Issue Ebookcover storyIssue CoverIssue Contents
List of IssuesDocument Types
- Abstract：The aim of this study was to explore the effects of drought occurred at grain-filling stages on maize endosperm from different ear positions. In this study, a hybrid ‘Zhengdan 958' was selected as experimental material. Except normal watering(CK), maize plants were subjected to drought stresses at early stage(ED, 16—25 days after pollination, DAP), middle stage(MD, 26—35 DAP)and late stage(LD, 36—45 DAP)of grain filling under potted plants, respectively. Then, the dynamics of dry matter accumulation in endosperms from the middle(superior position)and apical(inferior position)ears were monitored. The results showed that: The maximum filling rate was reduced by 1. 17% to 13. 70%, and the duration of filling was shortened by 1. 17% to 13. 70% of endosperm from both superior and inferior positions of the ear under drought treatments. Consequently, the grain weight, dry weight and starch content of endosperms at maturity stage were decreased(ED>MD>LD), but the protein content of endosperm was increased(LD>MD>ED). Specifically, under ED and MD treatments, the dry weight of endosperm was reduced by 12. 82% and 8. 74% from the superior position and 23. 0% and 14. 8% from the inferior position compared to CK, respectively. LD slightly decreased the dry weight of endosperm compared with CK without statistical significance. In addition, throughout the whole filling period, ED performed the most profound impact on the contents of soluble sugar and starch, particularly, it promoted the soluble sugar content of endosperm from the superior and inferior positions at 20 DAP, and suppressed starch content of endosperm from both positions by 16. 13% and 19. 42% at harvest, respectively. Whereas, LD performed the greatest effect on protein accumulation, by significantly increasing the protein content in endosperm form the superior and inferior positions by 14. 71% and 38. 01%, respectively. In summary, the endosperm from the inferior position was more vulnerable to drought than those from the superior position. During the grain filling stage, the earlier the drought occurred, the severer reduction in endosperm dry weight and grain weight is. Notably, drought stress at the later phase could promote protein content without yield penalty.Keywords：maize endosperm;grain-filling stages;drought;superior/inferior kernel;storage accumulation14|15|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to clarify the characteristics of grain filling of mechanical grain harvest variety of maize in Huang-Huai-Hai Rivers region and its response to plant density and nitrogen fertilizer rate, split plot experiment was conducted with the grain harvest variety ‘Jingnongke 728'(‘JNK 728')and common variety ‘Zhengdan 958'(‘ZD 958')as the main plot treatment, nitrogen fertilizer rates(120, 180, 240 kg/hm2)as the split plot treatment, and plant densities(45 000, 60 000, 75 000, 90 000 plants/hm2)as the split-split plot treatment to measure and analyze the dynamic of dry matter accumulation and grain filling characteristics in 2017-2019. The results showed that: The active grain filling period of ‘JNK 728' was 2. 9 d shorter than ‘ZD 958', and the effective grain filling period was 4. 7 d shorter than ‘ZD 958'; The average grain filling rate of ‘JNK 728' was 1. 0 mg/(kernel·d)larger than ‘ZD 958', the dry weight per kernel was 12. 0% larger than ‘ZD 958'. With the increase of plant density, the active grain filling period and effective grain filling period of the two varieties changed little, and the average grain filling rate, maximum grain filling rate, kernel weight at maximum grain filling rate and dry weight per kernel decreased. Compared with 45 000 plants/hm2, the average grain filling rate of ‘JNK 728' and ‘ZD 958' at the plant density of 90 000 plants/hm2 decreased by 6. 6% and 11. 5%, and the dry weight per kernel decreased by 3. 7% and 10. 4%, respectively. Under the conditions of this study, the grain filling parameters changed little among different nitrogen fertilizer rates and the nitrogen fertilizer rate had no significant effect on dry weight per kernel. In conclusion, the mechanical grain harvest variety ‘JNK 728' with shorter grain filling period, higher grain filling rate, and larger kernel dry weight than that of the common variety was suitable for summer sowing in Huang-Huai-Hai Rivers region. With the increase of plant density, the grain filling period changed little, and the grain filling rate and kernel dry weight decreased. The characteristics of ‘JNK 728' in grain filling rate and dry weight per kernel were insensitive to plant density than ‘ZD 958'. The effect of the variety was larger than the plant density, and the effect of plant density was larger than the nitrogen fertilizer rate.Keywords：maize;mechanical grain harvest variety;plant density;nitrogen fertilizer rate;grain filling characteristics23|16|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
Identification of related traits and classification of heterotic groups for 132 popcorn inbred lines
Abstract：In order to screen the excellent germplasm resources of different groups of popcorn, 132 popcorn inbred lines with extensive sources and rich genetic diversity were divided into heterosis groups by using 40 pairs of corn core SSR molecular markers, and the indexes of popcorn related traits were determined. The results showed that: The genetic coefficients of variation for kernel popping characteristics and ear traits among different popcorn inbred lines ranged from 3. 34% to 42. 26% with rich genetic diversity. The correlation analysis between popping characteristics and ear traits showed that popping rate was highly significantly positively correlated with popping volume and was significantly negatively correlated with the rows per ear and seeds per row; the popping volume was significantly negatively correlated with the rows per ear and seeds per row; there was a very significant positive correlation between ear length and ear diameter, row per ear, seeds per row, and bald length; ear diameter was extremely significantly positive correlation with row per ear and seeds per row; the number of rows per ear was highly significantly positively correlated with the number of grains per row, and significantly negatively correlated with the weight of 100 grains. The core markers were used to classify the popcorn lines into 5 heterotic groups. Combined with the identification of phenotypic traits, a total of 21 excellent inbred lines were identified from various groups. The popping volume of group Ⅱ ‘XF 133' was the highest among the excellent inbred lines of all groups and the most excellent germplasm resources.Keywords：popcorn;popping characteristics;ear traits;SSR;heterotic groups11|17|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27- Abstract：The aim of this study was to explore the function of staggered planting in improving the canopy structure and yield for summer maize population. In this study, the density-resistant cultivar ‘Zhengdan 958' was used as experimental material. Two panting patterns of parallel planting and staggered planting were arranged under the three planting densities, which were 67 500(D1 ), 82 500(D2)and 90 000(D3)plants/hm2, respectively. The leaf area index and diffuse non-interceptance of population canopy, chlorophyll fluorescence characteristics and SPAD value of ear leaf, yield and its components were measured in order to study the effects of staggered planting with close planting on summer maize. The results showed that: both density and staggered planting had significant influences on the canopy characteristics and yield of summer maize. The increased density level significantly advanced leaf area index, while declined diffuse non-interceptance of population canopy. The decreasing in Fv/Fm, Fv/Fo and SPAD value of era leaf achieved larger decline in planting density of 90 000 plants/hm2, indicating that the effect of the higher density level was adverse to the absorption and utilization of light energy by leaves. The staggered planting method effectively reduced the disadvantage of mutual shading of canopy leaves in dense planting population, which increased the Fv/Fm, Fv/Fo and SPAD value under D2 and D3 planting densities. The staggered planting optimized the canopy structure by increased leaf area index and decreased diffuse non-interceptance. Compared to planting of the parallel plant, and the optimal regulation was obtained in planting density of 82 500 plants/hm2. Simultaneously, the staggered planting method alleviated the adverse effects of planting density level on Fv/Fm, Fv/Fo and SPAD value at the density levels of 82 500 and 90 000 plants/hm2, respectively. Increased density levels to 82 500 and 90 000 plants/hm2 significantly increased yield by 18. 89% and 8. 12%, respectively. While the high density of 90 000 plants/hm2 resulted in declined of ear diameter, the number of kernels per ear, the thousand kernel weight, and the increased of ear tip-barren length. Compared with parallel planting, staggered planting method increased the thousand kernel weight by 6. 72% to 11. 94% in all density levels, and increased the harvested ear number in density levels of 82 500 and 90 000 plants/hm2, obtained advanced yield of 10. 23% to 14. 08%. The treatment of planting density level of 82 500 plants/hm2 with staggered planting method obtained the highest yield, resulted in an average increase of 30. 03%. In conclusion, the staggered planting pattern under 82 500 plants/hm2 density was the best mode to obtain increased yield for summer maize in the Huang-Huai-Hai Plain, which could improve the group canopy structure, enhance the interception and utilization of group's lighting. This study provided theoretical and technical supports for high yield cultivation of densely planted summer maize.Keywords：summer maize;staggered planting with close planting;canopy characteristic;yield;chlorophyll fluorescence characteristics16|19|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：A single-factor randomized group trial design was used to identify changes in the nutritional quality of kernels during the yield improvement process of maize varieties of different eras. Five representative high-yielding maize varieties from 1970s to 2010s were selected for a three-year field trial. The changes in canopy structure, dry matter accumulation and translocation, yield and its constituents, and nutritional quality of the grains in the process of yield improvement, as well as the relationship between the indicators were analyzed. The results showed that: Compared to the 1970s-2000s varieties, the yield of 2010s variety ‘DH 618' increased by 9. 37% to 55. 89%, and the number of harvested ears and 100-grain weight increased by 4. 18% to 10. 48% and 9. 85% to 33. 48%(P<0. 05). The 2010s variety(‘DH 618')had a higher effective spike number and 100-grain weight, mainly because the increase in 100-grain weight was dependent on the significant increase in total starch and soluble sugar content of the grains. Compared to the 1970s and 1990s varieties, the 2010s variety(‘DH 618')had 6. 56%-16. 48% and 0. 70%-2. 14% more soluble sugars and total starch in the grains respectively, but its crude protein content in the grains was 3. 98% to 8. 17% lower. At 65 d after anthesis, the net photosynthetic rate of the ear leaves of the 2010s variety(‘DH 618')was 31. 86% to 105. 35% higher than that of other varieties. At the maturity stage, the SPAD of the ear leaves of the 2010s variety(‘DH 618')was 8. 22%-42. 66% higher than that of other varieties(P<0. 05). The 2010s(‘DH 618')also showed a higher accumulation and translocation of dry matter per plant after anthesis than the 1970s(‘ZD 2'), 1980s(‘DY 13'), and 1990s(‘YD 13'), and 2000s(‘XY 335')by 0. 72%-33. 22% and 5. 34%-43. 77%, respectively. In summary, the 2010s variety(‘DH 618')had increased soluble sugar and total starch content in the grains, but reduced crude protein content in the grains. On the basis of the high net photosynthetic rate of the ear leaves at flowering, the SPAD of the ear leaves at the later stages of reproduction was further maintained, while significantly increasing the accumulation and translocation of dry matter per plant after anthesis was the main reason for the higher total starch and soluble sugar content of the grains of the 2010s variety(‘DH 618')compared to the 1970s and 1990s varieties.Keywords：maize;nutritional quality;canopy structure;matter accumulation;yield13|13|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To investigate the effects of different types of slow/controlled release ammonium sulfate fertilizers on the contribution of carbon and nitrogen to soil aggregates and crop growth, field trials were started in 2020. Completely randomized group experimental design of five treatments, conventional urea(AU), ordinary ammonium sulfate(AS), slow/controlled release of ammonium sulfate type I(ASN, ammonium sulfate+nitrification inhibitor), slow/controlled release ammonium sulfate type II(ASG, oil-coated ammonium sulfate)and slow/controlled release ammonium sulfate type III(ASD, oil-humic acid-coated ammonium sulfate)were conducted. The soil particle size was classified by the wet sieving method, and the particle size composition, stability status, aggregates of each particle size and silty organic carbon, total nitrogen content, and corn yield were analyzed. The result shows that: 1)ASG treatment had the highest mass fraction of >0. 250 to 2. 000 mm particle size aggregates, which increased by 68. 00% compared with AU treatment. The proportion of >0. 250 mm particle size aggregates was the highest in ASG treatment and the lowest in AU treatment. 2)The mean mass diameter(MWD), geometric mean diameter(GMD), and >0. 250 mm proportion of water-stable aggregate(R0. 25)of ASG treatment were higher than those of other fertilization treatments. Compared with AU and AS treatments, ASG treatment increased MWD by 36. 18% and 7. 62%, GMD increased by 70. 35% and 26. 54%, and R0. 25 increased by 50. 74% and 13. 37%, respectively. 3)The content of organic carbon in aggregates with particle sizes <0. 053 mm, 0. 053-0. 250, and >0. 250-2. 000 mm treated by ASG and ASD were higher than those treated by AU, AS, and ASN and the content of organic carbon in all particle sizes treated by ASD was significantly higher than that treated by ASG. However, the contribution rate of >0. 250 mm aggregates treated by ASG was significantly higher than that of other treatments, which was 1. 46 to 1. 59 times that of other treatments. 4)The total nitrogen content of aggregates treated by ASN, ASG and ASD were higher than that treated by AU and AS. In addition, the contribution rate of large aggregates to soil total nitrogen by ASG was significantly higher than that by AS and ASD treatments. 5)Compared with AU and AS treatments, the corn yield of ASG treatment increased by 18. 74% to 28. 95%, and the yield of ASD treatment increased by 9. 85% to 19. 30%. The yield was positively correlated with the organic carbon content of water-stable aggregates and silt particles of each particle size and was also positively correlated with the total nitrogen content of water-stable aggregates of each particle size. Therefore, the application of the new slow/controlled release ammonium sulfate type II(oil-coated ammonium sulfate)to calcareous brown soils is beneficial to soil structure stability and corn yield increase.Keywords：ammonium sulfate;slow/controlled release;aggregate;organic carbon;total nitrogen;yield20|15|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Based on the expression of TaMADS2 gene was up-regulated by the infection of leaf rust in compatible/incompatible wheat varieties and the response period was earlier in incompatible wheat than in compatible wheat, the function of TaMADS2 in wheat resistance to leaf rust was studied by using BSMV-VIGS technology. The phenotypes of TaMADS2-silenced plants(wheat cultivars ‘Chinese Spring' and ‘Zhengmai 9023')and the transcriptional level changes of pathogenesis-related genes were analyzed. The results showed a significant increase in disease severity of leaf rust on BSMV-infected wheat leaves, the length of infection hypha(IH)and infection area in wheat seedlings, as well as a remarkable decrease in the accumulation of reactive oxygen species(ROS)at single infection sites in TaMADS2-silenced plants, suggesting that the growth of pathogen fungus was promoted while the disease resistance response of plant was decreased in comparison to the non-silenced plants inoculated with leaf rust. Furthermore, qRT-PCR analysis showed that the expressing levels of pathogenesis-related genes TaPR1、TaPR2 and ROS-scavenging gene TaCAT were significantly down-regulated in the early stage of rust infection. In conclusion, TaMADS2 may inhibit the infection of leaf rust and positively regulate the resistance to leaf rust by regulating the expression of pathogenesis-related genes in wheat.Keywords：wheat;TaMADS;2;leaf rust;VIGS;pathogenesis-related genes17|14|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to comprehensively grasp the strategic position of China's pepper industry under the global competitive landscape, realize the technological innovation in pepper breeding, grasp the chip status of the pepper seed industry, and promote the high-quality development of China's pepper industry, the research methods such as research analysis, bibliometrics, and text mining in intelligence and economics are used to sort out the current development status of the global and China's pepper industry. In terms of scientific research papers, patent data, and industrial subjects, theprogress and development trend of pepper breeding in the world and China were summarized, and the research hotspots of pepper breeding were studied and judged. The results show that: The production scale and output of pepper in the world continue to expand; China's pepper production ranks first in the world. The scale of export trade remains high. The consumer demand is gradually diversified, and the pepper industry plays an important role in poverty alleviation. In view of the current problems in pepper breeding in China at present, the following suggestions are put forward: 1)Targeting market demand and reasonable layout of industrial structure; 2)Breaking through the key breeding technologies and cultivating professional chili varieties; 3)Developing information technology and strengthening the construction of big data breeding platform; 4)Focusing on standardization construction and enhancing brand market competitiveness. The above suggestions provide strong information support for promoting the high-quality development of pepper breeding and industry in China.Keywords：pepper breeding;pepper industry;pepper consumption;biological breeding12|15|11<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Applying mineral amendments is an effective way to meliorate acid soil, reduce heavy metal activity, and increase acid soil productivity. Pot experiment was conducted to investigate for the effects of silicon-calcium-potassium-magnesium fertilizer(T1), mineral amendment A(T2)and mineral amendment B(T3)on acidic soil acidity reduction and spinach cadmium accumulation. The results showed that: The mineral amendments at 10 g/kg significantly raised soil pH, decreased soil exchangeable Al3+, eventually led to a decrease in soil acidity. The higher reduction was found in mineral amendment B treatment(T3). Besides, the application of mineral amendments promoted spinach growth and the fresh weight were increased by 13. 8, 15. 9 and 15. 9 folds in T1, T2 and T3 treatments, respectively. T2 and T3 treatments also significantly reduced DTPA-Cd(41. 6% and 41. 0%)and plant Cd concentrations(48. 9% and 50. 9%), indicating that spinach Cd accumulation was deceased. Simultaneously, the BCF was reduced by 49. 1% and 50. 9%, respectively. In conclusion, the mineral amendment prepared by silicate minerals, oyster shell powder and dolomite can be utilized as potential amendments to meliorate acidic soil and decrease the bioavailability of Cd.Keywords：mineral amendments;soil acidification;exchangeable Al;3+;spinach biomass;Cd accumulation23|16|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The inhibition effects of copper(II)-phenolic nanocomplexes on algal growth and its effect on lettuce in hydroponics were studied. In this study, natural polyphenols(Bayberry tannin, Valonia tannin, Tara tannin, and Tannin acid)and functional metal ions(copper ions)were used as building blocks to engineer self-assembled copper(II)-phenolic nanocomplexes, and the inhibition experiment of copper(II)-phenolic nanocomplexes for Chlorella vulgaris and application of copper(II)-phenolic nanocomplexes on actual hydroponic lettuce were designed. The results showed that: 1)The polyphenol-induced interface interaction enabled the attachment of copper(II)-phenolic nanocomplexes on the surface of algal cells, which continuously and precisely delivered metal ions(copper ions)to algae, resulting in oxidative damage and cell death. Thus, the copper(II)-phenolic nanocomplexes presented long-lasting inhibition for algae, and the corresponding inhibition rate of CuII-BT still reached 99% on the 7th day for C. vulgaris. 2)The algal inhibition experiments showed that the inhibition ability of CuII-BT and CuII-VT for C. vulgaris was better than that of CuII-Tr and CuII-TA. 3)Plant experiments showed that copper(II)-phenolic nanocomplexes could inhibit algae during actual production, and there was no difference in fresh weight of lettuce seedlings compared with the control group. These results demonstrate the copper(II)-phenolic nanocomplexes had greater biosafety. Thus, the self-assembled copper(II)-phenolic nanocomplexes could inhibit algal blooms in actual hydroponic production, which contributed to reduce the problem of loss of crop yield caused by algal blooms.27|23|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To compare and analyze the toxicity of various extracts of salt Psoraleae Fructus on three kinds of cells, HK-2 cells, Hep-G2 cells and LLC-PK1 cells were used as evaluation models in this study, and CCK-8 method was used to detect the effects of water extract of salt Psoraleae Fructus, alcohol extract and their main components on the viability of three kinds of cells. The results showed that: 1)The ethanol extracts of salt-processed Psoraleae Fructus were more toxic to HK-2, Hep-G2 and LLC-PK1 cells than its aqueous extract. 2)At the same time point and concentration, bavachin, isobavachalcone, psoralidin, isopsoralidin and bavachinin A were more toxic to HK-2 and Hep-G2 cells, and bavachin was more toxic to HK-2 and Hep-G2 cells than the other major components. In contrast, psoralen, isopsoralen, corylin were relatively less toxic to HK-2 and Hep-G2 cells. In conclusion, the water and ethanolic extracts of salt Psoraleae Fructus had certain cytotoxicity to HK-2 cells, Hep-G2 cells and LLC-PK1 cells, and its ethanolic extract was more toxic; bavachin, isobavachalcone, bavachinin A, psoralen, isopsoralen, psoralidin, corylin were more toxic to HK-2 cells. Based on the results of this study, it can provide scientific basis for subsequent research on psoralea or its effective components, and reduce its toxic effects while exerting its pharmacological effects.Keywords：salt Psoraleae Fructus;cytotoxic effect;toxic components9|15|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to study the cashmere growth candidate gene set that regulated by Hippo signaling pathway in cashmere goat skin. Six Hanshan white cashmere goats were selected and randomly assigned to control group and melatonin treatment group with three replicates in each group. Take the natural year as the experiment period, skin samples were collected monthly for RNA sequencing analysis. Using Bowtie, TopHat, Cufflinks, Cuffmerge, Cuffdiff, Cuffcompare, CPAT and CPC software to analyze differentially expressed mRNA and lncRNA, combined with PCA to analyze that responded to the growth cycle of the secondary hair follicles, WGCNA to mine gene modules regulating cashmere growth, GSEA to analyze the biological functions of candidate gene set. The results showed that: 1)A total of 2 024 differentially expressed mRNAs and 329 differentially expressed lncRNAs were identified, which responded to the growth cycle of the secondary hair follicles in cashmere goat skin. 2)They were divided into 7 and 9 gene modules of biological significance in the control and treatment group. 3)In-depth analysis of Hippo signaling pathway gene module which enriched to balance mammalian skin growth and differentiation and hair follicle morphogenesis. The co-expression network of 191 mRNA and 49 lncRNA in the candidate gene set regulating goat cashmere growth in the treatment group was revealed. 4)The candidate gene set was remarkably related to skin development(|NES|>1 and FDR<25%), Hippo signaling pathway(|NES|>1 and FDR<25%), Wnt signaling pathway(|NES|>1 and FDR<25%)and Cell cycle(|NES|>1 and FDR<25%). In conclusion, the Hippo signaling pathway, a key pathway for regulating cashmere growth, has been identified, and the coexpression regulation relationship between mRNA and lncRNA regulating cashmere growth has been analyzed from the perspective of gene set at the omics level, which provide a reference for further investigations on the mechanism of melatonin promoting cashmere growth in goat.Keywords：cashmere goat skin;melatonin;RNA-seq;Hippo signaling pathway;candidate gene set11|16|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the feasibility of developing a new natural food additive, in the research, proanthocyanidins(PAS)was added to chicken breast myofibrillar protein to study its changes. Through rheology, infrared and Raman detection, low field nuclear magnetic resonance, texture analysis and other methods, the impact of PAS on gel formation and time variation was analyzed. The results showed as follows: 1)When the dosage of PAS was 0. 05~0. 20 g/kg, the protein gel had better water retention and could store more non-flowing water and free water for a longer time. 2)The addition of PAS increased the concentration of β-sheet in gels and made gels have more stable secondary structure. 3)The addition of PAS improved the gel viscoelasticity, which made the gel have a compact texture, larger density and denser pore size. 4)The addition of PAS improved the overall antioxidant level of the gel, making the gel have more stable biological characteristics in long-term storage. In conclusion, the addition of PAS could effectively improve the biostability of myofibrils and better protect their bioactivity during storage, which could provide new ideas for future food additives.Keywords：proantho cyanidins;chicken breast;fibrillin;gel strength13|17|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study was to better understand and evaluate the nutritional quality and characteristics of carp cultured in river-cages and common ponds. The sensory evaluation, color, inosinicacid(IMP)content, nutrient composition(crude protein, crude fat, moisture, ash), amino acid composition, protein digestibility in vitro, relative molecular mass distribution after simulated digestion and cooking yield of carp meat from two differently cultured carp meat were analyzed and evaluated. The results showed that: The sensory evaluation discovered that the raw meat of river-cages cultured carp had a stronger clear flavor, lower earthy smell and fishlike smell, and the cooked meat had a better texture and taste compared to ponds cultured carp. The overall acceptability of both raw and cooked meat of river-cages cultured carp was higher. The brightness value L* and whiteness were significantly(P<0. 05)higher in river-cages cultured carp meat than those in ponds cultured carp meat. The content of IMP, which is the main fresh taste substance, was significantly(P<0. 05)higher in river-cages cultured carp meat than that in ponds cultured carp meat. The protein mass fraction of carp cultured in river-cages(18. 16%)was significantly higher than that of carp cultured in ponds(17. 43%)(P<0. 05), but there was no significant difference in moisture and ash contents. The total amino acid content, total essential amino acid content, total non-essential amino acid content, total umami amino acid content, the ratio of total essential amino acid to total amino acid content, and the ratio of total essential amino acid content to total non-essential amino acid content in river-cages cultured carp meat were significantly higher than those in ponds cultured carp meat(P<0. 05). In vitro simulated digestibility of protein was significantly(P<0. 05)higher in river-cages cultured carp meat(67. 13%)than in ponds cultured carp meat(55. 86%). The steaming yield of carp meat from ponds culture(78. 91%)was significantly(P<0. 05)lower than that of river-cages culture carp meat(83. 11%). In conclusion, compared with ponds cultured carp, river-cages cultured carp has more protein and umami substances, better smell, texture and taste, and is more conducive to human digestion and absorption.Keywords：common carp;river-cages aquaculture;ponds aquaculture;nutrition quality8|15|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to carry out the performance evaluation of groundwater fallow policy process under the background of farmland rest and recuperation, Huang-Huai-Hai Plain is taken as the research object. Field investigation of relevant government departments and farmers in 2 cities and 5 counties of Huang-Huai-Hai Plain is conducted. Based on the public value theory, the performance evaluation index system of fallow policy process in groundwater overdraft area is constructed, and the performance of fallow policy process in serious groundwater overdraft area is evaluated by means of analytic hierarchy process and expert scoring method. The results show that: 1)The public value of the fallow policy in the groundwater overexploitation area of the Huang-Huai-Hai Plain is clarified and the performance evaluation index system of the fallow policy process is constructed from the four dimensions of fairness, participation, efficiency and sustainability; 2)The total score of the performance evaluation of the fallow policy process in the Huang-Huai-Hai Plain groundwater overexploitation area is 74. 38 points, and the performance level is at a ‘better' level; 3)The key links in the implementation process of fallow policy include the implementation of fallow policy area, fund management and use, government organization, and understanding of policy ecological objectives. The weak links in the implementation process of fallow policy include the implementation of fallow policy area, fund management and use, government organization and demonstration. In summary, the performance evaluation system of fallow policy process in groundwater overexploitation area constructed in this study is systematic, scientific and operable, which can provide research ideas and support for quantitative evaluation of fallow policy implementation process.Keywords：public value;fallow policy: process performance evaluation;improving strategies;groundwater overdraft area;Huang-Huai-Hai Plain12|16|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to improve urban ecological flood protection resilience and build a blue-green infrastructure network, the rainfall-runoff hydrological model was adopted to analyze the inundation range of dry month, normal month and wet month based on the Landsat remote sensing image data of Dengfeng City in April 2021. The inundation identification results were transformed into resistive surfaces and input into the identification and construction of potential ecological corridors. The connectivity analysis and circuit theory were used to screen and match the optimal diffusion distance and corridor "width" in Dengfeng City, and the corridors were comprehensively analyzed based on the key obstacles, pinch points and the current conditions of flood-prone areas. Finally the construction strategy of the blue-green infrastructure network in Dengfeng City was proposed. The result showed that: 1)The average rainwater reduction rates of forest land in the 14 catchment areas in dry, normal, and wet month gradually decreased by 94. 42%, 80. 85%, and 47. 46%, respectively. 2)With the increase of rainfall in the wet month, forest land gradually became the second largest runoff type under construction land, which caused 9. 10 km2 of construction land to be in the inundation risk area, and the inundated area of Gaocheng located in the flood high pressure area in the dry month expanded from 0. 29 km2 to 3. 13 km2. 3)A total of 26 important sources, 4 general sources, 56 potential corridors, 107 key obstacle points and 14 important pinch points were identified. Among them, the key corridors in the southeastern part of Dengfeng City were narrower and had higher current density. Many important pinch points were adjacent to the construction land, and each corridor had several key obstacle points, most of which were urban buildings, traffic roads and abandoned mines. This study proposed to strengthen the integration of blue and green spaces through ecological strategies such as restoring the river bank buffer zone, adding floodplains, and widening the flood section of the river in the lower reaches of the Ying River. It also proposed to form a safe and stable spatial pattern of rain and flood regulation and storage that is “dividing into parts and dispersion drainage”. This research provided reference for the construction of blue-green infrastructure network in Dengfeng City.Keywords：flood disaster;stormwater management;blue-green infrastructure;ecological network;Dengfeng City17|31|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study was to understand the spatial and temporal distribution characteristics of soil animal community diversity at different altitudes and vegetation types in Sejila Mountain. From May to September, 2021, soil samples of 0-10 cm depth were collected at 8 altitudes within the range of 3 400-4 500 m on the sunny slope of Sejila Mountain. Soil macrofauna were separated by Tullgren funnel and picked up by hand. The spatial and temporal distribution dynamics of soil fauna community structure, Shannon-Wiener diversity index, Pielou evenness index, richness index and similarity index were analyzed. The results showed that: 1)A total of 17 522 soil animals, belonging to 11 classes, 23 orders, 63 families(groups), were captured at 8 altitudes in Sejila Mountain(sunny slope). Collembola and Eucaridae are the dominant groups. The spatial and temporal dynamics of the number of groups and individuals of soil animals were quite different; 2)The seasonal difference of soil animal numbers at 3 700 m above sea level was the most significant(P<0. 05), and the seasonal difference of soil animal numbers at 4 400 m above sea level was the smallest; 3)Shannon-Wiener diversity was the highest in August and the lowest in July, and the overall change was small in May, June and September. Pielou uniformity was the highest in August, and significantly higher than other months(P<0. 05); 4)β diversity showed that the similarity of soil animal groups in the adjacent elevation of the sunny slope of Sejila Mountain was high. The greater the elevation difference, the lower the similarity is. With the change of altitude gradient and month, the number of individuals, groups and diversity of soil animals are quite different. In conclusion, the diversity of soil animal community in Sejila Mountain is sensitive to seasonal changes and altitude gradient changes.Keywords：Sejila Mountain;altitude gradient;soil animals;community diversity;spatiotemporal distribution;Tibet20|20|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the efficiency, economy and greenhouse gas emissions of the energy conversion process of biomass pyrolysis and liquefaction technology, based on the analysis principle of full life cycle assessment, a full life cycle model of waste straw pyrolysis to prepare liquid fuel technology was established, and the full life cycle analysis of the process was carried out. The assessment scope included straw collection and transportation, drying and crushing, biomass pyrolysis, charcoal processing and waste heat utilization. The results show that: The energy output-input ratio of biomass pyrolysis liquefaction conversion process is 20. 43; The net profit of wet straw treatment is about 289. 38 yuan/t, and the sales profit margin is 52. 11 %; CO2 equivalent emission is 34. 10 g/MJ. In conclusion, biomass pyrolysis and liquefaction is a potential biomass utilization technology with energy, economic and environmental benefits.Keywords：biomass straw;biomass pyrolysis and liquefaction;life cycle assessment;carbon emission18|20|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In view of the problems of the uncertainty in the acceleration characteristics and optimal parameters of a new-type swing separation sieve, the study investigated the variations of acceleration parallel and perpendicular to the sieve of each stage and the performance indexes of the separation sieve with the test factors, as well as the optimal parameter combination of the newly developed three-stage six-boom swinging separation sieve. The results showed that: 1)The acceleration parallel and perpendicular to the sieve increased with the increment of crank speed. When the suspender-connecting rod length combination was the same, the difference of parallel to the sieve between the first sieve and the second and third sieve acceleration was obvious, but the acceleration perpendicular to the first, second and third sieves showed obvious decreasing change step by step. With the increase of the tractor working speed, the acceleration parallel and perpendicular to the sieve on each stage showed a fluctuating trend of first decreasing, then increasing, and decreasing. 2)With the increase of the crank speed, the obvious rate fluctuated in the range of 96%-100%, while the skin breaking rate first decreased and then increased. Under the condition of five kinds of suspender-connecting rod length combination, the changing trends of the obvious rate and the skin breaking rate were consistent. With the increase of the tractor working speed, both the obvious rate and the skin breaking rate showed a changing pattern of first decreasing, then increasing and then decreasing. 3)The primary and secondary order of the factors affecting the obvious rate and the skin breaking rate respectively were: tractor working speed>suspender-connecting rod length combination>crank speed, crank speed>suspender-connecting rod length combination>tractor working speed. And the obtained optimal parameters were the crank speed of 180 r/min, suspender-connecting rod length combination with the parameters 270-370-1050(The lengths of the first and second sieve suspenders and connecting rod were 270 mm, 370 mm and 1 050 mm, respectively), and the tractor working speed of 1. 89 km/h. The study provided a theoretical and technical basis to determine the kinematic characteristics and performance of potato soil separation device.Keywords：swing separation sieve;acceleration;separation sieve performance;field experiment18|17|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the bending vibration problem of bar in dynamic analysis of arch greenhouse structure, the natural vibration characteristics of arch greenhouse were studied by direct stiffness method. Based on the analysis of bending deformation, shear deformation, axial compression deformation, second-order effect and translational inertia force and rotational inertia force based on distributed mass, the displacement control equation of circular arch is established, and the nonlinear translational Timoshenko circular arch dynamic model is obtained. The characteristic equation is obtained by the definite solution condition. By solving the characteristic equation, the calculation method of natural vibration period of arched greenhouse is given. By using the model established in this study and its degradation model, the natural vibration periods of arch shed and typical arched greenhouse structure under different models are calculated, and the calculation results of different models are analyzed. In conclusion, the geometric nonlinear compressible flat rotation Euler beam model established in this study can be used to calculate the natural vibration period of arched greenhouse structure.Keywords：greenhouse;circular arch;dynamic analysis;geometric nonlinearity;distributed mass model16|19|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to investigate the effect of agricultural product labeling cognition and consumption habit on consumers' willingness to pay premium of green agricultural products, based on the theory of planned behavior, an analytical framework that affects the willingness to pay premium for green agricultural products was constructed. Taking green fresh-potatoes as an example, based on the survey data of 402 consumers in three cities of Beijing, Zhengzhou and Chengdu, the contingent valuation method is used to evaluate the willingness to pay premium of urban consumers. On this basis, the ordered logit model was used to analyze the influence of behavioral attitude variables, subjective norm variables and perceived behavioral control variables on the willingness to pay premium of green fresh-potatoes. The results show that: 1)The average willingness of consumers to pay premium of green fresh-potatoes is between 10% and 30%, and the overall willingness level is relatively low. 2)The attitude of behavior variables have a significant impact on the willingness to pay premium of green fresh-potatoes. The higher the convenience of the place of purchase, the higher the willingness to pay premium. The better the consumers' perception of the quality of ordinary potatoes, the higher the willingness to pay premium. 3)The subjective norm variables also significantly affect urban consumers' willingness to pay premium for green fresh-potatoes. Among them, compared with QS product labeling and organic product labeling, the consumers' cognition of green product labeling has the greatest impact on their willingness to pay premium. 4)The effect of perceived behavior control variables on consumers' willingness to pay premium for the green fresh-potato is also significant. Male consumers who are older and in better health are more willing to pay a higher premium for green fresh potatoes. Therefore, green agricultural product market should be cultivated and the green development of agriculture should be promoted from the aspects of strengthening the publicity of the value of green agricultural products, improving consumers' cognition of green product labels, and promoting the convenience of consumers to purchase green agricultural products.24|22|5<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the effect of asset management of poverty alleviation projects on the income of poverty-stricken families, this study conducts empirical analysis by propensity score matching(PSM), quantile regression and other methods based on the survey data of 3 085 poverty-stricken families in 9 counties of 3 provinces. The results show that: The implementation of asset management of poverty alleviation projects can effectively increase the income of poverty-stricken families, and the conclusion is still valid after passing the PSM robustness test; The analysis of the mechanism of action found that the income of poverty-stricken families has been steadily increased through the division of ownership of assets, achieve employment nearby, and improvement of village collective income; Heterogeneity analysis found that it has the most significant effect on general poverty-stricken families, and has limited effect on Five Guarantee poverty-stricken families and low-income families. Therefore, In the strategic transition period of the two strategies: on the one hand, it is necessary to implement the asset management system for poverty alleviation projects; On the other hand, low-income groups such as poverty-stricken families under the Five Guarantees should be monitored to prevent returning to poverty, so as to achieve the goal of consolidating and expanding the achievements of poverty alleviation.Keywords：asset management of poverty alleviation projects;income of poverty-stricken families;action mechanism15|20|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the effects of the extensive use of direct seeding in southern China, based on the input—output data of 574 rice production cycles of 420 farmers in four southern provinces, this study investigated the impact of direct seeding technology on rice production efficiency from three perspectives including labor productivity, land productivity and technical efficiency. The results showed that: 1)Direct seeding technology significantly improved the labor productivity of rice; 2)Direct seeding technology had no significant effect on the land productivity of rice; 3)The adoption of direct seeding technology reduced the technical efficiency of rice. However, in the case of distinguishing farmers' planting scale, with the increase of rice planting scale the impact became insignificant when the planting scale reached a certain critical value. In conclusion, the adoption of rice direct seeding technology is an important coping strategy against the background of rising labor costs, and this technological change is an important embodiment of China's induced technological change theory. In addition, in order to save labor, farmers can bear a certain degree of output loss, indicating that the rice production mode has completely changed from intensive to extensive management. In order to give full play to the positive impact of direct seeding on rice production efficiency, we should tap the advantages and potential of direct seeding technology, focus on improving the supporting facilities and conditions of direct seeding technology, such as land leveling and land exchange, and further promote the popularization of direct seeding technology among farmers who have reached a certain rice planting scale.Keywords：direct seeding;production efficiency;peasant household;land scale25|21|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore whether smallholders' connection to modern agriculture can alleviate their constraints of formal credit, based on the data of rural inclusive finance survey in underdeveloped areas in 2019, this study identified and classified the ways smallholders connect to modern agriculture, analyzed the direct impact of smallholders' connection to modern agriculture on the availability of formal credit from three dimensions including whether they are connected, different connection methods, and the breadth of connection. The indirect effects of income-increasing mechanism and credit-enhancing mechanism and the heterogeneity of smallholders' resource endowments were investigated. The results showed that: Firstly, smallholders' connection to modern agriculture was beneficial to improve their formal credit availability. Secondly, the impact of different connection methods on formal credit availability presented different effects. Among them, the promotion effect of cooperation with leading enterprises was the strongest. Thirdly, the increase in the breadth of connection was conducive to improving the availability of formal credit for smallholders; Fourthly, the income-increasing mechanism and credit-enhancing mechanism were important channels for connecting modern agriculture to ease the constraints of formal credit for smallholders; Lastly, the smallholders with larger scale of labor force, stronger agricultural management ability and located in the western region obtained more obvious improvement in the availability of formal credit by connecting to modern agriculture.Keywords：smallholders;connect to modern agriculture;availability of formal credit;income-increasing mechanism;credit-enhancing mechanism17|16|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
