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Strain transfer behavior and crystallographic mechanism of crack initiation during cyclic deformation in zirconium

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Journal of Materials Science & Technology 2023年第31期162卷 234-246页

作者： Xiangkang Zeng Conghui Zhang Wenguang Zhu Mingliang Zhu Tongguang Zhai Chi Ma Tingchuang Shu KangKai Song School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Key Laboratory of Pressure Systems and Safety Ministry of EducationSchool of Mechanical and Power EngineeringEast China University of Science and TechnologyShanghai 200237China School of Materials Science and Engineering Shandong Jianzhu UniversityJinan 250101China

Fully-reversed cyclic deformation of a pure Zr(a thickness of 17 mm)was conducted at two different strain amplitudes(0.4%and 0.8%)to investigate the deformation and crack initiation behaviors based on slip trace analysis.It was found that prismaticaslip with a higher Schmid Factor(m>0.4)was the dominant deformation mode.The grains containing persistent slip bands(PSBs)tended to go towards[1210]pole and the Schmid Factor had a critical value of 0.4 above which prismatic and pyramidal slip were dominant.Fatigue cracks were mainly initiated at PSBs and grain boundaries(gbs).It showed that 61.1%of the cracks were PSB cracks under a strain amplitude of 0.4%,while it decreased to 53.5%at a strain amplitude of 0.8%.PSB cracks were mainly parallel to prismaticaslip with higher Schmid Factor while some cracks tended to be initiated at gbs with higher misorientation angles.The interaction of PSBs with gbs would result in strain transferring to the neighboring grain.Strain transfer was more likely to occur at the condition of the higher geometrical compatibility factor m,and lower residual Burgers vectorb,which could reduce strain localization.

关键词： Fatigue crack initiation Crystallographic orientation PSBs gbs Strain transfer

Genomic prediction of Fusarium head blight resistance in early stages using advanced breeding lines in hard winter wheat

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The Crop Journal 2022年第6期10卷 1695-1704页

作者： Jinfeng Zhang Harsimardeep S.Gill Navreet K.Brar Jyotirmoy Halder Shaukat Ali Xiaotian Liu Amy Bernardo Paul St.Amand Guihua Bai Upinder S.Gill Brent Turnipseed Sunish K.Sehgal Department of Agronomy Horticulture&Plant ScienceSouth Dakota State UniversityBrookingsSD 57007USA School of Computing Queen’s UniversityKingstonON K7L 3N6Canada USDA-ARS Hard Winter Wheat Genetics Research UnitManhattanKS 66506USA Department of Plant Pathology North Dakota State UniversityFargoND 58108USA

Fusarium head blight(FHB),also known as scab,is a devastating fungal disease of wheat that causes significant losses in grain yield and quality.Quantitative inheritance and cumbersome phenotyping make FHB resistance a challenging trait for direct selection in wheat breeding.Genomic selection to predict FHB resistance traits has shown promise in several studies.Here,we used univariate and multivariate genomic prediction models to evaluate the prediction accuracy(PA)for different FHB traits using 476elite and advanced breeding lines developed by South Dakota State University hard winter wheat breeding program.These breeding lines were assessed for FHB disease index(DIS),and percentage of Fusarium damaged kernels(FDK)in three FHB nurseries in 2018,2019,and 2020(TP18,TP19,and TP20)and were evaluated as training populations(TP)for genomic prediction(GP)of FHB traits.We observed a moderate PA using univariate models for DIS(0.39 and 0.35)and FDK(0.35 and 0.37)using TP19 and TP20,respectively,while slightly higher PA was observed(0.41 for DIS and 0.38 for FDK)when TP19 and TP20(TP19+20)were combined to leverage the advantage of a large training population.Although GP with multivariate approach including plant height and days to heading as covariates did not significantly improve PA for DIS and FDK over univariate models,PA for DON increased by 20%using DIS,FDK,DTH as covariates using multi-trait model in 2020.Finally,we used TP19,TP20,and TP19+20 in forward prediction to calculate genomic-estimated breeding values(GEBVs)for DIS and FDK in preliminary breeding lines at an early stage of the breeding program.We observed moderate PA of up to 0.59 for DIS and 0.54for FDK,demonstrating the promise in genomic prediction for FHB resistance in earlier stages using advanced lines.Our results suggest GP for expensive FHB traits like DON and FDK can facilitate the rejection of highly susceptible materials at an early stage in a breeding program.

关键词： FHB gbs Genomic selection Multi-trait models Winter wheat Wheat scab

Detection of quantitative trait loci(QTL)associated with spring regrowth in alfalfa(Medicago sativa L.)

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Journal of Integrative Agriculture 2022年第3期21卷 812-818页

作者： JIANG Xue-qian ZHANG Fan WANG Zhen LONG Rui-cai LI Ming-na HE Fei YANG Xi-jiang YANG Chang-fu JIANG Xu YANG Qing-chuan WANG Quan-zhen KANG Jun-mei Institute of Animal Science Chinese Academy of Agricultural SciencesBeijing 100193P.R.China College of Grassland Agriculture Northwest A&F UniversityYangling 712100P.R.China

Spring regrowth is an important trait for perennial plants including alfalfa,the most cultivated forage legume worldwide.However,the genetic and genomic basis of the trait is largely unknown in alfalfa due to its complex genetic background of the tetroploid genome.The objective of this study was to identify quantitative trait loci(QTLs)associated with spring regrowth using high-resolution genetic linkage maps we constructed previously.In total,36 significant additive effect QTLs for the trait were detected.Among them,10 QTLs individually explained more than 10%of the phenotypic variation(PVE)with four in P1 and six in P2.Six overlapped QTLs intervals were detected with two and four intervals distributed in P1 and P2,respectively.In P1,both overlapped genomic regions were located on homolog 7 D.In P2,the four QTLs with PVE>10%were co-localized on homolog 6 D.Meanwhile,six pairs of significant epistatic QTLs were identified in P2.Screening of potential candidate genes associated with four overlapped QTLs(q CP2019-8,q LF2019-5,q LF2020-4,and q BLUP-3)narrowed down one candidate annotated as MAIL1.The Arabidopsis homolog gene has been reported to play an important role in plant growth.Therefore,the detected QTLs are valuable resources for genetic improvement of alfalfa spring vigor using marker-assisted selection(MAS),and further identification of the associated genes would provide insights into genetic control of spring regrowth in alfalfa.

关键词： alfalfa gbs genetic map QTL spring regrowth

Comparison of sequencing-based and array-based genotyping platforms for genomic prediction of maize hybrid performance

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The Crop Journal 2023年第2期11卷 490-498页

作者： Guangning Yu Yanru Cui Yuxin Jiao Kai Zhou Xin Wang Wenyan Yang Yiyi Xu Kun Yang Xuecai Zhang Pengcheng Li Zefeng Yang Yang Xu Chenwu Xu Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops College of AgricultureYangzhou UniversityYangzhou 225009JiangsuChina State Key Laboratory of North China Crop Improvement and Regulation Hebei Agricultural UniversityBaoding 071001HebeiChina International Maize and Wheat Improvement Center(CIMMYT) 06600 Mexico D.F.Mexico

Genomic selection(GS)is a powerful tool for improving genetic gain in maize breeding.However,its routine application in large-scale breeding pipelines is limited by the high cost of genotyping platforms.Although sequencing-based and array-based genotyping platforms have been used for GS,few studies have compared prediction performance among platforms.In this study,we evaluated the predictabilities of four agronomic traits in 305 maize hybrids derived from 149 parental lines subjected to genotyping by sequencing(gbs),a 40K SNP array,and target sequence capture(TSC)using eight GS models.The gbs marker dataset yielded the highest predictabilities for all traits,followed by TSC and SNP array datasets.We investigated the effect of marker density and statistical models on predictability among genotyping platforms and found that 1K SNPs were sufficient to achieve comparable predictabilities to 10K and all SNPs,and BayesB,GBLUP,and RKHS performed well,while XGBoost performed poorly in most cases.We also selected significant SNP subsets using genome-wide association study(GWAS)analyses in three panels to predict hybrid performance.GWAS facilitated selecting effective SNP subsets for GS and thus reduced genotyping cost,but depended heavily on the GWAS panel.We conclude that there is still room for optimization of the existing SNP array,and using genotyping by target sequencing(GBTS)techniques to integrate a few functional markers identified by GWAS into the 1K SNP array holds great promise of being an effective strategy for developing desirable GS breeding arrays.

关键词： Genomic selection Maize gbs SNP array Marker density

Identification of a major QTL for Hessian fly resistance in wheat cultivar‘Chokwang’

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The Crop Journal 2022年第3期10卷 775-782页

作者： Lirong Zhang Yunfeng Xu Ming-Shun Chen Zhenqi Su Yang Liu Yuzhou Xu Guixiao La Guihua Bai Department of Plant Pathology College of Plant ProtectionHebei Agricultural UniversityBaoding 071001HebeiChina Department of Agronomy Kansas State UniversityManhattanKS 66506USA Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province Baoding 071001HebeiChina Hard Winter Wheat Genetics Research Unit USDA-ARSManhattanKS 66506USA State Key Laboratory for Agrobiotechnology and Key Laboratory of Crop Heterosis and Utilization(MOE)and Beijing Key Laboratory of Crop Genetic Improvement China Agricultural UniversityBeijing 100193China Institute of South Subtropical Crops Chinese Academy of Tropical Agricultural SciencesZhanjiang 524013GuangdongChina Industrial Crop Research Institute Henan Academy of Agricultural SciencesZhengzhou 450002HenanChina

The Hessian fly(HF,Mayetiola destructor)is one of the destructive pests of wheat(Triticum aestivum L.)worldwide.Resistant cultivars can effectively minimize wheat damage due to this insect pest.To identify new quantitative trait loci(QTL)for HF resistance,a population of recombinant inbred lines(RILs)was developed from a cross between the HF-resistant wheat cultivar‘Chokwang’and susceptible wheat‘Ning 7840’,and phenotyped for responses to HF attack.A linkage map was constructed using 1147 single nucleotide polymorphism(SNP)markers generated from genotyping-by-sequencing(gbs).One major QTL,QHf.hwwg-6 BS,for HF-resistance was identified on chromosome arm 6 BS,which explained up to84.0%of the phenotypic variation and was contributed by Chokwang.Two RILs showed recombination in the candidate interval of QHf.hwwg-6 BS,which delimited QHf.hwwg-6 BS to a 4.75 Mb physical interval between 6,028,601 bp and 10,779,424 bp on chromosome arm 6 BS of IWGSC Chinese Spring reference genome Ref Seq v2.0.Seven gbs-SNPs in the candidate interval were converted into Kompetitive allele specific polymerase chain reaction(KASP)markers.Two of them,KASP-6 B112698 and KASP-6 B7901215,were validated in a U.S.winter wheat panel.KASP-6 B112698 was nearly diagnostic,thus can be used to screen QHf.hwwg-6 BS and pyramid it with other resistance genes in breeding programs.

关键词： Wheat Hessian fly resistance Mayetiola destructor KASP gbs

GUILLAIN-BARRE SYNDROME IN SIX CITIES AND PROVINCES OF NORTHERN CHINA:IS IT A NEW ENTITY?

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Chinese Medical Journal 1995年第10期108卷 734-738页

作者：张晓君张振馨汤晓芙 Department of Neurology PCMC Hospital

Forty cases of Guillain-Barre Syndrome were reported, (gbs) which came from the regions where 'Chinese Paralytic Syndrome' and 'Acute Motor Axonal Neuropathy (AMAN)' were presented before. A study on their clinical, electrophysiological and pathological features was conducted, records on 3 733 gbs cases reported in northern China from 1978 to 1992 were reviewed and compared with cases of 'acute moter axonal nouropathy' . The results showed that the clinical, electrophysiological and pathological features of gbs in north China are similar to those of typical gbs cases in western countries, though there seemed to be some special epidemiological features in age, seasonal and regional distribution. It was concluded that the gbs in northern China is de-myelinating gbs dominantly, not a new entity.

关键词： gbs GUILLAIN-BARRE SYNDROME IN SIX CITIES AND PROVINCES OF NORTHERN CHINA In

Distant eQTLs and Non-coding Sequences Play Critical Roles in Regulating Gene Expression and Quantitative Trait Variation in Maize

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Molecular Plant 2017年第3期10卷 414-426页

作者： Haijun Liu Xin Luo Luyao Niu Yingjie Xiao Lu Chen Jie Liu Xiaqing Wang Minliang Jin Wenqiang Li Qinghua Zhang Jianbing Yan National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural University Wuhan 430070 China These authors contributed equally to this article

A detailed understanding of genetic architecture of mRNA expression by millions of genetic variants is important for studying quantitative trait variation. In this study, we identified 1.25M SNPs with a minor allele frequency greater than 0.05 by combining reduced genome sequencing （gbs）, high- density array technologies （600K）, and previous deep RNA-sequencing data from 368 diverse inbred lines of maize. The balanced allelic frequencies and distributions in a relatively large and diverse natural panel helped to identify expression quantitative trait loci （eQTLs） associated with more than 18 000 genes （63.4% of tested genes）. We found that distant eQTLs were more frequent （~75% of all eQTLs） across the whole genome. Thirteen novel associated loci affecting maize kernel oil concentration were identified using the new dataset, among which one intergenic locus affected the kernel oil variation by controlling expression of three other known oil-related genes. Altogether, this study provides resources for expanding our understanding of cellular regulatory mechanisms of transcriptome variation and the landscape of functional variants within the maize genome, thereby enhancing the understanding of quantitative variations.

关键词： eQTL RNA-seq gbs GWAS non-coding regulation Zea mays

基于gbs简化基因组测序评估3个麦洼牦牛保种群的遗传结构研究

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草业学报 2022年第9期31卷 183-194页

作者：马士龙李小伟李响谢书琼刘益丽唐娇江明锋西南民族大学畜牧兽医学院四川成都610041 青藏高原动物遗传育种资源保护与利用国家教育部重点实验室四川成都610041 西南民族大学青藏高原研究院四川成都610041 四川省龙日种畜场四川红原624401

麦洼牦牛是青藏高原地区优良的乳肉兼用型牦牛品种,本研究旨在探究四川省龙日种畜场麦洼牦牛保种群的遗传多样性和遗传结构,评价3个不同保种群的保种效果并挖掘重要种质特性基因。对麦洼牦牛3个保种群粉嘴群(n=140)、全黑群(n=211)、弗... 详细信息

麦洼牦牛是青藏高原地区优良的乳肉兼用型牦牛品种,本研究旨在探究四川省龙日种畜场麦洼牦牛保种群的遗传多样性和遗传结构,评价3个不同保种群的保种效果并挖掘重要种质特性基因。对麦洼牦牛3个保种群粉嘴群(n=140)、全黑群(n=211)、弗洛群(n=55)进行gbs简化基因组测序,基于检测到的126122个单核苷酸多态性(SNPs)标记计算遗传统计量,结果表明,整个牦牛群的平均观测杂合度(Ho)和平均期望杂合度(He)为0.3038和0.3036,麦洼牦牛的遗传多样性较丰富。全黑群、粉嘴群、弗洛群的观测杂合度Ho分别为0.3029、0.3042、0.3044,近交系数Fis分别为0.0144、0.0152、0.0209,弗洛群和粉嘴群受人工选择的强度大于全黑群,较低的近交水平说明3个群的保种效果较好。Structure分析中全黑、弗洛群部分个体血缘较纯正,而其他个体血缘关系非常混杂;粉嘴群和全黑群的遗传分化系数(Fst)和遗传距离(DR)最大为0.03513、0.0358,结合系统进化树表明两者亲缘关系最远,有遗传分化趋势。利用Fst和π法对3个保种群进行选择信号分析,发现有104个受选择基因广泛参与生殖机能、免疫系统、胚胎发育、脂质代谢等条目以及生殖激素、内/外分泌、信号传递等通路,其中部分基因提示麦洼牦牛的繁殖、肉质、毛色性状以及应激反应得到了人工选择,如PPP3CC、KCNMA1、ROCK2、GNAQ、MEF2C、KIT等。现有的麦洼牦牛保种策略是可行的,研究结果为未来麦洼牦牛的保种选育和遗传改良提供了参考依据。

关键词：麦洼牦牛 gbs 遗传多样性遗传结构选择信号

Strengthening effects of various grain boundaries with nano-spacing as barriers of dislocation motion from molecular dynamics simulations

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Science China(Physics,Mechanics & Astronomy) 2017年第3期60卷 48-54页

作者： FuPing Yuan State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Science Beijing 100190 China School of Engineering Science University of Chinese Academy of Sciences Beijing 100190 China

Strengthening in metals is traditionally achieved through the controlled creation of various grain boundaries(gbs),such as low-angle gbs,high-angle gbs,and twin boundaries(TBs).In the present study,a series of large-scale molecular dynamics simulations with spherical nanoindentation and carefully designed model were conducted to investigate and compare the strengthening effects of various gbs with nano-spacing as barriers of dislocation motion.Simulation results showed that high-angle twist gbs and TBs are similar barriers and low-angle twist gbs are less effective in obstructing dislocation motion.Corresponding atomistic mechanisms were also given.At a certain indentation depth,dislocation transmission and dislocation nucleation from the other side of boundaries were observed for low-angle twist gbs,whereas dislocations were completely blocked by high-angle twist gbs and TBs at the same indentation depth.The current findings should provide insights for comprehensive understanding of the strengthening effects of various gbs at nanoscale.

关键词：分子动力学模拟位错运动纳米压痕孪晶界强化效应间距压痕深度 gbs