Journal of Shenyang Agricultural University

Identification, Full-length Genomic Sequence Amplification and Phylogenetic Analysis of Bell Pepper Alphaendornavirus in Liaoning Province

[Objective]In this study, pepper samples suspected of viral infection were collected from Shenyang, Liaoning Province.Bell pepper endornavirus(BPEV) was detected in the samples using small-RNA deep sequencing, which was designated as BPEV-Liaoning(BPEV-LN). The identification, full-length genome amplification and phylogenetic analysis of the endogenous RNA virus were performed. [Method]Through reverse transcription-polymerase chain reaction(RT-PCR) method, the segmented sequences of BPEV-LN genome were amplified, ultimately obtaining a full-length sequence of 14 728 bp(GenBank: PP842643). [Result]The nucleotide sequence homology analysis revealed that BPEV-LN exhibited the highest homology(99.21%) with the isolate BPEV-XJ(MH182675.1) from Xinjiang. Phylogenetic tree analysis indicated that BPEV-LN and BPEV-XJ isolates were aggregated into one branch, indicating the closest genetic relationship between them. Furthermore, based on the RNA-dependent RNA polymerase(RdRp)sequence of BPEV, specific detection primers were designed and used to test 19 pepper samples suspected of viral infection collected from the same location. BPEV was detected in 17 of these samples. [Conclusion]This study represents the first identification of BPEV in Liaoning Province, obtains the full-length genomic sequence of BPEV-LN and establishes an RT-PCR detection method. These findings provide a theoretical basis for understanding the origin and control of BPEV, as well as technical support for its identification and detection.

Response of Primary Root Elongation Induced by Nitrogen Deficiency to Regulation Involving OsDGL1-Mediated Cell Wall Rhamnose Metabolism

[Objective]Under nitrogen-deficient conditions, plants can enhance nitrogen uptake by promoting primary root growth; yet the molecular mechanisms underlying this adaptive response remain poorly understood. This study aimed to elucidate the intrinsic regulatory mechanisms of root morphological adaptation in rice in response to nitrogen deficiency, with a specific focus on clarifying the relationship between primary root growth regulation and nitrogen uptake efficiency. [Methods]Wild-type rice and the Osdgl1 mutant were used as experimental materials. Plants were subjected to either normal nitrogen supply or nitrogen-deficient conditions.Primary root growth phenotypes were systematically observed and measured. Concurrently, changes in the content of root cell wall components—including rhamnose, xylose, and cellulose, were analyzed. [Results]Nitrogen-deficient treatment significantly promoted primary root elongation of rice and partially restored the short-root phenotype of the Osdgl1 mutant. Genetic evidence indicated that OsDGL1 plays a crucial role in nitrogen deficiency-induced root growth. Further analysis revealed that changes in root length were primarily correlated with the content of rhamnose and xylose in the cell wall, but not with cellulose content. These findings suggest that rhamnose biosynthesis may serve an important function in this adaptive process. [Conclusion]OsDGL1 likely mediates the growth response of rice primary roots under nitrogen-deficient conditions by regulating the rhamnose biosynthesis pathway. This study provides novel insights and identifies future research directions for unraveling the molecular mechanisms through which nitrogen deficiency modulates root development in rice.

Genetic Diversity and Flowering Time Traits Analysis of Soybean Germplasm Resources

[Objective]This study aimed to systematically analyze the genetic diversity and the genetic basis of flowering time traits in soybean germplasm resources, identify germplasm with complementary flowering time and genetic backgrounds, and provide a theoretical basis for improving ecological adaptability and molecular design breeding in soybean. [Methods]A total of 294 soybean cultivars and intermediate germplasm accessions were used as materials. Whole-genome sequencing was performed using the 180K gene chip. Population structure and the heritability of flowering time were analyzed through principal component analysis, cluster analysis, genetic distance and genetic similarity calculations, combined with a kinship matrix. [Results]The flowering time of the 294 soybean accessions ranged from 36 to 69 days, with a mean of 41 days, a coefficient of variation of 15.688%, and a heritability of 0.42. After quality control, 71 880 SNPs were obtained. Principal component analysis showed that PC1 and PC2 cumulatively explained 12.05% of the phenotypic variation. Cluster analysis divided the 294 accessions into three major groups, with Group I further subdivided into four subgroups, and it contained 261 accessions, while Groups II and III were smaller but exhibited significant genetic differentiation. Genetic distance analysis revealed that genetic distances among accessions ranged from 0.000 578 to 0.491 218,with an average of 0.249 783. Genetic similarity analysis showed that the average genetic similarity among accessions was 0.745 1.The difference in flowering time between accessions with the largest and smallest genetic distances was 24 and 8 days, respectively,and significant differences in flowering time were observed among groups. [Conclusion]The 294 soybean germplasm accessions exhibit rich phenotypic variation in flowering time and moderate heritability, with a clear population genetic structure. Some groups retain unique gene pools and show significant genetic differentiation from mainstream cultivars. These findings provide important data support and a theoretical basis for mining flowering time-related genes, selecting parents based on genetic complementarity, and directionally improving the ecological adaptability of soybean.

Screening and Evaluation of Chestnut Germplasm Resources in the Shenyang Region

[Objective]To enrich chestnut germplasm resources in the Shenyang region, systematic observation and evaluation were conducted on 10 excellent individual plants previously selected by our research group, with the aim of identifying candidate individuals with stable continuous fruiting capacity that can be cultivated in the Shenyang area. [Methods]Indicators such as phenological stages, morphological traits, fruit characteristics, and major nutrient components of chestnut were measured. Principal component analysis was used to comprehensively evaluate the data collected in 2024, and the trends of trait changes over two consecutive years(2023—2024) were compared and analyzed. [Results]The budding period of the 10 chestnut plants was concentrated in mid-to-late April, and the fruit ripening period was concentrated in mid-to-late September, with relatively stable phenological periods across the two years. The 23-1-8 exhibited outstanding nutritional quality, with superior water content(55.43%), starch content(36.63%), soluble sugar content(10.71%), and protein content(4.97%). The 23-2-1 displayed excellent comprehensive quality and fruit traits, with the largest bur size(longitudinal diameter of 9.02 cm, transverse diameter of 8.41 cm) and single nut weight(13.65 g); its comprehensive indicators, including leaf, inflorescence, fruit size, branch, and nutrient content, were superior to those of most other individual plants. The comprehensive evaluation score of principal components for 23-2-1 was 0.899, ranking first among the 10 individual plants. [Conclusion]Based on the comprehensive performance of tree growth vigor, yield and quality, the 23-2-1 and 23-1-8 were identified as superior candidate plants, which could be used as the key materials for the breeding of excellent chestnut varieties in the Shenyang region.

Whole-genome Sequencing Analysis of Bacillus velezensis Apcs-1 and Its Effects on Soil Microbial Community

[Objective]In previoaus studies, our research group isolated a strain of Apcs-1 with significant antagonistic activity against potato common scab. [Method]To further elucidate its biocontrol mechanism, whole-genome sequencing and analysis of strain Apcs-1 were performed in this study, and the effects of this biocontrol bacterium on soil microbial communities were also determined.[Results]The results showed that the complete genome of strain Apcs-1 is 3 929 735 bp in length with a GC content of 46.50%, and harbors multiple functional genes related to biocontrol traits such as antibiosis, growth promotion and induced resistance. AntiSMASH analysis predicted abundant biosynthetic gene clusters encoding lipopeptides, polyketides, siderophores and other secondary metabolites, indicating a strong potential to produce diverse antimicrobial substances. Prediction using the VFDB database revealed that the strain carries defensive virulence factors, nonspecific virulence factors, aggressive virulence factors, and virulence-related regulatory genes. Further analysis of rhizosphere soil microbial communities after application of the strain fermentation broth demonstrated that B. velezensis Apcs-1 significantly increased the abundance and community evenness of beneficial rhizosphere.microorganisms(e.g., phylum Actinobacteria, class Bacilli), and significantly enriched genes associated with key metabolic pathways including amino acid metabolism and carbohydrate metabolism in soil. [Conclusion]This study reveals the genetic basis and biocontrol functions of strain Apcs-1 at the genomic level and from the perspective of microbial community effects, providing a theoretical foundation for the development and application of this strain in the green control of potato common scab.

Design and Experiment of Spraying Device for Rice Seedling Nursery Assembly Line

[Objective]In order to solve the problems of poor spray uniformity and low stability of the spraying device of high -speed rice industrial seedling raising assembly line， which led to the waste of chemicals and water， a spraying device was designed. [Method] Through the analysis of the spraying process， the key parts and working parameters were determined; using Fluent fluid simulation， several different spray pipeline structures were studied. The single-factor and three-factor three-level response surface tests of the sprinkler pedestal were carried out using the angle between the sprinkler holes and the horizontal plane， the aperture diameter of the sprinkler holes， and the height of the sprinkler pipe as the test factors， and the Christensen's coefficient of uniformity， Cu， and the coefficient of variation， Cv， as the evaluation indexes.[Results]:The results showed that the order of the influence of each factor on the spray uniformity and stability is ranked as the size of the spray pipe aperture， the size of the spray hole and the horizontal angle size and the height of the spray pipe; through the extreme value analysis and ANOVA， the optimal parameter combination is obtained as the size of the angle between the spray hole and the level of 60°， the size of the spray hole of 1.27 mm， and the height of the spray pipe of 29.8 mm， then the uniformity coefficient of the spray is 95.189%， and the coefficient of variation 5.988%. [Conclusion]The results of the study can provide a reference for the optimal design of the spraying device in the rice factory seedling production line.

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.

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.

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.

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.