2025 Vol.32(4): 1–8    [Abstract] ( 10 )    [PDF 1097 KB ] ( 2 )

In order to better describe the community structure of phytoplankton in the Tianjin waters of the Bohai Bay and its relationship with major environmental factors, three cruise surveys were conducted in 2022, including the spring（May）, summer （August）, and autumn（October）of 2022. The results showed that in the spring, the abundance, Shannon-Wiener diversity index （H’）, Margalef index（D）, and Pielou index（J）of phytoplankton in the reef area were 0.54×104 cell/m3, 1.10, 0.31, and 0.61, respectively, while those in the control area were 0.55×104 cell/m3, 1.30, 0.36, and 0.67, respectively. The abundance, Shannon- Wiener diversity index, Margalef index, and Pielou index of phytoplankton in the summer reef area were 2.51×104 cell/m3, 2.62, 0.70, and 0.90, respectively, while those in the control area were 4.84×104 cell/m3, 2.65, 0.63, and 0.90, respectively. The abundance, Shannon-Wiener diversity index, Margalef index, and Pielou index of phytoplankton in the autumn reef area were 1.30×104 cell/m3, 2.26, 0.44, and 0.96, respectively, while those in the control area were 1.23×104 cell/m3, 2.31, 0.48, and 0.95, respectively. The results indicated that the construction of artificial reefs had an effect in improving the diversity of phytoplankton but weakened the promotion of phytoplankton growth and reproduction with the extension of deployment time. The results of RDA showed that the main environmental factors affecting the community structure of phytoplankton in the Tianjin sea area of Bohai Bay in spring were temperature, salinity, pH, and ammonia nitrogen, while in summer they were temperature, total phosphorus, DO, and nitrite, and in autumn they were total nitrogen, total phosphorus, and ammonia nitrogen.

2025 Vol.32(4): 9–17    [Abstract] ( 9 )    [PDF 5930 KB ] ( 1 )

Halomonas binhaiensis Y2R2 is a novel species of the genus Halomonas with a phosphate-solubilizing function, which was isolated from Tianjin coastal saline-alkali land. In this paper, the genome function of strain Y2R2 was annotated and compared, and the gene cluster of secondary metabolites synthesis was predicted to explore its potential functions. Functional annotation of GO, COG and KEGG databases of strain Y2R2 showed that there were 341 and 336 genes involved in carbohydrate metabolism and amino acid metabolism, respectively. Comparative genomic analysis between Y2R2 and three closely related model strains showed that there were 3 623 gene families and 663 unique genes, among which the homology with Halomonas huangheensis NTU-107 was the highest. A number of strain Y2R2 secondary metabolite synthesis gene clusters were predicted, including tetrahydropyrimidine and bacterial terpenoid sodorifen. The similarity between tetrahydropyrimidine synthesis gene cluster and that of Methylophaga thalassica was as high as 75%. Through bioinformatics analysis, the mechanism of strain Y2R2 adapting to high osmotic pressure environment and dissolving phosphorus was explored, and the potential function of strain Y2R2 in promoting the growth of saline-alkali plants was explored, which provided support for the application of novel species Y2R2 of Halomonas in coastal saline-alkali land improvement.

2025 Vol.32(4): 18–25    [Abstract] ( 11 )    [PDF 3746 KB ] ( 4 )

EpCSP gene is a cold shock protein gene cloned from Exiguobacterium profundum, and bioinformatics analysis suggests that the protein encoded by this gene may be located in the nucleus or cytoplasm matrix. To further investigate the function of the gene, the CDS region of the EpCSP gene was amplified using PCR technology and cloned onto the expression vector pCAMBIA1300-EGFP-MCS to construct a recombinant plasmid for transient expression of EpCSP protein. After PCR identification, the recombinant plasmid was transformed into Agrobacterium tumefaciens LBA4404 using electric shock transformation method and transformed into onion epidermal cells. Its subcellular localization was determined by fluorescence microscopy observation. The results showed that the inserted fragment was completely consistent with the expected sequence and formed a complete gene expression system with the vector. Subcellular localization results showed that the EpCSP protein was distributed in the cytoplasm matrix.

2025 Vol.32(4): 26–31    [Abstract] ( 8 )    [PDF 1111 KB ] ( 1 )

This experiment focused on exploring the effects of different phosphate fertilizer treatments applied to seed coating agents on the growth of rice under aluminum stress. By comparing four rice varieties treated with varying amounts of phosphate fertilizer（0,0.5,and 1.0 g）in their seed coating agents, the study aimed to provide insights into improving rice’s resistance to aluminum stress. The experimental design employed a completely randomized approach, which allowed for a robust analysis of the data by minimizing the influence of any potential confounding variables. The main focus was on measuring basic agronomic traits and root activity indexes of the rice plants. The results revealed that rice treated with 0.5 g of phosphate fertilizer in the seed coating agent performed significantly better than rice without any phosphate fertilizer treatment and rice treated with 1.0 g of phosphate fertilizer. Specifically, the agronomic trait indexes and root activity of the 0.5 g phosphate-treated rice were superior. Furthermore, rice without any phosphate fertilizer treatment also outperformed the rice treated with 1.0 g of phosphate fertilizer in all measured indexes. Under the stress of 3.75 mmol/L aluminum chloride, the rice treated with 0.5 g of phosphate fertilizer showed enhanced aluminum tolerance. This treatment not only improved the rice’s ability to withstand aluminum stress but also enhanced its germination and growth conditions. In conclusion, the study found that a moderate amount of phosphate fertilizer （0.5 g）in the seed coating agent had a beneficial effect on rice growth under aluminum stress. This treatment improved both the agronomic traits and root activity of the rice plants, making them more resilient to aluminum stress. The results provide valuable insights for future cultivation practices aimed at enhancing rice's resistance to aluminum stress.

2025 Vol.32(4): 32–38    [Abstract] ( 9 )    [PDF 651 KB ] ( 1 )

The study of crop water demand and water deficit can provide a theoretical basis for local agricultural irrigation and effective defense against meteorological drought. In this study, daily observed meteorological data from 1961 to 2017 were used to calculate the precipitation during the main growing periods of maize in Ningxia. The Penman-Monteith formula, recommended by Food and Agriculture Organization of the United Nations（FAO）, was used to calculate the water requirement during the main growing periods of maize, then the water deficit was calculated and its spatial-temporal distribution characteristics were analyzed. The results showed that from 1961 to 2017, the average precipitation of maize in Ningxia at the sowing to emergence, emergence to jointing, jointing to tasseling, tasseling to milk ripening and milk ripening to maturity periods were 41.4, 32.8, 61.0, and 64.2 mm, respectively. The average maize water demand was 94.6, 87.6, 178.6, and 102.2 mm, respectively. And the average water deficit was 53.2, 54.8, 117.6, 38.1 mm respectively. In the past 57 years, the precipitation of maize in Ningxia showed an increasing trend during the emergence to jointing stage and the jointing to tasseling stage, while showed a decreasing trend during the tasseling to milk ripening stage and milk ripening to mature stage. Overall, the change trend of water demand was inconsistent, but some stations with an upward trend passed the significance test. The water deficit showed a decreasing trend during the emergence to jointing stage, and an increasing trend was observed in most areas during the other growth stages. Overall, the spatial distribution of water deficit gradually decreased from north to south. It can be seen that the northern part of the study area, especially during the tasseling to milk ripening period, has a high demand for irrigation water for maize, so irrigation is necessary to ensure high and stable yield.

2025 Vol.32(4): 39–46    [Abstract] ( 11 )    [PDF 2037 KB ] ( 4 )

Evapotranspiration is a key factor in the exchange of material and energy between the land surface and the atmosphere. Accurate estimation of evapotranspiration is essential for formulating reasonable irrigation plans and improving water use efficiency. In this study, summer maize in the North China Plain in 2017 and 2018 was used as the research object. Based on the observation data of eddy covariance system and automatic weather station, the variation of evapotranspiration（ET）of summer maize and its influencing factors at different time scales were discussed. The results showed that the hourly scale ET showed a ‘几’ shape change, with a maximum value between 12:00-14:00 and a minimum value around 0:00. The ET values of heading-filling stage and filling-milk ripening stage were larger than that of other growth stages, and the ET value of sowing-emergence stage was the smallest（0.031 5 mm and 0.021 5 mm, respectively）. On the daily scale, with the growth of summer maize, ET increased first and then decreased, and the maximum value appeared at the jointing-heading stage（the average values were 3.7 mm and 4.5 mm, respectively）. The minimum daily mean value of the whole growth period was sowing- emergence stage（the average values were 2.72 mm and 1.86 mm, respectively）. On the monthly scale, the maximum value of ET appeared in August（125.10 mm and 117.80 mm respectively）, and the minimum value appeared in June（50.08 mm and 34.04 mm respectively）. The correlation between ET and average sunlight and effective radiation was the largest, and the determination coefficient R2 was 0.270 4. The second was the daily average air temperature, with R2 0.074 2, and the correlation between average daily air relative humidity and ET was the smallest, with the coefficient of determination R2 0.020 7. The results of this study will provide a scientific basis for water management of farmland underlying surface.

2025 Vol.32(4): 47–53    [Abstract] ( 13 )    [PDF 1478 KB ] ( 0 )

To optimize the irrigation system for greenhouse tomato in Tianjin, combined with crop modeling, this study used EFAST to complete the sensitivity analysis of the model output results under different irrigation treatments（60%θf, 70%θf, 80%θf, θf: field capacity）to the model input variety parameters based on the soil, weather and field management data of greenhouse tomato in Tianjin from 2021 to 2022. Parameter correction and validation of the Cropgro-Tomato model were carried out with reference to the results of the sensitivity analysis, measured phenology, LAI, aboveground dry matter mass and yield data of tomato from 2020 to 2022. Using the validated model to simulate of the dry matter mass, yield of tomato under different irrigation treatments（W1-W7: 50%θf, 55%θf, 60%θf, 65%θf, 70%θf, 75%θf, 80%θf）, the scores were comprehensively evaluated by principal component analysis. The results showed that: the most sensitive variety parameter for anthesis days, maturity days, LAI, aboveground dry matter mass, and fresh weight yield were EMFL, and the model has high simulation accuracy for tomato phenology, LAI, aboveground dry matter mass, and yield. The yield and irrigation water use efficiency of the simulation results were maximum at W6 and W3 treatments with 83.7 t/hm2 and 33.55 kg/m3, respectively; the treatment with the highest scores was W5, and the lowest one was W1. It showed that the optimal irrigation treatment is the irrigation lower limit of 70%θf-75%θf.

2025 Vol.32(4): 54–61    [Abstract] ( 7 )    [PDF 2682 KB ] ( 1 )

A study on the antioxidant activity of Tremella fuciformis polysaccharides from four different regions demonstrated that the polysaccharides from Jilin Changbai Mountain exhibited the strongest reducing power, with superior performance in hydroxyl radical scavenging capacity, superoxide anion radical scavenging capacity, and DPPH radical scavenging capability compared to those from other three regions. Using Changbai Mountain Tremella fuciformis as materials, high-temperature steam extraction was optimized through single-factor and response surface methodology（RSM）experiments. The optimal extraction conditions were determined as: solid-liquid ratio（1:68）g/mL, extraction temperature 121℃, and extraction duration 1.0 hour. Under these conditions, the polysaccharide extraction yield reached（41.31±1.02）%. This optimized extraction process significantly improves the efficiency of Tremella polysaccharide extraction, laying a theoretical foundation for the future development and utilization of Tremella fuciformis-based products.

2025 Vol.32(4): 62–67    [Abstract] ( 9 )    [PDF 1888 KB ] ( 1 )

In order to increase the added value of shrimp processing by-products, this study used protease to hydrolyze shrimp shell protein and prepare a freshness enhancing, and unique flavor umami peptide.The effects of feed liquid ratio, enzyme dosage, enzyme hydrolysis time, and the temperature on the enzymatic hydrolysis efficiency of shrimp shells were studied using protein hydrolysis degree, solid dissolution rate, and soluble calcium ion content as indicators. Based on the single- factor experiment, the optimal enzymatic hydrolysis process conditions were determined through orthogonal optimization, and the free amino acids and volatile flavor components in the enzymatic hydrolysis solution were analyzed.The results showed that under the conditions of a solid-liquid ratio of 1∶2 and an initial pH of 7.0, adding 4 000 U/g of neutral protease resulted in a hydrolysis degree of 18.76% after 5 hours of enzymatic hydrolysis at 50 ℃. Fifteen amino acids were detected in the enzymatic hydrolysate, with glutamic acid accounting for 12.26%, highlighting its distinct flavor characteristics. 24 flavor components with high content were detected in the enzymatic hydrolysis solution, among which pyrazine components accounted for 40.08% and benzaldehyde content was 33.48%, which are characteristic aromas in the enzymatic hydrolysis products of shrimp shells.

2025 Vol.32(4): 68–73    [Abstract] ( 10 )    [PDF 1047 KB ] ( 1 )

To understand the volatile flavor compounds in raw vegetables and conduct comparative analysis, the volatile substances of four types of raw vegetables, namely Mesembryanthemum crystallinum, chrysanthemum, edible Andrographis paniculata, and head lettuce, were determined using solid-phase microextraction combined with gas chromatography-mass spectrometry（SPME-GC-MS）. The relative content of each substance was calculated using area normalization method, and a comprehensive evaluation was conducted using the method of principal component analysis（PCA）. The results showed that a total of 10 major categories of volatile substances were detected in these four vegetables, with higher levels of aromatic compounds in Mesembryanthemum crystallinum and head lettuce, higher levels of aldehydes in chrysanthemums and edible Andrographis paniculata, and higher levels of alcohols in all four vegetables. There are 57 main volatile substances in two or more types of vegetables, and 7 main volatile substances in all four types of vegetables. There are 14 key flavor substances, and because each vegetable contains different key flavor substances, its aroma and flavor were also different. The PCA results showed that there were two main components that can be used as effective components for differentiation, indicating significant differences in volatile substances in Mesembryanthemum crystallinum, chrysanthemums, edible Andrographis paniculata, and head lettuce. The research results can provide reference for the processing, development, and application of the four types of raw vegetables.

2025 Vol.32(4): 74–77    [Abstract] ( 7 )    [PDF 1126 KB ] ( 0 )

In order to effectively catalyze the synthesis of cinnamyl acetate as an essence, it is necessary to enhance the nonaqueous stability of enzymes. The usual method is to prepare a native enzyme into an enzyme immobilized in some carriers. This article investigates the effects of two types of carriers on the catalytic activity of the lipase. Pseudomonas cepacia lipase selected as a biocatalyst, copper phthalocyanine and absorbent cotton as carriers, immobilized lipase was prepared through physical adsorption. The immobilized lipase was used to catalyze the transesterification reaction between cinnamyl alcohol and vinyl acetate. It was found that when preparing immobilized enzymes, the ideal dosage of copper phthalocyanine as a single carrier was 10 mg, and the ideal dosage of absorbent cotton as a single carrier was 25 mg when the enzyme dosage was 10 mg. The ideal dosage of both carriers when used simultaneously was also 10 mg and 25 mg, respectively. The prepared dual carrier immobilized lipase showed a decrease of less than 1% in the ability of the immobilized enzyme to convert substrates and a decrease of 23% in the ability of native lipase to convert substrates during multiple repeated catalytic transesterification reactions. It means that the dual carrier immobilized lipase behaves fine nonaqueous stability and has industrial application potential.

2025 Vol.32(4): 78–85    [Abstract] ( 8 )    [PDF 1566 KB ] ( 1 )

The environmental pollution caused by industrial dye wastewater is serious,and the treatment of dye wastewater has become an important problem to be solved urgently. Chitosan is a kind of biodegradable natural polymer material with extensive sources,non-toxic and harmless. The functional groups such as amino group and hydroxyl group on the molecular chain of chitosan interact with organic dyes,so as it was used as a dye adsorption material. This review summarized the research status of chitosan-based adsorbents,including the research progress of chitosan,chitosan derivatives and chitosan modified materials as dye adsorbents,and looks forward to the research direction and application prospect of chitosan based adsorbents,in order to provide theoretical references for the preparation of chitosan-based dye adsorption materials with excellent performance and low price.

2025 Vol.32(4): 86–91    [Abstract] ( 11 )    [PDF 2270 KB ] ( 2 )

Image semantic segmentation is a pixel-level image classification method, which plays an important role in un-manned driving, robot vision and other fields. Aiming at the problems of inaccurate edge segmentation and easy loss of small target details in the process of semantic segmentation, an image semantic segmentation algorithm based on deep learning and superpixel segmentation was proposed. The image features were learned by using variational auto-encoder, and rough full- resolution semantic labels were predicted by multi-decoder structure. At the same time, the rough semantic segmentation results are further optimized on the basis of superpixel image segmentation, and finally verified on COCO2017 datasets. After experimental analysis, the proposed algorithm achieved a 4.4% improvement in global pixel accuracy（GA）compared to the pre-fused approach. Additionally, the average intersection over union（MIoU）increased by 8.2% compared to the pre-fused method, resulting in a 24.3% enhancement in segmentation precision over the SegNet network. The proposed algorithm achieves good results in both the segmentation accuracy and the segmentation speed, and achieves a good balance between real-time and accuracy.

2025 Vol.32(4): 92–95    [Abstract] ( 8 )    [PDF 769 KB ] ( 0 )

The prevalence of the COVID-19 has brought an impact on all aspects of agricultural product sales in China to varying degrees, and many fresh food e-commerce enterprises have suffered serious impacts during the epidemic. On the other hand, the epidemic has also allowed more consumers to have access to online sales of agricultural products, expanding the user base of fresh food e-commerce. In the post-epidemic era, and the development of the fresh food e-commerce industry faces both challenges and opportunities. This article summarizes the basic situation of China’s fresh food e-commerce industry in recent years, and analyzes the problems of the fresh food e-commerce industry in the post epidemic era from multiple perspectives based on the SWOT model. Finally, relevant suggestions are proposed for the future development path of the fresh food e-commerce industry.

2025 Vol.32(4): 96–102    [Abstract] ( 8 )    [PDF 760 KB ] ( 2 )

In the new era, targeted support from universities is a policy action aimed at enhancing the comprehensive capacity of regional higher education, which plays a significant role in promoting the development of higher education in assisted areas. On the basis of clarifying the characteristics, subjects, and responsibility boundaries of university counterpart support cooperation, this paper analyzes the multidimensional constraints faced by the university counterpart support ecosystem, such as policy implementation “suspension”, cooperation relationship “alienation”, platform function “virtualization”, talent flow “blockage”, and evaluation system “shortsightedness”. From the perspective of modern university governance, it is proposed that the construction of the university counterpart support cooperation ecosystem should be based on the principles of systematicity, synergy, and sustainability. Through a multidimensional linkage framework of strategic layer, resource layer, guarantee layer, and feedback layer, steady-state regulation can be achieved, and a closed-loop structure of “goal resource mechanism efficiency” can be constructed to continuously improve the effectiveness of education governance and promote the balanced and sustainable development of higher education.