varieties were studied,so as to provide reference for N and Zn application in the maize production.The results showed that HN treatment had the highest yield,followed by MN treatment,and there was no significant difference between HN treatment and MN treatment.HN treatment increased grain weight at different positions.MN treatment delayed the time with the maximum grain-filling rate(TGmax)at different positions,and increased the maximum grain-filling rate(Gmax)at upper position and active grain-filling period(D)at basal position of ZD958 ear,while HN treatment delayed TGmax,prolonged D of different positions,and enhanced the grain weight with the maximum grain-filling rate(WGmax)at upper and basal positions of LP638 ear,thus increasing grain yield.Compared with F0 treatment,F1 treatment significantly decreased the bare tip length by 9.9%,significantly increased the yield by 2.0%,increased the grain weight,extended D and postponed TGmax at upper and basal positions of ZD958 ear,and increased WGmax.The grain yield was significantly positively correlated with TGmax at basal position of ear,and the grain weight at middle position of ear was extremely significantly positively correlated with the grain weight at basal position of ear.To sum up,applying 180 kg/ha N and spraying 4.5 kg/ha Zn of 1∶1 at jointing stage and flare opening stage can delay TGmax at upper and basal positions of ear,extend D,and increase WGmax and grain weight of high Zn efficiency maize genotype,thus promoting the increase of yield.

Abstract:Four treatments were set up,which were rice-turtle-Trionyx-fish comprehensive planting and breeding(DGBY),rice-turtle-fish comprehensive planting and breeding(DGY),rice monoculture(DCK)and rice ecological blank planting(DCK0).The effects of different comprehensive planting and breeding modes on the control of diseases,pests and weeds in paddy fields and rice yield and quality were studied,so as to promote the quality and efficiency of rice-fish comprehensive planting and breeding productivity.The results showed that compared with DCK0 treatment,DGBY and DGY treatments had control effects on rice sheath blight,rice blast and rice false smut.Among them,the control effect on rice sheath blight was the best,but the control effect was significantly lower than that of DCK treatment,which was 15.36%and 13.19%,respectively.The control effects of DGBY and DGY treatments on the 5th generation of rice planthopper were better,and the number of insects decreased by 56.79%and 48.85%compared with DCK0 treatment,and decreased by 32.29%and 16.95%compared with DCK treatment,respectively;Followed by the 3rd generation of Chilo suppressalis,the number of insects decreased by 39.29%and 33.93%compared with DCK0 treatment,and decreased by 15.00%and 7.50%compared with DCK treatment,respectively.At fifty days after the animals were stocked,the control effects of DGBY treatment on weed density and dry weight were 38.38%and 40.15%,respectively,and those of DGY treatment were 32.99%and 35.39%,respectively,which were not significantly different from those of DCK treatment.Except that the actual rice yield of DCK treatment was significantly higher than that of DCK0 treatment,there was no significant difference among other treatments.The milled rice rate of DGBY and DGY treatments were extremely significantly higher than that of DCK0 treatment,and the chalky grain rate and chalkiness were lower than those of DCK treatment,so DGBY and DGY treatments had the effect of improving rice quality.In summary,the rice-turtle-Trionyx-fish and rice-turtle-fish comprehensive planting and breeding models can reduce the harm of diseases,insects pests and weeds to a certain extent,achieve stable yield and improved quality,and reduce the use of chemical fertilizers and pesticides.

Abstract:Using the new wheat line of China Agricultural University,Nongda 136,as the experimental object,a pot planting method was used to study the effects of adding 5%,10%,15%biochar and various concentrations of biochar+plant growth promoting bacteria(PGPB)to soil under mine wastewater irrigation on wheat yield and soil environment.The results showed that compared with ordinary well water irrigation,soil enzyme activity was weakened and microbial carbon and nitrogen content was reduced under mine wastewater irrigation;The vitality of wheat root system decreased,with the highest performance at the jointing stage,followed by the flowering stage,and the lowest at the heading stage;The plant height,single stem dry matter weight,actual yield and biomass yield of wheat at different growth stages showed a decreasing trend.However,adding various concentrations of biomass charcoal and PGPB treatment was beneficial for improving soil environment,promoting wheat growth and yield increase.Compared with the control treatment,the soil catalase,sucrase,polyphenol oxidase,acid phosphatase,and dehydrogenase activities increased by 90.6%,37.5%,60.3%,55.7%,and 69.2%respectively when treated with 10%biomass charcoal+PGPB under mine wastewater irrigation;The soil pH value,total nitrogen,and available potassium content increased by 11.1%,185.4%and 63.9%,respectively;The soil microbial biomass nitrogen content reached 139.1 mg/kg and microbial biomass carbon content reached 253.4 mg/kg during the wheat heading stage treated with 10%biomass charcoal+PGPB;The biological yield and actual yield of mature wheat increased by 24.4%and 24.0%,respectively.In summary,the addition of different concentrations of biomass charcoal and PGPB treatment can improve soil enzyme activity,microbial carbon and nitrogen content under mine wastewater irrigation,significantly improve soil physicochemical properties,increase relative chlorophyll content,net photosynthetic rate and root vitality of wheat at different growth stages,increase plant height,single stem dry weight and yield at maturity.Among them,the best yield increase effect is achieved under the treatment of 10%biomass charcoal+PGPB.

Abstract:The application of phosphate fertilizer and mineral weathering are the main sources of soil phosphorus,but the low utilization rate of phosphorus and the limited ability of crops to absorb and utilize phosphorus lead to the accumulation of soil phosphorus,which limits the growth of crops.Intercropping system can improve soil phosphorus availability.The effects of intercropping on phosphorus utilization rate were summarized.The mechanism of intercropping to improve soil phosphorus availability was reviewed from three aspects:soil microorganisms,crop roots,and changes in endogenous hormones.It is suggested that in the future,we should focus on the in-situ characterization of plant root morphology,auxin-related gene expression,soil microorganisms and related functional genes,in order to provide reference for improving phosphorus utilization rate through intercropping.

Abstract:To improve the quality and usability of low-grade tobacco leaves,aroma-producing yeast(Y8-12)and different biological enzyme preparations were used to co-ferment low-grade tobacco leaves,and the best combination of microbe-enzyme preparations that could significantly improve the quality of tobacco leaves was screened.Subsequently,based on the degree of quality improvement,fermentation parameters were systematically optimized using single factor experiments combined with response surface methodology.Finally,changes in chemical composition and sensory quality before and after fermentation under optimal conditions were comparatively analyzed.The results showed that different biological enzyme preparations combined with aroma-producing yeast fermentation could effectively improve the quality of tobacco leaves.Among them,the G4 group composed of cellulase+pectinase+hemicellulase+lipase+aroma-producing yeast had the most obvious improvement effect,its quality improvement degree reached 0.94,and the content of total volatile aroma components increased to 197.57 μg/g.Through the response surface optimization combined with the actual production operation,the optimum process conditions were determined as follows:Fermentation time 4 d,fermaentation temperature 37℃,enzyme addition 0.4％.Under these conditions,the quality improvement degree increased to 1.15.After fermentation,the reducing sugar,chlorine and total sugar contents increased by 18.28％,-13.33％and 9.62％,respectively.The content of characteristic aroma substances such as phenylethanol,4-oxo-isophorone,geranylacetone,megastigmatrienone and phenethyl acetate were increased significantly.In summary,microbe-enzyme synergistic fermentation under suitable conditions offers a rapid and effective strategy for improving low-grade tobacco leaves and provides a reference for microbial applications in the tobacco industry.

Abstract:Fresh fruits and vegetables,due to their high water content and vigorous respiratory metabolism,are highly prone to quality decline and spoilage after harvest.As the world's largest producer and consumer of fruits and vegetables,China has a persistently high post-harvest loss rate of fruits and vegetables.The development of efficient and safe preservation technology has become an urgent need for the industry.Coating preservation technology is a new food preservation method,which can effectively maintain the quality of fresh fruits and vegetables and extend the shelf life of fruits and vegetables.Chitosan,as a natural biopolymer,is regarded as the most promising preservation coating material due to its wide source,degradability and biosafety,as well as excellent film forming property,antibacterial activity and biocompatibility.A systematic review is conducted on the basic characteristics of chitosan and the preparation methods of coatings.The research and application of chitosan coatings in the field of fruit and vegetable preservation are described in detail.The preservation effect of chitosan coatings on fruits and vegetables is discussed from the perspectives of appearance quality,nutrients,flavor substances and shelf life,and mechanism of preservation and the key factors affecting the preservation efficiency are summarized.Finally,the preservative chitosan coating technical bottlenecks and future development directions are pointed out,with the expectation of providing theoretical references for the in-depth research and industrial application of this technology.

Abstract:By detecting the susceptibility of Magnaporthe oryzae to tebuconazole in Hainan Province and studying the fitness of resistance strains,the resistance risk of M.oryzae to tebuconazole was understood,which would provide theoretical reference for the scientific use of fungicides and resistance management.The mycelial growth rate method was used to determine the susceptibility to tebuconazole of 144 strains of M.oryzae collected and isolated from Hainan Province in 2022,and the susceptibility baseline of M.oryzae in Hainan Province to tebuconazole was established based on the susceptibility frequency distribution of the strains.Fifteen susceptible strains with low effective inhibitory mid-concentration(EC50)measured during the establishment of the susceptibility baseline were selected for resistance domestication under continuous selection pressure,and the domesticated strains were classified into resistance levels,and the genetic stability and suitability of the resistant strains as well as the cross-resistance to the fungicides pyraclostrobin,flucycloxazole,imidacloprid,fenpyroximate,and aliconazole were determined.The EC50 values of the 144 strains tested ranged from 0.176 9 to 0.998 0 μg/mL.The EC50 value of the least sensitive strain was 5.64 times that of the most sensitive strain.The average EC50 value was(0.476 3±0.174 5)μg/mL.The susceptibility frequencies of the strains were distributed in a continuous single-peak curve,and the susceptibility baseline to tebuconazole of M.oryzae in Hainan Province was 0.476 3 μg/mL.Through indoor domestication of 15 sensitive strains,a total of two resistant strains were obtained.EC50 values were 1.289 5 μg/mL and 1.868 4 μg/mL respectively,and resistance folds were 5.38 times and 6.65 times respectively,both of which were low resistance level.And after eight consecutive generations of transfer,the two resistant strains always maintained low-level resistance.The EC50 values of pyraclostrobin,epoxiconazole,prochloraz,difenoconazole,and diniconazole were measured and compared between the strains resistant to tebuconazole and their parental strains.The results showed that there was no cross-resistance in M.oryzae in Hainan Province between tebuconazole and the above chemicals.Through the in vitro fitness test of the tebuconazole-resistant strains,it was found that compared with the parental strains,the mycelial growth rate of the two resistant strains was significantly reduced,and the conidia production was reduced to varying degrees.In addition,they were more sensitive to strong acid and alkali environment,and their pathogenicity was greatly reduced.Therefore,the frequency of resistance mutations to tebuconazole in rice blast strains in Hainan Province is low,and the environmental suitability of their resistant strains is significantly reduced,resulting in a low risk of resistance.In addition,there is no cross-resistance between tebuconazole and commonly used fungicides in Hainan Province,and the development of resistance can be delayed by strategies such as cross-rotation or mixing with multi-site-of-action protectants in production.

Abstract:To explore the quality differences and its influencing factors of Lingwuchangzao different glossiness fruit[high glossiness fruit(S fruit)surface is flat and smooth,fruit shape is typical of long oval,with appearance of good quality;Low glossiness fruit(R fruit)surface is uneven,fruit shape for the top of the fruit is sharply convex or concave,with appearance of poor quality],taking 7 Lingwuchangzao plantations in Lingwu City,Ningxia as the object of investigation,the investigation recorded the tree age,seedling type,jujube hanging thickness,jujube hanging length and other indexes,and collected different glossy fruits(S,R fruits)as the experimental materials,determined its glossiness,single fruit quality,fruit transverse and longitudinal diameter,etc.,and the soluble solids,soluble sugar,vitamin C(Vc),titratable acid content and other intrinsic quality indexes of the fruits and carried out the comparison and correlation analysis.The results showed that different plantations had Lingwuchangzao fruits with different glossiness(S and R fruits),and the ratio of R fruits had a tendency to decrease with the increase of the age of the trees;the glossiness of S fruits was 1.56 times larger than that of R fruits.And single fruit quality,fruit longitudinal and transverse diameter,fruit shape index,fruit skin thickness,pulp thickness,nuclear longitudinal and transverse diameter,single nucleus quality,fruit hardness were all very significantly smaller than R fruits.S fruits had a lower vitamin C content,sugar-acid ratio,and solid-acid ratio than R fruits.However,there were no significant differences in soluble solids,soluble sugar,titratable acid,anthocyanoside content,and other indexes between the two types of fruits.There was a significant correlation between the ratios of S and R fruits in Lingwuchangzao plantations and various factors such as seedling type,tree age,jujube hanging thickness,leaf chlorophyll content,and others.In summary,Lingwuchangzao plantations have different glossiness fruit(both S fruit and R fruit).The quality of different glossiness fruit has its own advantages and disadvantages:S fruit has the advantages of good appearance quality,normal fruit shape,sweet and sour taste;R fruit has the advantages of large fruit size,high vitamin C content,good for storage and transportation.