Genome-Wide Analysis for Yield-Related Agronomic and Biochemical Traits of Chinese and Bangladeshi Grass Pea Genotypes Using SSR Markers

Grass pea(Lathyrus sativus L.)is an imperative food crop cultured in dryland agricultural ecology.It is a vital source of dietary protein to millions of populaces living in low-income countries in South-East Asia and Africa.This study highlights the improvement of genomic properties and their application in marker-trait relationships for 17 yield-related characters in 400 grass pea genotypes from China and Bangladesh.These characters were assessed via 56 polymorphic markers using general linear model(GLM)(P+G+Q)and mixed linear model(MLM)(P+G+Q+K)in the tassel software based on the linkage disequilibrium and population structure analysis.Population structure analysis showed two major groups and one admixed group in the populace.Statistically significant loci pairs of linkage disequilibrium(LD)mean value(D′)was 0.479.A total of 99 and 61 marker-trait associations in GLM and MLM models allied to the 17 traits were accepted at a 5%level of significance.Among these markers,21 markers were associated with more than one trait;12 marker-trait associations passed the Bonferroni correction threshold.Both models found six markers C41936,C39067,C34100,C47146,C47638,and C43047 significantly associated with days to maturity,flower color,plant height,and seed per pod were detected in the Hebei and Liaoyang location(p≤0.01),and the interpretation rate(R^(2)value)11.2%to 43.6%.Conferring to the consequences,the association analysis methodology may operative system for quantitative,qualitative,and biochemical traits related to gene position mapping and support breeders in improving novel approaches for advancing the grass pea quality.

Evaluation and Projection of Population Exposure to Temperature Extremes over the Beijing−Tianjin−Hebei Region Using a High-Resolution Regional Climate Model RegCM4 Ensemble

Temperature extremes over rapidly urbanizing regions with high population densities have been scrutinized due to their severe impacts on human safety and economics.First of all,the performance of the regional climate model RegCM4 with a hydrostatic or non-hydrostatic dynamic core in simulating seasonal temperature and temperature extremes was evaluated over the historical period of 1991–99 at a 12-km spatial resolution over China and a 3-km resolution over the Beijing−Tianjin−Hebei(JJJ)region,a typical urban agglomeration of China.Simulations of spatial distributions of temperature extremes over the JJJ region using RegCM4 with hydrostatic and non-hydrostatic cores showed high spatial correlations of more than 0.8 with the observations.Under a warming climate,temperature extremes of annual maximum daily temperature(TXx)and summer days(SU)in China and the JJJ region showed obvious increases by the end of the 21st century while there was a general reduction in frost days(FD).The ensemble of RegCM4 with different land surface components was used to examine population exposure to temperature extremes over the JJJ region.Population exposure to temperature extremes was found to decrease in 2091−99 relative to 1991−99 over the majority of the JJJ region due to the joint impacts of increases in temperature extremes over the JJJ and population decreases over the JJJ region,except for downtown areas.Furthermore,changes in population exposure to temperature extremes were mainly dominated by future population changes.Finally,we quantified changes in exposure to temperature extremes with temperature increase over the JJJ region.This study helps to provide relevant policies to respond future climate risks over the JJJ region.

The wheat sucrose synthase gene TaSus1 is a determinant of grain number per spike

Some haplotypes of the sucrose synthase gene TaSus1 are associated with thousand-grain weight(TGW)in wheat(Triticum aestivum L.).However,no mutations have been identified within the gene to test this association.The effects of TaSus1 on grain number per spike(GNS)also are largely unknown.Our previous genome-wide association study identified TaSus-A1 as a candidate gene controlling fertile spikelet number per spike(FSN).In the present study,we generated two independent mutants for the three TaSus1 homoeologs by CRISPR/Cas9-mediated genome editing.The triple mutants displayed lower FSN,GNS,grain number per spikelet(GNST),and TGW than wild-type plants.In 306 hexaploid wheat accessions,two single-nucleotide polymorphisms in TaSus-A1 contributed differently to GNS.Introgression of the two alleles into a wheat genetic background confirmed their effects.The alleles differed in geographical distribution among the accessions.

Characterization of a 4.1 Mb inversion harboring the stripe rust resistance gene YR86 on wheat chromosome 2AL

Wheat cultivar Zhongmai 895 was earlier found to carry YR86 in an 11.6 Mb recombination-suppressed region on chromosome 2AL when crossed with Yangmai 16.To fine-map the YR86 locus,we developed two large F2 populations from crosses Emai 580/Zhongmai 895 and Avocet S/Zhongmai 895.Remarkably,both populations exhibited suppressed recombination in the same 2AL region.Collinearity analysis across Chinese Spring,Aikang 58,and 10+wheat genomes revealed a 4.1 Mb chromosomal inversion spanning 708.5-712.6 Mb in the Chinese Spring reference genome.Molecular markers were developed in the breakpoint and were used to assess a wheat cultivar panel,revealing that Chinese Spring,Zhongmai 895,and Jimai 22 shared a common sequence named InvCS,whereas Aikang 58,Yangmai 16,Emai 580,and Avocet S shared the sequence named InvAK58.The inverted configuration explained the suppressed recombination observed in all three bi-parental populations.Normal recombination was observed in a Jimai 22/Zhongmai 895 F2 population,facilitating mapping of YR86 to a genetic interval of 0.15 cM corresponding to 710.27-712.56 Mb falling within the inverted region.Thirty-three high-confidence genes were annotated in the interval using the Chinese Spring reference genome,with six identified as potential candidates for YR86 based on genome and transcriptome analyses.These results will accelerate map-based cloning of YR86 and its deployment in wheat breeding.

Identification of a new stripe rust resistance gene in Chinese winter wheat Zhongmai 175

Stripe rust is a serious foliar disease posing a grave threat to wheat production worldwide. The most economical and environmentally friendly way to control this disease is to breed and deploy resistant cultivars. Zhongmai 175 is an elite winter wheat cultivar conferring resistance to a broad spectrum of Puccinia striiformis f. sp. tritici（Pst） races. To identify the resistance gene in the cultivar, genetic analysis was conducted using the parents, F1, F2 and F2：3 populations derived from the cross of Lunxuan 987/Zhongmai 175. Segregations in the F2 and F2：3 populations indicated a single dominant gene conferring resistance to stripe rust in Zhongmai 175, temporarily designated Yr ZM175. Bulked segregant analysis（BSA） with wheat i Select 90 K SNP array determined a preliminary location of Yr ZM175. Subsequently, Yr ZM175 was mapped on chromosome 2AS using simple sequence repeats（SSR）, expressed sequence tags（EST） and newly-developed kompetitive allele specific PCR（KASP） markers, being flanked by Xgwm636 and Xwmc382 at genetic distances of 4.9 and 8.1 c M, respectively. Comparison of reaction patterns of Yr ZM175 on 23 Pst races or isolates and pedigree analysis with other genes on chromosome 2AS suggested that it is likely to be a new gene for resistance to stripe rust. The resistance gene and linked molecular markers will be useful in wheat breeding targeting for the improvement of stripe rust resistance.

Identification of QTL for adult-plant resistance to powdery mildew in Chinese wheat landrace Pingyuan 50

Powdery mildew caused by Blumeria graminis f. sp. tritici is one of the major wheat diseases worldwide. The Chinese wheat landrace Pingyuan 50 has shown adult-plant resistance(APR)to powdery mildew in the field for over 60 years. To dissect the genetic basis of APR to powdery mildew in this cultivar, a mapping population of 137 double haploid(DH) lines derived from Pingyuan 50/Mingxian 169 was evaluated in replicated field trials for two years in Beijing(2009–2010 and 2010–2011) and one year in Anyang(2009–2010). A total of 540 polymorphic SSR markers were genotyped on the entire population for construction of a linkage map and QTL analysis. Three QTL were mapped on chromosomes 2BS(QPm.caas-2BS.2), 3BS(QPm.caas-3BS),and 5AL(QPm.caas-5AL) with the resistance alleles contributed by Pingyuan 50 explaining 5.3%,10.2%, and 9.1% of the phenotypic variances, respectively, and one QTL on chromosome 3BL(QPm.caas-3BL) derived from Mingxian 169 accounting for 18.1% of the phenotypic variance.QPm.caas-3BS, QPm.caas-3BL, and QPm.caas-5AL appear to be new powdery mildew APR loci.QPm.caas-2BS.2 and QPm.caas-5AL are possibly pleiotropic or closely linked resistance loci to stripe rust resistance QTL. Pingyuan 50 could be a potential genetic resource to facilitate breeding for improved APR to both powdery mildew and stripe rust.

Value Circulation Theory——Based on Practices of Agricultural Circular Economy

If all material units in the economic entities (including inorganic substances and organisms) can fully realize value circulation, the entities will be able to produce the largest total value. Total value refers to the "net value" by subtracting "negative value" from "positive value". The "positive value" is the direct value of products provided by the economic entities, and the "negative value" refers to the value loss caused by the negative influence of economic entities on resource environment and social economy. This paper makes exposition of circular economy from three aspects: circulation of material units in the production process within economic entities is the core of circular economy; circular economy aims at bringing material units out the economic entities by being affiliated to products; branding material units with value for recycling in economic entities is the guarantee of circular economy.

A review of the pangenome:how it affects our understanding of genomic variation,selection and breeding in domestic animals?

As large-scale genomic studies have progressed,it has been revealed that a single reference genome pattern cannot represent genetic diversity at the species level.While domestic animals tend to have complex routes of origin and migration,suggesting a possible omission of some population-specific sequences in the current reference genome.Conversely,the pangenome is a collection of all DNA sequences of a species that contains sequences shared by all individuals(core genome)and is also able to display sequence information unique to each individual(variable genome).The progress of pangenome research in humans,plants and domestic animals has proved that the missing genetic components and the identification of large structural variants(SVs)can be explored through pangenomic studies.Many individual specific sequences have been shown to be related to biological adaptability,phenotype and important economic traits.The maturity of technologies and methods such as third-generation sequencing,Tel-omere-to-telomere genomes,graphic genomes,and reference-free assembly will further promote the development of pangenome.In the future,pangenome combined with long-read data and multi-omics will help to resolve large SVs and their relationship with the main economic traits of interest in domesticated animals,providing better insights into animal domestication,evolution and breeding.In this review,we mainly discuss how pangenome analysis reveals genetic variations in domestic animals(sheep,cattle,pigs,chickens)and their impacts on phenotypes and how this can contribute to the understanding of species diversity.Additionally,we also go through potential issues and the future perspectives of pangenome research in livestock and poultry.

Evaluating the Effects of Sustainable Chemical and Organic Fertilizers with Water Saving Practice on Corn Production and Soil Characteristics

The rapidly growing world population,water shortage,and food security are promising problems for sustainable agriculture.Farmers adopt higher irrigation and fertilizer applications to increase crop production resulting in environmental pollution.This study aimed to identify the long-term effects of intelligent water and fertilizers used in corn yield and soil nutrient status.A series of field experiments were conducted for six years with treatments as:farmer accustomed to fertilization used as control(CON),fertilizer decrement(KF),fertilizer decrement+watersaving irrigation(BMP1);combined application of organic and inorganic fertilizer+water-saving irrigation(BMP2),and combined application of controlled-release fertilizer(BMP3).A significant improvement was observed in soil organic matter(14.9%),nitrate nitrogen(106.7%),total phosphorus(23.9%),available phosphorus(26.2%),straw yield(44.8%),and grain yield(54.7%)with BMP2 treatment as compared to CON.The study concludes that integrating chemical and organic fertilizers with water-saving irrigation(BMP2)is a good approach to increasing corn productivity,ensuring water safety and improving soil health.The limitations of the current study include the identification of fertilizer type and its optimum dose,irrigation water type,and geographical position.

Integrated genomic and transcriptomic analysis reveals genes associated with plant height of foxtail millet

Foxtail millet(Setaria italica)is an important C4 model crop;however,due to its high-density planting and high stature,lodging at the filling stage resulted in a serious reduction in yield and quality.Therefore,it is imperative to identify and deploy the genes controlling foxtail millet plant height.In this study,we used a semi-dwarf line 263A and an elite high-stalk breeding variety,Chuang 29 to construct an F2 population to identify dwarf genes.We performed transcriptome analysis(RNA-seq)using internode tissues sampled at three jointing stages of 263A and Chuang 29,as well as bulk segregant analysis(BSA)on their F2 population.A total of 8918 differentially expressed genes(DEGs)were obtained from RNA-seq analysis,and GO analysis showed that DEGs were enriched in functions such as‘‘gibberellin metabolic process”and‘‘oxidoreductase activity”,which have previously been shown to be associated with plant height.A total 593 mutated genes were screened by BSA-seq method.One hundred and seventy-six out of the 593 mutated genes showed differential expression levels between the two parental lines,and seven genes not only showed differential expression in two or three internode tissues but also showed high genomic variation in coding regions,which indicated they play a crucial role in plant height determination.Among them,we found a gibberellin biosynthesis related GA20 oxidase gene(Seita.5G404900),which had a single-base at the third exon,leading to the frameshift mutation at 263A.Cleaved amplified polymorphic sequence assay and association analysis proved the single-base in Seita.5G404900 co-segregated with dwarf phenotype in two independent F2 populations planted in entirely different environments.Taken together,the candidate genes identified in this study will help to elucidate the genetic basis of foxtail millet plant height,and the molecular marker will be useful for marker-assisted dwarf breeding.

Effects of dissolved oxygen on intestinal bacterial community and immunity of Atlantic salmon Salmo salar

Dissolved oxygen(DO)is one of most important factors which affect wide range physiologic features of including immune responses and intestinal bacterial community.However,the underlying mechanisms remain enigmatic.To address this question,the intestinal bacterial community compositions and the immune features of Atlantic salmon(Salmo salar)grown in recirculating aquaculture systems(RAS)were characterized.Fish were reared under different DO saturation levels,e.g.,200% saturation named high group(H),100%saturation named control group(CK),and 60%saturation named lower group(L).Large variations in the operational taxonomic units(OTUs)frequency distribution for the intestinal bacterial community of Atlantic salmon were observed.The intestinal bacterial community of all groups was dominated mainly by three phyla,e.g.,Proteobacteria.Firmicutes,and Bacteroidetes.Interestingly,Acinetobacter baumannii,an opportunistic pathogen of salmon was increased significantly in L group.We further monitored the immunity features of fish under different DO levels.The results show that leucocyte number,cortisol level,the expressions of interleukin-1β(IL-1β),Toll-like receptor 4(TLR4),and nucleotide-binding oligomerization domain like protein 2(NOD2)were higher at significant levels in the L group than those in the other two groups.TLR4 and NOD2 are usually related with the bacterial infections;therefore,it is reasonable to believe that the stronger immune responses observed in the L group might be related with the higher abundance of A.baumannii in the inte stine of Atlantic salmon.Overall,these findings demonstrated that low DO level may induce stronger immunity responses in Atlantic salmon.

Assessment of Nutrient Leaching Losses and Crop Uptake with Organic Fertilization,Water Saving Practices and Reduced Inorganic Fertilizer

The increasing world population has forced excessive chemical fertilizer and irrigation to complete the global food demand,deteriorating the water quality and nutrient losses.Short-term studies do not compile the evidences;therefore,the study aimed to identify the effectiveness of reduced doses of inorganic fertilizer and water-saving practices,hence,a six-year experiment(2015-2020)was conducted in China to address the knowledge gap.The experimental treatments were:farmer accustomed fertilization used as control(525:180:30 kg NPK ha^(-1)),fertilizer decrement(450:150:15 kg NPK ha^(-1)),fertilizer decrement+water-saving irrigation(450:150:15 kg NPK ha^(-1)),application of organic and inorganic fertilizer+water-saving irrigation(375:120:0 kg NPK ha^(-1)+4.5 tones organic fertilizer ha^(-1)),and application of controlled-release fertilizer(80:120:15 kg NPK ha^(-1)).Each treatment was replicated thrice following a randomized complete block design.The results achieved herein showed that control has the highest losses in the six-year study for total nitrogen(225.97 mg L^(-1)),total soluble nitrogen(121.58 mg L^(-1)),nitrate nitrogen(0.93 mg L^(-1)),total phosphorus(0.57 mg L^(-1)),and total soluble phosphorus(0.57 mg L^(-1))respectively.Reduced fertilizer and water application improved crop nutrient uptake,nitrogen concentration was significantly enhanced with organic and inorganic fertilizer+water-saving irrigation,P concentration was increased with fertilizer decrement+water-saving irrigation,and K concentration was improved with fertilizer decrement+water-saving irrigation.Hence,this study concludes that reduced inorganic fertilizer dose combined with water-saving practices is significantly helpful in reducing nutrient leaching losses and improving nutrient uptake and water pollution.Further studies are needed to explore the impacts of reduced fertilization and water-saving irrigation on leaching losses.The benefits at different climatic conditions,soil types,and fertilizer types with application methods are also a research gap.

Identification of genetic loci for grain yield-related traits in the wheat population Zhongmai 578/Jimai 22

The identification of stable quantitative trait locus(QTL)for yield-related traits and tightly linked molecular markers is important for improving wheat grain yield.In the present study,six yield-related traits in a recombinant inbred line(RIL)population derived from the Zhongmai 578/Jimai 22 cross were phenotyped in five environments.The parents and 262 RILs were genotyped using the wheat 50K single nucleotide polymorphism(SNP)array.A high-density genetic map was constructed with 1501 non-redundant bin markers,spanning 2384.95 cM.Fifty-three QTLs for six yield-related traits were mapped on chromosomes 1D(2),2A(9),2B(6),2D,3A(2),3B(2),4A(5),4D,5B(8),5D(2),7A(7),7B(3)and 7D(5),which explained 2.7-25.5%of the phenotypic variances.Among the 53 QTLs,23 were detected in at least three environments,including seven for thousand-kernel weight(TKW),four for kernel length(KL),four for kernel width(KW),three for average grain filling rate(GFR),one for kernel number per spike(KNS)and four for plant height(PH).The stable QTLs QKl.caas-2A.1,QKl.caas-7D,QKw.caas-7D,QGfr.caas-2B.1,QGfr.caas-4A,QGfr.caas-7A and QPh.caas-2A.1 are likely to be new loci.Six QTL-rich regions on 2A,2B,4A,5B,7A and 7D,showed pleiotropic effects on various yield traits.TaSus2-2B and WAPO-A1 are potential candidate genes for the pleiotropic regions on 2B and 7A,respectively.The pleiotropic QTL on 7D for TKW,KL,KW and PH was verified in a natural population.The results of this study enrich our knowledge of the genetic basis underlying yield-related traits and provide molecular markers for high-yield wheat breeding.

Characteristics of genetic basis copy number variation in production and adaptation traits of Chinese indigenous sheep

Copy number variations(CNVs)range in size from 50 base pairs(bp)to several megabases(Mb)and encompass various types of structural variations,such as insertions,deletions,duplications,and complex multiallelic events(MacDonald et al.,2014).These genomic alterations modulate phenotype by altering gene dosage and transcriptional regulation,and are key drivers of biological evolution and determinants of genetic diversity and phenotypic variation.In recent years,CNVs have been detected in the genomes of various livestock species(Yuan et al.,2021;Chen et al.,2022).Upadhyay et al.(2017)conducted a comprehensive analysis of CNV distribution in the European cattle genome and determined that the Kit gene is associated with color-sidedness in English longhorn cattle.Another study presented extensive genome-wide information on CNVs in wild,commercial,and local chicken breeds to gain an integrated understanding of the domestication process and exclusively identified the genes involved(Chen et al.,2022).

Allelic Variation at the TaZds-A1 Locus on Wheat Chromosome 2A and Development of a Functional Marker in Common Wheat

ζ （zeta）-carotene desaturase （ZDS） is a key enzyme for carotenoid biosynthesis, demonstrating high association with the yellow pigment （YP） content in wheat grain. Cloning ZDS gene and developing functional markers are important for marker-assisted selection in wheat breeding. In the present study, the full-length DNA sequence of a ZDS gene on wheat chromosome 2A, designated TaZds-A1, was cloned, with 14 exons and 13 introns, and it has an open reading frame （ORF） of 1 707 bp, encoding 568 amino acid residues. A co-dominant functional marker, YP2A-1, was designed based on the polymorphisms of two alleles at the locus, TaZds-Ala and TaZds-Alb, yielding 183- and 179-bp fragments in TaZds-Ala and TaZds-Alb genotypes, respectively. A new QTL for YP content was detected on chromosome 2A, co-segregating with the functional marker YP2A-1 and TaZds-A1; it explained 11.3% of the phenotypic variance for YP content in a doubled haploid （DH） population from Zhongyou 9507/CA9632. Among 217 Chinese wheat cultivars and advanced lines, the average grain YP content of 126 cultivars with TaZds-Alb allele was 7.8% higher than that of 91 cultivars with TaZds- Ala allele.

Highly Efficient Photoelectrocatalytic Reduction of CO2 to Methanol by a p–n Heterojunction CeO2/CuO/Cu Catalyst

Photoelectrocatalytic reduction of CO2 to fuels has great potential for reducing anthropogenic CO2 emissions and also lessening our dependence on fossil fuel energy.Herein,we report the successful development of a novel photoelectrocatalytic catalyst for the selective reduction of CO2 to methanol,comprising a copper catalyst modified with flower-like cerium oxide nanoparticles(CeO2 NPs)(a n-type semiconductor)and copper oxide nanoparticles(CuO NPs)(a p-type semiconductor).At an applied potential of−1.0 V(vs SCE)under visible light irradiation,the CeO2 NPs/CuO NPs/Cu catalyst yielded methanol at a rate of 3.44μmol cm^−2 h^−1,which was approximately five times higher than that of a CuO NPs/Cu catalyst(0.67μmol cm^−2 h^−1).The carrier concentration increased by^108 times when the flower-like CeO2 NPs were deposited on the CuO NPs/Cu catalyst,due to synergistic transfer of photoexcited electrons from the conduction band of CuO to that of CeO2,which enhanced both photocatalytic and photoelectrocatalytic CO2 reduction on the CeO2 NPs.The facile migration of photoexcited electrons and holes across the p–n heterojunction that formed between the CeO2 and CuO components was thus critical to excellent light-induced CO2 reduction properties of the CeO2 NPs/CuO NPs/Cu catalyst.Results encourage the wider application of composite semiconductor electrodes in carbon dioxide reduction.

The Potential Contribution of Subsurface Drip Irrigation to Water-Saving Agriculture in the Western USA

Water shortages within the western USA are resulting in the adoption of water-saving agricultural practices within this region. Among the many possible methods for saving water in agriculture, the adoption of subsurface drip irrigation （SDI） provides a potential solution to the problem of low water use efficiency. Other advantages of SDI include reduced NO3 leaching compared to surface irrigation, higher yields, a dry soil surface for improved weed control, better crop health, and harvest flexibility for many specialty crops. The use of SDI also allows the virtual elimination of crop water stress, the ability to apply water and nutrients to the most active part of the root zone, protection of drip lines from damage due to cultivation and tillage, and the ability to irrigate with wastewater while preventing human contact. Yet, SDI is used only on a minority of cropland in the arid western USA. Reasons for the limited adoption of SDI include the high initial capital investment required, the need for intensive management, and the urbanization that is rapidly consuming farmland in parts of the western USA. The contributions of SDI to increasing yield, quality, and water use efficiency have been demonstrated. The two major barriers to SDI sustainability in arid regions are economics （i.e., paying for the SDI system）, including the high cost of installation; and salt accumulation, which requires periodic leaching, specialized tillage methods, or transplanting of seedlings rather than direct-seeding. We will review advances in irrigation management with SDI.

Effects of dietary fiber on human health

Dietary fiber(DF)is believed to provide important health benefits and it has become a research hotspot.DF exists in most natural foods,including fruits(16.74%-91.24%),vegetables(6.53%-85.19%),grains(9.76%-69.20%)and so on.DF has different physicochemical properties such as water holding capacity(WHC)(2.01-25.03 g/g),water swelling capacity(WSC)(0.95-23.90 mL/g),oil holding capacity(OHC)(0.65-29.00 g/g),glucose adsorption capacity(GAC)(0.17-4.65 mmol/g),cholesterol adsorption capacity(CAC)(0.03-37.10 mg/g)and viscosity,which make it exhibits different physiological functions such as reducing the risk of obesity,diabetes,cancer,and intestinal diseases.On the basis of consulting related databases,the physicochemical properties of DF and its derived physiological functions are reviewed.It is found that DF has effect on the prevention and treatment of obesity due to good WHC,WSC,OHC and CAC.Good GAC can relieve the symptoms of diabetes.The physicochemical properties of WHC and WSC can reduce the risk of cancer.The WHC,WSC and viscosity are beneficial to intestinal health.

Price Transmission in China's Swine Industry with an Application of MCM

The paper studies the relationship, adjustment ability, path, efficiency and intensity of price transmission in the swine industry chain in China, which consists of the prices of corn, compound feed for fattening pig, piglet, pig and pork. Monthly prices covering a period of 18 yr （1994-2011） are analyzed using a Market-Chain Cooperated Model （MCM）. The empirical results show that there exists a stable long-term cointegration and short-term dynamic relationship in the price system. First, the adjustment speed of each price series is very slow and the transmission path is top-down and one-way significantly. Second, the price from upstream to downstream lags about 2 mort, while there is no lag in price transmission from midstream to downstream. Third, in terms of price transmission intensity, the price of pig impacted greatly on pork price, not only in the current period but also through the whole period. Besides, the price of corn has the largest lagged effects on pork price. According to the above empirical results, we suggest that government should strengthen monitoring and early warning of the swine industry chain, especially the upstream and midstream, attach great importance to the timely adjustment of feed prices and perfect the measures of price subsidy.

Development of image-based wheat spike counter through a Faster R-CNN algorithm and application for genetic studies

Spike number(SN) per unit area is one of the major determinants of grain yield in wheat. Development of high-throughput techniques to count SN from large populations enables rapid and cost-effective selection and facilitates genetic studies. In the present study, we used a deep-learning algorithm, i.e., Faster Region-based Convolutional Neural Networks(Faster R-CNN) on Red-Green-Blue(RGB) images to explore the possibility of image-based detection of SN and its application to identify the loci underlying SN. A doubled haploid population of 101 lines derived from the Yangmai 16/Zhongmai 895 cross was grown at two sites for SN phenotyping and genotyped using the high-density wheat 660 K SNP array.Analysis of manual spike number(MSN) in the field, image-based spike number(ISN), and verification of spike number(VSN) by Faster R-CNN revealed significant variation(P < 0.001) among genotypes, with high heritability ranged from 0.71 to 0.96. The coefficients of determination(R^(2)) between ISN and VSN was 0.83, which was higher than that between ISN and MSN(R^(2)= 0.51), and between VSN and MSN(R^(2)= 0.50). Results showed that VSN data can effectively predict wheat spikes with an average accuracy of 86.7% when validated using MSN data. Three QTL Qsnyz.caas-4 DS, Qsnyz.caas-7 DS, and QSnyz.caas-7 DL were identified based on MSN, ISN and VSN data, while QSnyz.caas-7 DS was detected in all the three data sets. These results indicate that using Faster R-CNN model for image-based identification of SN per unit area is a precise and rapid phenotyping method, which can be used for genetic studies of SN in wheat.