Agricultural science and technology service serves as a vital link in transforming agricultural science and technological achievements into tangible productive forces. Talent team is a crucial resource for delivering the service. Science and technology commissioners and grassroots agricultural technology extension personnel are 2 key forces in the agricultural science and technology service system. Their collaborative cooperation is crucial for accelerating the transformation of agricultural scientific and technological achievements and improving the quality and effectiveness of agricultural technology services. This paper indicated that barriers to collaboration exist between the two entities in areas such as institutional mechanisms， performance evaluation and incentive systems， resource integration， and capability alignment. These barriers constrained the holistic effectiveness of the agricultural science and technology innovation system. Based on above analysis， this paper proposed targeted implementation pathways， including innovating institutional mechanisms， optimizing resource allocation， strengthening capacity building， and improving the policy support system. The aim was to adduce both theoretical and practical support for the high-quality development of agriculture.
The construction of seed production bases serves as a core link ensuring seed quality and supply security， acting as a key cornerstone for driving seed industry revitalization and agricultural modernization. The continuous penetration of digital technology throughout the entire seed production value chain has advanced standardized production， informatized services， and intelligent management in these bases， becoming a powerful support for high-quality development of the seed industry， improved seed production efficiency， and increased income for farmers. This paper analyzed practical issues such as limited foundational development conditions， insufficient core technological support and constraints on implementation applications in the digital transformation of corn seed production bases. Facing the development trends toward standardized， digitized and intelligent operations in base production and management， 6 dimensions were proposed for advancement： solidifying foundations， strengthening standards， highlighting applications， leading markets， optimizing mechanisms and promoting innovation. These efforts aimed to comprehensively establish digital systems across all sectors of seed production， processing， packaging， transportation， sales， services and management， thereby enabling digital empowerment for high-quality development in China’s corn seed industry.
As a plant-specific transcription factor， growth regulating factor （GRF） plays an important role in plant growth and development. To identify the members of the rice GRF gene family， protein physicochemical properties， sequence comparison， secondary and tertiary structure prediction， subcellular localisation， gene structure， cis-acting elements， chromosomal localisation， evolutionary tree construction and covariance were analyzed using the bioinformatics methods. The results showed that 12 GRF genes were identified. The length of rice GRF proteins was 211~456 aa， the molecular weight was 22.3~49.3 kD， the isoelectric point was 4.78~9.85， and the subcellular localisation was mainly located in the nucleus. The rice GRF genes contained 2~5 exons， and the promoter elements were mainly related to hormone regulation， stress response and light response. 12 GRF genes were unevenly distributed on chromosomes 2， 3， 4， 6， 7， 11 and 12. GRF genes in rice were closely related to maize， and had low homology with tomato and Arabidopsis. There were no tandem duplication events in the rice GRF genes， and large segmental duplications were the main expansion modes. Above results provided a theoretical basis for the in-depth study of rice GRF gene function.
To investigate the effects of 5-azacytidine （5-azaC） on the expression of the GhDMT7 gene and seed germination of cotton （Gossypium hirsutum L.）， this paper analyzed the expression level of GhDMT7 and the growth traits of cotton seed. The GhDMT7 gene was cloned and performed comprehensive bioinformatics analysis. The results showed that GhDMT7 protein was a stable hydrophilic protein with no signal peptide and transmembrane domains. Under salt stress conditions， the malondialdehyde content in cotton leaves increased， indicating exacerbated membrane damage. 5-azaC exhibited a dosage effect on GhDMT7 expression with slightly up-regulated expression at low dosage and down-regulated expression at high dosage， and decreased 5-methylcytosine （5mC） content. Furthermore， the treatment with 50 μmol·L-1 5-azaC significantly enhanced seed germination potential and growth parameters， which promoted seed germination. Above results laid a foundation for further studying the function of GhDMT7 on cotton growth and development， and provided genetic resources for breeding new varieties of saline-resistant cotton.
In order to explore the effect of exogenous ethephon on leaf shedding and yield of pigmented pepper， the variety ‘Jinjiao 801’ was used as material， and different dosages of ethephon were set up including 200 （T200）， 400 （T400）， 600 （T600）， 800 （T800） and 1 000 mg·L-1 （T1000） ， with water as control （CK）. The deciduous rate of pigmented pepper leaves was investigated， and the contents of photosynthetic pigments， carbohydrates， antioxidant enzymes in pigmented pepper leaves and fruit yield were determined. The results showed that after processing for 12 and 15 d， the deciduous rates of T600 treatment were 43.95% and 54.11%， respectively， which were 5.06 and 5.46 times that of CK. The fruit yield of T600 treatment was significantly higher than that of CK at 5 sampling times， and the yield were the maximum at 5 sampling times. Exogenous ethephon treatment could reduce the contents of chlorophyll， reducing sugar and soluble sugar in pigmented pepper leaves， reduce the activities of superoxide dismutase （SOD） and peroxidase （POD）， reduce starch accumulation， accelerate leaf senescence， increase malonaldehyde （MDA） content in pigmented pepper leaves， and improve fruit yield. With the increase of ethephon dosage， the contents of chlorophyll， reducing sugar， soluble sugar content and starch gradually decreased， the SOD and POD activities graduallies decreased， and the MDA content gradually increased. After processing for 15 d， compared with CK， T600 treatment significantly accelerated the senescence of pigmented pepper leaves， and the chlorophyll content， starch content， SOD activity and POD activity decreased by 80.83%， 31.42%， 73.67% and 37.19%， respectively， the content of MDA increased by 57.60%. To sum up， exogenous 600 mg·L-1 ethephon treatment had the best effect on promoting leaf senescence and increasing fruit yield of pigmented pepper. Above results provided theoretical basis for artificially regulating leaf shedding of pigmented pepper and improving the mechanized harvesting efficiency of pigmented pepper.
R2R3-MYB transcription factors are the largest MYB subfamily in plants and are widely involved in regulating plant growth and development and stress response. R2R3-MYB gene family of Chinese chestnut was genome-widely identified， and the chromosome distribution of these genes， subcellular localization prediction， phylogenetic relationships， protein motif， gene structure and sequence alignment of conserved domains were analyzed. Finally， the expression of the CmR2R3-MYB gene family under drought stress was analyzed by transcriptome and RT-qPCR. The results showed that total 141 CmR2R3-MYB genes were unequally distributed on 12 chromosomes and 1 contig fragment. And the phylogenetic tree divided them into 6 groups. There were 7 CmR2R3-MYB genes differentially expressed under drought stress. Among them， CmMYB89 was upregulated， while CmMYB32， CmMYB95， CmMYB91， CmMYB119， CmMYB131 and CmMYB104 were downregulated， which indicated that these 7 genes could be involved in drought resistance of Chinese chestnut. Above results provided theoretical foundations for further exploring the role of the R2R3-MYB gene family in response to drought stress of Chinese chestnut.
Cation/H+ exchanger （CHX） gene family participate in the regulation of plants proton and cation transport， and play an important role in plant growth and development and abiotic stress response. To analyze the ArabidopsisAtCHX genes in response to salt-alkali stress， 28 AtCHX genes of Arabidopsis were analyzed. The results showed that AtCHX genes were divided into 5 subfamilies， and their structures and protein sequence motifs were very conserved. Tissue expression and abiotic stress expression analysis found that AtCHX19 expressed in roots of Arabidopsis and up-regulated by salt-alkali stress. Further salt-alkali tolerance analysis of Arabidopsis mutant showed that the deletionof AtCHX19 gene reduced tolerance to high salt and soda saline stress， and Na+ content of mutant was significantly higher than that of wild type. Above results initially clarified that the AtCHX19 gene responded to saline-alkali stress by regulating Na+ transport， which provided data support for further elucidating the stress resistant molecular mechanism and signaling transduction pathway mediating by CHX.
Xylanase （EC 3.2.1.8） is an important industrial enzyme， which is widely used in industries such as food， feed， papermaking， textile and biofuels. Pm10868 is derived from the genome of rumen ciliates， which could be expressed in yeast， but could not be expressed in Escherichia coli BL21. In order to increase the expression level of xylanase Pm10868 in Escherichia coli and further explore the relationship between soluble expression level and amino acid sequence in Escherichia coli， by utilizing the existing generation model MPB-MUT and expression level prediction model MPB-EXP in the laboratory， the top 3 xylanase Pm10868 mutants were screened out for the detection of enzymatic properties such as expression level， thermostability and catalytic efficiency. The results showed that the expression levels of 3 mutants in E. coli were significantly increased. Among them， the specific activity of Pm10868-117 （138.9 U·mg-1） was approximately 2 folds that of the wild type expressed in yeast （62.5 U·mg-1）. The kcat/Km of Pm10868-117 was 228.09 mL·min-1·mg-1， which was about 1.2 times that of wild type. When incubated at 45 ℃ for 1 h， the enzyme activity of wild-type Pm10868 was 27% of original enzyme activity， while the enzyme activity of Pm10868-117 was 81% of original enzyme activity， approximately 3 times that of the wild type. When incubated at 50 ℃ for 20 min， the enzyme activity of the wild-type Pm10868 was only 6% of original enzyme activity， while the enzyme activity of Pm10868-117 was 49% of original enzyme activity. In conclusion， the specific activity， catalytic efficiency and thermostability of Pm10868-117 were all greatly improved. Molecular dynamics simulation analysis of the wild type and mutant found that the CBM（cellulose-binding motif） fluctuation of Pm10868-117 was significantly reduced， which helped to improve the overall thermostability and binding ability with the substrate， thereby enhancing the catalytic efficiency. Above results had great significance for clarifying the structure-activity relationship of xylanase with different enzymatic properties， and layed a theoretical foundation for the molecular design of xylanase to meet the requirements of different application scenarios.
In order to rapidly and accuratelely diagnose and recognize potassium stress degree of rice， The Huanghuazhan variety of late rice was used as material， and 4 potassium fertilization levels were set respectively for base fertilizer and topdressing at jointing stage. Taking scanned images of 3 spread leaves of main stem at tiller stage and jointing stage as data set， and MobileViT as the skeleton， the CA_MobileViT model was constructed after introducing Coordinate Attention to the BN Layer of each 3×3 convolution in the layer of MobileViT and introduce transfer learning. The results were verified by comparing EfficientNet-V2， ConvNeXt， MobileViT and CA_MobileViT models. The results showed that the accuracy rates of the 4 models were 98.4%， 98.5%， 94.2% and 95.3%， respectively. The accuracy of CA_MobileViT model was 95.3%， 1.1 percent point higher than that of MobileViT model， but 3.1 percent point lower than that of EfficientNet-V2 model and 3.2 percent point lower than that of ConvNeXt model. However， the number of parameters of CA_MobileViT models was about 1/4 of the EfficientNet-V2 and ConvNeXt large models， and the training time was reduced by about 1/3. The improved CA_MobileViT model has a high accuracy for the diagnosis of potassium stress degree of rice， and could effectively guide the scientific potassium topdressing management of rice， and also provide a universal and feasible method for the rapid and accurate diagnosis of nutrition of other crops.
Chlorophyll plays a key role in the process of plant photosynthesis， and the relative chlorophyll content （soil and plantan alyzer development，SPAD） is an important indicator to measure the growth status of crops. In order to construct an inversion model of SPAD value of processing tomato， this study used unmanned aerial vehicle（UAV） remote sensing technology to predict the SPAD value of canopy leaves at 4 key growth periods of processing tomato by machine learning method， and drew a visual mapping of SPAD value of processing tomato based on the optimal prediction model. The results showed that random forest （RF）， support vector machine （SVM） and back propagation（BP）neural network prediction model of SPAD values at different growth periods of processing tomato， the multispectral vegetation index as the independent variable， the RF model had the best prediction effect at the first flowering period， with determination coefficient（R2 ）of 0.89 and root mean square error（RMSE） of 1.15， the SVM model was the best at the full flowering period， with R2 of 0.87 and RMSE of 1.46， the SVM model was the best at the fruit setting period， with R2 of 0.88 and RMSE of 1.25， and the BP neural network model was the best at the maturity period， with R2 of 0.89 and RMSE of 1.07. In the full flowering period of crops， the flowering process would consume most of the nutrients inside the plant， resulting in different changes in chlorophyll content， and its prediction effect was relatively low， and the selection of appropriate models for modeling in different growth periods could achieve high-precision monitoring of chlorophyll content in processing tomato. The stability of the prediction results and verification results of SVM model in each growth period of processing tomato was better， with R2 of 0.88， 0.87， 0.88， 0.85 and RMSE of 0.95， 1.46， 1.25，1.91， respectively， so the SPAD value of processing tomato was visualized and mapped at each growth stage based on the optimal SVM model to realize the dynamic monitoring of chlorophyll in processing tomato. Above results could be used to quickly and efficiently estimate the relative chlorophyll content of processing tomatoes， and provided decision-making information and technical support for the precision agriculture management of processing tomatoes.
To overcome hindrances such as low accuracy of small target pitaya recognition， poor real-time performance， and difficulties in fruit counting under expansive field conditions， a method was proposed for pitaya target detection and enumeration within large visual fields. This should allow for precision identification and quantification of small target pitayas， thereby refining the preparatory guidance tasks associated with robotic pitaya harvesting. In the feature extraction stage， the dynamic deformable convolution C2F_DCNV2_Dynamic was employed to replace the C2F module of the YOLOv8 backbone network. Conv_offer_mask was introduced to obtain deformable offsets and masks of input feature maps， enabling the network to better adapt to the features of target shapes and enhance the capability of extracting target features from complex backgrounds. The mechanism module MPCA （multipath coordinate attention） was improved to perform multi-path processing on the input， allowing the model to simultaneously focus on the spatial and channel information of the input tensor， thus improving the feature perception ability of the network for different scales and contexts， and thereby enhancing the accuracy of small target recognition. In the target prediction stage， the Decoder Head of the detection model RT-DETR based on end-to-end Transformer was used to replace the YOLO Head. Through ensemble prediction methods， targets were directly predicted and associated， eliminating the traditional non-maximum suppression （NMS）step to improve inference speed and further enhance the real-time performance of the network. In the target counting stage， the Deep Sort algorithm was combined to achieve fruit area counting. The results showed that the improved object detection network had an average accuracy of 99.0% for dragon fruit detection， transmits 32 frames per second in the real-time test， the model size was 11.8 MB， and the fruit counting accuracy reached 82.96%， with the average detection speed 17 frames·s-1. This method could accurately identify and count small target dragon fruits under large field of view conditions， with real-time performance meeting the actual production environment of fruit orchards.
In order to isolate a biocontrol bacteria with antagonistic effects on Botrytis cinerea，the antagonistic bacteria were screened from grape rhizosphere soils by plate confrontation method and liter paper method. A strain with strong antagonistic effect was selected and identified by morpholoigical， physiological and biochemical characteristics， 16S rDNA sequences analysis. The safety， growth-promoting and the control effect of the strain were tested by the blood plate method， seed germination experiments and detached fruit method. The results showed that 5 antagonistic bacteria were screened from 142 bacterial strains isolated from grape rhizosphere soils. These 5 antagonistic bacteria had different inhibitory effect on grape gray mold disease with the inhibition rates from 81.74% to 89.13%， and the inhibition zone were from 2.42 to 11.08 mm， among which the inhibitory effect of strain B1-4 was the highest. By morph-oloigical， physiological and biochemical characteristics， 16S rDNA sequences， strain B1-4 was identified as Bacillus velezensis，which had no hemolysis， could produce cellulase， protease and siderophores， and had nitrogen fixation effect. The germination rate and radicle length of cucumber and rapeseed seeds could be significantly improved by 100 times dilution of B1-4 fermentation solution. The protective effect of B1-4 fermentation liquid reached 70.31% and the rapeutic effect was 69.53% on postharvest grape fruit gray mold， which was no significant difference with 5 000 times dilution of 50% fludioxonil （71.88%）. Above results showed that B. velezensis B1-4 was a protential biocontrol strain for control B.cinerea.
In order to screen medicinal plant endophytes with good antibacterial activity against super drug-resistant Escherichia coli that simultaneously carry New Delhi metal-β lactamase （NDM） gene NDM1/NDM5 and NDM4/NDM5， the endophytes of Forsythia suspensa that had antagonistic effects on the super drug-resistant E. coli carrying NDM1/NDM5 and NDM4/NDM5 were isolated and screened by surface disinfection method and plate confrontation method. Morphological and molecular biological identification of these endophytes were performed， and their antibacterial activities were investigated by genome-wide analysis. The results showed that 23 strains of endophytes were isolated from root， stem， leaf and fruit different of Forsythia suspensa. A Gram-positive endophyte with good antibacterial effect was obtained from 23 endophyte strains by plate confrontation assay. It was identified as Paenibacillus spby morphology and molecular identification， and named as HNYJ2209J. HNYJ2209J could effectively inhibit the super drug-resistant E. coli. Whole genome sequencing analysis showed that the genome size of HNYJ2209J was 5 827 342 bp， the content of GC was 46.22%， and the number of coding genes was 5 232. There were 5 229， 3 648， 4 107， 3 493 and 2 495 annotated genes by NR， Swiss-Prot， COG， GO and KEGG databases， respectively， and 8 gene clusters related to secondary metabolite synthesis were predicted by antiSMASH. The main secondary metabolites were cyclolipopeptide antibiotics （fusaricidin B）， tridecaptin， polymyxin B， paenibacillin， marthiapeptide A， paeninodin， paenilipoheptin and aurantinin B/C/D. Among them， fusaricidin B， tridecaptin， polymyxin B and paenibacillin showed 100%， 100%， 100% and 90% homology between the predicted synthetic gene cluster and the known gene cluster. To sum up， HNYJ2209J had the potential to develop new drugs against super drug-resistant E. coli carrying NDM1/NDM5 and NDM4/NDM5 and as a feedable microorganism.
Coffea belongs to the Coffea genus， Rubiaceae family， and is an important tropical economic crop. Coffee is widely popular due to its unique flavor and biological functions. Caffeine and trigonelline are key components， which comprise the main flavor of coffee. They have various biological activities such as anti-inflammatory， anti-cancer， metabolism regulation， neuroprotection and diabetes treatment. The extraction and determination methods of coffea alkaloids， the synthetic metabolic pathways of major compounds， and their biological activities were reviewed. Future research directions were explored， including the diversity of coffea alkaloid compounds， extraction and determination methods， biological activities and the development of coffea products， which provided a theoretical reference for further research on coffea-related applications.
To investigate the nutrient composition and functional properties of protein powder and starch from 3 legumes （chickpea， pea and soybean）， the mineral content， amino acid composition， dietary fiber content and functional properties （including water-holding capacity， oil-holding capacity， surface hydrophobicity， emulsification， emulsion stability， foaming and foam stability） of these fractions were systematically analyzed. The results showed that chickpea protein powder had significantly higher Ca， Mg and Mn contents， as well as a higher proportion of essential amino acids （40%）， compared to the other 2 legumes. Moreover， chickpea protein powder exhibited the highest surface hydrophobicity （187.02 μg） and oil holding capacity （0.90 g·g-1）， while the soy protein powder had the highest water holding capacity （5.25 g·g-1）. The chickpea starch possessed higher Ca， K， Mg and Na contents than pea starch. A small amount of residual cellulose was present in the starch fractions and the cellulose content of chickpea starch was 172 times higher than that of pea starch. In addition， protein powder generally exhibited better emulsification and foaming properties than starch， with chickpea protein powder showing the most remarkable emulsion stability and foaming stability.
The evolution characteristics and driving factors of carbon emissions from animal husbandry in Shandong province were analyzed by using the life-cycle assessment method and the generalized divisia index method. The results showed that the total carbon emissions from animal husbandry in Shandong province decreased from 6 360.91×104 t in 2011 to 5 576.21×104 t in 2022， with an average annual growth rate of -1.19%. The proportion of carbon emissions from enteric fermentation and manure management gradually decreased， and the proportion of feed consumption system in 2019 exceeded that of gastrointestinal fermentation and manure management system， and becomed the most important source of carbon emissions. In terms of livestock species， poultry carbon emissions accounted for the largest share， and the total amount of poultry carbon emissions showed growing trend. From the perspective of spatial and temporal series， Linyi， Weifang and Heze had larger total carbon emissions， while Tai’an， Qingdao and Jining had lower carbon intensity. In terms of comprehensive driving factors， the carbon intensity of total mechanical power consumption and carbon intensity of economic output were the main contributing factors， and the contributing effect of the intensity of total mechanical power consumption was relatively low. Above results showed that adjusting the industrial structure and improving the efficiency and effectiveness of livestock and poultry production were effective way to improve the resource utilization efficiency of the livestock industry in the future， and improving the efficiency of livestock machinery while introducing advanced and low-carbon livestock machinery and equipment was an important direction for the green development of the animal husbandry industry in Shandong province in the future.
To investigate limestone mines for the purpose of restoring soil fertility levels and rebuilding mine soil ecosystems，slag was collected at a limestone mine located in Luquan District， Shijiazhuang city， and mixed with nearby farmland soil in varying ratios. The physicochemical properties and enzyme activities of the reconstructed soils were determined， and their fertility was comprehensively evaluated using the gray correlation method. The results showed the bulk density， porosity， water holding capacity， total porosity， and capillary porosity of different reconstructed soils varied significantly； as the proportion of farmland soil increases， each water holding capacity index also increased； additionally， the bulk density and non-capillary porosity exhibited an inverse relationship. Significant differences were observed in pH， total phosphorus， total potassium， and available nutrients among the various reconstructed soils， however， no differences were observed in organic carbon and total nitrogen. The pH decreased gradually with an increase in the proportion of agricultural soils， while the total and available nutrients of soils increased gradually. All enzymes except dehydrogenase showed significant differences in different reconstructed soils. Alkaline phosphatase activity， urease activity， sucrase activity， polyphenol oxidase activity， and catalase activity were all maximal at the ratio of agricultural soil and slag of 7∶3. Correlation analysis revealed significant correlations between the physicochemical properties of reconstituted soils and enzyme activities excepted for dehydrogenase. The gray correlation degree method was used to conduct a comprehensive analysis of reconstituted soil fertility. Soil fertility level was optimal when the ratio of agricultural soil to slag was 7∶3. The study demonstrated that the reconstruction of mine soil with farmland soil has a significant impact. The addition of farmland soil can greatly enhanced the physical， chemical， and biological characteristics of mine soil， which was beneficial for improving the fertility of mine soil and protecting the soil ecosystem.
It has become a general consensus that overapplication of common nitrogen fertilizer causes low crop benefit and soil environmental pollution. Regulating nitrification process is an effective way to ensure stable crop yield， reduce fertilizer dosage and soil nitrogen loss. On the basis of the same amount of phosphorus and potassium fertilizer， 6 nitrogen gradients were set： no nitrogen fertilizer （N0）， farmer fertilization （N130）， optimal fertilization （N100）， optimal reduction of common nitrogen fertilizer 20% （N80）， optimal reduction of slow release nitrogen fertilizer 25% （N4575）， optimal reduction of slow release nitrogen fertilizer 40% （N4560）.The effects of slow-release nitrogen fertilizer on winter wheat yield and soil nitrate/ammonium nitrogen content were analyzed under drip irrigation under the condition of reducing common nitrogen fertilizer. The results showed that the effective panicle number， kernel number per spike and 1 000-grain weight of winter wheat did not decrease significantly by applying slow release nitrogen fertilizer under the condition of reducing total nitrogen input， and the yield was still high. The agronomic efficiency of nitrogen fertilizer of N4575 treatment was higher than that of other treatments， especially the increase of 44.57% compared with N130 treatment. The nitrogen partial productivity of optimal reduction treatment was higher than that of N130 treatment， and the nitrogen partial productivity of slow release nitrogen treatment was higher than that of common nitrogen treatment. The nitrogen partial productivity of N4560 and N4575 treatment was higher than that of N130 treatment by 79.08% and 63.32%， respectively. Nitrogen reduction treatment improved nitrogen use efficiency， and N4575 treatment had the highest nitrogen use efficiency， which was 29.53% higher than that of N130 treatment. Reasonable application of slow release nitrogen fertilizer could reduce the content of nitrate/ammonium nitrogen in deep soil layer， thus reducing the risk of nitrogen leaching into deep soil layer. Therefore， the rational application of slow release nitrogen fertilizer could be an effective choice to stabilize the yield of winter wheat under drip irrigation and reduce environmental pollution. Above results provided theoretical support for the rational fertilization of winter wheat with drip irrigation， and had important significance for improving the production capacity of winter wheat and ensuring environmental safety.
In order to explore the dynamic development of maize plant height and stem diameter and its accumulated temperature model and characteristic parameters based on effective accumulated temperature， field experiments were conducted in spring and summer sowing in 2023 using Zhuyu216（ZY216）， Yufeng303（YF303）， Zhongkeyu505（ZKY505） and Zhengdan958（ZD958） as experimental materials. Logistic model was used to fit the dynamic development equations of maize plant height and stem diameter based on effective accumulated temperature， and their characteristic parameters were used to analyze the dynamic development characteristics of maize. The results showed that there was a highly significant correlation between the plant height and stem diameter of spring and summer sowing maize and the effective accumulated temperature， with a correlation coefficient of over 0.96 for spring sowing and above 0.94 for summer sowing， showing an S-shaped unidirectional increasing dynamic trend with the effective accumulated temperature. The logistic model for maize plant height and stem diameter established with effective accumulated temperature as the independent variable had the good biological significance. The determination coefficient of the plant height equation were 0.982 7~0.996 8 for spring sowing and 0.982 8~0.993 5 for summer sowing， the determination coefficient of the stem diameter equation were 0.989 4~0.999 0 for spring sowing and 0.987 7~0.998 7 for summer sowing， the correlation coefficients were 0.991 3~0.998 4 and 0.993 8~0.999 5， respectively； the standardized root mean square errors of plant height were 3.55%～10.71% for spring sowing and 6.96%～10.30% for summer sowing， and stem diameter were 14.93%～26.84% for in spring sowing and 5.93%～13.75% in summer sowing， the simulation curve had a high fitting degree with the measured values， achieving a good predictive effect level. The effective accumulated temperature required of plant height for entering the maximum growth rate， entering the rapid increase period， and entering the enter the slow increase period were shown as follows： in spring sowing of ZKY505，YF303>ZD958，ZY216， while in summer sowing of YF303>ZY216>ZKY505>ZD958. There was no significant difference in the effective accumulated temperature required for the maximum stem diameter growth rate among the 4 varieties sown in spring， and the results of summer sowing were ZY216>ZD958，YF303>ZKY505. On the whole，the logistic model could simulate and predict the dynamic development of maize plant height and stem diameter based on effective accumulated temperature， and could predict maize growth， which had strong utilization value. Above results provided theoretical basis for predicting dynamic development of maize plant height and stem diameter by effective accumulated temperature.
Soil salinization is an important obstacle factor for agricultural development and ecological environment protection， and it is a feasible method to improve saline soil and reduce the harm of salt stress through the formulation and application of amendments and new materials. 10 treatments including no fertilizer （CK）， chemical fertilizer （CF）， CF+organic fertilizer （CFM）， CFM+different dosage of choline chloride （CFMC1， CFMC2， CFMC3）， CFM+rhamnolipids （CFMS1）， and CFM+choline chloride+different dosage of rhamnolipids （CFMC2S1， CFMC2S2， CFMC2S3） were setting. The effects of organic fertilizers with rhamnolipid and choline chloride on the physicochemical properties of salinized soil and the growth and development of tomato and salt tolerance were studied. The results showed that CFM， CFMC1， CFMC2， CFMC3， CFMS1， CFMC2S1， CFMC2S2 and CFMC2S3 treatments could improve the soil environment， and reduce the soil pH and soil sodium adsorption ration. Organic fertilizer combined with choline chloride and rhamnoolide could improve the salt tolerance of tomato， and compared with CFM treatment， the content of malondialdehyde and the superoxide anion production rate decreased by 2.81%~26.76% and 9.52%~42.86%， respectively；peroxidase activity and proline content increased by 1.39%~27.78% and 5.15%~31.17%， respectively； leaf K+ content increased by 1.29%~21.03%， and Na+ content decreased by 2.16%~14.59%. Tomato photosynthesis was enhanced and fruit quality and yield increased，compared with CFM treatment， soluble sugar， vitamin C content and yield of fruits increased by 2.94%~20.59%， 3.42%~12.43% and 8.90%~33.81%， respectively， chlorophyll content and net photosynthetic rate increased by 3.85%~38.46% and 2.40%~42.51%， respectively. In moderately saline soil， the best effect was achieved when organic fertilizer was added at a rate of 15 000 kg·hm-2 with 9 kg·hm-2 choline chloride and 0.72 kg·hm-2 20% rhamnolipid. In conclusion， the application of organic fertilizer with rhamnolipid and choline chloride could reduce the harm of salt stress on tomato， promote the growth of tomato， and increase its salt tolerance to a certain extent. Above results provided a reference for the improvement of saline soil and high quality and high yield of tomato.
In order to safely utilize the Cd-contaminated soil， and explore the deactivation effect of amendments on Cd contaminated soil， different types of amendments were selected including biochar （BC）， inorganic amendment （TB） and organic amendment （OA）， and no amendment was control （CK）， and 3 experimental sites were set up in northern， eastern and southern of Henan， respectively. The deactivation of 3 amendments and their effects on soil microbial community structure were studied. The results showed that 3 amendments could significantly reduce the available Cd contents in soil， and the Cd content in wheat grains decreased ultimately. The pH of soil in south of Henan was incrrased after the application of amendments. Compared with CK， the available Cd content of soil in northern， eastern and southern of Henan decreased by 48.1%~86.1%， 24.2%~33% and 33.5%~54.3%， respectively， and the Cd content of wheat grains decreased by 22.2%~84.7%， 51.8%~58.2% and 24.9%~44.1%， respectively. In addition， amendments significantly changed the community composition and structure of bacteria and fungi in soil. In the northern experimental site， the abundances of Solicoccozyma and Purpureocilliun in fungi were increased by 3 amendments. In the eastern experimental site， TB treatment significantly increased the abundance of Chryseolinea in fungi， OA and TB treatments significantly increased the abundance of Subulicystidium in fungi. In the southern experimental site， BC treatment significantly increased the abundance of bacteria such as Bradyrhizobium， Bryobacter and Reyranella. In conclusion， the effects of amendment BC and OA in northern and eastern of Henan were significant， but amendment TB effect was the most significant in southern of Henan. Among them， the Cd content of grain in the northern of Henan was lower than 0.1 mg kg-1 （national food safety standard limit）after amendment BC and OA application. Above results provided reference for achieving food security production.
In order to reveal the distribution rules and influencing factors of forest soil organic carbon content in Tianshan mountains， the soil organic carbon content and spatial distribution characteristics of different depths in the study area were estimated by combining the forest soil measured data and the technical tools of geographic information system. The results showed that，according to different models， the average values of organic carbon content in 0 to 10， 10 to 20， 20 to 30， 30 to 40， 40 to 50， 50 to 70， 70 to 100 cm soil layers were 144.054， 147.087， 122.343， 122.302， 72.941， 61.260 and 49.527 g·kg-1， respectively. In the depth of 0 to 40 cm， the areas with high soil organic carbon content were mainly located in the middle of the study area， while only the central area maintained a high distribution in 40 to 100 cm soil layer. The soil organic carbon content of natural forests in the study area showed significant spatial differences， in which the soil organic carbon content decreased with the increase of soil depth and increased with the increase of stand development stage， which was manifested in mature forests > overmature forests > near-mature forests > middle-aged forests > young forests. Soil physicochemical properties played a decisive role in the accumulation and distribution of soil organic carbon. There was a significant correlation between soil physical and chemical properties and soil organic carbon content， and there was a significant correlation between soil organic carbon and soil pH， total phosphorus and bulk density， among which pH and bulk density were significantly negatively correlated， while total phosphorus was significantly positively correlated. Above results provided a scientific basis for assessing the potential of soil carbon sequestration in typical forest areas of the Tianshan mountains.
To establish an efficient virus-induced gene silencing （VIGS） system in important Brassicaceae vegetables， Brassica rapa subsp. chinensis and Brassica juncea were chosen as the material and the endogenous phytoene desaturase （PDS） gene was selected as the marker gene. The pTRV2-BrPDS， pTRV2-BjuPDS-g and pTRV2-BjuPDS-c vectors were constructed， and the infection efficiency of Agrobacterium was optimized to construst VIGS system with high efficient. The results showed that the pTRV2-BrPDS， pTRV2-BjuPDS-g and pTRV2-BjuPDS-c vectors were successfully constructed. The albinism phenotype of B. rapa subsp. chinensis plants was the most obvious with OD600=1.0 of Agrobacterium， while the silencing efficiency of B. juncea was optimal with OD600=0.8 of Agrobacterium. The qRT-PCR analysis confirmed that the observed albinism phenotype was resulted from the silencing of the endogenous PDS gene in plant infected with the TRV-based recombinant virus. Above results provided theoretical basis for studing the gene functions of B. rapa subsp. chinensis and B. juncea using VIGS technology.
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