Journal of Shenyang Agricultural University

Effect of Immersion Freezing in Regulating Ice Crystal Formation to Improve Quality of Frozen Strawberries

[Objective]Current quick-freezing remains highly energy-consume and cost,during frozen storage, temperature fluctuations could lead to repeated freezing and melting of ice crystals, resulting in the formation of larger ice crystals. These larger crystals could damage the cellular structure of the raw marterial, causing undesirable quality changes such as reduced firmness and juice loss upon thawing. This study focused on strawberries and employed immersion freezing technology to accelerate freezing process, allowing it to pass through the maximum ice crystal formation zone faster to form smaller、more uniform ice crystals and reduce cellular damage,to preserve the superior quality of strawberries after thawing. [Method]Based on previously optimized immersion solutions, this study compared immersion freezing at-20 ℃ and-30 ℃ with air freezing as a control, investigating their effects on strawberry quality and underlying mechanisms. [Results]Immersion freezing significantly reduced freezing time(29.49%-54.86%, P<0.05), increased hardness(143%-147%, P<0.05), decreased juice loss rate(21.54%-36.36%, P<0.05), and effectively delayed the degradation and consumption of cell wall components(7%-10%, P<0.05). The microscopic structure and ice crystal morphology analysis revealed smaller, uniformly distributed ice crystals and tightly arranged cells. The low-field nuclear magnetic resonance(LF-NMR) analysis demonstrated that the immersion freezing stabilized the bound water and reduced free water conversion(4%-17%, P<0.05), effectively inhibited water migration. [Conclusion]The immersion freezing treatment addresses the issue of strawberries developing a soft and mushy texture after thawing, to some extent, by regulating ice crystal formation and cell wall stability. The research results provide theoretical and technical support for the application of immersion freezing technology in quality control of frozen strawberries.

Source-sink Relationship of Soybean Germplasm at Bulging Stage and Screening of Identification Indexes of Grain Wrinkles

[Objective]The bulging stage is a critical period for grain formation and filling of soybean germplasm. The co-ordination of source-sink relationships directly affects the rate and fullness of seed filling. The study of the relationship between source-sink relationship and grain wrinkling at the bulging stage of soybean germplasm can help to reveal the physiological mechanism of wrinkling grain formation, so to provide breeders with more precise breeding goals and strategies. [Methods]355 soybean germplasm from different sources were used as test materials, and indicators such as source-sink relationship at grain filling stage and seed wrinkling at maturity were determined. [Results]355 soybean germplasm could be classified into 5 grades of wrinkling, namely grade 0(9), grade 3(321), grade 5(3), grade 7(21) and grade 9(1), and the higher the grade, the more serious the wrinkling of the seeds. The correlation analyses of seed wrinkling and source-sink relationships revealed negative correlations between leaf net photosynthetic rate, dry weight of nutrient organ, leaf-to-pod ratio and seed starch content and wrinkling level; the leaf area index and reproductive organ dry weight were positively correlated with wrinkling level. [Conclusion]Fourteen source-sink relationship traits of soybean germplasm were combined into four principal component factors with a cumulative contribution of 78.836%; multiple linear regression analyses showed that major source-sink relationship traits such as net photosynthetic rate of leaves, leaf area index, dry weight of nutrient organs, dry weight of reproductive organs, and starch content of grains were the main factors affecting the grade of seed wrinkling.

Genome-Wide Association Study of Panicle Traits in Japonica Rice from Northeast China

[Objective]Rice(Oryza sativa L.) panicle traits are critical agronomic determinants of yield, and elucidating their genetic mechanisms is essential to address global food security challenges. This study aims to identify key genetic loci and functional genes regulating panicle morphology in japonica rice, providing theoretical support for high-yield breeding. [Methods]Using 410 japonica rice accessions from Northeast China, we systematically measured panicle morphological and structural traits, including panicle length,primary/secondary branch numbers, and conducted genome-wide association study(GWAS) to locate significant loci. Candidate gene functions were validated through haplotype analysis and PARMS marker-based genotyping. [Results]A total of 7 significant QTL(qPW2, qGNP3, qPW6/qTGW6, qPL8, qPBN8/qTGW8, qPL9 and qTGW9) sites were identified, and 10 candidate genes including GW6a and DEP1 were screened. Haplotype analysis revealed significant divergence in panicle weight and grain weight traits among GW6a haplotypes, while DEP1 haplotypes exhibited highly significant differences in panicle length. Molecular marker-based genotyping confirmed the superior allelic variants of GW6a and DEP1. [Conclusion]This study demonstrates significant genetic associations between GW6a/DEP1 allelic variations and panicle weight/length traits. The PARMS marker-based genotyping system enables efficient screening of favorable panicle-related alleles. These findings provide validated genetic targets for molecular design breeding of panicle architecture in Northeast japonica rice. Multi-gene polymerization strategies can optimize panicle structure and advance high-yield smart breeding technologies.

Effects of Biochar Application Rates on Growth, Development and Fruit Quality of Oriental Melon with Fennel Companion Cultivation

[Objective]As a soil amendment, biochar has the advantages in increasing soil fertility, promoting crop growth, and enhancing crop yield. This study investigated the effects of different biochar application rates on plant growth, fruit quality, and mineral nutrient uptake of oriental melon with fennel companion cultivation in a solar greenhouse. [Methods]The treatments included the application of 10 g(BOF10), 20 g(BOF20), and 40 g(BOF40) of straw-derived biochar. The aim was to determine the optimal biochar application rate for oriental melon with fennel companion cultivation and provide a theoretical and practical basis for improving its effectiveness. [Results]The experimental results showed that under the oriental melon with fennel companion cultivation,different biochar application rates(BOF10, BOF20, and BOF40) promoted root growth to varying degrees, enhanced root activity and photosynthetic capacity, facilitated mineral nutrient uptake, and increased plant dry and fresh weight. Among them, the BOF20treatment exhibited the most significant effects. Regarding fruit quality, both BOF20 and BOF40 treatments significantly increased the soluble solids content, vitamin C content, and single fruit weight. [Conclusion]BOF20 was identified as the optimal biochar application rate for the oriental melon with fennel companion cultivation.

Quantitative Analysis of Temperature Difference Changes at Different Depths of Soil in a Solar Greenhouse at Night

[Objective]To find out the amplitude and depth of soil temperature reduction below the ground caused by heat-releasing from soil in solar greenhouse at night, to calculate the heat storage capacity of soil at different depths, and to provide theoretical guidance for determination of soil heating depth and study on heating effect. [Methods]This study was carried out in test greenhouse in Jinan,Shandong province, at the intersection of the middle of east-west length and the middle of north-south span, 0, 0.1, 0.2, 0.3,0.5, 0.6 m below the ground was selected as the measuring point, temperature sensors T₀, T₁, T₂, T₃, T₅, T₆was set respectively on the point, and the heat flow plate H0was set on the ground. Selecting the test data from 6∶00 to next 6∶00 on the sunny day and cloudy day to qualitatively analyze the changes of T₀, T₁, T₂, T₃, T₅, T₆caused by T₀changes and the test data from 18∶00 to next 6∶00 to quantitatively analyze the decrease of T₀, T₁, T₂, T₃, T₅, T₆caused by T₀decrease, to show soil temperature reduction amplitude at different depths, to calculate soil exothermic depth and soil temperature difference integral; the heat release intensity H0was integrated to calculate heat-releasing volume, and then to calculate heat storage capacity of the soil. [Results]T_he study showed: the soil temperature difference decreased sharply with increasing depth. on sunny day night the depth of releasing heat was 0.25 m, and the heat-releasing volume was 5.56×10⁵J·m^-2, and heat storage capacity between 0～0.25 m was 1.16×10⁶J·m^-3·℃^-1; on cloudy day night the depth of releasing heat was 0.67 m, and the heat-releasing volume was 6.05×10⁵J·m^-2and 83.33% of which was released from 0～0.3 m soil, and heat storage capacity between 0～0.67 m soil was 2.52 × 10⁶J · m^-3·℃^-1. [Conclusion]The results showed soil temperature difference decreased sharply with the depth at night. Heat releasing volume was concentrated in 0～0.3 m area in this test,heating soil in this area could affect nighttime air temperature in the greenhouse. The heat storage capacity of deep soil was much greater than that of shallow soil, and in this greenhouse the heating effect of shallow soil was obvious.

Research Progress of Mechanism of Atractylodes macrocephala Koidz Polysaccharide in Veterinary Clinical Application

Atractylodes macrocephala Koidz, as a widely used medicinal herb of the Asteraceae family, is one of the important components of many traditional Chinese patent medicine preparations. Many countries in Asia often use its rhizomes as medicine for the treatment and prevention of diseases. As an important extract of Atractylodes macrocephala Koidz, Atractylodes macrocephala Koidz polysaccharide is mainly composed of glucose, galactose, arabinose, mannose and other monosaccharides. It has the effects of anti-inflammatory, anti-oxidation, regulating glucose and lipid metabolism and improving immune function. It is often used to protect the gastrointestinal tract, liver, heart, breast, and used as anti-tumor, anti-stress and an immune enhancer. It plays an important role in ensuring animal health of livestock and poultry, and has been widely concerned and studied because of its small side effects and no drug resistance. This paper reviews the biological activity and action mechanism of Atractylodes macrocephala Koidz polysaccharide, as well as its latest research progress in the prevention and treatment of clinical diseases in livestock and poultry, and provides a theoretical basis for the wide application of Atractylodes macrocephala Koidz polysaccharide in livestock and poultry.

Pomegranate Disease Detection Based on Improved YOLOv10n

[Objective]Aiming at the problems of low detection accuracy, insufficient generalization ability, and complex feature extraction in pomegranate disease detection under complex backgrounds, variable environments, and multi-scale target recognition, a pomegranate disease detection model named MBC-YOLOv10n is proposed. [Methods]Firstly, a Mixed Local Channel Attention mechanism(MLCA) is integrated into all C2f modules of the YOLOv10n model to enhance the model's sensitivity to pomegranate disease features and improve detection precision. Secondly, considering the variability and multi-scale characteristics of pomegranate diseases, a Bi-directional Feature Pyramid Network(BiFPN) is incorporated to fuse features at different scales, thereby improving both precision and recall without significantly increasing the number of parameters. Finally, a Convolutional Block Attention Module(CBAM) is introduced to strengthen the model's anti-interference ability against complex backgrounds through spatial and channel attention mechanisms.[Results]The improved MBC-YOLOv10n model shows significant performance gains compared to the original YOLOv10n. The mean Average Precision at 0.5 IoU(mAP50) increases by 1.3% to 90.1%, Precision improves by 2.4% to 90.5%,Recall increases by 2.0% to 88.4%, and the mean Average Precision across IoU thresholds from 0.5 to 0.95(mAP50-95) improves by5.0% to 57.9%. The parameter count remains low at only 2.9 M, significantly enhancing the model's capability for pomegranate disease detection. The MBC-YOLOv10n achieves excellent detection accuracy while maintaining a lightweight structure, ensuring both high precision and real-time performance. [Conclusion]The proposed MBC-YOLOv10n model can effectively detect pomegranate diseases under natural environmental conditions, balancing high accuracy and lightweight design. It provides a reliable technical foundation for early warning and precise prevention of pomegranate diseases in smart agriculture and lays a theoretical basis for the optimization and future application of disease detection models.

Effects of Different Regenerated Species on Soil Chemical Properties,Enzymatic Activities, and Microbiota Characteristics in Larix kaempferi Plantation

[Objective]This study aimed to investigate the effects of different regeneration species on soil chemical properties, enzyme activities, and microbial characteristics in Larix kaempferi plantations, identify suitable regeneration species, and provide a theoretical basis for establishing multi-storied forests in large-scale pure larch plantations in the mountainous regions of eastern Liaoning Province. [Methods]Soil samples were collected from a 34-year-old Larix kaempferi plantation in eastern Liaoning after uniform thinning and under-canopy regeneration with different tree species, including Pinus koraiensis, Fraxinus mandshurica, and a 1∶1mixed planting of Pinus koraiensis and Fraxinus mandshurica. Soil chemical properties, enzyme activities, and microbial community composition were analyzed to evaluate the impacts of regeneration species. [Results]Under-canopy regeneration with different species improved soil nutrient content, enzyme activities, and alleviated soil acidification. Regeneration with Fraxinus mandshurica showed the most significant effects, yielding the highest values in soil pH, total nitrogen(TN), total potassium(TK), available potassium(AK), total phosphorus(TP), available phosphorus(AP), polyphenol oxidase, alkaline phosphatase, and urease activities. The mixed regeneration(Pinus koraiensis + Fraxinus mandshurica) ranked second, with the highest soil organic carbon(SOC) and ammonium nitrogen(NH₄⁺-N) content among the four treatments. The total number of bacterial operational taxonomic units(OTUs) showed minor differences across treatments, with a slight decrease in regeneration plots compared to the control. In contrast, fungal OTUs increased by 373.7%,121.3%, and 72%in Fraxinus mandshurica, Pinus koraiensis, and mixed regeneration plots, respectively, indicating enhanced fungal diversity, particularly under Fraxinus mandshurica regeneration. The sequencing identified nine dominant bacterial phyla and five dominant fungal phyla. The relative abundance of dominant bacterial phyla showed no significant correlation with soil nutrients or enzyme activities, while Basidiomycota, Mortierellomycota, Rozellomycota, and Glomeromycota exhibited significant correlations with soil chemical properties and enzymatic indices. [Conclusion]Under-canopy regeneration with Pinus koraiensis and Fraxinus mandshurica improves soil quality in Larix kaempferi plantations, with Fraxinus mandshurica achieving the most effective results,followed by mixed regeneration(Pinus koraiensis + Fraxinus mandshurica). Pinus koraiensis alone showed limited improvement.

The Effect of Different Irrigation Methods on the Stability of Soil Aggregates and Organic Carbon Content in Greenhouse Soil

[Objective]Irrigation is the primary way to obtain water for greenhouse crops. Different irrigation methods affect the formation and stability of aggregates. In addition, the formation of aggregates is not only affected by environmental factors, but also by the types and forms of cementing materials. This study aims to explore the effects of different irrigation methods on the stability of soil aggregates and organic carbon in facilities, and provide theoretical basis for water regulation in facilities agriculture and improvement of soil structure in facilities. [Methods]The soil cultivated under different irrigation methods(drip irrigation, infiltration irrigation and trench irrigation) for 12 consecutive years was used as the research object, and the test crop was tomato(Huafang 5). The stability of aggregates and the content and distribution characteristics of organic carbon in 0～40 cm soil were analyzed. [Results]Through the analysis of the composition and stability of aggregates by wet screening method, it was found that drip irrigation significantly increased the content of large aggregates in 20～40 cm soil layer, increased the average weight diameter and geometric average diameter, and reduced the average weight specific surface area and fractal dimension. Drip irrigation significantly increased the organic carbon content of large aggregates in 20～40 cm soil layer. The contents of granular organic carbon, mineral-bound organic carbon and easily oxidized organic carbon in macroaggregates were also increased. The redundancy analysis on aggregate related organic carbon is82.09%, among which large aggregate organic carbon and microaggregate mineral bonded organic carbon are the main contributions to aggregate stability index. [Conclusion]Under long-term facility cultivation conditions, drip irrigation is more conducive to improving soil aggregate stability and organic carbon content.

Research Progress of Genetic Improvement and Breeding Technology of Fraxinus mandshurica Rupr

Fraxinus mandshurica Rupr., a broad-leaved tree species in the genus Fraxinus, is a precious timber tree in northeast China. It plays a vital role in improving the growth environment, enhancing carbon sequestration capacity of ecosystems, promoting community succession, and maintaining ecosystem stability, demonstrating high economic and ecological values. In recent years, to protect the genetic resources of F. mandshurica and improve tree quality, and with breeding objectives of high-quality, stress resistance, fast-growing and high yield, researchers carried out technical research on germplasm resource collection and evaluation,crossbreeding, molecular marker-assisted breeding, and propagation techniques,to accelerate its genetic improvement process. This paper elaborates on the current research progress in multiple aspects, including high-quality germplasm resource collection and evaluation, provenance trials, selection of superior families and clones, crossbreeding, and genetic engineering breeding, to provide references for genetic improvement and elite variety propagation of F. mandshurica. In terms of genetic improvement, efforts should be strengthened to collect and protect genetic resources of F. mandshurica, while molecular techniques should be used to explore the genetic regulatory mechanisms controlling traits such as tree growth. Furthermore, attempts can be made to hybridize F. mandshurica with more Fraxinus species from distant geographical regions or with special excellent traits to increase genetic diversity. In terms of reproductive utilization, it is necessary to improve the rooting rate of cuttings and the survival rate of grafting to achieve large-scale and industrialized asexual propagation of F. mandshurica. Meanwhile, the utilization value of F. mandshurica should be expanded,industrial development paths broadened, and resource comprehensive utilization rate enhanced.

Soil-sickness Problem in the sustainable Development for the Protected Production of Vegetables

As the development of specialized production of vegetable crops, soil sickness has been a problem for the sustainable production of vegetable crops. Soil sickness is mainly caused by soil--borne pests, disorder of soil physical and chemical properties, and autotoxicity. The present paper discussed possible role of cropping system, biological control and grafting in the soil--borne pest control, role of organic fertilizer, desalting and reasonable fertilization in soil restoration, and the alleviation of autotoxicity by grafting, adsorption with charcoal and degradation by microbes.

Current Situation and Prospects of Green House Industry Development in China

This paper summarized comprehensively the history, current development of the green house industry and its researches. The historic significance, problems, and prospects were also analyzed. The summary was expected to provide references for determining the historic position and future developmental direction of green house industry.

Effect of Lodging Resistance on Yield and Its Relationship with Stalk Physical Characteristics

Stalk physical characteristics and tilt angle of matured plant of eighteen populations from six cultivars wereinvestigated under three conditions. The relationships between lodging resistance and yielding were also studied. TheresultS indicated that: the intensity of lodging of rice population could be grouped into three categories-lodging, slantand erect types according to the tilt angle of matured plant. Lodging resistance is significantly negatively correlatedwith the length of the first internode, and significantly positively correlated with the area of the basal stalk and withthe thickness of the hasal stalk. Difference among varieties and lodging resiStance was also found. Nitrogenapplication also had an obvious effect upon population lodging of rice. But if only yielding was considered, the highyield populations were given usually in the medium fertilization treatment. Therefore, rice resistance to the lodgingcould be improved by means of shortening length between the first and the second internode, strongtheningthe hardnes of the basal stalk, lowering the position of panicle, and elonging panicle or the neck-panicle internode.So the contradiction between lodging resiStance and plant height could be settled at a level of higher yielding.

Comparison of A New Model of Light Response of Photosynthesis with Traditional Models

Photosynthetic rates increase gradually with light intensity in the traditional models of light response curve of photosynthesis,i.e.rectangular hyperbolic model and nonrectangular hyperbolic model.So the maximum net photosynthetic rates calculated by nonrectangular hyperbolic model and rectangular hyperbolic model were far more than the measured data,and the saturation light point was not obtained.A new model of light-response of leaf net photosynthesis was proposed in this paper.Some properties of the new model of light-response of leaf net photosynthesis were discussed in detail.Results showed that the data of light-response of leaf photosynthesis of winter wheat under different environmental conditions were modeled by three models.The results fitted by nonrectangular hyperbolic model,rectangular hyperbolic model and the new model were compared.In addition,the measured data of light response of photosynthesis under different temperatures and CO2 concentrations could be dealt with,and the main parameters of photosynthesis,i.e.the maximum photosynthetic rates,saturation light point,light compensation point and the rate of dark expiration could be calculated without any hypotheses.The response data of leaf photosynthetic rate to irradiance under low irradiance and photo inhibition could be fitted by the new model.The measured data of light response of photosynthesis under different temperatures,CO2 concentrations and light intensity,including at low photon fluxes and photo inhibition could be dealt with.The fitted results were tallied with very well the measured data.So the new model has generality.

Current Situation of Remediating Techniques of Petroleum Contaminated Soil and Its Prospects

Current situations and damage of petroleum contaminated soils were summarized. Several main methods and techniques of remediating petroleum contaminated soil, application as well as advantages and disadvantages of the techniques were introduced in the paper. It points that traditional methods and techniques should combined with the bioremediation in the process cleaning the pollution, which will play the advantages of respective techniques. In the same time, the economic benefit, social benefit and environmental benefit should be considered together in treating petroleum contaminated soils.

A COMPARISON OF METHODS OF MEASUREMENT OF CHLOROPHYL IN PLANTS

Current Situation and Prospects of Green House Industry Development in China

This paper summarized comprehensively the history, current development of the green house industry and its researches. The historic significance, problems, and prospects were also analyzed. The summary was expected to provide references for determining the historic position and future developmental direction of green house industry.

Status and Developing Prospects of Biopesticide Research and Application

Biopesticides have many advantages over the traditional chemical pesticides,being safe to human,livestock and nontarget organisms,having wonderful environmental compatibility,stable controlling effects and benefit to protect the biodiversity,and having many resources etc.Status of research and application of biopesticides were reviewed in this paper.The authors pointed out the major problems in the research and application of biopesticides.The developing prospects of biopesticides were discussed and some advices were given for biopesticide development in future.

Determination of Blueberry Anthocyanins through pH Differential Method

For determinieg the contents of blueberry anthocyanins more exactly,the blueberry pigments were extracted by acidic alcohol and were identified anthocyanins by UV-VIS spectra and chemical methods.The blueberry anthocyanins were quantitatively analyzed through pH differential method.The results indicated that the content of blueberry anthocyanins was 313.24mg.100g-1 and the relative standard deviation was 1.39%.The influence on measuring results by impurity in the solution was eliminated by pH differential method.

Current Situation of Remediating Techniques of Petroleum Contaminated Soil and Its Prospects

Current situations and damage of petroleum contaminated soils were summarized. Several main methods and techniques of remediating petroleum contaminated soil, application as well as advantages and disadvantages of the techniques were introduced in the paper. It points that traditional methods and techniques should combined with the bioremediation in the process cleaning the pollution, which will play the advantages of respective techniques. In the same time, the economic benefit, social benefit and environmental benefit should be considered together in treating petroleum contaminated soils.