In order to accelerate the breeding of pink-tomato varieties,a rapid breeding strategy was used to generate pink-fruited tomato material by CRISPR/Cas9-mediated gene editing of SlMYB12.Two adjacent target sites within the first exon of SlMYB12 were selected to construct the CRISPR/Cas9 binary vector, and then the vector was introduced into red-fruited inbred line R18-10C through Agrobacterium-mediated transformation. The homozygous mutants without exogenous Cas9 were screened using specific primers and their agronomic traits and fruit nutritional quality were analyzed. Sequencing results showed that three homozygous mutants of different mutation types were obtained and all of which were frame shift mutations caused by base deletion. Compared with wild-type red fruit tomatoes, SlMYB12-edited plants grew and developed normally,and there were no significant difference in plant height,single-fruit weight,total yield per plant,fruit total soluble solid content and lycopene level,but the mature fruit showed pink and the flavonoid naringenin chalcone(NarCh)content of tomato peels was significantly reduced in MYB12-edited plants.In summary,the procedure for the generation of pink-fruited tomato plants through CRISPR/Cas9-mediated targeted mutagenesis of SlMYB12 was set up and new pink-fruited tomato germplasms with stable inheritance were obtained.

Cucumber powdery mildew is one of the main diseases that adversely impacts cucumber production,posing a significant challenge to its sustainable cultivation.Identifying genes related to cucumber resistance to powdery mildew can help understand the genetic principles and molecular mechanisms of cucumber resistance to powdery mildew,and provide diverse gene resources for disease resistant breeding.This study constructed F₁ and F₂ populations of QK×QG using cucumber resistant inbred line QK and susceptible inbred line QG as parents.Using the extreme trait mixed pool resequencing (BSA-seq) method,the genomic regions harboring the resistance genes of cucumber powdery mildew were preliminarily located.By integrating transcriptome data with gene annotation information,the association interval of the disease phenotype was narrowed,sequence variations were identified,and key genes were screened.The results showed that the resistance of powdery mildew may be controlled by recessive genes,and the population of F₂ showed a continuous normal distribution from resistant to susceptible.The BSA-seq analysis,combining the SNP-Index method and QTG(quantitative trait genomics)-seq method analysis highlighted the 19—21 Mb region of chromosome 5,where there were 77 annotated genes with SNP differences between samples,including 33 non-synonymous mutations.The transcriptome sequencing (RNA-seq) results showed that there were 309 upregulated genes and 697 downregulated genes in the susceptible material.The expression levels of 13 genes within the candidate segment of chromosome 5 showed significant differences after infection.Through a comprehensive analysis of differentially expressed genes and BSA,the candidate genes in this segment were narrowed to 3,and only SNP mutations were detected in the LOC101207011 gene.The candidate gene LOC101207011 was characterized by a mutation resulting in an amino acid change from Valine at position 656 to Leucine.This gene emerges as the primary focus of our investigation due to its potential role in conferring resistance to powdery mildew.

The identification and expression pattern analysis of CmPIPs gene family in melon could provide theoretical basis and support for further exploring the function of CmPIPs gene family and the genetic improvement of melon.TBtools,MEME,MEGA X and Plant-CARE tools were used to analyze the bioinformatics of CmPIPs,and the expression level of CmPIP2;7 in the pericarp of melon at different stages after pollination,and the expression level of each member of CmPIPs in different tissues and different concentrations of plant hormone treated young leaves were visualized in the software GraphPad Prism 10.The results showed that CmPIP2;7 and CsPIP2;8 had nearest kinship;the 12 members of the CmPIPs family were mainly distributed on chromosomes 1,3,4,5,9,10 and 11;except that CmPIP2;8 had 3 CDS regions,the other members had 4 CDS regions.The promoter regions of each member of CmPIPs had multiple cis-acting elements,hormone responsive elements,such as auxin,gibberellin,and abscisic acid.The expression level of CmPIP2;7 was significantly up-regulated during rapid development and maturity of melon fruit.Members of various families of CmPIPs were expressed in different tissues of melon.After treatment with 40.0 μmol/L auxin,the expression level of CmPIP2;4 was significantly up-regulated,while the expression level of CmPIP1;1,CmPIP 2;1,CmPIP2;2 and CmPIP2;3 were extremely significantly down-regulated,and when the concentrations of abscisic acid were 0.4,4.0 and 40.0 μmol/L,the expression level of CmPIP1;1,CmPIP2;1,CmPIP2;3,CmPIP2;9 were significantly down-regulated.After treatment with 44.640 μmol/L methyl jasmonate,the expression level of CmPIP2;1 and CmPIP2;5 were significantly down-regulated,while the expression level of CmPIP2;2,CmPIP2;3,CmPIP2;7 and CmPIP2;9 were significantly up-regulated.When the concentration of ethylene glycol was 4.0 mmol/L,the expression level of each member of CmPIPs was significantly up-regulated.The gene structure,sequence characteristics,evolutionary relationship and collinearity of CmPIPs gene family members were clarified,and their expression pattern were analyzed.

In order to explore the effects of combined application of amino acid fertilizer and urea on soil active organic carbon components and enzyme activities in pepper,and to clarify the fertilization mode to increase the content of soil active organic carbon components in pepper.Seven treatments were set up,including no fertilization(CK),single application of urea(N0),80% urea + 20% amino acid fertilizer(N20),60% urea + 40% amino acid fertilizer(N40),40% urea + 60% amino acid fertilizer(N60),20% urea + 80% amino acid fertilizer(N80)and single application of amino acid fertilizer(N100).The changes of soil physical and chemical properties,soil active organic carbon content and enzyme activity under each treatment were studied.The results showed that the combined application of amino acid fertilizer and urea could effectively increase the contents of nitrogen,phosphorus and potassium,organic matter,enzyme activity,organic carbon and its active components in soil.The content of soil organic carbon increased with the increase of amino acid fertilizer application,and the content of soil active organic carbon components and enzyme activity increased first and then stabilized or decreased slightly with the increase of amino acid fertilizer application.The soil easily oxidized organic carbon content,particulate organic carbon content,microbial biomass carbon content,cellulase activity,catalase activity and amylase activity of N60 treatment were the best:in 0-20 cm soil layer,compared with CK treatment,they were increased by 105.50%,19.43%,142.60%,126.57%,22.28% and 308.20%,respectively.In the 20-40 cm soil layer,compared with CK treatment,it increased by 39.75%,59.32%,59.00%,130.27%,33.24% and 342.16%,respectively.Correlation analysis showed that soil total organic carbon and active organic carbon components were significantly positively correlated with enzyme activity.It can be seen that the combined application of amino acid fertilizer and urea can effectively improve the soil active organic carbon content and enzyme activity in pepper,and the treatment of 40% urea combined with 60% amino acid fertilizer has the greatest potential for improvement.

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.

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.

The folding mode of Chinese cabbage leaf ball is the main character that determines the appearance shape,taste and stress resistance of commercial organs.In order to explore the internal molecular mechanism of the formation of the folding mode of Chinese cabbage,we cloned the full length sequence of the transcription factor BrPIF5 gene from overlaping and outward-curling Chinese cabbage as experimental materials,and conducted bioinformatics analysis,constructed the plant overexpression vector,and used Agrobacterium to mediate the transformation into tobacco to obtain positive transformation plants.The expression level of BrPIF5 gene in tobacco was detected by qRT-PCR.The results showed that the protein encoded by BrPIF5 gene was a hydrophilic protein with a continuous and complete open reading frame of 634 bp,containing 210 amino acids.The protein was composed of more α-helical structure and random curl,including an AP2/ERF domain.BrPIF5 protein and the other 9 gene family members contained a conserved motif 1,and the position was different from that of other gene family members,which was located in the front of the protein sequence.Phylogenetic tree showed that BrPIF5 gene had close evolutionary relationship with SoPIF15,BhPIF1,BoPIF4,AtPIF4 and BrPIF4 family members.The tobacco strain with overexpression of BrPIF5 was obtained by Agrobacterum-mediated genetic transformation,and the leaves of the tobacco positive transformation strain showed inward curling.qRT-PCR showed that the expression level of BrPIF5 gene in the overlaping Chinese cabbage was higher than that in the outward-curling Chinese cabbage,and the gene expression level in the positive tobacco plants was higher than that in the control.It was further proved that BrPIF5 gene controlled the inward curling of Chinese cabbage leaves,thus promoting the formation of leaf ball folding type.

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.

Serine hydroxymethyltransferase(SHMT),as an important enzyme involved in basic metabolism,plays an important role in plant cell metabolism,photorespiration and defense activities.To understand the bioinformatics function of the SHMT gene family in watermelon,explore its gene expression characteristics under abiotic stress,and provide a basis for the functional development of watermelon SHMT and the breeding of watermelon stress-resistance genes.Bioinformatics methods were used to identify SHMT family,and RT-qPCR was used to analyze the expression patterns of ClSHMTs in different tissues and abiotic stresses.The results showed that 8 ClSHMTs gene family members were identified in the whole genome of watermelon,which were unevenly distributed on 6 chromosomes and named ClSHMT1—ClSHMT8 in turn.There were some differences in the physical and chemical properties of each gene family member,such as the number of amino acids,molecular weight,isoelectric point.The protein contained 471—585 amino acids,with molecular weight of 51.87—65.00 ku and isoelectric point of 6.57—8.52,all of which were hydrophilic proteins.The subcellular localization prediction was mainly distributed on mitochondria.Gene structure and protein conserved motifs analysis showed that the ClSHMTs structure consisted of 4—15 exons and 3—14 introns,and all ClSHMTs contained conserved SHMT domains.Furtherly,phylogenetic analysis with 6 species such as cucumber and wheat showed that 50 SHMTs were divided into 3 sub-families,Group Ⅰ—Ⅲ.Promoter of ClSHMTs contained cis-acting elements related to light response,plant hormone response and stress response.The expression pattern analysis showed that 6 ClSHMTs were expressed in different tissues of watermelon,and the expression levels of ClSHMT1,ClSHMT4,ClSHMT5,ClSHMT8 in leaves were significantly higher than those in other tissues.Under low temperature,drought and salt stress,the expression abundance of ClSHMTs varies,but the expression was mainly up-regulated.In conclusion,this study systematically analyzed the SHMT gene family in watermelon,and will provide a reference for the further study of the biological functions of ClSHMTs.

In order to explore the effects of high temperature stress on different heat-tolerant watermelon inbred lines,heat-sensitive (D27) and heat-tolerant (K53) watermelon seedlings were treated at 42 ℃ for 48 h,and their phenotype,tissue structure,photosynthetic characteristics,antioxidant enzyme activities and osmotic regulators were measured and analyzed every 12 h.The results showed that the leaf thickness,fence tissue thickness,sponge tissue thickness and tissue compactness of heat-tolerant K53 were larger than those of heat-sensitive D27 after high temperature stress.The proportion of sponge tissue in the palisade tissue of D27 decreased more than that of K53.With the increase of high temperature stress time,the net photosynthetic rate (Pn),transpiration rate (Tr) and stomatal conductance (Gs) of the two inbred lines decreased,and the intercellular CO₂ concentration (Ci) increased.And the change amplitude of D27 was greater than that of K53.Among the four photosynthetic pigment contents,the heat-tolerant type was higher than the heat-sensitive type under high temperature stress at different treatment times.The superoxide dismutase (SOD) and peroxidase (POD) of the two inbred lines increased first and then decreased with the increase of high temperature stress time,and the enzyme activity was the highest at 24 h,and the enzyme activity of K53 was significantly higher than that of D27.After high temperature stress,the relative conductivity of the two inbred lines increased,and the relative conductivity of K53 increased less than that of D27.The malondialdehyde (MDA) content of D27 was reduced;the MDA content of K53 decreased after an increase.With the increase of high temperature stress,the soluble protein content and proline content (Pro) of K53 were significantly higher than those of D27 at 24 h.In summary,the heat-tolerant type K53 had a stronger resistance to high temperature stress than the heat-sensitive type D27.

This study revealed the changes of bacterial community structure and diversity in facility cucumber rhizosphere soil affected by different reactors,aiming at providing theoretical basis and practical basis for cucumber rhizosphere soil improvement and sustainable utilization of protected soil.This experiment was based on the V3-V4 region of the 16S rRNA gene,seven treatments namely,original greenhouse soil(CK),untreated cucumber rhizosphere soil for 100 days(CK1) and 200 days(CK2),corn straw bioreactor-treated cucumber rhizosphere soil for 100 days(S1)and 200 days (S2),and sheep manure bioreactor-treated cucumber rhizosphere soil for 100 days(M1)and 200 days(M2).High-throughput sequencing technology using Illumina Miseq was used to analyze the diversity,structure,and physical and chemical properties of the bacterial communities in the rhizosphere soils of different bioreactor treatments on facility cucumber.The results showed that 6 344 OTUs were obtained from soil samples after sequencing,which mainly belonged to 39 phyla,315 orders and 980 genera.M2 treatment could improve the bacterial richness in cucumber rhizosphere soil and significantly increase the diversity of bacterial community.At the phylum level,the dominant population structure of bacterial phylum in soil treated by corn straw bioreactor and sheep manure bioreactor was similar,among which Actinobacteriota and Proteobacteria were the dominant phylum.At the genus level,norank_f_JG30-KF-CM,Arthrobacter,norank_f_norank_o_Gaiellales,norank_f_67-14,Blastococcus,Gaiella and Marmoricola were significantly different among different treatments.According to the composition of bacterial community abundance,M2 and S2 treatments increased the relative abundance of some beneficial bacterial groups in cucumber rhizosphere to some extent.RDA analysis showed that the soil bacterial community was significantly affected by soil environmental factors,and the contents of ammonium nitrogen(P=0.015),total potassium(P=0.002)and available potassium(P=0.005)had significant effects on the bacterial community.Therefore,M2 treatment can improve the bacterial richness in facility cucumber rhizosphere soil,increase the diversity of bacterial community and change the bacterial community structure,which is beneficial to the improvement of facility cucumber rhizosphere soil.

MADS-box transcription factors are widely found in plants and play important roles in plant growth and development and secondary metabolism.To investigate the expression of MADS-box transcription factor family in different accumulation periods of capsaicin.MADS-box transcription factor family was identified by using transcriptome data from different accumulation periods of capsaicin,and their functions were preliminarily analyzed.Subcellular localization,conserved motifs,phylogenetic tree and chromosomal localization of members of the MADS-box transcription factor family of chili peppers were carried out.The results showed that a total of 95 MADS-box transcription factors were identified in the Capsicum annuum L.transcriptome data;containing 105-395 amino acids;with molecular weight ranging from 11.55-44.46 ku;with theoretical isoelectric points ranging from 5.16-10.01;mainly expressed in the nucleus,and all of them contained MADS conserved structural domains,and phylogenetic analysis showed that MADS proteins could be divided into eight subfamilies.There were 73 CaMADS family members localized to 12 chromosomes.There were 26 differentially expressed MADS-box genes,six of which were up-regulated during C1 vs C2 and down-regulated during C2 vs C3.Based on KEGG enrichment and protein interactions,it was predicted that CaMADS13 might be involved in lignin synthesis in chili peppers.CaMADS24 might be involved in the synthesis of capsaicin and lignin synthesis precursor,coumaroyl-coenzyme A.Bioinformatics analysis was used to identify the MADS-box family of transcription factors in chili peppers,which provides data reference and theoretical basis for in-depth study of the molecular mechanism of action in the secondary metabolism of capsaicin.

In order to identify the key genes controlling rind hardness and breed crack-resistant watermelon varieties.An F₂ segregating population was created using the high-firmness line 901 and the low-firmness line BSH.Both BSA-seq and RNA-seq approaches were utilized to map the genes responsible for rind hardness.The results of BSA-seq revealed an interval region of 2.14 Mb on chromosome 10,spanning from 1 620 000 to 3 760 000,where the intersection of SNPs and InDels identified 150 candidate genes.Among these,two genes showed non-synonymous mutations,and one gene exhibited a frameshift mutation.Correlation analysis between BSA-seq and RNA-seq identified 6 correlated genes,including Cla97C10G187120, Cla97C10G187020,Cla97C10G187430,Cla97C10G187510,Cla97C10G187280,and Cla97C10G186540.Through bioinformatics analysis,the candidate gene Cla97C10G187120 was identified.The result of qRT-PCR indicated that the transcriptome data was reliable.And the relative expression of the candidate gene Cla97C10G187120 was lower in the line 901 than the line BSH.This study lays a crucial foundation for understanding the molecular mechanisms underlying watermelon rind hardness.

In order to screen out suitable water and nitrogen combinations for watermelons in Yellow River irrigation area of Ningxia, different water and nitrogen treatments were designed to study the effects of water and nitrogen interaction on SPAD value of watermelon leaves, fruit quality,yield and nitrogen uptake and utilization. The results showed that SPAD values were higher by W1N4,W2N3,W2N4,W3N3 and W3N4 treatment,the quality was better under nitrogenous fertilizer amounts at N2 and N3.The yield was the highest under W3N4 treatment,reaching 76 565.36 kg/ha and increased by 8.34% to 37.57% compared with other treatments significantly.Followed by W3N2 and W3N3 treatment.Compared with other levels,when the irrigation water level was W1,the water use efficiency of facility watermelon irrigation was higher.Among them,the irrigation water use efficiency of W1N3 and W1N4 treatment was higher,reaching 43.91,45.32 kg/ha respectively,while it was significantly increased by 14.00% to 56.40% from other treatments.Fruit nitrogen accumulation and total nitrogen accumulation under W3N4 treatment were all the highest compared with other treatments significantly,increasing by 22.75% to 192.36% and 17.00% to 123.39% respectively compared with the other treatments.Partial factor productivity of nitrogen and nitrogen fertilizer utilization rate under W3N2 treatment were all the highest compared with other treatments significantly.Partial factor productivity of nitrogen increased by 11.00% to 343.68%separately compared with the other treatments and nitrogen fertilizer utilization rate increased by 3.34 to 10.02 percentage points compared with other treatments.The correlation analysis showed that SPAD,the center of soluble solids,Vc,yield,irrigation water use efficiency and nitrogen accumulation,were all significantly positively correlated with each other,and they were significantly negatively correlated with partial factor productivity of nitrogen and nitrogen use efficiency,the edge of soluble solids was positively correlated with nitrogen accumulation of the plants,and negatively correlated with partial factor productivity of nitrogen and nitrogen use efficiency.To sum up,the watermelon had better quality when nitrogenous fertilizer amounts were N2(80 kg/ha) and N3(160 kg/ha),the yield-increasing effect was the best under the combination of water amount for W3(2 200 m³/ha)and nitrogenous fertilizer amount for N4(240 kg/ha).The interaction between high amount of irrigation water and nitrogenous fertilizer application is beneficial to the nitrogen absorption in watermelon,and the interaction between low nitrogen application amount and high nitrogenous fertilizer amount is conducive to utilization of nitrogen fertilizer.

Abstract:To explore the effects of phosphorus fertilizer reduction ratio and phosphorus fertilizer management method on tomato yield,phosphorus utilization rate and soil fertility level under simultaneous reduction of chemical fertilizer nitrogen,phosphorus and potassium in high fertilizer application areas,an experiment was conducted in a greenhouse located in Dingxing County,Hebei Province.Overwintered long-season tomato was chosen as the experimental plant.Treatments included CF(N-P₂O₅-K₂O,1 009.5-774.0-1 458.0 kg/ha),P1(N-P₂O₅-K₂O,750.0-375.0-1 125.0 kg/ha),PB2(N-P₂O₅-K₂O,750.0-225.0-1 125.0 kg/ha),PT2(N-P₂O₅-K₂O,750.0-225.0-1 125.0 kg/ha),P3(N-P₂O₅-K₂O,750.0-75.0-1 125.0 kg/ha)and P4(N-P₂O₅-K₂O,750.0-0.0-1 125.0 kg/ha).Fertilizer phosphorus was applied basally in the PB2 treatment,and the other fertilizer-reduced treatment fertilizer phosphorus was applied in a "Basal dressing and topdressing" method.The result showed that compared to CF,tomato yield of PT2 treatment over the three-year period revealed an average increase of 12.0%,with the highest increase.After three years of fertilizer reduction,the root dry weight of P1,PB2 and PT2 significantly increased,along with improvements in the chemical phosphorus fertilizer utilization rate,phosphorus fertilizer agronomic utilization rate,and the chemical phosphorus fertilizer harvest index.Compared to CF,PT2 treatment resulted in an increase in root shoot ratio of 48.2%, phosphorus fertilizer recovery rate and phosphorus fertilizer harvest index increased by an average of 32.9 and 2.7 percent points, phosphorus fertilizer agronomic utilization rate was 9.02 times higher than that of CF.PT2 treatment was the highest among all fertilizer reduction treatments.Compared to the CF treatment,soil $NO_3^{-}$-N,Available P and Available K contents were reduced by an average of 8.2%—14.9%,4.4%—19.9%,and 7.3%—24.8%,respectively,over the three-year period.In conclusion,a 35.2% reduction in chemical fertilizer,which included a 70.9% decrease in chemical phosphorus fertilizer,did not have a negative impact on yield in greenhouses with excessive fertilizer use.Additionally,the combination of "Basal dressing and topdressing" method for phosphate management enhances tomato yield in comparison to basal dressing alone.This method also reduces available phosphorus content and increases the efficiency of chemical phosphorus fertilizer utilization.

Calmodulin-like proteins(CMLs),one of the Ca²⁺ receptors in plants,are involved in the process of plant growth and development,as well as adaptation to environmental changes.To understand the sequence characteristics of garlic CMLs and their responses to osmotic stress,AsCML15 and AsCML42 genes from garlic variety Cangshan siliuban were cloned,and their expression patterns under drought and salt stress conditions were determined.The results showed that the open reading frame of AsCML15 and AsCML42 genes were 498 and 543 bp in length,respectively,encoding 165 and 180 amino acid residues.AsCML15 and AsCML42 harbored four and three EF-hand domains,respectively.AsCML42 was closer to Arabidopsis AtCML42 and AtCML43 in evolutionary relationship,whereas AsCML15 was more closely related to Arabidopsis AtCML15 and AtCML16.Real-time Quantitative PCR technology showed that AsCML15 and AsCML42 were expressed in bulbs,leaves,and roots,and these two genes can be induced by 200 mmol/L NaCl and 15% PEG6000.The AsCML15 and AsCML42 genes may be involved in the process of garlic resisting salt and drought stress,and their biological functions can be further identified.

In order to study the mechanism of PSY1 gene in different ripe fruit colors of peppers, Y15016,Y15016-2,SP01,SP02 and Z1 were used as materials,and the functional properties of PSY protein and the expression of PSY1 gene in different fruit color materials of pepper were studied and analyzed by combining some bioinformatics methods.The results showed that the full-length PSY1 gene could be cloned in all five pepper varieties,and there was no difference in sequence.Gene structure analysis showed that the PSY1 gene contained six exons and five introns with a total length of 2 844 bp,and its CDS contained 1 260 bp and encoded 419 amino acids.Sequence alignment and phylogenetic tree analysis showed that the PSY protein of pepper was the closest to the homologous PSY protein of tomato and tobacco of the same family.The results of qRT-PCR analysis showed that the expression level of PSY1 gene in the five materials was lowest in the root tissue and highest in the leaf tissue.Besides,the PSY1 gene was expressed in all the tissues of these materials.The expression level of orange mutant Y15016-2 was higher than that of wild-type Y15016,while that of yellow mutant SP02 was significantly lower than that of wild-type SP01.At different stages of fruit development,the expression of PSY1 gene increased with the development of fruits,except for the decrease in stage Ⅲ,and reached the maximum value at the maturity stage(Ⅳ—Ⅴ)of different fruit color materials.The results of PSY1 gene promoter analysis showed that there was no difference in the sequences in the test materials.The results suggest that the differential expression of PSY1 gene may play an important role in the formation of peppers with different fruit colors.

In order to determine whether Tomato brown rugose fruit virus(ToBRFV)occurs in Zhangjiakou and Yinchuan tomato producing areas,and to explore the genetic information and evolution of ToBRFV,so as to provide an important scientific basis for the diagnosis and control of ToBRFV and the genetic engineering of tomato resistance to viral diseases.Molecular detection was carried out in Zhangjiakou and Yinchuan suspected diseased fruits,and sequence analysis and genome-wide phylogenetic analysis of the virus gene were carried out by relevant molecular biology software.The results showed that the genome structure similarity between the virus isolates from Zhangjiakou and Yinchuan fruit was more than 99% similar to most of the ToBRFV isolates in GenBank,and the tomato fruit virus in the two places was determined to be ToBRFV.ToBRFV isolates were highly regional,and ToBRFV viruses from different regions of China were associated with many countries and regions from Europe and Asia,and the Zhangjiakou isolate was most closely related to the Chinese isolate(MT018320.1),and the Yinchuan isolate was clustered with the Peruvian isolate,indicating that the Yinchuan isolate may have originated from South America.The similarity of the four ORF amino acids of the Zhangjiakou isolate from China(MT018320.1)was the highest,while the similarity between the Yinchuan isolate and the Zhangjiakou isolate was low.In addition,this study found for the first time that the 444th base of the Yinchuan isolate CP protein changed from A to G,resulting in a meaningful mutation of the 131st amino acid of the CP protein from V(valine)to A(alanine).In summary,ToBRFV disease occurred in Zhangjiakou and Yinchuan tomato producing areas,and the virus came from different places in the two regions.

In order to quickly obtain homozygous and stable DH lines of Chinese cabbage resistant to clubroot disease,and to provide basic materials for breeding Chinese cabbage resistant varieties to clubroot disease,5 resistant genotypes of Chinese cabbage were used as materials for isolated microspore culture in this study,and phenotype and resistance of the obtained microspore regenerated plants were identified by combining molecular markers,morphological observation,and artificial inoculation of P.brassicae.The results showed that all 5 genotypes were induced to produce embryos,with a variation of 0.02 to 1.72 embryos per bud.Three genotypes,20aCR12,21aCR6,and 21aCR12,obtained regenerated plants,with regeneration rates of 27.09%,1.45%,and 26.07%,respectively.Resistance marker identification showed that molecular markers linked to CRa and CRb^kato all amplified the resistant bands in 50 obtained microspore plants.Phenotypic investigation showed that there were significant differences in the shape and color of basal leaves,bolting timing,and fertility among 50 microspore plants at reproductive growth stage,and 29 DH lines obtained through self-pollination also showed exhibited diversity in plant type,leaf traits,and heading traits at nutritional growth stage.Resistance inoculation showed that the disease index of 11 DH lines to races 4 and 1 of P.brassicae was less than 33.33,indicating resistance or tolerance to clubroot disease.Among them,there were 3 highly resistant DH lines with a disease index less than 5.0 for two races of P.brassicae,namely 20aCR12-23,20aCR12-29,and 21aCR12-39.The research results have shown that the homozygous DH lines resistant to clubroot can be obtained quickly by microspore culture combined with molecular marker assisted identification.

Photoperiod is one of important environmental factors affecting plant bolting and flowering which are regulated by plant phytochrome proteins.The signal network mediated by PHYB has an important inhibitory effect on plant bolting and flowering.Previous studies revealed that there were large segment insertion/deletion differences between the PHYB gene promoter of the Chinese cabbage late-bolting line 06-247 and the easy-bolting line He102.In order to further investigate the impact of promoter mutation on PHYB and the key genes of its downstream pathways,this study was conducted.Based on bioinformatics methods,the redundancy characteristics of phytochrome genes in genome Chinese cabbage were firstly analyzed.It was found that the Chinese cabbage genome contained six phytochrome genes,of which PHYA had two copies,and PHYB,PHYC,PHYD,and PHYE all had only one copy.Then amino acid sequence alignment was used for screening of the specific sequence of PHYB.Antigenic determination clusters were designed based on the specific sequence and the antibodies against PHYB was prepared.The fluorescence quantitative RT-PCR technology and Western Blot technology were used to study the relative content of PHYB in 06-247 and He102.At the same time,the dynamic changes of key regulatory genes such as CCA1,FLC,CO and FT which in the downstream of PHYB pathway were also compared.The results showed that the promoter mutation caused significant differences both in level of mRNA in 06-247 and then significantly increased the protein level of PHYB.At the same time,the downstream regulatory genes such as CCA1,FLC,CO and FT were highly expressed in 06-247,which had an important impact on bolting resistance of 06-247.

In order to investigate the physiological stress response mechanism of pepper fruits to UV-B radiation and further elaborate the mechanism of fruit quality deterioration in vegetables in high UV-B radiation areas,the young fruits,green fruits and red fruits of UV-sensitive variety Huamei 105 and UV-resistant variety Ledu long pepper were selected as test materials. The effects of different UV-B radiation duration (dose)of 0 (CK),2,4 and 6 h on fruit growth and development,prototype protection and nutrient quality related substances content were studied. The results showed that with the extension of radiation time,the single fruit weight and transverse diameter of Huamei 105 decreased significantly at the green and red fruit stages,which inhibited the fruit growth. The contents of protective substances Vc and total phenol in fruits of the two varieties at each growth stage increased gradually as the extension of treatment time,while the contents of soluble protein decreased gradually. The contents of Vc and total phenol significantly increased after 6 h,and the contents of soluble protein decreased the most. The contents of Vc,total phenol and soluble protein of Huamei 105 changed greater than those of Ledu long pepper. With the extension of radiation time,the content of soluble sugar showed a trend of first increasing and then decreasing,while the content of cellulose showed a trend of first decreasing and then increasing. In conclusion,UV-B had little effect on the indexes in the young fruit stage of the two varieties. High-dose UV-B could significantly inhibit the growth of the UV-sensitive varieties at the green and red fruit stages,and significantly increase the contents of Vc,total phenol,cellulose and other substances in the two varieties,and significantly reduce the contents of soluble protein and soluble sugar. However,low dose UV-B could significantly increase the soluble sugar content,and the increase or decrease amplitude was higher in UV-sensitive varieties than in UV-resistant varieties. Therefore,lower than 1/4 lethal dose of UV-B can promote fruit quality,and higher than 1/2 lethal dose of UV-B can make pepper fruit quality start to deteriorate.

In order to explore the effects of different concentration of exogenous GABA on tomato seedlings dry matter accumulation,root development,antioxidant enzyme activities and photosynthetic characteristics under high temperature stress,the tomato variety Fenteli was selected as the test material,and five treatments,including spraying distilled water (CK),1 mmol/L GABA(T1),5 mmol/L GABA(T2),10 mmol/L GABA(T3)and 20 mmol/L GABA (T4),were set up in this study. Spraying once every two days for two consecutive times. After spraying,the seedlings were exposed to high temperature stress at 40 ℃/35 ℃ (day/night),14 h (light)/10 h (dark)with light intensity of 250 μmol/(m²·s)for 7 days. The results showed that compared with CK,spraying GABA with the concentration of 10 mmol/L or less (T1,T2 and T3)significantly promoted the growth of tomato seedlings,and the plant height,stem thickness,aboveground dry weight and seedling index increased by 4.96%—6.92%,7.65%—19.26%,29.41%—52.94%,20.00%—26.67%,respectively. Noteworthy,compared with CK,T2 treatment significantly increased the total root length,total surface area,total volume and tip numbers of root system by 23.04%,13.95%,11.76% and 18.30%,respectively. Moreover,compared with CK,T2 treatment not only increased the leaves activities of SOD,POD and CAT in (increasing by 22.58%,51.73% and 148.80% respectively),but also decreased the relative conductivity and malondialdehyde content (decreasing by 12.84% and 21.89%),and thus significantly increasing the photosynthetic rate,stomatal conductance and transpiration rate of leaves (increasing by 81.38%,36.19% and 41.26% respectively)by ensuring the integrity of the cell membrane structure and function of leaves. However,there were no significance differences for the dry matter accumulation,photosynthetic characteristics and relative conductivity of tomato seedlings under T4 and CK treatments,and even the former inhibited the root development. In a word,our study demonstrated that foliar spraying with an appropriate GABA concentration could alleviate the inhibition of photosynthesis under high temperature stress through protecting the integrity of leaf cell membrane by improving capacity of leaf osmotic adjustment and antioxidant enzyme activities. Additionally,spraying GABA could also improve the heat tolerance of tomato seedlings by promoting dry matter accumulation and root development. The effect of GABA with 5 mmol/L was the best in this study.

Using tomato as experimental material and using sand cultivation method,the effects of exogenous addition of potassium humate and amino acid fertilizer on the metabolic pathway,plant biomass,nutrient uptake,yield and quality index of tomato at seedling stage were explored.The experimental results showed that:the root growth of tomato increased by 118% and 13% at the seedling stage and flowering and fruiting stage under potassium humate treatment,and the nitrogen,phosphorus and potassium carrying in the stem increased significantly by 31%,45% and 26%.The amount of phosphorus carried out in leaves increased significantly by 92%.Phosphorus carrying from fruit also increased significantly by 45%.The metabolomic results showed that potassium humate treatment mainly affected tomato glutathione metabolism,glycine serine and threonine metabolism,porphyrin and chlorophyll metabolism,while amino acid fertilizer treatment mainly affected tomato propionic acid metabolism,pantothenic acid and coenzyme A biosynthesis and TCA cycling.Compared with the blank control,the yield of tomatoes under potassium humate treatment increased by 35%,the fresh weight and dry weight of the aboveground increased by 21% and 5%,and the soluble sugar content,sugar-acid ratio and soluble solids content in tomato fruits were also significantly increased,with increases of 30%,41% and 0.39 percentage point,respectively.The application of amino acid fertilizer significantly increased the root length,aerial fresh weight and fruit yield of tomato during the flowering and fruiting stage,which increased by 19%,18% and 26%,respectively,and the soluble solids content of tomato fruit increased by 0.30 percentage point,the solid-acid ratio increased by 16%,and the weight per fruit increased by 15.6%.In summary,the application of potassium humate and amino acid fertilizer can significantly change the carbon and nitrogen metabolism process of sand tomato plants,promote tomato growth and fruit quality,and is an effective agronomic measure to achieve high-yield and high-quality tomato cultivation.

WRKY transcription factor is a family of transcription factors unique to plants.Studies have demonstrated that WRKY transcription factor played an important role in plant growth and development and in plant response to biological and abiotic stress.In order to reveal the function of tomato WRKY gene,two inbred lines of tomato with high resistance to bacterial wilt Hm 2-2(R)and high susceptibility to bacterial wilt BY 1-2(S)were used as experimental materials based on the preliminary transcriptome data,and a WRKY transcription factor SlWRKY75 gene(Solyc05g015850.3)was cloned.The structure,expression pattern and function of the gene and its encoded protein were analyzed by bioinformatics analysis,multiple alignment of amino acid sequences,phylogenetic tree construction,Real-time Quantitative PCR(qRT-PCR)and virus induced gene silencing(VIGS).The results showed that the full length of the cDNA of this gene was 653 bp,its maximum open reading frame was 519 bp,encoding 172 amino acids,the relative molecular weight of the protein was 19.878 51 ku,the theoretical isoelectric point was 9.32.The protein belonged to the hydrophilic non-secreted protein,and there was no transmembrane structure.Meanwhile,the protein had a highly conserved WRKY domain and a CX₄CX₂₃HXH zinc finger motif,which belonged to the Class Ⅱ family.Phylogenetic tree analysis showed that SlWRKY75 was closely related to Solanum pennellii SpWRKY75 and clustered into a group with other Solanaceae,while it was far related to Hevea brasiliensis HbWRKY75 and Gossypium hirsutum GhWRKY75 and was in different branches in the phylogenetic tree.The results of qRT-PCR analysis showed that the expression of SlWRKY75 gene were tissue-specific and could be induced by Ralstonia solanacearum,salicylic acid and jasmonic acid.VIGS result showed that silencing SlWRKY75 reduced plant resistance to bacterial wilt,indicating that SlWRKY75 positively regulated tomato resistance to bacterial wilt.These results suggested that SlWRKY75 gene played an important role in regulating tomato resistance to bacterial wilt.

Glutamate decarboxylase(GAD)is a cleavage enzyme that catalyzes the decarboxylation of glutamic acid,plays a key role in GABA synthesis pathway and has an important influence on plants' resistance to abiotic stress.Three watermelon GAD gene family members(Cla97C01G007270,Cla97C01G007290 and Cla97C04G079700)were screened by the association analysis of metabolomics and transcriptomes.On this basis,three watermelon GAD family genes were cloned,named ClGAD1,ClGAD2 and ClGAD3 respectively,and their bioinformatics and expression patterns were analyzed.The results showed that the CDS of ClGAD1,ClGAD2 and ClGAD3 were 1 524,1 497 and 1 497 bp,respectively,and the number of amino acids encoded by them was 507,498 and 498,respectively.All three proteins were hydrophilic proteins and were located in mitochondria.It was highly conserved,and the conserved domain was glutamic acid decarboxylase.Its promoter region contained a large number of CAAT-box and TATA-box,as well as corresponding elements related to adversity stress such as MYB and MYC.The secondary structures of the three GAD proteins were mainly α-helix and random coil.The tertiary structures were all homohexamer structures.Phylogenetic tree showed that members of GAD gene family were closest to GAD of Momordica charantia and Arabidopsis thaliana.qRT-PCR analysis indicated that the highest expression levels of ClGAD1 and ClGAD2 were showed in stems,while that of ClGAD3 was showed in flowers.The expression levels of ClGAD1,ClGAD2 and ClGAD3 were the highest under salt stress for 12,24 and 48 h,respectively.Under cold and drought stress,the expression patterns of the three GAD genes were similar,and all of them were expressed in large quantities in the early stage of stress,and the expression of ClGAD3 under abiotic stress was higher than that of the other two family members.The full-length cDNA of three GAD genes in watermelon was obtained,and their bioinformatics and expression patterns were analyzed,which provided an experimental basis for enriching the abiotic stress resistance gene resources of watermelon.

In order to explore the response of ARP to low temperature stress in ornamental pepper,and provide a theoretical basis for subsequent research on gene function in ornamental pepper under low temperature stress.This study cloned homologous ARP gene from ornamental pepper using RT-PCR technology,named CfARP,and analyzed their expression in different tissues of ornamental peppers and under low temperature treatment;Using bioinformatics analysis to study gene protein coding,physicochemical properties,and genetic relationships,and using qRT-PCR technology to detect the expression level of CfARP in different tissues of ornamental pepper and under low temperature treatment.The results showed that the CDS sequence of the CfARP gene was 342 bp,with 100% homology with Zunla 1.It could encode 113 amino acids and contained a conserved Auxin-repressed domain;protein physicochemical analysis revealed that the molecular weight of CfARP protein was 12.156 ku,its isoelectric point was 10.22,and the average coefficient of hydrophilicity was -0.913.It was preliminarily predicted that CfARP was a hydrophilic protein;compared with other species' ARP amino acid sequences,it was found that CfARP was highly conserved in Solanaceae plants.The Real-time Fluorescence Quantitative PCR results showed that the expression level of CfARP gene was the highest in the stems of ornamental pepper,followed by roots,and relatively less in leaves and flowers;the expression level of CfARP gene continuously increased with the increase of low-temperature treatment duration.It was preliminarily speculated that CfARP had a certain role in the response of ornamental pepper to low temperature stress.

In order to improve the selection efficiency of melon materials with different pulp firmness types and accelerate developing varieties.The F₂ and BC₁F₁ populations were constructed with crisp melon materials 19A21,19A75 and soft melon materials N84,20S66 as parents.According to sensory testing statistics,the theoretical values of 3∶1 and 1∶1 for crispy and soft materials were consistent,indicating that the melon pulp firmness was controlled by a single gene,and crisp was dominant to soft.The changes of ACO activity and expression pattern of CmACO1 with different firmness types were analyzed with 4 materials.The results showed that the ACO activity of soft melon appeared at a peak during fruit development,but the crispy melon did not appear.The expression of CmACO1 in soft melon was significantly higher than that in crispy melon.This gene may be involved in regulating pulp firmness.According to the difference of insertion and deletion sites of CmACO1 in different materials,the InDel-Pf marker was developed.The InDel marker was used to detect the genotypes of 32 melon materials.Among them,crisp melon showed deletion band type,soft melon showed non-deletion band type,the marker polymorphism and pulp firmness were co-separated.Two F₂ populations were used to validate the InDel-Pf,the genotype and phenotype coincidence rates were 95.3% and 98.1%.The results showed that InDel-Pf marker had high accuracy in the actual identification of melon pulp firmness,which could effectively improve the efficiency of breeding selection and shorten the breeding cycle of improved varieties.

GDSL is an important gene affecting the development of cuticle.This study cloned cucumber GDSL lipase gene and analyzed its expression pattern,in order to lay a foundation for the study of cuticle development and the glassiness of cucumber.The gene sequence was cloned to clarify its role in cucumbers with different glossiness by using six cultivars with different glossiness as materials.The promoter of CsGDSL lipase gene was cloned to analyze its functional elements.According to the reference sequence in cucumber genome database,we cloned the GDSL lipase gene of cucumber and analyzed by bio-informatics.The expression of the gene in different tissue parts of cucumber was confirmed by qRT-PCR technique.The CDS of CsGDSL length 1 059 bp which encoded 352 amino acids,and the secondary structure was mainly random curl(45.45%)and α-helix(33.24%).This gene was conservative in the process of evolution and was most closely related to CmGDSL.The expression level was the highest in the male flower of cucumber on the flowering day,and the expression level in the ovary at 3 days after flowering was higher than that at 0 days after flowering.The CDS sequence of CsGDSL gene was conservative in six cultivars. CsGDSL gene was responsive to stress,hormone and light.We obtained the CsGDSL lipase gene in this study,and identified its expression in different tissue parts of cucumber,the gene is relatively conserved in different cultivars,suggesting that CsGDSL may affect cucumber glossiness.

Neutral/alkaline invertases,as important substances in plant sucrose metabolism,are mainly involved in processes such as plant growth and development,and response to adversity stress.To investigate the response pattern of AsNI to stress,this study cloned two garlic neutral/alkaline invertase genes,using Ledu purple skin garlic as the test material and they were subjected to bioinformatics and expression characterization.The results showed that the open reading frames of AsNI1 and AsNI2 were 522,1 203 bp,encoded 173,400 amino acids.AsNI1 and AsNI2 were both hydrophilic proteins predicted to be localized in the cytoplasm with a Glyco_hydro_100 structural domain.However,the amino acid sequence similarity between the two was only 25.75%,and AsNI2 contained one glycosylation site,while no glycosylation site was detected in AsNI1,and the two were distantly related.The analysis of the protein interaction network showed that AsNI2 and AsNI1 might participate in different biochemical processes.The promoter sequence analysis revealed that the promoter regions of AsNI1 and AsNI2 contained multiple cis-acting elements related to stress response,with the AsNI2 promoter having a significantly larger number of drought and low temperature stress response elements than AsNI1.The prediction of promoter transcription factor binding sites showed that they contained different kinds and numbers of binding sites,indicated that AsNI1 and AsNI2 could perform different gene functions.The qRT-PCR assay revealed that the expression of AsNI was significantly tissue-specific,with the highest expression of AsNI1 and AsNI2 in the roots and bulbs,respectively.Meanwhile,adversity stress was able to induce AsNI expression,and the response of AsNI2 was stronger than that of AsNI1 under both low temperature and drought treatments.Among them,low temperature stress mainly induced the expression of AsNI2 in leaves,and drought stress mainly induced the expression of AsNI2 in roots.The sequence characteristics and expression pattern of AsNI were analyzed to verify the stress resistance function of AsNI.

In order to investigate the effects of chemical fertilizer reduction and combined application of organic fertilizer on soil microbial quantity,nutrient content,eggplant yield,quality and water use efficiency in Hexi oasis,the field experiments of seven different treatments were carried out in 2019 and 2020 with purple long eggplant Tianlong 8 as the test material.Seven treatments were set up,including 100% common chemical fertilizer(FH),80% common chemical fertilizer+20% organic fertilizer(FE),60% common chemical fertilizer+40% organic fertilizer(FS),40% common chemical fertilizer+60% organic fertilizer(FF),20% common chemical fertilizer+80% organic fertilizer(FT),100% organic fertilizer(FZ)and no fertilizer control(CK).The changes of soil microbial quantity,nutrient content and yield in 0-20 cm after eggplant harvest were analyzed.The results showed that chemical fertilizer reduction combined with organic fertilizer could increase the number of bacteria,fungi,actinomycetes and the contents of total nitrogen,total phosphorus,total potassium and organic matter in soil.Among them,60% chemical fertilizer+40% organic fertilizer had the best improvement effect,followed by 80% chemical fertilizer+20% organic fertilizer.The combined application of pure chemical fertilizer had little effect on the growth dynamics of eggplant,but the combined application of organic fertilizer could significantly promote the nutrient absorption of eggplant,increase plant height,stem diameter and leaf area index,and regulate the yield components,laying the foundation for high yield of eggplant.Chemical fertilizer reduction combined with organic fertilizer can promote the distribution of eggplant photosynthetic products to fruit and improve eggplant yield.The economic yield of 60% chemical fertilizer+40% organic fertilizer treatment was the highest(42 716.15 kg/ha),followed by 40% ordinary chemical fertilizer+60% organic fertilizer(41 922.06 kg/ha)and 80% ordinary chemical fertilizer+20% organic fertilizer(40 302.74 kg/ha),which were 53.64%,50.78% and 44.96% higher than CK.Chemical fertilizer reduction combined with organic fertilizer can improve the water and heat status of soil tillage layer and improve the water use efficiency of eggplant.The water use efficiency of FS was the highest(10.46 kg/m³),followed by FF(10.37 kg/hm³)and FT(9.79 kg/hm³),which was 47.53%,46.19% and 38.08% higher than that of CK.Therefore,considering the soil environment,yield and water use efficiency,the best recommended treatment is chemical fertilizer and organic fertilizer is 60%+40% organic fertilizer.

Calmodulin is an important Ca²⁺ receptor protein in plants,which plays an important role in calcium signaling pathway and stress resistance.It is of great significance to study the mechanism of CaM protein in tomato under low temperature stress for cold tolerance breeding of tomato.Tomato calmodulin genes SlCaM3, SlCaM4 and SlCaM5 were cloned from tomato varieties Heinz1706,LA3969,Jifen 2,Jifen 3 and Nongbofenba 15,and their sequences and protein sequences were analyzed by bioinformatics;the cis acting elements in the promoter regions of SlCaM3,SlCaM4 and SlCaM5 were analyzed by plantcare;Quantitative Real-time PCR was used to analyze the expression patterns of SlCaM3,SlCaM4 and SlCaM5 under 15,5 ℃ temperature stress in different tomato varieties,and the specific expression of SlCaM3,SlCaM4 and SlCaM5 in different tissues was analyzed in combination with RNA-seq data.The results showed that the coding sequence of SlCaM3,SlCaM4 and SlCaM5 were 450 bp,and their similarity was 93.63%;the encoded amino acid sequences were identical,belonging to acidic stable hydrophilic protein with typical conservative domain of cam protein.The analysis of cis acting elements showed that the promoter regions of the three genes contained not only the necessary core elements,but also a variety of biotic and abiotic stress response elements,and showed a complementary pattern.The analysis of the expression patterns of different degrees of low temperature stress showed that the expression patterns of SlCaM3,SlCaM4 and SlCaM5 in five tomato materials showed a trend of first decreasing and then increasing at 15 ℃,and the expression of SlCaM5 increased more significantly.At 5 ℃,SlCaM3 and SlCaM4 did not change significantly,but the expression level of SlCaM5 gene increased significantly in the later stage of treatment.The high expression of SlCaM5 gene in the process of tomato resistance to low temperature indicated that it maintained the translation level of cam protein under low temperature and ensured that the function of CaM protein was not affected.The analysis of SlCaM3,SlCaM4 and SlCaM5 specific expression in different tissues of Heinz1706 showed that SlCaM3 and SlCaM4 were highly expressed in meristem,while the expression of SlCaM5 different tissues was not significantly different.

In order to reveal the molecular mechanism of MiPDCD6 protein suppressing tomato PTI immunity,the MiPDCD6 overexpression seedlings of tomato variety Xinjinfeng 1 were used as experimental materials,and the tissue culture seedlings of tomato variety Xinjinfeng 1 were used as control.Transcriptome sequencing was performed on tomato MiPDCD6 overexpressing seedlings and control seedlings,respectively.With tomato cultivars Heinz 1706,comparing the genome as a reference genome,FPKM method was used to calculate quantity of gene expression,set parameters(|log₂ FC|>1 and P<0.05)in screening the differentially expressed genes(DEGs).Gene ontology(GO)database was used to analyze the GO functional enrichment of DEGs,count the number of DEGs in each GO term,calculate the significance of gene enrichment,and find out the functional term with significant enrichment.KEGG database was used for Pathway enrichment analysis of DEGs,and hypergeometric distribution test was used to calculate the significance of enrichment of DEGs in each Pathway.The enrichment degree of KEGG was measured by FDR and gene number.Combined with gene differential expression analysis and functional enrichment analysis,the effect of MiPDCD6 protein on tomato PTI immune-related pathway genes was studied.The results showed that there were 2 366 DEGs in MiPDCD6 overexpressed tomato plants compared with wild-type tomato,including 1 354 up-regulated genes and 1 012 down-regulated genes.In these DEGs,a large number of differentially expressed genes were concentrated in KEGG pathways such as plant hormone signal transduction(sly4075),plant-pathogen interaction(sly04626),plant MAPK signal pathway(sly04016)and procycloid biosynthesis(sly00940)through GO and KEGG annotation.SA biosynthesis pathways included ICS and PAL.In the MiPDCD6 overexpressed tomato plants,PAL1 and PAL-like genes in SA synthesis pathways and TGA9,TGA10-like and PR1a2 genes in SA signal transduction pathways were significantly down-regulated,suggesting that MiPDCD6 may inhibit SA synthesis thus inhibiting plant PTI immunity.

To explore the relationship level between CaMADS6 expression and floral organ development of pepper,CaMADS6 was cloned for bioinformatics prediction from the sterile line 9704A and the maintainer line 9704B,and the spatiotemporal expression characteristics of this gene were analyzed.The results showed that the CaMADS6 cloned from 9704A and 9704B had the same coding sequence,with a full length of 744 bp and encoding 247 amino acid residues.CaMADS6 protein had the relative molecular weight of 28.67 ku and theoretical isoelectric point of 8.98.It was a hydrophilic protein with no transmembrane structure.The secondary structure of CaMADS6 consisted of 57.49% α-helices,8.91% extended chains and 28.74% irregular coils.The CaMADS6 protein shared 100% homology with CaFUL2,which possessed a typical MADS-box characteristics.CaMADS6 was expressed in different organs of 9704A and 9704B at different developmental stages and the expression was the highest in flower buds,followed by leaves and stems,and almost no expression in roots.The expression of CaMADS6 in stems of 9704A was significantly lower than that of 9704B at seedling,flower bud and adult stages,and the expression of CaMADS6 in leaves was significantly lower than that of 9704B at the adult stage.The expression level of CaMADS6 in flower buds of 9704A was extremely significantly higher than that of 9704B at flower bud and adult stage,and its expression level was 2.2 and 3.5 times higher than in 9704B,respectively;CaMADS6 gene was expressed in different parts of flower organs of 9704A and 9704B,and the expression of CaMADS6 gene from high to low was calyx,corolla,ovary and anther.The expression level of CaMADS6 in the calyx and corolla of 9704A was extremely significantly or significantly lower than that of 9704B,the expression level of CaMADS6 were 66%,83% of 9704B,respectively.The expression level of CaMADS6 in 9704A anther was 34 times higher than in 9704B,and the difference between the two groups was extremely significant,predicting the abnormal expression of CaMADS6 in anthers was closely related to pepper male sterility.

Gibberellin pathway is an important pathway in plant flowering regulation.In order to understand the role of gibberellin pathway related genes in the regulation of radish flowering. The structure,physicochemical properties,chromosome distribution,promoter cis-elements and tissue-specific expression of gibberellin biosynthesis and signal transduction related genes in radish were analyzed by bioinformatics.The expression levels of these genes in radish varieties with different florescence were detected by Real-time fluorescence quantitative PCR(qPCR).The results showed there were 46 genes related to gibberellin biosynthesis and signal transduction in radish genome,among them,the gene numbers of CPS,KS,KO,KAO,GA20OX,GA3OX,GA2OX,GAI,RGA,RGL,GID1 and SKP2 were 2,1,2,2,9,5,12,1,1,4,3 and 4,respectively.They were unevenly distributed on 9 chromosomes,molecular weight of their coding proteins were 21.32—127.80 ku,and the isoelectric points of the proteins were from 4.72 to 9.04.The analysis of gene structure and conserved domain showed that the number of exons of these 46 genes ranged from 1 to 21,and some conserved motifs were shared by most genes.Promoter cis-elements analysis showed that the promoters of these 46 genes contained cis-elements related to light,gibberellin,auxin,ABA,SA,low temperature,drought,etc.Using radish gene expression database analysis,it was found that the expression levels of these 46 genes were different in different tissues and at different developmental stages;qPCR detection showed that there were significant differences in the expression of these genes between early flowering material Xinlimei and late flowering material wild radish,suggesting that they may be closely related to the reproductive growth of radish.

To further analyze the biological characteristics and expression of TrPLD family genes in Trichothecium roseum,four TrPLD genes were obtained by the whole-genome sequencing of Trichothecium roseum,the online tools of SMART,MEGA 7,ProtScale,SOPMA and other software were used to conduct bioinformatics analysis of TrPLD genes and their encoded proteins;RT-qPCR technology was employed to analyze TrPLD genes expression during the pathogen infection muskmelon fruit.Phylogenetic tree analysis showed that TrPLD1 had the closest genetic relationship with Colletotrichum aenigma with a homology of 63.89%;TrPLD2 had 74.57% homology with Purpureocillium lilacinum;TrPLD3 and TrPLD4 had the closest genetic relationships with Fusarium graminearu and Paecilomyces lilacinus,with homology of 65.38% and 55.45%,respectively.Bioinformatics analysis showed that the proteins of TrPLD1,TrPLD2,TrPLD3 and TrPLD4 all had two conserved domain HKD motifs.TrPLD3 contained PX and PH domains,besides the HKD structure.The four proteins belonged to unstable hydrophilic proteins,without signal peptide and transmembrane structure,and belonged to non-secretory proteins.The four proteins contained different numbers of phosphorylation sites,among which,TrPLD3 contained the most phosphorylation sites.Subcellular localization prediction showed that TrPLD1 and TrPLD3 were mainly located in the nucleus,and TrPLD2 and TrPLD4 were mainly located in the plasma membrane.RT-qPCR analysis showed that,during of simulation the pathogen infecting muskmelon fruit,taking the control expression as a control,the gene expressions of TrPLD1,TrPLD2,TrPLD3 and TrPLD4 increased significantly with the infection process,and the expression of TrPLD3 gene was significantly higher than other genes during the whole infection process.In summary,the four TrPLDs have different structures and biological functions,among which TrPLD3 plays an important regulatory role during the process of T.roseum infecting muskmelon fruit.

To investigate the genetic polymorphism of the inbred lines and hybrids derived from Cucurbita moschata (MO)×Cucurbita maxima (MA),the genetic diversity of 53 pumpkins,including commercial varieties,core parent materials and inter-specific hybrids offspring,were investigated by thirty morphological traits and twenty SSR markers.The results showed that the core parent materials and offspring of inter-specific hybrids had more polymorphism in plant type,growth vigor,fruit skin color and shape than commercial varieties.Twenty SSR primers were screened and showed 90% of polymorphism ratio.Based on the principal components,the cluster results of morphological and SSR markers were consistent with each other very well.The two methods and three times cluster results showed that the commercial varieties and core parent materials of Cucurbita maxima were clustered into one group,firstly.This mean the commercial varieties and core parent materials of Cucurbita maxima had relatively close genetic distance and shared the severely homogenized genetic background.It's very hard to produce the new and different varieties in this situation.Secondly,the offspring of inter-specific hybrids derived from MO×MA were clustered into one group,which was distinguished from commercial varieties and core parent materials of Cucurbita maxima and the genotypes of Cucurbita moschata.The offspring of inter-specific hybrids had relatively long genetic distance and more polymorphism than commercial varieties.It's possible to derive the new and different pumpkin varieties by crossing with the genotypes having the heterogeneous genes produced from interspecies hybrids.Meanwhile,the 6 principal component factors derived from principal component analysis would be used to simplify the edible pumpkin survey indicators.

In order to give Ningxia an excellent combination of high yield and disease resistance.Dtopsis method was used to evaluate 50 hybrid combinations of pink fruit and tomato and 2 controls(Fengshou 128 and Meifen 869)planted in solar greenhouse for two consecutive years(2020,2021),the botanical traits,fruit traits,yield traits and disease resistance traits were analyzed.The fruit characters of cross combinations were different from each other,but the ripening property was consistent.The optimal combination was 33,whose theoretical yield was more than 20% higher than that of the two controls in two years.It was "moderately resistant" to three diseases and above,with a hardness of more than 5.0 kg/cm² and a pulp thickness of more than 8.0 cm,which was a combination of storage and transportation resistance.The second was combination 47 and 1.The theoretical output of these two combinations was relatively large,and the theoretical output of 47 has increased by more than 45% in two years.Combination 1 had better commercial properties,higher soluble solid content,higher hardness,and better appearance quality.After two years' comprehensive evaluation,combinations 33,47 and 1 were finally selected to be suitable for solar greenhouse planting in Ningxia.

In order to explore the application effect of a new type of biochar-based compound fertilizer prepared by low temperature carbonization of waste organic sulfuric acid,a pot experiment was carried out with Xiaoding bacunshen as the test carrot variety and saline fluvo-aquic soil as the test soil. A total of 11 treatments were set up with 5 kinds of compound fertilizers and their carbon-based compound fertilizer formula treatments,and the effects of 5 kinds of biochar-based compound fertilizer formulas on carrot yield and soil nutrient content were studied. Results showed different fertilization significantly promoted the increase of fresh weight of carrot fleshy roots. Among them,carrots treated with 12-6-10 sulfur-based compound fertilizer with 15% carbon content had the highest fresh weight of fleshy root biomass,with a fresh weight of 313.85 g/plant,and the 10-5-20 chlorine-based fertilization treatment had the lowest yield of carrots. In contrast,10-5-20 chlorine based compound fertilizer had the lowest carrot yield. Compared with common compound fertilizers,those 5 kinds biochar-based compound fertilizers had significant effects on the increase of fresh weight of carrot fleshy root,with the range of increase of 2.1%-11.3%,and increased the accumulation of nitrogen,phosphorus and potassium in different degrees. In addition,the soil available N,P and K supply could be maintained by applying biochar-based compound fertilizer with 15% reduction of N,P and K nutrient application,and soil nutrients were still significantly increased in some periods. Application of biomass sulfonated carbon fertilizer could reduce the soil pH at the early stage of carrot growth,but there was no significant difference in soil pH at the mature stage of carrot. In conclusion,compared with common compound fertilizer,the application of biomass sulfonated carbon fertilizer could reduce the soil pH,increase the accumulation of nitrogen,phosphorus and potassium of carrot and the soil available nitrogen,olsen phosphorus and available potassium supply,which was conducive to carrot yield increase.

CYP79B2 is a related gene that regulates auxin synthesis in Arabidopsis.By cloning the homologous gene BrcCYP79B2-1 of CYP79B2 in B.rapa ssp. cninensis,analyzing its expression in different tissues and periods,and studying its regulatory mechanism on vernal flowering in B.rapa ssp. cninensis,to lay a theoretical foundation for the subsequent functional verification of the auxin-encoding gene in B.rapa ssp. cninensis.The homologous gene of CYP79B2 was cloned from B.rapa ssp. cninensis by qRT-PCR and named as BrcCYP79B2-1.The structure,physicochemical properties and relationship of its protein were analyzed by bioinformatics method,and its protein was analyzed by qRT-PCR method.Expression levels in different tissues and growth stages in B.rapa ssp. cninensis.And its expression in different tissues and growth stages of B.rapa ssp. cninensis was analyzed by qRT-PCR method.The results showed that the full-length coding sequence of BrcCYP79B2-1 gene was 1 623 bp,encoding 540 amino acids.The physicochemical analysis of the protein showed that the molecular mass of the protein was 60.849 73 ku,and the theoretical isoelectric point was 8.71.Compared with the amino acid sequences of other species,it was found that BrcCYP79B2-1 was highly conserved in cruciferous plants,and had the highest homology with turnip,up to 99.52%;the expression levels of different organs of B.rapa ssp. cninensis were analyzed by qRT-PCR, and it was found that the expression level of BrcCYP79B2-1 was the highest in roots, followed by leaves, and the lowest in flower buds.The expression of BrcCYP79B2-1 in seedlings after 0,10,15 and 16 days of low temperature treatment showed that the expresion of BrcCYP79B2-1 reached its peak on the 10th day of low temperature treatment, that is, the vegetative growth period, while the expression of BrcCYP79B2-1 decreased during flower bud differentiation, which indicated that the expression of BrcCYP79B2-1 was related to low temperature vernalization and could affect flower bud differentiation.

In order to select rotation crops suitable for tomato in southeastern of Shanxi Province,we planted six cropsrotation patterns,namely maize(LVZm),zucchini(LVCp),peanut(LVAh),green onion(LVAf),okra(LVAe),and cucumber(LVCs),taking treatment with continuous tomato cultivation(LLLe,CK)as control. The changes in the microbial community structure and diversity in the ITS1 region of soil fungi were analyzed by Illumina Miseq high-throughput sequencing technology. At the same time,the quality indicators(soluble total sugar,organic acid content,sugar-acid ratio,Vc content,soluble protein,soluble solids,lycopene content,nitrate)and yield indicators(single fruit weight,yield)of the following tomatoes were measured. The results showed that Ascomycote was the dominant phyla in the 7 treatments,and the species and abundance were quite different,LVCs,LVZm,LVAh and LVAe increased the diversity index of fungal,while LVCp decreased the index. LVZm had better taste;LVAe and LLLe had the highest Vc content;no significant difference in soluble protein content;the content of soluble solids were the highest in LLLe and LVCp;the content of lycopene was highest in LVCp;LVAe had the highest nitrate content. The yields significantly increased in LVAe and LVCp patterns,and the quality of single fruit significantly increased in LVCp rotation. Principal component analysis(PCA)showed that the scores of quality and yield among different patterns from high to low were LVCp>LVAe>LLLe> LVAh>LVAf> LVZm>LVCs. In summary,crop rotation changes the soil fungal community structure,affects the index of the fungal,the quality and yield of tomatoes in subsequent crops. Based on various factors,zucchini and okra are the dominant rotation crops suitable for the growth of local tomatoes.

In order to study the response mechanism of pepper CaWRKY30 transcription factor and Tomato spotted wilt orthotospovirus,it was experimental materials with pepper Xiangyan 11.The CaWRKY30 coding sequence was obtained by RNA extraction,RT-PCR,split gel and cloning.Biological information analysis results showed that CaWRKY30 full length was 1 122 bp,encoding 373 amino acids,the gene encoded protein contains 1 WRKY conservative domain and 1 C₂H₂ domain,belonged to a typical Ⅱ(e)subfamily member.System evolution analysis showed that the relative relationship with the potato StWRKY22 amino acid sequence was recently.It was found that CaWRKY30 was positioned in the nucleus and cell membranes in its cigarette seedlings,and leads to cell membranes.The results of Real-time fluorescence quantitative PCR analysis showed that the viral accumulation of Tomato spotted wilt orthotospovirus mechanical friction-vaccination was found that the viral accumulation was gradually increased from 1 to 14 days after inoculation,and virus accumulation reached its maximum in 14 days,after inoculation 14 days,viral accumulation gradually declined.At the same time,CaWRKY30 was induced by Tomato spotted wilt orthotospovirus,when the inoculation 1-14 days,the CaWRKY30 expression was raised,and the peak was reached in 14 days,the expression in 14 days gradually decreased.In summary,it obtained the CaWRKY30 transcription factor gene sequence,which was located in the nucleus and cell membrane,and preliminarily explained the expression trend of CaWRKY30 transcription factors under the stress of Tomato spotted wilt orthotospovirus.

In order to analyze the molecular mechanism of different watermelon peel firmness,and provided a theoretical basis for discovering key genes related to watermelon peel firmness,the high firmness(901)4-1-1-M and low firmness BSH with similar growth period but significant difference in peel hardness were used as experimental materials.The peel with the maximum difference 30 days after pollination was selected for transcriptome sequencing analysis and the Illumina HiSeq^TM sequencing platform was used to analyze the molecular mechanism of different watermelon peel firmness,Real-time fluorescence quantitative PCR (qRT-PCR) was used to verify the sequencing results.A total of 1 085 differentially expressed genes (DEGs) were screened by transcriptome sequencing,including 555 up-regulated genes and 530 down-regulated genes.Gene Ontology(GO)analysis showed that 1 085 DEGs were significantly enriched in cell components,molecular functions and biological processes,including cell wall,cell periphery,external encapsulation structure,extracellular region,tetrapyrrole skeleton,redox enzyme activity,transferase activity and pectin esterase activity.Kyoto Encyclopedia of Genes and Genomes (KEGG)analysis indicated that 19 DEGs,including Cla97C04G075800,Cla97C02G044950,Cla97C09G165820,Cla97C10G195660,Cla97C01G025380,etc.,were enriched in the most significant enrichment biosynthesis of phenylpropanoid,which eventually lead to the metabolites of Syringyl lignin,5-Hydroxy-guaiacy lifnin,Guaiacy lifnin and P-Hydroxy-phenyl lifnin.The correlation coefficient of DEGs expression levels by qRT-PCR and RNA-seq data was 0.791,which indicated that the transcriptome test data were reliable.This study explained the reason of watermelon peel firmness difference between(901)4-1-1-M and BSH from the transcriptional level.

Carotenoids are the most widely distributed class of pigments in nature,which endow plants flowers,fruits and other organs with bright colors.The synthesis process of carotenoids contains a variety of metabolic enzyme genes.In order to reveal the molecular mechanism of carotenoid accumulation in yellow peeled zucchini,lay a foundation for further studying the function of carotenoid synthase gene in zucchini,this study identified zucchini carotenoid anabolism family genes based on the zucchini genome database,and further screened and cloned the key enzyme genes for carotenoid synthesis and metabolism by publicly published transcriptome data and qRT-PCR verification.The results showed that 48 carotenoid metabolizing enzyme gene members were detected in zucchini genome;and two key genes PSY1 and LCYE2 were screened out and showed different expression during the different developmental stages based on the transcriptome data of Sweet REBA/Lady Godiva.qRT-PCR analysis also showed that, except for PSY1 gene 0 d and LCYE2 gene 2 d, the relative expression of PSY1 and LCYE2 in different developmental stages of yellow peeled zucchini were significantly higher than that of white peeled zucchini.The full-length CDS of PSY1 and LCYE2 genes were cloned and sequencing analyzed from white and yellow peeled zucchini,respectively,which suggested that PSY1 genes of both materials were 51 bp more than the predicted coding sequence in zucchini reference genome,and were all consistent with the published sequence of PSY gene(GenBank number:XM_023695146.1),while the sequences of LCYE2 gene was not significantly different from the reference genome.Phylogenetic tree analysis showed that zucchini PSY1 was homologous to the reported Cucurbita moschata PSY(JN176311.1)with the best similarity as high as 98.80%.

To reveal the effect process and mechanism of nitrogen application level on the chlorophyll fluorescence characteristics of cucumber in fruit stage under high-temperature stress,the Jinyou 101 cucumber was used as the tested material,the air temperatures were set at 35 ℃/25 ℃,38 ℃/28 ℃,41 ℃/31 ℃,in the same time the 28 ℃(daily maximum temperature)/18 ℃(daily minimum temperature)was as the control(CK);the nitrogen(N)application level was set at 0(N0),160(N1),240(N2),320 kg/ha(N3);total 16 treatments and three duplicates.The dynamic parameters of chlorophyll fluorescence of cucumber functional leaves were measured systematically after 9-days high-temperature stress in fruit stage,the differences between in various treatments were also discussed.The PSⅡ reaction centre of cucumber leaves were significantly damaged and the maximum fluorescence(Fm),maximum photochemical quantum yield(Fv/Fm),photosynthetic performance index(PIabs),area enclosed by Fm and fluorescence curve(Area)were significantly decreased after high-temperature stress in fruit stage.Under the 35 ℃ high-temperature stress,the values of ΔW_O-J and ΔW_O-K were negative in treatment N1—N3,and the oxygen evolution complex(OEC)was not inactivated.At the same time,the energy transfer between PSⅡ central thylakoids was unhindered.However,the ΔW_O-J of leaves was positive in treatment N1 under 38 ℃ and treatment N2 under 41 ℃,which means the OEC was inactivated.Therefore,the energy transfer between PSⅡ central thylakoids was blocked due to the positive ΔW_O-K in treatment N1—N3 under the 38,41 ℃.Under the high-temperature stress,the nitrogen application significantly increased the chlorophyll content,Fm,Fv/Fm,PIabs,PItotal,Area and Sm of cucumber leaves,and enhanced the OEC activity and smooth the energy transfer between the PSⅡ central thylakoids;the ABS/RC,TRo/RC and DIo/RC of cucumber leaves also decreased with the increase of nitrogen application level while the electron transfer energy(ETo/RC)increased.Nitrogen application rate and temperature had significant interactive effects on the fluorescence characteristics and yield of cucumber leaves.Under the 35,38,41 ℃high-temperature stress in fruit stage,when the nitrogen application rates were 236,283,177 kg/ha respectively,the photosynthesis of cucumber leaves was stronger and higher yield could be obtained.Therefore,the reasonable nitrogen application could improve the OEC activity of PSⅡ,promote energy transfer,and slow down the inhibition of electron receptor pool on the side of PSⅠ receptor of cucumber leaves under the high-temperature stress in fruit stage,and also improve the orderly progress of photosynthesis.

To investigate the effects of zeolite and Ca-Mg-based bentonite on the passivation of cadmium in calcareous soil in Northern China and the growth of pakchoi,a pot experiment was conducted to study the effects of two modifiers(mass fraction of zeolite was 0.5%,1.0%,2.0% and mass fraction of calcium-magnesium bentonite was 0.2%,0.3%,0.4%,0.5%,0.6%,0.8%)on pH value,available cadmium content of calcareous cadmium-contaminated soil in Northern China and cadmium content,dry matter accumulation and chlorophyll content of aboveground part of pakchoi.The results showed that compared with the control,adding different doses of zeolite could increase the soil pH value.With the increasing of zeolite application dose,the available cadmium content of soil,the aboveground cadmium content,the dry matter accumulation and chlorophyll content of pakchoi decreased gradually.The germination rate of pakchoi increased gradually,but the effects of zeolite treatments on the indexes determined in the experiment were not significant.The application of Ca-Mg-based bentonite significantly increased the soil pH value(0.70—1.07)and decreased the Cd content in the aboveground part of pakchoi(63.83%—93.62%).The aboveground dry matter accumulation(5.56%—29.22%)and chlorophyll content(5.42%—11.72%)of pakchoi increased,and the soil available cadmium content significantly decreased by a higher dose(≥0.4%).However,the germination rate of pakchoi decreased significantly and inhibited germination.The research showed that Ca-Mg-based bentonite was more suitable for the passivation of cadmium in calcareous soil in Northern China than zeolites.The content of available cadmium in calcareous soil and the content of cadmium in the aboveground part of pakchoi could reduce by applying Ca-Mg-based bentonite.However,the amount of application should be strictly controlled to avoid affecting the germination of pakchoi and reducing yield.The comprehensive analysis of quality and yield factors showed that the addition of 0.3% Ca-Mg-based bentonite could effectively reduce the aboveground cadmium content of pakchoi and increase the aboveground dry matter accumulation and chlorophyll content of pakchoi.

To explore bacterial wilt resistance genes,RNA sequencing was used to characterize the transcriptomes of resistant and susceptible tomato inbred lines with Ralstonia solanacearum inoculation(RsI).The results showed that a total of 75.02 Gb high-quality data were generated in 12 libraries.With the fold change(FC)≥2 and false discovery rate(FDR)<0.01 as the standard,970 and 695 differentially expressed genes(DEGs)were identified in the two tomato lines,respectively.The 1 312 DEGs accounted for 3.71% of the total.Among them,the numbers of up-regulated genes were 457 and 450,respectively,totaling 693;the numbers of down-regulated genes were 513 and 245,respectively,totaling 621.Among these DEGs,836 genotype-specific DEGs were highlighted.These DEGs were mainly divided into 47 functional groups such as metabolism,regulation,response,binding,and catalysis,and 88 metabolic pathways such as DNA replication,secondary metabolite synthesis,plant-pathogen interaction,and signal transduction by GO and KEGG annotation.Specifically,4 NBS resistance genes,6 plant-pathogen interaction genes,11 plant hormone signal transduction genes,22 defense response genes,32 protein kinases,65 transcription factors,and several other important functional genes were involved,indicating that they played important roles in response to Rs.Promoter analysis revealed that these genes possessed multiple defense and stress response elements.The output was confirmed using RT-qPCR for 50 representative genes.It was found that more than half of the genes were consistent with RNA-seq in expression.Solyc02g086980.3 and Solyc04g011670.3 might be involved in the resistance response,whereas Solyc01g073985.1,Solyc09g092580.4,Solyc09g098100.4,and Solyc10g081300.1 might be the opposite.Together,these gene expression profiles serve as fundamental information to understand the potential molecular basis in the response to Rs in tomato,and facilitate the application of related resistance genes in breeding.

Tomato belongs to the cold sensitive model plant,which is vulnerable to chilling injury during its growth,thus affecting its yield.In order to provide a theoretical basis for further revealing the molecular mechanism of cold resistance of tomato plants and breeding tomato cold resistant varieties,tomato germplasm resource No.25 of vegetable genetics,Breeding and Biotechnology Laboratory was used as material,and tomato transcription factor SlMYB-related 2 was used as research object.Based on CRISPR/Cas9 gene knockout vector,tomato positive plants were obtained by Agrobacterium transformation.The VIGS transient silencing expression vector was constructed,and the wild-type and and virus transformed plants without inserted target gene fragment were used as control.The three groups of plants were treated with low temperature at 4 ℃(16 h day / 8 h night,60% humidity).The contents of physiological indexes related to cold resistance were measured and its cold tolerance was compared.The results showed that CRISPR/Cas9 gene knockout vector was constructed and two CRISPR silenced positive plants were obtained.Constructed the expression vector of VIGS silence,after low temperature treatment,it was found that with the extension of low temperature treatment time,the growth trend of proline and soluble sugar in SlMYB-related 2 gene transformation group was slower than that in control tomato group(wild type carrying TRV,CK)and wild group(WT),and the content was lower than that in CK group and wild group.However,the content of malondialdehyde was higher than that of CK group and wild group,which proved that the cold resistance of tomato plants with transient expression of VIGS was significantly lower than that of CK group and wild group.Through the analysis of cold resistance of tomato plants after gene transient silencing expression,it was found that SlMYB-related 2 gene played a positive regulatory role in low temperature stress.

MLO gene,acting as susceptibility factor,play an important role in regulating responses of host plants against powdery mildew.To determine the gene function of bitter gourd McMLO1 gene,cloning,bioinformatics and expression analysis were carried out in the present study.The results suggested that the full-length of McMLO1 was 4 019 bp,among which the CDS sequence was 1 707 bp,encoding 568 amino acids.ProtParam prediction indicated McMLO1,whose molecular weight and theoretical isoelectric point was 65.40 ku and 9.36,respectively,was an unstable hydrophilic protein which located in cell membrane.McMLO1 protein,harboring a conserved MLO domain of 477 amino acids,was consisted of random coil and alpha helix on secondary structure.Multiple sequence alignment and phylogenetic analysis revealed high homology between McMLO1 and cucumber MLO protein.qRT-PCR analysis suggested that the expression level of McMLO1 in leaf was much higher than that in other tissues.Moreover,the expression level of McMLO1 was significantly up-regulated and reached peak at 6 hours after inoculation with powdery mildew pathogen,indicating McMLO1 participate in the process in response to powdery mildew in bitter gourd.

To investigate the effects of corn straw as the main component of the cultivation substrate on crop growth and fruit quality under brackish water and fresh water irrigation. Four treatments were designed, including the pure corn stalk(S-control), biochar(SB), S added with earthworm compost(SE), biochar and earthworm compost(SBE).Brackish water and fresh water irrigation were applied with each of the four substrate treatments, respectively, leading to a total of eight available treatments. The results showed that with same cultivation substrates, irrigational water had insignificant effect on the relative growth rates of plant height and stem volume at seedling stage. Compared with fresh water irrigation, brackish water irrigation had more positive effect on increasing the relative growth rate of plant height at later stage in SE treatment groups, with a 79.49% more increase in the relative growth rate. However, there were no significant differences in total biomass and root shoot ratio between SE-treated plants irrigated by fresh water and those irrigated by brackish water Brackish water irrigation promoted photosynthetic rate and transpiration rate compared to the fresh water irrigation in the S and SB treatments. Moreover, transpiration rate was reduced in SE, WUE was increased in SBE and SB. SB had the best effect of alleviating brackish water stress. Under the same culture substrate, brackish water significantly increased the soluble solid content compared to fresh water irrigation, and the highest soluble solid content was detected in SB, which was increased by 5.56%. SE and SB treatments significantly increased soluble sugar content in brackish water compared with fresh water irrigation by 53.84% and 50.15%, respectively, but there was no significant difference in yield. Compared with S treatment, SE increased transpiration rate under fresh water irrigation and had the highest Fv/Fm. SBE decreased the root-shoot ratio and SB increased the water use efficiency under fresh and brackish water irrigation. Compared with S treatment, SB treatment had the most significant effect on increasing soluble solid under brackish water irrigation, while SE treatment had the most significant effect on decreasing organic acid content and increasing soluble sugar content. Therefore, adding biochar and organic matter under different water irrigation can promote tomato growth, alleviate salt stress and improve fruit quality.

To investigate the effects of organic and inorganic fertilizers on yield and soil nutrient content in protected cultivation.Under the condition of facility cultivation, tomato field experiments were conducted to study the effect of the yield and soil nutrient content when reduced organic and inorganic fertilizers and combined the both application.Compared with the traditional organic fertilizer application amount of 105.00×10³ kg/ha, organic and inorganic combined application increased the yield by 12.99%, and the total fertilization of tomato could be reduced by 25% and 50%, it can make the yield of tomato was increased by 8.55% and 8.84%, when inorganic fertilizer was reduced to 50%, the yield decreased significantly.In the middle growth of tomato, there was no significantly difference between each treatments, but compared with the traditional application of organic fertilizer and when the organic fertilizer reduced 25%, organic matter content, total nitrogen content, available potassium content in soil respectively increased by 1.41%, 2.64%, 10.34%;after the harvest of tomato, soil nutrient content decreased with the amount of fertilizer decreased, no significant difference;Compared with the middle growth of tomato, the nitrate nitrogen content in the 0-20 cm and 20-40 cm soils treat with organic and inorganic fertilizers increased from 67.33 mg/kg and 28.93 mg/kg to 90.95 mg/kg and 40.66 mg/kg, respectively, and the nitrate nitrogen content in the 40-60 cm soils decreased from 21.40 mg/kg to 14.97 mg/kg, while the nitrate nitrogen content in the 60-80 cm and 80-100 cm soil layers was basically the same; in all treatments after harvest, with the reduction of nitrogen application rate, the accumulation of nitrate in soil and leaching risk both decreased.Compared with the traditional organic fertilizer application amount of 105.00×10³ kg/ha, the local tomato fertilizer amount can be reduced by 25%-50%, and the appropriate use of organic fertilizers, which can not only make the tomato yield slightly and reducing nitrate leaching risk of soil, also can make the soil nutrient content is more suitable for crop growth and maintain soil productivity.