Bioinformatics and expression patterns of Dicer-like(DCL),Argonaute(AGO)and RNA-dependent RNA polymerase(RDR)gene families in the whole genome of Solanum habrochaites were analyzed,so as to provide references for further study on the functions of DCL,AGO and RDR gene families in the response of S.habrochaites to abiotic and viral infection.Using Arabidopsis thaliana DCL,AGO and RDR genes as reference sequences,the genome of S.habrochaites LA1777 was searched by local perl language and software such as Pfam and SMART,and the members of ShDCL,ShAGO and ShRDR gene families were determined.Bioinformatics analysis of DCL,AGO and RDR family genes in S.habrochaites was carried out by means of ExPASy,GSDS 2.0,MEGA,Tbtools and SWISS-MODEL.According to abiotic stress treatment,Tomato chlorosis virus(ToCV)treatment and Real-time Fluorescence Quantitative PCR technology,the expression patterns of these genes were analyzed.Seven ShDCL,15 ShAGO and 6 ShRDR genes were identified from S.habrochaites,which were distributed on chromosome 5,7 and 6 respectively.The encoded proteins were similar in structure to DCL,AGO and RDR in other plants,and all of them contained conserved domains unique to this family.Phylogenetic analysis showed that these genes were divided into 4 subgroups,and there were high structural and functional similarities between S.habrochaites and S.lycopersicum.ShDCL2a,ShDCL2c,ShDCL3,ShDCL4,ShAGO1b,ShAGO3,ShAGO4b,ShAGO5,ShAGO7,ShAGO10a,ShAGO10b,ShRDR1,ShRDR2,ShRDR3a,ShRDR6a and ShRDR6b were significantly up-regulated after various abiotic stresses and ToCV infection.It is speculated that these genes play important roles in abiotic stress and virus infection.

In order to investigate the function of watermelon calcium-dependent protein kinase (CDPK) in grafted seedlings and abiotic stress environments, this study used RT-PCR technology to clone the ClCDPK(Cla97C01G019720) gene from watermelon grafted seedlings and performed bioinformatics analysis on it. Further designed specific primers with Kpn Ⅰ and Sal Ⅰ enzyme cleavage sites based on the ClCDPK sequence,conducted amplification and double enzyme cleavage, and connected with pCAMBIA1300 to successfully construct the expression vector pCAMBIA1300-35S-ClCDPK for the target gene.Using RT-qPCR technology, the gene expression levels of ClCDPK were measured in self rooted seedlings (ZG) and grafted seedlings (JJ) after being subjected to salt and drought stress, respectively.The results showed that the ORF of ClCDPK gene was 1 647 bp, encoding 548 amino acids. Its protein contained STKc_CAMK and FRQ1 functional domains, and was a hydrophilic protein. Subcellular localization prediction showed that the protein was located in the nucleus. Evolutionary tree analysis of ClCDPK with CDPK from six other plants revealed that it was closely related to CDPK from Cucurbitaceae melons and pumpkins, with protein sequence homology alignment exceeding 92.64%, indicating high homology.The RT-qPCR expression results showed that the expression level of ClCDPK in grafted seedlings was significantly higher than that in self rooted seedlings. With the duration of stress, the expression levels of ClCDPK in grafted and self rooted seedlings first increased and then decreased, and under the same stress treatment, the expression level of ClCDPK in grafted seedlings was higher than that in self rooted seedlings.This study indicated that ClCDPK responded positively to salt and drought stress, and the ability of grafted seedlings to resist stress was higher than that of self rooted seedlings. It is speculated that ClCDPK is one of the key factors in watermelon's response to grafting, thereby improving the salt and drought resistance of watermelon grafted seedlings.

In order to study the problem of strong winter/spring Brassica napus seed germination and flowering period under different winter sowing dates.Two strong winter rapeseeds and two spring rapeseeds provided by Gansu Agricultural University were used as materials.The experiment was carried out in the experimental field of Gansu Agricultural University from October 2022 to August 2023.The winter rapeseeds was carried out on October 11,2022.The winter/spring rapeseeds was sown every 20 days from December 10,2022,and the sowing ended on February 8,2023.The flowering period was recorded,and the germination seeds of winter rapeseed were sampled every 20 days to determine their physiological and biochemical characteristics and analyze the expression characteristics of vernalization genes(FLC,VRN2,FRI,FT).The results showed that the flowering period of winter/spring rape seeds was different by 22—34 days.The difference of flowering time between autumn sowing and spring sowing was 4—7 days.The flowering time of winter rapeseed in autumn sowing(October 11 th)was close to that of spring rapeseed under different winter sowing dates(December 10th,December 30th,January 19th,February 8th),and the flowering overlap time was as long as 15—20 days.With the delay of the sowing date,the relative expression levels of FLC,FRI and FT genes in germinating seeds of winter sowing were down-regulated.The relative expression of VRN2 gene was down-regulated in the early vernalization and up-regulated in the late vernalization.The activities of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)and the contents of soluble protein(SP),gibberellin(GA3)and salicylic acid(SA)in germinating seeds were increased in the early vernalization,but those were decreased in the late vernalization.The contents of malondialdehyde(MDA)and abscisic acid(ABA)were increased in rapeseed germinating with the increase of vernalization time.

This study explored the effects of intercropping and rotation on the growth,yield and quality of continuous cropping peanut,to provide theoretical basis for achieving high yield in peanut production.From 2022 to 2023,sweet potato-peanut rotation system(PSP)and maize-peanut intercropping and rotation system(PMP)were set up in the experimental farm of Henan University of Science and Technology on the basis of continuous cropping peanut for 2 years and 11 years respectively,with continuous cropping peanut as control(CCP1 and CCP2,respectively).The effects of PSP and PMP on photosynthetic characteristics,root characteristics,dry matter accumulation and distribution and yield of peanut were studied.The results showed that compared with CCP1,the leaf area index(LAI)of rotating peanut in PSP system(SRP)was significantly increased by 35.08%—53.68% and 24.32%—33.52% at pod-setting stage(PSS)and full pod maturity stage(PMS),respectively.The SPAD value at PSS and pod bulking stage(PBS)increased by 11.93%—18.55% and 5.95%—9.63%,respectively.Compared with CCP2,the LAI of rotating peanut in PMP system(MRP)increased by 46.81%—57.96% and 27.00%—61.78% at PSS and PMS,respectively.At PSS and PBS,compared with CCP2,the SPAD value of MRP and intercropping peanut(MIP)increased by 3.32%—3.69%,7.50%—8.64% and 5.47%—18.37%,15.73%—31.11%,respectively.At PSS and PBS,compared with CCP1,the net photosynthetic rate of SRP increased by 23.68%—41.31% and 26.52%—32.55%,and compared with CCP2,MRP increased by 12.77%—17.81% and 16.88%—62.07%,respectively.They both significantly improved the root length and root tip number,and promoted the dry matter accumulation and the distribution to pods during PMS,and the yields increased by 31.42%—47.36% and 54.12%—75.09%,respectively.Compared with CCP2,MIP reduced the LAI,net photosynthetic rate,root length,root tip number,as well as dry matter accumulation and yield of peanut under the influence of maize shading.At the same time,the content of peanut oleic acid and oleic acid-linoleic acid ratio was significantly increased after rotation.Among them,SRP increased by 1.63—1.65 percentage point and 6.59%—10.52%,respectively,compared with CCP1,and MRP increased by 1.95—2.82 percentage point and 9.75%—14.16% compared with CCP2,respectively.In summary,sweet potato-peanut rotation and maize-peanut rotation increased the peanut yield compared with continuous cropping peanut,the reason was that sweet potato-peanut and maize-peanut rotation promoted peanut root growth,delayed the leaf senescence,and increased photosynthetic rate,especially the photosynthetic rate during late growth period,which promoted the dry matter accumulation and distribution to seeds.Besides that,they could improve the quality of peanut to a certain extent.

This study systematically investigates the effects of silicon-modified biochar (MSC) on the chemical properties of acidic soil,organic carbon and silicon fractions,and the growth of tomato plants.Silicon-modified biochar was prepared,with a focus on investigating its impacts on carbon and silicon chemical fractions,and the availability in acidic soils;tomato growth and soil microbial activity were also evaluated.The results showed that silicon-modified biochar significantly increased soil pH,cation exchange capacity,electrical conductivity,available phosphorus and potassium.MSC also raised the levels of water-soluble sodium and iron in the soil and enhanced the activities of hydrogen peroxidase and sucrase enzymes,thereby improving soil quality.Both biochar modification and unmodified biochar significantly increased the content of different carbon fractions in the soil.Compared with unmodified biochar,silicon-modified biochar significantly increased soil microbial biomass carbon(21.9%) and water-soluble organic carbon (898.3%).Furthermore,silicon-modified biochar significantly increased the contents of soil available silicon,water-soluble silicon,free silicon,active silicon,iron-manganese-bound silicon and amorphous silicon by 362.6%,158.9%,18.1%,34.9%,193.8%,and 74.1%,respectively.Meanwhile,the application of biochar promoted the growth of tomato plants and the absorption of silicon nutrients,with modified biochar showing more pronounced effects.The accumulation of plant dry matter,silicon content,and absorption rate increased by 82.0%,98.9%,and 261.5%,respectively.In summary,silicon-modified biochar significantly affected the carbon and silicon chemical forms and transformation in the soil,increased soil effectiveness and enzyme activity,thereby promoting nutrient absorption and growth of crops,demonstrating its good potential application in agricultural production.

To study the photosynthetic characteristics,fluorescence parameters and yield response to phosphorus in maize,and to clarify the optimal phosphorus application rate for maize under drip irrigation and water fertilization technology.Providing solid theoretical basis and technical support for high-yield and high-efficiency cultivation of maize in Ningxia region.The experiment was carried out at Pingjipu Farm,Yinchuan,Ningxia,from 2019 to 2020,with six phosphorus treatments in the order of 0(P0),60(P1),120(P2),180(P3),240(P4),and 300 kg/ha(P5).Analysis of the changing patterns of photosynthetic and fluorescence parameters of spring maize leaves and their correlation with yield under different phosphorus fertilizer treatments.In two years,during the big bell mouth stage,leaf area index (LAI) was increased by 4.21% to 12.78% and 4.68% to 15.60% for P3 compared to other treatments,respectively.Phosphorus fertilizer at 180 kg/ha was most effective in promoting leaf area index and photosynthetic potential(LAD) of maize.LAD was significantly increased by 14.42% under P3 treatment compared to no phosphorus fertilizer treatment during the full two year period.The photosynthetic characteristics of maize responded differently to the intensity of phosphorus application,and as the intensity of phosphorus application increased,the net photosynthetic rate (Pn) all reached the maximum value after the stamen pumping stage,and at the R1 stage of the 2 years,the Pn was significantly increased by 10.68% under the P3 treatment as compared to the no-phosphorus-fertilizer treatment.The coefficient of determination (R²) was 0.926 5,0.889 9,and 0.832 0,respectively.Phosphorus application increased the maize photosystem Ⅱ composite performance index (PI),which had its maximum peak at the R1 stage in 2 years,and PI increased by 1.12% to 8.50% and 8.47% to 15.40% under the P3 treatment compared with the other treatments,respectively.The maximum yield was obtained at 180 kg/ha of phosphorus application,which was 17.27% higher as compared to no phosphorus treatment.Based on the analysis of the yield fitting equation,it was shown that the maximum corn yield of 13 823.84 kg/ha was reached at 179.34 kg/ha of phosphorus applied.Pearson's correlation analysis showed that appropriate leaf area index significantly affected maize yield in the late stage,and the photosynthetic parameters all had highly significant effects on maize yield completion;principal component analysis showed that the P3 treatment had the highest composite score for the optimization effect on maize yield.Reasonable transportation of phosphorus fertilizer can effectively ensure higher SPAD value,PSⅡ reaction center activity,improve the capture and utilization of light energy in spring maize,and promote photosynthesis,so as to improve the yield and economic benefits of maize.

In order to clarify the role of the Zn(Ⅱ)2Cys6 transcription factor gene VDAG_ 04814 in the growth, development and pathogenicity of the Verticillium dahliae. It constructed a VDAG_04814 gene knockout mutant using homologous recombination mediated by polyethylene glycol. Wild-type and mutant strains were inoculated separately onto PDA media supplemented with hydrogen peroxide, sodium chloride, potassium chloride, sorbitol, sodium dodecyl sulfate, Congo red, as well as onto media overlaid with sterile cellophane, to analyze their levels of resistance to oxidative stress, salt stress, osmotic stress, stress on cell wall and plasma membrane integrity, and strain penetration ability. Their pathogenicity was assayed, and the fungal biomass in potato plants was detected. After hygromycin selection and PCR validation, the correct knockout transformants were able to amplify DNA bands of 1 500 bp upstream and downstream, respectively, as well as the full-length 4 500 bp knockout fragment sequence. The results demonstrated that the growth rate and melanin formation ability of the ΔVDAG_04814 mutants were significantly reduced. On media subjected to oxidative stress and salt stress with the addition of hydrogen peroxide, sodium chloride, and potassium chloride, ΔVDAG_04814 showed a higher inhibition rate compared to the wild-type. On osmotic stress media with sorbitol, the growth inhibition rate of ΔVDAG_04814 was significantly lower than the wild type. No growth inhibition was observed for ΔVDAG_04814 on media subjected to cell wall and membrane integrity stress with the addition of sodium dodecyl sulfate and Congo red. On media overlaid with sterile cellophane, no colonies grew for ΔVDAG_04814, whereas the wild-type strain produced normal colonies. Pathogenicity tests indicated that the wilting index of ΔVDAG_04814 was significantly reduced compared to the wild-type, with wilting index ranging from 47.22 to 55.56. It has been demonstrated that VDAG_04814 can regulate the growth, development, stress resistance, penetration ability and pathogenicity of V. dahliae towards potato. This study provides a new target for the control of potato Verticillium wilt disease.

Investigating the predominant genotypes of Bovine viral diarrhea virus(BVDV)infecting cattle in Tongliao,Inner Mongolia,to provide reference for the BVDV epidemiology and prevention and control.In the preliminary phase of the experiment,fecal samples from diarrheic calves were collected at a cattle farm in Tongliao,Inner Mongolia.These samples were tested using PCR to detect BVDV positivity.Positive fecal samples were then inoculated into madin-darby bovine kidney cells(MDBK)for isolation.The isolated strains were identified using RT-PCR and indirect immunofluorescence staining.Subsequently,the full-length genome of the isolates was sequenced,followed by genetic evolution analysis and genotype determination based on sequences of the 5'UTR,N^pro,and E2 genes.The results indicated that this experiment successfully isolated a strain of BVDV,designated as NM-21.Inoculation of NM-21 into MDBK did not induce cytopathic effects,indicating it was a non-cytopathic strain(NCP).Both RT-PCR and indirect immunofluorescence staining confirmed its positivity,with a virus titer of 10^-3 TCID₅₀/mL.Based on the full-length genomic sequence,and homology and genetic evolution analysis of the 5'UTR,N^pro,and E2 gene sequences,the isolate NM-21 showed the highest nucleotide homology with the BVDV-1c subtype strain NM2103(GenBank accession number ON337882.1)from Inner Mongolia,China.

The highly contagious gastrointestinal infectious disease caused by Porcine epidemic diarrhea virus(PEDV)has led to significant economic losses in China's pig industry.It aimed to establish a basis for PEDV antibody detection methods and functional research of the N protein through the screening of specific nanobodies(Nbs)using phage display technology.Peripheral blood lymphocytes were isolated from a camel immunized with the N protein,and total RNA was extracted and reverse transcribed into cDNA.The variable domain of the heavy chain of heavy chain antibodies(VHH)was amplified by PCR,subcloned into the pCANTAB5E-ccdb vector,and electroporated into ER2738 competent cells to construct the VHH phage antibody display library.Subsequently,the library was subjected to four rounds of panning against the PEDV N protein,and positive phage clones were cloned into the pET-30a vector.The binding affinity and specificity of the Nbs were determined by indirect ELISA and Western Blot.The results showed that after the fifth immunization,the antibody titer reached 1∶25 600.The constructed phage display library had a capacity of 4.72×10⁸ and an abundance of 4.3×10¹⁰ cfu/mL,with a 93.75% positive rate.After four rounds of screening,16 Nb clones with different amino acid sequences were obtained,and Nb45 was validated to possess excellent specificity and binding ability to the PEDV N protein.This study successfully screened and obtained specific N protein-targeting Nbs,providing biological materials for the establishment of PEDV detection methods and foundational research.

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

The EXORDIUM(EXO) gene was identified in Arabidopsis thaliana as an brassinosteroid(BR)-responsive gene that promotes plant growth by mediating cell expansion.In order to investigate the function of EXO gene in Brassica napus and its expression pattern in different tissues at flowering stage,we used B.napus Zhongshuang 6 as the material,cloned the sequence of the coding region of the EXO gene named BnEXO,and carried out bioinformatics analysis,and used Real-time Fluorescence Quantification to determine the relative expression of BnEXO gene in B.napus in roots,stems,leaves,petals,buds,and pericarps at flowering stage.The results showed that the CDS sequence of BnEXO gene was 945 bp,BnEXO was a stable hydrophilic non-transmembrane protein,which belonged to secreted proteins and was expressed extracellularly,and the secondary structure of the protein was dominated by the random coil.The results of expression analysis in different tissues showed that the expression of BnEXO gene in different tissues was in the order of petals,pericarps,buds,stems,roots and leaves,and the highest expression was found in petals.In addition,20 B.napus EXO genes(BnaEXO),11 B.rapa EXO genes (BraEXO),and 11 B.oleracea EXO genes (BoEXO)were identified in this study based on the protein sequences of eight EXO gene family members in A.thaliana.Most proteins of gene family members were stable proteins,localized extracellularly,with amino acid lengths ranging from 271 to 411 aa,isoelectric point predictions ranging from 5.76 to 9.60,and molecular masses ranging from 28.76 to 46.21 ku.Phylogenetic analysis classified the EXO genes into five subgroups,EXOA,EXOB,EXOC,EXOD,and EXOE,with the least number of members in the EXOB subgroup.Gene structure analyses showed that most members contained only one exon and no intron,and the sequences of EXO gene family members were highly conserved.The results of cis-element analysis of the promoter region of the members in B.napus indicated that the BnaEXO genes play important roles in plant growth and development and in adversity stress.

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