Issue Ebookcover storyIssue Cover
List of IssuesDocument Types
- Abstract：Hybrid breeding has great significance in cotton genetic improvement as well as that in other crops.Eleven stocks from areas of Yangtze River and Yellow River,with Bt resistance or not,were divided into two groups of 4 or 7 respectively,and made crosses according to NCⅡ design of the incomplete diallel cross (4×7) to analysis the heterosis and combining ability of hybrid of upland cotton based on the evaluation in two years.The results show that both broad sense heritability and narrow sense heritability were relatively low;but the narrow heritability of lint percentage,lint index,fiber strength and seed index was over 54.64%,and the broad heritability of lint percentage was even reached to 92.16%.The narrow heritability of F2 for some traits was higher than that of F1.The heterosis was checked in F1 and F2 generations.The heterosis of lint yield in F1 was with an average of 11.31%,34.17% and 13.33% over competitive control,the mid-parent and high-parent,respectively.The lint yield of a cross of P4/P7(EZAMIAN 12/5H303)showed 27.4% higher than a local commercial variety Han284.The depression showed in crosses of F2 generation while the heterosis remained in some crosses in F2 generation.The cross P4/P7(EZAMIAN 12/5H303) showed the highest specific combining ability (SCA) of yield in the crosses of F1 generation,while the crosses P4/P10 (EZAMIAN 12/5H335),P1/P11 (611/5H336) showed the highest SCA in the crosses of F2 generation.The parent with best general combining ability (GCA) were P8 (5H309) and P5 (5H181) in yield and P1 (611),P2 (05-5317),P4 (EZAMIAN 12).So it is possible to bred commercial hybrid with Bt-resistance of upland cotton by using stocks from different regions.Keywords：Gossypium hirsutum;Bt resistance;heterosis;combining ability2|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：It is well known that salinity levels are seldom uniform in saline fields.A new split-root system established through grafting was conducted to study the effects of nitrogen forms (NH4+ and NO3-) on nutrient elements uptake and plant growth under unequal salt distribution in a greenhouse.The results indicated that a significant interaction was detected between unequal salt distribution and nitrogen forms (NH4+ and NO3-) on nutrient uptake and seedlings growth.Compared with equal salt distribution,unequal salt distribution decreased Na+ concentration,and increased main nutrient elements (N,P,K,Ca,Mg,Fe,Mn,Cu,Zn) uptake,leaf photosynthesis (17.1%) and biomass accumulation (18.5%);the main nutrient elements (N,P,K,Mg,Fe,Mn) uptake and biomass in NO3--N treatment were higher than that in NH4+-N treatment;Under unequal salt distribution,the main nutrient elements (N,P,K,Ca,Mg,Fe,Mn,Cu,Zn) uptake,leaf photosynthesis (13.5%) and biomass (7.2%) in NO3--N were higher than that in NH4+-N treatment.It is concluded that NO3--N is superior to NH4+-N in improvement of main nutrient elements uptake and plant growth under unequal salt distribution.Keywords：cotton;unequal salt distribution;nitrogen form;nutrient uptake1|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：We explored tentatively expression patterns of two iso-nuclear alloplasmic lines in kenaf (P3A and P3B) by using a oligo microarray from cotton.The results showed that the signal of microarray hybridization was clear,and the images had a lower background and higher signal-noise ratio.Expression for 85.93% (37 640) of 43 803 probes was detected in anthers of P3A,and expression of 85.90% (37 629) of probes was observed in anthers of P3B.Of the probes on the arrays,34 290 (78.28%) consistently hybridized to labeled cotton probe in P3A and P3B.High heterologous hybridization rate suggest that it is viable using cotton oligo microarray to investigate gene expression in kenaf.We could successfully demonstrate that heterologous microarray hybridizations allow deep insights into the transcriptom of kenaf.4|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To understanding the distribution of wheat dwarfing genes is crucial for improvement of yield and plant height.In this study,four pairs of molecular markers,BF and MR1、BF and WR1、DF and MR2、DF2 and WR2,and microsatellite Xgwm261,were used to identify Rht-B1b、Rht-D1b and Rht8 dwarfing genes in the major Chinese wheat varieties.The results showed that:1)The screening of 129 varieties revealed that 58(45.0%) genotypes with the Rht-B1b,24(18.6%) genotypes with the Rht-D1b,73(56.6%) genotypes with the Rht8,35(27.1%) genotypes with Rht-B1b+Rht8,at and 16(12.4%) genotypes with Rht-D1b+Rht8.None of the combination of the three dwarfing genes and Rht-B1b+Rht-D1b were identified in this study.2)the distribution frequency of the three dwarfing genes in bread varieties from different ecological regions were different.Dwarfing genes Rht-B1b and Rht8 were mostly identified from varieties from Yellow and Huai Valley Facultative Wheat Region,and the frequency were 55.4% and 71.1%,respectively;The Rht-D1b gene was mainly found in Southwestern China Autumn-sown Spring Wheat Region with a frequency of 37.5%;The Rht8 gene extensively distributed in all the ecological regions.From this study,we concluded that different dwarfing genes have different regional distribution,but the Rht8 gene extensively distributed in Chinese bread wheat varieties.Keywords：bread wheat;dwarfing genes;Rht-B1b;Rht-D1b;Rht8;molecular marker;microsatellite2|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Four wheat near-isogenic lines with different Glu-B1 locus were used to analyze dynamic changes of glutenin and GMP content of kernel from 12 to 35 days after anthesis under normal and late sowing dates.The results showed that under the identical genetic background,dynamic changes of glutenin content for each line accumulated from low to high under normal and late sowing dates.A large amount of glutenin was accumualted at 30-35 d after anthesis,during which accumulation rate was faster especially for the materials with the HMW-GS compositions related with good quality.A higher accumulation for GMP was found at about 12 d after anthesis,then decreased sharply to the lowest point during the middle stage of grain filling.It was found that days to the lowest point were different among lines with different HMW-GS compositions.The lines with subunit 17+18 take shortest time to the lowest point.These lines also accumulated more than other groups.GMP content showed a downward trend in later stage of grain filling under late sowing date.Late sowing had significant effects on glutenin content and GMP content and stable time of dough in four materials with different Glu-B1 locus,and the effect degree was 17+18>7+9>14+15>7+8.The differences of accumulation dynamics between glutenin and GMP may be the key factors affecting quality and stability in materials with different HMW-GS compositions.Keywords：wheat;Glu;-B1 locus;near-isogenic lines;glutenin;stable time of dough4|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：By chromosome walking PCR technique,the 5'flanking sequences of the exogenous integration in the genome of in the pCAMBIA1301 plasmid of transgenic soybean OsDREB3 were cloned,and sequenced with the specific nested primers based on the border.According to the flanking sequence,the event specific primers were designed to amplify the fragment,which could span the exogenous DNA and carnation genome,and length was 344 bp.The event specific qualitative PCR detection method for transgenic soybean OsDREB3 was established.This assay was applied to detect typical genetically transgenic soybean OsDREB3,with high specificity,and the limit of detection exhibited 0.1%.The results showed that the qualitative PCR assay was accurate,rapid and efficient for detection of transgenic soybean OsDREB3.Keywords：transgenic soybean;OsDREB3;chromosome walking;event specificity;PCR detection6|12|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The study was established at the Luancheng Agro-Ecosystem Experimental Station with three tillage practices under winter wheat growing season:conventional tillage (CT),rotary tillage (RT),and no-tillage (NT).Farmland soil carbon storage,hidden carbon cost (HCC) and benefit evaluation in long-term tillage practice were studied.The results showed that:SCS was increased with times in the condition of straw back and fertilizer input.The average value of SCS was increased from 37 867.06 to 48 316.33 kg/hm2 from 2004 to 2010.The amount of SCS followed the order:CT>NT>RT.HCC of each treatment (NT,RT and CT) was 499.50,516.91 and 564.84 kg/(hm2·a).Ecological benefit was the highest under NT.Economic benefit was the highest under RT,differences of economic benefit index values between NT and RT were not significant.It is better to adopt minimum and no tillage in North China Plain.Keywords：tillage practice;soil carbon storage;minimum and no tillage;hidden carbon cost;benefit evaluation3|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：This study,the effects of nitrogen application rates on the productivity,nitrogen uptake and dry matter yield were investigated in mung bean‖oat intercropping system.Under the condition of different fertilizer amount (0,30,60,90 and 120 kg/hm2),naked oat "Baiyan2" and the mung bean "Bailv11" were used as the experiment materials.The results showed that,compared with sole cropping system,on average,intercropping significantly increased system productivity by 30%.The productivity,dry matter yield,and nitrogen uptake and utilization efficiency did not go up along with the increase of nitrogen application rate.Under high nitrogen fertilizer and intercropping,all nitrogen fixers have a character that they will loss ability of nitrogen fixation,called "ammonia repress",indicating that over abundant nitrogen uptake exited.Without or with lower the supply of N fertilizer,intercrops of mung bean and oat showed higher productivity,LER,biological yield,nitrogen uptake and utilization efficiency,but without influencing the total intercrop grain yield.3|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To understand the change of the biomass and carbohydrate,in each organ of Nitraria tangutorum when parasitized by Cynomorium songaricum,weighing and anthrone colorimetric methods were used to analyse their accumulation and distribution.After parasitization by C.songaricum,it was found that:1)the biomass of N.tangutorum in roots,stems and leaves were reduced by 2.58,6.87 and 4.61 g/plant respectively,and the biomass of parasitic complex of Nitraria-Cynomorium was reduced by 2.82 g/plant;2)the content of sugar in roots,leaves of N.tangutorum were increased by 0.8% and 0.17%,whereas in stems the content decreased by 0.61%;the content of starch in roots,stems and leaves of N.tangutorum were increased by 6.24%,1.87%,0.39%;the content of non-structural carbohydrates in roots,stems and leaves of N.tangutorum were increased by 7.05%,1.25%,0.56%;3)the allocation ratio of non-structural carbohydrates in roots,stems and leaves of N.tangutorum were reduced by 3.59%,25.09%,16.35% respectively.In a word,when N.tangutorum parasitized by C.songaricum,more carbohydrates were accumulated and distributed to C.songaricum.Keywords：Cynomorium songaricum;Nitraria tangutorum;soluble sugar;starch;non-structural carbohydrates0|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Changing of lycorine and galantamine contents in the bulb of Lycoris aurea under different light intensity conditions were analyzed in order to provide scientific information for cultivation of Lycoris aurea.Contents of lycorine and galantamine in the bulbs under 100% natural light,50% shading and 85% shading were determined by HPLC.The contents of lycorine and galantamine in the bulbs under the three different conditions were as following:50% shading >85% shading >100% natural light.The contents of lycorine and galantamine under 50% shading were both the highest,and increased 35.88% and 20.56% compared with those under 100% natural light,respectively with high significant level (P<0.01).The results determined by HPLC were highly repeatable,indicating that the method used in this study was reliable.Proper shading,such as 50% shading,increased contents of lycorine and galantamine in the bulb of Lycoris aurea.Thus Lycoris aurea was suitable for cultivation under moderate shading.Keywords：Lycoris aurea;shading;HPLC;lycorine;galantamine1|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The research was to investigate non-S factors interacting with S-RNase in SI through the yeast two-hybrid(Y2H)system.Yeast cDNA library was successfully constructed for apple ‘Ralls Genet’ style,and being inserted by inserting sequences of 300-2 000 bp in size.One cDNA fragment of 371 bp was obtained from the library screening by apple pGBKT7:S1-mat as bait through the yeast two-hybrid(Y2H)system.With comparison in NCBI and structure projection,the fragment had highly homology with calmodulin binding protein in Arabidopsis thaliana,and had the peculiar phosphodiesterase structure domain with calmodulin binding protein.The the calmodulin binding protein gene named as MdCaMBP could be considered as the segment,located on chromosome 9 of apple and interacted with calmodulin(CaM).This gene had one complete ORF of 552 bp and expressed in leaf、sepal、petal、ovary and pollen,style of apple ‘Ralls Genet’.The Y2H assay showed that MdCaMBP interacted with mature peptide area of S1-RNase,S2-RNase,S9-RNase.All these results indicated that apple MdCaMBP might be one of style non-S factors interacting with S-RNase nonspecifically in SI.Keywords：apple;style;S-RNase;calmodulin binding protein;yeast two-hybrid4|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To evaluate resistance of Malus germplasms to Alternaria mali and definite the inheritance rule of resistance,260 Malus germplasm accessions and 1089 seedlings of Zisaimingzhu×Fuji were inoculated on the detached leaves with the suspension of germinated conidia of a tissue-isolated strain of Alternaria mali.Diverse performance of disease incidence and severity was found among different germplasm accessions.Disease incidence was higher and severity was more serious of Malus sieversii and Malus domestica germplasms than those among Chinese domestica cultivars and wild genotypes.Due to analysis of frequency distribution and calculation of genetic parameters,occurrence is dominant to nonoccurrence,with occurrence/nonoccurrence segregation ratio of 3:1.According to the evaluation,29 germplasms were highly resistant.While,27 moderately resistant and 48 low resistant accessions were found.The severity is a quantitative character controlled by the segregation of 2 major gene loci.Respectively,heritability of major genes and polygenes for severity is 86.33% and 10.51%.Keywords：Alternaria mali;resistance evaluation;germplasms;seedlings;inheritance analysis4|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：This paper is concerned on the relation of bud dormancy to carbohydrate metabolism,The annual shoots from underground stem was used as the experimental materials.The components of carbohydrates and the enzymes activities were measured in phloem and bud of dormant Cerasus humilis (Bge.) Sok.The results indicated that soluble sugar content was higher than starch in phloem and bud in dormancy period.The highest ratio of soluble sugar and starch reached to 4.77.Most sugar was sucrose and then fructose,sorbitol and glucose.A few amount of fructose in bud were detected in natural dormancy stage.But its content increased rapidly in enhanced dormancy stage and in germination period,reaching to 2.05% in germination period.The changes in enzyme activities in phloem and bud were in line with that of soluble sugar.The activity of SPS was higher than that of other enzymes,but quickly decreased in natural dormancy stage,and reached to minimum at the end of the natural dormancy.The reduction in bud and phloem was 94.18% and 84.78% respectively.The activity of β-amylase was higher that of α-amylase.Based on the integrated analyses above,the main accumulated carbohydrate in dormant Chinese dwarf cherry was soluble sugar.The relief of natural dormancy was obviously linked with the change of sucrose and reduction of the SPS activity.Change in the fructose contents was related to the dormancy and germination of bud.0|5|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The pMD18-CP containing CP gene of Grapevine leafroll associated virus 3 (GLRaV-3) was used for PCR amplification in order to obtain a specific antiserum for reliable GLRaV-3 diagnosis in routine tests.The PCR products of GLRaV-3 CP gene were cloned into the expression vector pET-28a.The resulted recombinant plasmid pET-G3CP was transformed into E.coli BL21 (DE3).SDS-PAGE analysis showed that the recombinant GLRaV-3 CP was expressed as a 40 ku inclusion body protein at high level induced by IPTG at final concentration of 1 mmol/L.Antiserum was prepared after the rabbit was immunized with the purified recombinant CP.The antiserum titer was determined to be 1/214,and the antiserum was specific and sensitive for different GLRaV-3 isolates detection.0|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to understand the mechanism in enhancing the chlorophyll concentration in strawberry leaves,DA-6 was sprayed at 20mg/L on the young and expanded leaves of ’Sweet Charlie’(Fragaria×ananassa Duch.cv.Sweet Charlie)strawberry grown in greenhouse one month before fruit harvest.The concent of chlorophyll precursors and the relative enzyme activity were measured.The results showed that chlorophyll content in either young or expanded leaves increased after treatment.In particular,the chlorophyll content in young leaves increased by 18% but only 5% in the expanded leaves.DA-6 significantly increased the contents of chlorophyll intermediate products of porphobilinogen (PBG) and uroporphyrinoge (UrogenⅢ),but decreased the chlorophyll precursor of 5-aminolevulinic acid (ALA).The activity of the key enzyme of 5-aminolevulinate dehydratase (ALAD) catalyzing the conversion of ALA to PBG was also enhanced.Our study demonstrated that foliar spray of DA-6 increased the conversion efficiency of ALA to PBG,regulated the chlorophyll biosynthesis pathway and resulted in higher chlorophyll content in leaves.1|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：This paper is concerned on the molecular mechanisms of gibberellin decrease in mutant catkins.We used cDNA sequence alignment of the gibberellin biosynthesis key enzymes ent-copalyl diphosphate synthase (CPS),ent-kaurene synthase (KS),ent-kaurene oxidase (KO),ent-kaurenoic acid oxidase (KAO),GA 20-oxidase 1 (GA20ox1) and GA 3-oxidase 1(GA3ox1),and KO DNA sequence alignment between wild type and mutant catkins.The result revealed that there were three different bases in 872,1 115 and 1 150 bp in KO open reading frame,which converted Glu,Tyr,Tyr to Gly,Phe,His,leding to the change of the transmembrane region.The cDNA point mutations were caused by sequence differences of DNA.It is speculated that the short catkin may be caused by the mutation of the KO gene.0|5|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：This paper is concerned on the characteristics of climate change in seasons,months and in different areas of northern farming-pastoral transition zone with the general meteorological data of 33 sites from 1960 to 2010.The results showed that the annual average temperature had a clear upward trend for about 2.0℃ in the past 50 years.The seasonal temperatures increased by 0.057℃/a for winter,0.043℃/a for spring,0.035℃/a for autumn and 0.030℃/a for summer.In particular,the temperature in February increased largely by 4℃ in past 50 years,following by March and April.The annual precipitation reduced by about 40.0 mm in last 50 years.The summer precipitation change was similar to the annual precipitation trends.In fall and spring,the precipitation fluctuated annually.There was a slight increase in spring,but a decrease in autumn.The precipitation decreased drastically in July and August,but no obvious regularity in other months.It was evident that the eastern section of the north area,the western section of the middle area and the most parts of the western area all had a continuous warming-drying trend.0|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The aim of this study was to clone the CDS area of α-TTP of Tan Sheep and constructed its original nuclear expression vector.RNA of theTan Sheep liver was extracted through Trizol method,and it was reverse transcripted to cDNA.The CDS area of α-TTP was got through synthetic method and PCR amplify method,and it was eventually cloned to original nuclear expression vector pET28a,and named pET28a-TTPA.The results showed that,the CDS area of α-TTP was not only amplified and cloned to the original nuclear expression vector pET28a successfully,but alsoshowed a 99.76% sequence homology with the published sheep α-TTP gene.These results established the foundation for α-TTP prokaryotic expression and the preparation of its antibody.Keywords：Tan Sheep;α-tocopherol transfer protein;gene cloning;original nuclear expression vector0|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：There are three main receptors in the skin for melatonin,MT1,MT2 and RORα while only the RORα was expressed in goat.In order to study the function and structure of RORα in Cashmere goat,we combined rapid amplification of cDNA ends (RACE) and transcriptome to obtain two isoforms of RORα gene,as accession No.HM_061155 and HM_358053.Sequence analysis showed that the length of the RORα1 cDNA sequence was 1 620 bp,including 5'UTR (Untranslated Region) 29 bp,3' untranslated region of 211 bp and an open reading frame (open reading frame,ORF) 1 380 bp,encoding 459 amino acids,molecular weight of about 52.3 ku,theoretical isoelectric point of 6.25,and the length of the RORα2 cDNA sequence was 1 694 bp,including 5'UTR 76 bp,3'UTR of 211 bp and an ORF 1 407 bp,encoding 468 amino acids is similar to the isoform D of RORα in human with 99% sequence identity,molecular weight of about 53.4 ku,theoretical isoelectric point of 6.25.The goat RORα-LBD tertiary structure was predicted to be similar as the structure of human RORα-LBD.RORα1 lacks A/B region which contains the motif of strands (YFV) compared with RORα2,and result in different third structure.Phylogenetic analysis showed that the region from DBD to LBD of RORα is under purifying selection,and the A/B region is high-diversity for sequence and length.The expression of RORα in different tissues could be regulated by changing the length and structure of the A/B region.Keywords：Cashmere goat;RORα;gene;RACE;encoding protein;evolution0|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To investigate the feasibility of the cloned high performance breeding boar by the technology of somatic cell nuclear transfer in actual production.The nuclear donors were selected from boars,ear organization cells,and the nuclear receptors come from some oocytes through in-vitro maturation.There are 3 437 pieces of 1~4 cells cloned embryos were transplanted to 18 receptors successively.Sixteen receptors were pregnancy (88.89%) at 28 d by B ultrasonic detection,and 53 piglets were obtained from 11 pregnancy receptors (68.75%).The cloned production efficiency was 2.80% (birth piglet/embryos).The determination results of growth characteristics showed that there is no significant difference in the measurement of cloned bodyweight and length (P>0.05) from ordinary boars at 0 and 7 d.Therefore,the cloned boars from the technology of somatic cell nuclear transfer can extend the space and span of a boar and enlarge the use value of the outstanding boar.Keywords：boar;somatic cell nuclear transfer;embryo transfer;clone0|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To determine correlation and variation of milk fatty acids and figure out proper sample size in experiments,dairy cattle in early lactation from Daxing farm were used in this study.The determination for fatty acids in milk was accomplished through gas chromatography and data were analyzed by SAS 8.0.The results suggested that coefficients of variation of FA in milk varied from 5.57% to 28.02%.There are significant positive correlations among C6-C14,however,negative correlations were observed between C17,C18,c9C18:1 and C6-C16.The best sample size for experiments would be 10~16 with the confidence level of 95%.There were extensive correlation existed among FA in milk,and the FA sample size for studies should be determined especially according to the targets.Keywords：milk;fatty acids;descriptive statistics;correlation;sample size4|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In vitro digestion method was used to investigate the carbohydrate digestion rate of 10 rice cultivars,and amylose contents,gel consistency,gelatinization temperature and texture of these samples were also measured during the investigation.The results showed that the waxy Japaonica rice ranks the highest in terms of starch digestion index (SDI),followed by the japonica rice cultivars,which are also significantly higher than that of the indica rice cultivars.However,the SDI differs considerably among the indica rice samples.Amylose contents,gel consistency and gelatinization temperature have significant correlation with the resistant starch contents(r=0.846,P<0.05;r=-0.765,P<0.01;r=-0.735,P<0.05),but the amylose contents could not serve as an indicator to predict starch digestion characteristics.It is noticed that the cohesiveness have a significant positive correlation with SDI (r=0.634,P<0.05),which suggests that the textural properties of cooked rice may be used to estimate the postprandial glycemic response of the rice cultivars.Keywords：rice;in vitro digestion;amylose;gel consistency;gelatinization temperature;texture0|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Packages of fresh pre-treated mirror carp were stored under refrigerated (0℃) and ice conditions (0℃) respectively in order to study the quality changes of Songpu mirror carp at different conditions.The influences of different storage conditions on freshness of Mirror carp were evaluated by monitoring the changes in sensory,microorganism and chemical indicators.The results showed that the total viable count、total volatile basic nitrogen (w(TVB-N))、K value、electric conductivity、and the drip loss was 5.89×106 cfu/g、 27.93 mg/100g,88.85%,1 374.00 μS/cm,7.19% respectively on the 18th day at 0℃ refrigerated conditions.While at the same day of ice storage,the total viable count、w(TVB-N)、K、electrical conductivity and the drip loss was 3.80×104 cfu/g,19.51 mg/100 g,77.62%,1 197.30 μS/cm,7.19% respectively.The sensory quality exceeded the acceptability limit with the score of 8.33 on the 15th day of storage at 0℃ refrigerated condition,and it got obvious odorous scent with the score of 7.50 on the 21th day exceeding the acceptability limit under ice storage.It can be concluded that the shelf life is 12 days at 0℃ refrigerated conditions and 18 days at ice storage according to the changes of all indicators.Although the temperatures were the very same,both at 0℃,the use of ice can extend the shelf life compared to 0℃ refrigerated storage.Keywords：Songpu mirror carp;refrigerated storage;ice storage;total viable count;sensory characteristics;chemical analysis10|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The seeds of gramineous pasture hold the properties of thin and long in size and light for its thousand grain weight,which leads them to be lack of flowability and intertwined during metering and even make the seed-metering device could not work smoothly.To solve this problem,we designed an intermittent boost seed-metering device consisting of seed tank,seed box,roller,seed brush,seed-pushing board,connecting rod and crank.During working,the rotating crank drives the seed-pushing board move reciprocatingly to complete the process of seed-filling,seed clearing,seed protection.The process of seeding is active and different from passive discharging that relies on the gravity.According to the seed-metering design requirements,the relevant parameters to the working performance was confirmed,and the stability of sowing quantity was tested.The experiment results show that the seeding process of the intermittent boost seed-metering device is easy and smooth.The weight of seeding each time is 0.1375 g,which meet the requirements.The coefficient of variation of the sowing quantity stability is 5.5,and satisfies the standard of GB/T 25421-2010.Keywords：seed-metering device;gramineous pasture;mechanical design1|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to reduce the cost of solar greenhouse and guarantee the normal crop growth,the thickness of greenhouse wall must be optimized.The paper analyzes the composition of costs for an earth wall system of solar greenhouse in energy saving project,and a technical and economical evaluation index,namely,a ratio of energy saving and unit cost,is proposed for solar greenhouse energy saving renovation.The relationship of the ratio with earth wall thickness was deduced by analyzing the state coefficient,the thermal conductivity of wall and the constant costs.When the constant cost is 43.08 yuan per square meters,the maximization of the energy saving and unit cost is 1.18 m,so the construction thickness is 2.30 m.Technical and economic parameters of the wall are effectively connected.Taking Yangling area as an example,the optimization formula of earth wall of solar greenhouse was obtained.Keywords：solar greenhouse;earth wall;energy saving renovation;optimization of technology and economy2|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the problem of multicollinearity and low precision predictions by the regression prediction model of carbon storage,this study used forest resource inventory data and SPOT5 image to retrieve the aboveground forest carbon storage of Populus forests in Yanqing County.Firstly,10 factors were analyzed by principal components analysis.Then this paper introduced a method based on PCA and radial basis function (RBF) neural network for predicting forest carbon storage.The research results show that forest resource inventory data combined SPOT5 image is very useful for retrieving study of carbon storage of Populus forests;the fitting precision of the PCA-RBF neural network model was 99.90%,and the average prediction reached 96.71%.The model has a good retrieval accuracy,which can be well used for retrieval of regional aboveground forest carbon storage.Keywords：forest carbon storage;SPOT5;principal component analysis;remote sensing retrieval;RBF neural network2|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to solve the production reduction of corn,or even no harvest,caused by lack of timely diagnosis and cure of diseases,pests and weeds,for the shortage of plant protection professionals,an expert diagnosis system was developed by using the search algorithm on binary tree based on the symptom of the diseased part of the plant and the image and text knowledge of pests and weeds.The application result shows that the system can realize management of the image knowledge of pests and weeds,the management of the text and image knowledge of rule-based reasoning,and the intelligence diagnosis of plant diseases,pests and weeds.The system also can accomplish the identifying recognition and interpret the process and results of reasoning.By using the diagnostic conclusions of diseases,pests and weeds,farmers can prevent and cure the diseases in time to reduce the loss of corn yield.Keywords：corn diseases;expert diagnosis system;image rule-based reasoning;binary tree1|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to reduce the investment and operating costs of rural power grid,we developed a model to describe the effects of annual cost of unit supply area on the radius of line power supply,the number of substations and the density of load,by using the line voltage drop and the maximum load limit as control conditions,under the demand of load and the limits of technical indices.The comparisons of economies of three modes of power distribution of China’s rural power grid,110/35/10 kV,110/20 kV and 110/10 kV,were performed by the approach above.The results show that when the load density is below 250 kW/km2,the annual cost of 110/10 kV distribution mode is the lowest;when the load density is greater than 250 kW/km2,110/20 kV distribution is the most economical;and for 110/35/10 kV distribution mode,there is still high value to preserve it due to its wildly use and the similar cost to the other two distribution modes.Keywords：rural power grid;distribution modes;load density;power supply radius;optimal selection0|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：For the investigation of purification capacity of hybrid constructed wetlands,the tidal flow-horizontal flow (TF-HF) system and horizontal flow-tidal flow (HF-TF) system were constructed on laboratorial scale.At the flood drain ratio of 12 h:12 h in tidal wetlands,hydraulic retention time of 4 d in horizontal flow wetlands,and recirculation of 1:1,the average total organic carbon (TOC) removal rates of the two systems were 90.2% and 91.3%,but the average removal rates of NH4+-N were 19.5% and 39.2%,respectively.The average removal rates of total nitrogen (TN) were 10.3% for TF-HF and 30.5% for HF-TF.Results indicated that the purification capacity of HF-TF system was much higher than that of the TF-HF system.The findings of this work may provide a theoretical basis for the application of combined tidal flow and horizontal subsurface flow constructed wetlands in practice.Keywords：constructed wetlands;wastewater treatment;hybrid tidal flow-horizontal subsurface flow constructed wetlands;nitrification/denitrification3|7|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Since Chinese government began to implement agricultural subsidy policy in 2004,it has achieved its goal in terms of improving grain yield and farmers’ income.However,it is also important to pay attention to the issue whether agricultural subsidy has some distortion on agricultural inputs,further affecting adversely on the environment such as agricultural non-point pollution.More chemical fertilizer might be used to improve grain yield after agricultural subsidy.If so,subsidy would be blamed for aggravating agricultural non-point pollution.In this study,the impact of subsidy on chemical fertilizer as input was analyzed by employing province level panel data to regress fertilizer demand function based on the theoretical model of agricultural subsidy,inputs and agricultural non-point pollution.The conclusion is that agricultural subsidy doesn’t induce more chemical fertilizer usage,which implies that agricultural subsidy doesn’t aggravate agricultural non-point pollution.Keywords：agricultural subsidy;chemical fertilizer demand;agricultural non-point pollution;fixed effect model0|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to investigate the development situation,the malmquist index measuring method was applied in this paper to estimate the total factor productivity of the agro-food processing industry and to decompose it into technical efficiency and technological progress based on the panel data of 17 subdivisions of agricultural food processing industry during 2003-2009.The result shows that, the overall change of the total factor productivity for the agricultural food processing industry was nearly little from 2003 to 2009 in China and the development of agricultural and sideline food processing industry got benefits from technology progressing.The growth of the total factor productivity for the 17 subdivisions is different due to the reason that the increase of the substantial consumption restrains the productivity rising,however,the increase of human capital investment is helpful for the improvement of productivity.It is an absolute convergence for the increase rate of the 17 subdivision industries,and the average annual rate reaches 10.7 percent.Keywords：agro-food processing industry;total factor productivity;malmquist productivity index;technical progress;convergence0|6|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The purpose of the study is to investigate the consumption behavior of Chinese rural residents,to reveal the characteristics of consumption behavior and development trend for rural residents in China,to discuss ways for increasing income of rural residents,and to expand the policy mechanism of rural consumption.Based on a linear system and a nonlinear system,the authors used econometric research methods to build State Space Model of consumption behavior of China’s rural residents.Moreover,based on Kalman filter estimation of the model related time-varying parameters,detailed analysis was taken for the movements and the relationship between the average propensity to consume (APC) and the marginal propensity to consume (MPC) of China’s rural residents from 1978 to 2010.Meanwhile,a serial correlation test,a heteroscedasticity test and a cointegration test have been done with the model to determine its reasonableness and effectiveness.Through the estimation of the State Space Model for time-varying parameter,detailed analysis was carried out for the static characteristics and dynamic characteristics of China’s rural residents’ consumption behavior and their relationship,which has better explained the impact mechanism for China’s rural residents’ consumption behavior affected by external environment and their intrinsic motivation.Studies have shown that the State Space Model is reasonable and effective for consumption behavior of China’s rural residents.The consumption behavior of China’s rural residents shows that with increased volatility for the expected consumption psychology,deviation of the propensity to consume decreases.This is entirely in line with the objective reality of China’s rural social and economic development.Keywords：rural areas;consumption behavior;average propensity to consume;marginal propensity to consume;state space model;Kalman filter3|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
