Identification of tolerance to high density and lodging in short petiolate germplasm M657 and the effect of density on yield-related phenotypes of soybean

Soybean yield has traditionally been increased through high planting density,but investigating plant height and petiole traits to select for compact architecture,lodging resistance,and high yield varieties is an underexplored option for further improving yield.We compared the relationships between yield-related traits,lodging resistance,and petioleassociated phenotypes in the short petiole germplasm M657 with three control accessions during 2017–2018 in four locations in the Huang–Huai region,China.The results showed that M657 exhibited stable and high tolerance to high planting density and resistance to lodging,especially at the highest density(8×105 plants ha–1).The regression analysis indicated that a shorter petiole length was significantly associated with increased lodging resistance.The yield analysis showed that M657 achieved higher yields under higher densities,especially in the northern part of the Huang–Huai region.Among the varieties,there were markedly different responses to intra-and inter-row spacing designs with respect to both lodging and yield that were related to location and density.Lodging was positively correlated with planting density,plant height,petiole length,and number of effective branches,but negatively correlated with stem diameter,seed number per plant,and seed weight per plant.The yield of soybean was increased by appropriately increasing the planting density on the basis of the current soybean varieties in the Huang–Huai region.This study provides a valuable new germplasm resource for the introgression of compact architecture traits that are amenable to providing a high yield in high density planting systems,and it establishes a high-yield model of soybean in the Huang–Huai region.

Insights into triterpene synthesis and unsaturated fatty-acid accumulation provided by chromosomallevel genome analysis of Akebia trifoliata subsp . australis

Akebia trifoliata subsp.australis is a well-known medicinal and potential woody oil plant in China.The limited genetic information available for A.trifoliata subsp.australis has hindered its exploitation.Here,a high-quality chromosomelevel genome sequence of A.trifoliata subsp.australis is reported.The de novo genome assembly of 682.14 Mb was generated with a scaffold N50 of 43.11 Mb.The genome includes 25,598 protein-coding genes,and 71.18%(485.55 Mb)of the assembled sequences were identi fi ed as repetitive sequences.An ongoing massive burst of long terminal repeat(LTR)insertions,which occurred~1.0 million years ago,has contributed a large proportion of LTRs in the genome of A.trifoliata subsp.australis.Phylogenetic analysis shows that A.trifoliata subsp.australis is closely related to Aquilegia coerulea and forms a clade with Papaver somniferum and Nelumbo nucifera,which supports the well-established hypothesis of a close relationship between basal eudicot species.The expansion of UDP-glucoronosyl and UDP-glucosyl transferase gene families and fi-amyrin synthase-like genes and the exclusive contraction of terpene synthase gene families may be responsible for the abundant oleanane-type triterpenoids in A.trifoliata subsp.australis.Furthermore,the acyl-ACP desaturase gene family,including 12 stearoyl-acyl-carrier protein desaturase(SAD)genes,has expanded exclusively.A combined transcriptome and fatty-acid analysis of seeds at fi ve developmental stages revealed that homologs of SADs,acyl-lipid desaturase omega fatty acid desaturases(FADs),and oleosins were highly expressed,consistent with the rapid increase in the content of fatty acids,especially unsaturated fatty acids.The genomic sequences of A.trifoliata subsp.australis will be a valuable resource for comparative genomic analyses and molecular breeding.

Genome-wide association study and genomic prediction of Fusarium ear rot resistance in tropical maize germplasm

Fusarium ear rot(FER)is a destructive maize fungal disease worldwide.In this study,three tropical maize populations consisting of 874 inbred lines were used to perform genomewide association study(GWAS)and genomic prediction(GP)analyses of FER resistance.Broad phenotypic variation and high heritability for FER were observed,although it was highly influenced by large genotype-by-environment interactions.In the 874 inbred lines,GWAS with general linear model(GLM)identified 3034 single-nucleotide polymorphisms(SNPs)significantly associated with FER resistance at the P-value threshold of 1×10^(-5),the average phenotypic variation explained(PVE)by these associations was 3%with a range from 2.33%to 6.92%,and 49 of these associations had PVE values greater than 5%.The GWAS analysis with mixed linear model(MLM)identified 19 significantly associated SNPs at the P-value threshold of 1×10^(-4),the average PVE of these associations was 1.60%with a range from 1.39%to 2.04%.Within each of the three populations,the number of significantly associated SNPs identified by GLM and MLM ranged from 25 to 41,and from 5 to 22,respectively.Overlapping SNP associations across populations were rare.A few stable genomic regions conferring FER resistance were identified,which located in bins 3.04/05,7.02/04,9.00/01,9.04,9.06/07,and 10.03/04.The genomic regions in bins 9.00/01 and 9.04 are new.GP produced moderate accuracies with genome-wide markers,and relatively high accuracies with SNP associations detected from GWAS.Moderate prediction accuracies were observed when the training and validation sets were closely related.These results implied that FER resistance in maize is controlled by minor QTL with small effects,and highly influenced by the genetic background of the populations studied.Genomic selection(GS)by incorporating SNP associations detected from GWAS is a promising tool for improving FER resistance in maize.

直流牵引供电系统弓网电接触特性研究

为避免电气化铁路弓网烧蚀,毁坏受电弓断接触网,结合列车运行工况数据,建立弓网电接触模型,研究接触网拉出值、列车运行速度、运行工况及受电弓碳滑板设计与弓网电接触温升之间的关系,计算了电力机车动力负荷条件下弓网温升过程。研究表明,弓网温升随着列车运行速度增大而减小,牵引工况双受电弓六碳滑板情况,弓网接触温升超出标准限制。研究为接触网设计、弓网异常事故应急处理提供理论依据和数据支持。

以环境约束促进钢铁行业的产业升级

基于长三角地区钢铁行业发展案例研究,本文小结了该地区钢铁行业产业升级的路径依赖,阐述了环境约束对产业升级的促进作用,提出了提升环境生产力推动经济发展绿色转型的理念。

STABILITY AND BIFURCATION OF UNBALANCE ROTOR/LABYRINTH SEAL SYSTEM

The influence of labyrinth seal on the stability of unbalanced rotor system was presented . Under the periodic excitation of rotor unbalance , the whirling vibration of rotor is synchronous if the rotation speed is below stability threshold, whereas the vibration becomes severe and asynchronous which is defined as unstable if the rotation speed exceeds threshold . The. Muszynska model of seal force and shooting method were used to investigate synchronous solution of the dynamic equation of rotor system. Then , based on Floquet theory the stability of synchronous solution and unstable dynamic characteristic of system were analyzed.

A novel reconfiguration of the solar array to enhance peak power and efficiency under partial shading conditions:experimental validation

Non-homogeneous irradiation patterns and temperature levels immensely affect the performance of solar photovoltaic arrays.Partial shading conditions on solar arrays reduce the peak power and efficiency.This paper provides a new remedy called a novel Ramanujan reconfiguration(NRR)to eliminate this physical shading problem in solar photovoltaic systems.NRR is a static-based reconfigured technique that is built using a three-diode model with the help of the MATLAB®/Simulink®tool.The special feature of the proposed NRR technique is that when shade occurs on the solar modules,it gets realigned in a particular row,column,diagonal,corner,centre and middle peripheral cages.This helps over a wide range of shade dispersion on the solar array.The novel topology is tested against the conventional total cross-tied(TCT)model and recently introduced advanced reconfigured models,namely odd–even topology(OET)and Kendoku topology(KDT).The results are tested under certain shading conditions.The proposed NRR technique increases the peak power by 4.45,2.15 and 2.17 W under the first shading condition regarding TCT,OET and KDT.Its efficiency is improved by 0.51–2.18%under the third shading condition compared with other considered models in this study.In addition,NRR leads to smooth output curves under the second,third and fourth shading conditions,effectively mitigating the local power peaks.The experimental results show the proposed enhanced performance of the novel model against the other models.Graphical Abstract Remedy for physical problem correlated with solar photovoltaics Comparison with traditional and recent solar models Conclusion:NRR has effectively handled the problem related with solar models.It has improved the efficiency up to 31.44%under S4.Also,smooth output curves under S2-S4 shows its effectiveness in mitigating the local power peaks.Greater power gain at 3.94%under S4 is achieved by novel model.Real-time verification proves the supremacy of novel proposed model over other considered models in this work.

Priority-based Residential Demand Response for Alleviating Crowding in Distribution Systems

The dynamic pricing environment offers flexibility to the consumers to reschedule their switching appliances.Though the dynamic pricing environment results in several benefits to the utilities and consumers,it also poses some challenges.The crowding among residential customers is one of such challenges.The scheduling of loads at low-cost intervals causes crowding among residential customers,which leads to a fall in voltage of the distribution system below its prescribed limits.In order to prevent crowding phenomena,this paper proposes a priority-based demand response program for local energy communities.In the program,past contributions made by residential houses and demand are considered as essential parameters while calculating the priority factor.The non-linear programming(NLP)model proposed in this study seeks to reschedule loads at low-cost intervals to alleviate crowding phenomena.Since the NLP model does not guarantee global optima due to its non-convex nature,a second-order cone programming model is proposed,which captures power flow characteristics and guarantees global optimum.The proposed formulation is solved using General Algebraic Modeling System(GAMS)software and is tested on a 12.66 kV IEEE 33-bus distribution system,which demonstrates its applicability and efficacy.

大数据时代下高校学报在促进科技创新中的作用与创新发展改革路径研究

十九大报告提出要实施创新驱动发展战略,加快建设创新型国家,高校在其中具有举足轻重的地位。高校学报是反映本校科研和教学成果为主的学术理论刊物,在高校科技创新中起到促进学术交流、凸显特色和促进专业协同发展等重要作用。作者探讨了在大数据时代下,高校学报自身存在的问题以及其在促进科技创新中的作用,提出了高校学报创新发展的改革途径,建立了一种协同发展模式。该模式立足高校专业建设的可持续发展,对其他高校学报的建设和发展具有一定的借鉴意义。

Proximal and remote sensing in plant phenomics: 20 years of progress, challenges, and perspectives

Plant phenomics(PP)has been recognized as a bottleneck in studying the interactions of genomics and environment on plants,limiting the progress of smart breeding and precise cultivation.High-throughput plant phenotyping is challenging owing to the spatio-temporal dynamics of traits.Proximal and remote sensing(PRS)techniques are increasingly used for plant phenotyping because of their advantages in multi-dimensional data acquisition and analysis.Substantial progress of PRS applications in PP has been observed over the last two decades and is analyzed here from an interdisciplinary perspective based on 2972 publications.This progress covers most aspects of PRS application in PP,including patterns of global spatial distribution and temporal dynamics,specific PRS technologies,phenotypic research fields,working environments,species,and traits.Subsequently,we demonstrate how to link PRS to multi-omics studies,including how to achieve multi-dimensional PRS data acquisition and processing,how to systematically integrate all kinds of phenotypic information and derive phenotypic knowledge with biological significance,and how to link PP to multi-omics association analysis.Finally,we identify three future perspectives for PRS-based PP:(1)strengthening the spatial and temporal consistency of PRS data,(2)exploring novel phenotypic traits,and(3)facilitating multi-omics communication.

SC Currents Minimization in Distributed Generation Embedded Distribution Networks with Optimal Application of FCLs

For meeting the increased demand of electrical power,distributed generation(DG)based on renewable energy resources(RERs),has become a potential alternative to large plants based on fossil fuels.The power from environmentally friendly RERs is available at a competitive price due to technological advancements in recent times.Moreover,optimal allocation of DG at the distribution network(DN)level may result in power loss reduction,improvement in voltage profile and the network’s overall reliability.However,integration of DG may increase the short circuit(SC)level beyond the capacity of the protection gear,conductors,transformers and other components of a DN.The high short circuit currents(SCCs)may be reduced by application of a fault current limiter(FCL).However,most of the existing literature proposes optimization of FCLs size by considering only normal configurations of a DN.This approach is inappropriate as it may fail to produce the desired reduction in SCCs in different N−1 contingency scenarios.In this paper,a new strategy is presented that considers both normal as well as various contingency situations for optimal allocation of FCLs in a DN with DG connection.The strategy is implemented in the IEEE 30-bus system in a MATLAB environment using a genetic algorithm(GA).The simulation results prove that the proposed strategy is effective in determining the optimal FCLs size that restricts the SCCs to a safe level in different operating conditions including N−1 contingencies and thus,improves network safety and reliability.The strategy described in the paper can play an important role in DN planning involving optimal application of DG and FCLs.

FED:a web tool for foreign element detection of genome-edited organism

Dear Editor,Genome editing,especially the newly developed CRISPR technology,is now widely implemented for diverse medical and agricultural applications(Puchta,2018).However,for genome editing,the DNA cassettes encoding the editing components are usually assembled and delivered into the cells of organisms(Cong et al.,2013).