Cotton fiber is one of the main raw materials for the textile industry.In recent years,many cotton fiber quality QTL have been identified,but few were applied in breeding.In this study,a genome wide association study(...Cotton fiber is one of the main raw materials for the textile industry.In recent years,many cotton fiber quality QTL have been identified,but few were applied in breeding.In this study,a genome wide association study(GWAS)of fiber-quality traits in 265 upland cotton breeding intermediate lines(GhBreeding),combined with genome-wide selective sweep analysis(GSSA)and genomic selection(GS),revealed 25 QTL.Most of these QTL were ignored by only using GWAS.The CRISPR/Cas9 mutants of GhMYB_D13 had shorter fiber,which indicates the credibility of QTL to a certain extent.Then these QTL were verified in other cotton natural populations,5 stable QTL were found having broad potential for application in breeding.Additionally,among these 5 stable QTL,superior genotypes of 4 showed an enrichment in most improved new varieties widely cultivated currently.These findings provide insights for how to identify more QTL through combined multiple genomic analysis to apply in breeding.展开更多
Phenotypic plasticity, or the ability to adapt to and thrive in changing climates and variable environments, is essential for developmental programs in plants. Despite its importance, the genetic underpinnings of phen...Phenotypic plasticity, or the ability to adapt to and thrive in changing climates and variable environments, is essential for developmental programs in plants. Despite its importance, the genetic underpinnings of phenotypic plasticity for key agronomic traits remain poorly understood in many crops. In this study, we aim to fill this gap by using genome-wide association studies to identify genetic variations associated with phenotypic plasticity in upland cotton (Gossypium hirsutum L.). We identified 73 additive quantitative trait loci (QTLs), 32 dominant QTLs, and 6799 epistatic QTLs associated with 20 traits. We also identified 117 additive QTLs, 28 dominant QTLs, and 4691 epistatic QTLs associated with phenotypic plasticity in 19 traits. Our findings reveal new genetic factors, including additive, dominant, and epistatic QTLs, that are linked to phenotypic plasticity and agronomic traits. Meanwhile, we find that the genetic factors controlling the mean phenotype and phenotypic plasticity are largely independent in upland cotton, indicating the potential for simultaneous improvement. Additionally, we envision a genomic design strategy by utilizing the identified QTLs to facilitate cotton breeding. Taken together, our study provides new insights into the genetic basis of phenotypic plasticity in cotton, which should be valuable for future breeding.展开更多
Polyploidization has long been recognized as a driver for the evolutionary formation of superior plant traits coupled with gene expression novelty.However,knowledge of the effect of regulatory variation on expression ...Polyploidization has long been recognized as a driver for the evolutionary formation of superior plant traits coupled with gene expression novelty.However,knowledge of the effect of regulatory variation on expression changes following polyploidization remains limited.In this study,we characterized transcriptional regulatory divergence by comparing tetraploid cotton with its putative diploid ancestors.We identified 144,827,99,609,and 219,379 Tn5 transposase-hypersensitive sites(THSs)in Gossypium arboreum,G.raimondii,and G.hirsutum,respectively,and found that the conservation of promoter THSs was associated with coordination of orthologous genes expression.This observation was consistent with analysis of transcription-factor binding sites(TFBS)for 262 known motifs:genes with higher TFBS conservation scores(CS)showed less change than those genes with lower TFBS CS in expression levels.TFBS influenced by genomic variation were involved in the novel regulation networks between transcriptional factors and target genes in tetraploid cotton.We describe an example showing that the turnover of TFBS was linked to expression pattern divergence of genes involved in fiber development(fiber-related genes).Our findings reveal the regulatory divergence of the transcriptional network in cotton after polyploidization and characterizes the regulatory relationships of genes contributing to desirable traits.展开更多
Chemical defoliation stands as the ultimate tool in enabling the mechanical harvest of cotton, offering economic and environmental advantages. However, the underlying molecular mechanism that triggers leaf abscission ...Chemical defoliation stands as the ultimate tool in enabling the mechanical harvest of cotton, offering economic and environmental advantages. However, the underlying molecular mechanism that triggers leaf abscission through defoliant remains unsolved. In this study, we meticulously constructed a transcriptomic atlas through single-nucleus mRNA sequencing (snRNA-seq) of the abscission zone (AZ) from cotton petiole. We identified two newly-formed cell types, abscission cells and protection layer cells in cotton petiole AZ after defoliant treatment. GhRLF1 (RAPID LEAF FALLING 1), as one of the members of the cytokinin oxidase/dehydrogenase (CKX) gene family, was further characterized as a key marker gene unique to the abscission cells following defoliant treatment. Overexpression of GhRLF1 resulted in reduced cytokinin accumulation and accelerated leaf abscission. Conversely, CRISPR/Cas9-mediated loss of GhRLF1 function appeared to delay this process. Its interacting regulators, GhWRKY70, acting as “Pioneer” activator, and GhMYB108, acting as “Successor” activator, orchestrate a sequential modulation of GhWRKY70/GhMYB108–GhRLF1–CTK (cytokinin) within the AZ to regulate cotton leaf abscission. GhRLF1 not only regulates leaf abscission but also reduces cotton yield. Consequently, transgenic lines that exhibit rapid leaf falling and require less defoliant but show unaffected cotton yield were developed for mechanical harvesting. This was achieved using a defoliant-induced petiole-specific promoter, proPER21, to drive GhRLF1 (proPER21::RLF1). This pioneering biotechnology offers a new strategy for the chemical defoliation of machine-harvested cotton, ensuring stable production and reducing leaf debris in harvested cotton, thereby enhancing environmental sustainability.展开更多
Cotton is an irreplaceable economic crop currently domesticated in the human world for its extremely elongated fiber cells specialized in seed epidermis,which makes it of high research and application value.To date,nu...Cotton is an irreplaceable economic crop currently domesticated in the human world for its extremely elongated fiber cells specialized in seed epidermis,which makes it of high research and application value.To date,numerous research on cotton has navigated various aspects,from multi-genome assembly,genome editing,mechanism of fiber development,metabolite biosynthesis,and analysis to genetic breeding.Genomic and 3D genomic studies reveal the origin of cotton species and the spatiotemporal asymmetric chromatin structure in fibers.Mature multiple genome editing systems,such as CRISPR/Cas9,Cas12(Cpf1)and cytidine base editing(CBE),have been widely used in the study of candidate genes affecting fiber development.Based on this,the cotton fiber cell development network has been preliminarily drawn.Among them,the MYB-b HLH-WDR(MBW)transcription factor complex and IAA and BR signaling pathway regulate the initiation;various plant hormones,including ethylene,mediated regulatory network and membrane protein overlap fine-regulate elongation.Multistage transcription factors targeting Ces A 4,7,and 8 specifically dominate the whole process of secondary cell wall thickening.And fluorescently labeled cytoskeletal proteins can observe real-time dynamic changes in fiber development.Furthermore,research on the synthesis of cotton secondary metabolite gossypol,resistance to diseases and insect pests,plant architecture regulation,and seed oil utilization are all conducive to finding more high-quality breeding-related genes and subsequently facilitating the cultivation of better cotton varieties.This review summarizes the paramount research achievements in cotton molecular biology over the last few decades from the above aspects,thereby enabling us to conduct a status review on the current studies of cotton and provide strong theoretical support for the future direction.展开更多
High-temperature(HT)stress causes male sterility in crops,thus decreasing yields.To explore the possible contribution of histone modifications to male fertility under HT conditions,we defined the histone methylation l...High-temperature(HT)stress causes male sterility in crops,thus decreasing yields.To explore the possible contribution of histone modifications to male fertility under HT conditions,we defined the histone methylation landscape for the marks histone H3 lysine 27 trimethylation(H3K27me3)and histone H3 lysine 4 trimethylation(H3K4me3)by chromatin immunoprecipitation sequencing(ChIP-seq)in two differing upland cotton(Gossypium hirsutum)varieties.We observed a global disruption in H3K4me3 and H3K27me3 modifications,especially H3K27me3,in cotton anthers subjected to HT.HT affected the bivalent H3K4me3–H3K27me3 modification more than either monovalent modification.We determined that removal of H3K27me3 at the promoters of jasmonate-related genes increased their expression,maintaining male fertility under HT in the HT-tolerant variety at the anther dehiscence stage.Modulating jasmonate homeostasis or signaling resulted in an anther indehiscence phenotype under HT.Chemical suppression of H3K27me3 deposition increased jasmonic acid contents and maintained male fertility under HT.In summary,our study provides new insights into the regulation of male fertility by histone modifications under HT and suggests a potential strategy for improving cotton HT tolerance.展开更多
Centromere positioning and organization are crucial for genome evolution;however,research on centro-mere biology is largely influenced by the quality of available genome assemblies.Here,we combined Oxford Nanopore and...Centromere positioning and organization are crucial for genome evolution;however,research on centro-mere biology is largely influenced by the quality of available genome assemblies.Here,we combined Oxford Nanopore and Pacific Biosciences technologies to de novo assemble two high-quality reference genomes for Gossypium hirsutum(TM-1)and Gossypium barbadense(3-79).Compared with previously published reference genomes,our assemblies show substantial improvements,with the contig N50 improved by 4.6-fold and 5.6-fold,respectively,and thus represent the most complete cotton genomes to date.These high-quality reference genomes enable us to characterize 14 and 5 complete centromeric regions for G.hirsutum and G.barbadense,respectively.Our data revealed that the centromeres of allotetraploid cotton are occupied by members of the centromeric repeat for maize(CRM)and Tekay long terminal repeat families,and the CRM family reshapes the centromere structure of the At subgenome after polyploidization.These two intertwined families have driven the convergent evolution of centromeres between the two subgenomes,ensuring centromere function and genome stability.In addition,the reposi-tioning and high sequence divergence of centromeres between G.hirsutum and G.barbadense have contributed to speciation and centromere diversity.This study sheds light on centromere evolution in a sig-nificant crop and provides an alternative approach for exploring the evolution of polyploid plants.展开更多
The issue of unoccupied or abandoned homesteads(courtyards)in China emerges given the increasing aging population,rapid urbanization and massive rural-urban migration.From the aspect of rural vitalization,land-use pla...The issue of unoccupied or abandoned homesteads(courtyards)in China emerges given the increasing aging population,rapid urbanization and massive rural-urban migration.From the aspect of rural vitalization,land-use planning,and policy making,determining the number of unoccupied courtyards is important.Field and questionnaire-based surveys were currently the main approaches,but these traditional methods were often expensive and laborious.A new workflow is explored using deep learning and machine learning algorithms on unmanned aerial vehicle(UAV)images.Initially,features of the built environment were extracted using deep learning to evaluate the courtyard management,including extracting complete or collapsed farmhouses by Alexnet,detecting solar water heaters by YOLOv5s,calculating green looking ratio(GLR)by FCN.Their precisions exceeded 98%.Then,seven machine learning algorithms(Adaboost,binomial logistic regression,neural network,random forest,support vector machine,decision trees,and XGBoost algorithms)were applied to identify the rural courtyards’utilization status.The Adaboost algorithm showed the best performance with the comprehensive consideration of most metrics(Accuracy:0.933,Precision:0.932,Recall:0.984,F1-score:0.957).Results showed that identifying the courtyards’utilization statuses based on the courtyard built environment is feasible.It is transferable and cost-effective for large-scale village surveys,and may contribute to the intensive and sustainable approach to rural land use.展开更多
In this study,the physical properties of F ion-implanted GaN were thoroughly studied,and the related electric-field modulation mechanisms in ion-implanted edge termination were revealed.Transmission electron microscop...In this study,the physical properties of F ion-implanted GaN were thoroughly studied,and the related electric-field modulation mechanisms in ion-implanted edge termination were revealed.Transmission electron microscopy re.sults indicate that the ion-implanted region maintains a single-crystal structure even with the implantation of high-energy F ions,indicating that the high resistivity of the edge termination region is not induced by amorphization.Alternately,ion implantation-induced deep levels could compensate the electrons and lead to a highly resistive layer In addition to the bulk ffect,the direct bombardment of high-energy F ions resulted in a rough and nitrogen-deficient surface,which was confirmed via atomic force microscopy(AFM)and X-ray photoelectron spectroscopy,The implanted surface with a large density of nitrogen vacancies can accommodate electrons,and it is more conductive than the bulk in the implanted region,which is validated via spreading resistance profiling and conductive AFM measurements.Under reverse bias,the implanted surface can spread the potential in the lateral direction,whereas the acceptor traps capture electrons acting as space charges,shifting the peak electric field into the bulk region in the vertical direction.As a result,the Schottky barrier diode terminated with high-energy F ion-implanted regions exhibits a breakdown voltage of over 1.2 kv.展开更多
基金supported by National Key Research and Development Program of China(2022YFF1001400)the National Natural Science Foundation of China(31830062 and 32172071)+1 种基金Innovation and Application of Superior Crop Germplasm Resources of Shihezi(2021NY01)Breeding of New Cotton Varieties and Application of Transgenic Breeding Technology(2022NY01)。
文摘Cotton fiber is one of the main raw materials for the textile industry.In recent years,many cotton fiber quality QTL have been identified,but few were applied in breeding.In this study,a genome wide association study(GWAS)of fiber-quality traits in 265 upland cotton breeding intermediate lines(GhBreeding),combined with genome-wide selective sweep analysis(GSSA)and genomic selection(GS),revealed 25 QTL.Most of these QTL were ignored by only using GWAS.The CRISPR/Cas9 mutants of GhMYB_D13 had shorter fiber,which indicates the credibility of QTL to a certain extent.Then these QTL were verified in other cotton natural populations,5 stable QTL were found having broad potential for application in breeding.Additionally,among these 5 stable QTL,superior genotypes of 4 showed an enrichment in most improved new varieties widely cultivated currently.These findings provide insights for how to identify more QTL through combined multiple genomic analysis to apply in breeding.
基金This study was supported by the National Key Research and Development Program of China(2021YFF1000900)the National Natural Science Foundation of China(32170645)This study was also supported by the Foundation of Hubei Hongshan Laboratory(2021hszd014)。
文摘Phenotypic plasticity, or the ability to adapt to and thrive in changing climates and variable environments, is essential for developmental programs in plants. Despite its importance, the genetic underpinnings of phenotypic plasticity for key agronomic traits remain poorly understood in many crops. In this study, we aim to fill this gap by using genome-wide association studies to identify genetic variations associated with phenotypic plasticity in upland cotton (Gossypium hirsutum L.). We identified 73 additive quantitative trait loci (QTLs), 32 dominant QTLs, and 6799 epistatic QTLs associated with 20 traits. We also identified 117 additive QTLs, 28 dominant QTLs, and 4691 epistatic QTLs associated with phenotypic plasticity in 19 traits. Our findings reveal new genetic factors, including additive, dominant, and epistatic QTLs, that are linked to phenotypic plasticity and agronomic traits. Meanwhile, we find that the genetic factors controlling the mean phenotype and phenotypic plasticity are largely independent in upland cotton, indicating the potential for simultaneous improvement. Additionally, we envision a genomic design strategy by utilizing the identified QTLs to facilitate cotton breeding. Taken together, our study provides new insights into the genetic basis of phenotypic plasticity in cotton, which should be valuable for future breeding.
基金supported by the National Natural Science Foundation of China(31922069,32170645)the Fundamental Research Funds for the Central Universities(2662020ZKPY017)。
文摘Polyploidization has long been recognized as a driver for the evolutionary formation of superior plant traits coupled with gene expression novelty.However,knowledge of the effect of regulatory variation on expression changes following polyploidization remains limited.In this study,we characterized transcriptional regulatory divergence by comparing tetraploid cotton with its putative diploid ancestors.We identified 144,827,99,609,and 219,379 Tn5 transposase-hypersensitive sites(THSs)in Gossypium arboreum,G.raimondii,and G.hirsutum,respectively,and found that the conservation of promoter THSs was associated with coordination of orthologous genes expression.This observation was consistent with analysis of transcription-factor binding sites(TFBS)for 262 known motifs:genes with higher TFBS conservation scores(CS)showed less change than those genes with lower TFBS CS in expression levels.TFBS influenced by genomic variation were involved in the novel regulation networks between transcriptional factors and target genes in tetraploid cotton.We describe an example showing that the turnover of TFBS was linked to expression pattern divergence of genes involved in fiber development(fiber-related genes).Our findings reveal the regulatory divergence of the transcriptional network in cotton after polyploidization and characterizes the regulatory relationships of genes contributing to desirable traits.
基金supported by funding from the National Key Project of Research and the Development Plan of China(2021YFF1000103)the National Natural Science Foundation of China(32171942)The development fund for Xinjiang talents XL,and the Agricultural GG Project of Xinjiang Production and Construction Corps(NYHXGG,2023AA102).
文摘Chemical defoliation stands as the ultimate tool in enabling the mechanical harvest of cotton, offering economic and environmental advantages. However, the underlying molecular mechanism that triggers leaf abscission through defoliant remains unsolved. In this study, we meticulously constructed a transcriptomic atlas through single-nucleus mRNA sequencing (snRNA-seq) of the abscission zone (AZ) from cotton petiole. We identified two newly-formed cell types, abscission cells and protection layer cells in cotton petiole AZ after defoliant treatment. GhRLF1 (RAPID LEAF FALLING 1), as one of the members of the cytokinin oxidase/dehydrogenase (CKX) gene family, was further characterized as a key marker gene unique to the abscission cells following defoliant treatment. Overexpression of GhRLF1 resulted in reduced cytokinin accumulation and accelerated leaf abscission. Conversely, CRISPR/Cas9-mediated loss of GhRLF1 function appeared to delay this process. Its interacting regulators, GhWRKY70, acting as “Pioneer” activator, and GhMYB108, acting as “Successor” activator, orchestrate a sequential modulation of GhWRKY70/GhMYB108–GhRLF1–CTK (cytokinin) within the AZ to regulate cotton leaf abscission. GhRLF1 not only regulates leaf abscission but also reduces cotton yield. Consequently, transgenic lines that exhibit rapid leaf falling and require less defoliant but show unaffected cotton yield were developed for mechanical harvesting. This was achieved using a defoliant-induced petiole-specific promoter, proPER21, to drive GhRLF1 (proPER21::RLF1). This pioneering biotechnology offers a new strategy for the chemical defoliation of machine-harvested cotton, ensuring stable production and reducing leaf debris in harvested cotton, thereby enhancing environmental sustainability.
基金the National Natural Science Foundation of China(32200286)the China Postdoctoral Science Foundation(2022TQ0240,2022M722470)。
文摘Cotton is an irreplaceable economic crop currently domesticated in the human world for its extremely elongated fiber cells specialized in seed epidermis,which makes it of high research and application value.To date,numerous research on cotton has navigated various aspects,from multi-genome assembly,genome editing,mechanism of fiber development,metabolite biosynthesis,and analysis to genetic breeding.Genomic and 3D genomic studies reveal the origin of cotton species and the spatiotemporal asymmetric chromatin structure in fibers.Mature multiple genome editing systems,such as CRISPR/Cas9,Cas12(Cpf1)and cytidine base editing(CBE),have been widely used in the study of candidate genes affecting fiber development.Based on this,the cotton fiber cell development network has been preliminarily drawn.Among them,the MYB-b HLH-WDR(MBW)transcription factor complex and IAA and BR signaling pathway regulate the initiation;various plant hormones,including ethylene,mediated regulatory network and membrane protein overlap fine-regulate elongation.Multistage transcription factors targeting Ces A 4,7,and 8 specifically dominate the whole process of secondary cell wall thickening.And fluorescently labeled cytoskeletal proteins can observe real-time dynamic changes in fiber development.Furthermore,research on the synthesis of cotton secondary metabolite gossypol,resistance to diseases and insect pests,plant architecture regulation,and seed oil utilization are all conducive to finding more high-quality breeding-related genes and subsequently facilitating the cultivation of better cotton varieties.This review summarizes the paramount research achievements in cotton molecular biology over the last few decades from the above aspects,thereby enabling us to conduct a status review on the current studies of cotton and provide strong theoretical support for the future direction.
基金supported by the Major Project of Hubei Hongshan Laboratory(2022hszd004)the National Cotton Production System,Ministry of Agriculture and Rural Affairs of China(CARS-15-04)+1 种基金the National Key R&D Program of China(2022YFF1003502)the National Natural Science Foundation of China(32072024).
文摘High-temperature(HT)stress causes male sterility in crops,thus decreasing yields.To explore the possible contribution of histone modifications to male fertility under HT conditions,we defined the histone methylation landscape for the marks histone H3 lysine 27 trimethylation(H3K27me3)and histone H3 lysine 4 trimethylation(H3K4me3)by chromatin immunoprecipitation sequencing(ChIP-seq)in two differing upland cotton(Gossypium hirsutum)varieties.We observed a global disruption in H3K4me3 and H3K27me3 modifications,especially H3K27me3,in cotton anthers subjected to HT.HT affected the bivalent H3K4me3–H3K27me3 modification more than either monovalent modification.We determined that removal of H3K27me3 at the promoters of jasmonate-related genes increased their expression,maintaining male fertility under HT in the HT-tolerant variety at the anther dehiscence stage.Modulating jasmonate homeostasis or signaling resulted in an anther indehiscence phenotype under HT.Chemical suppression of H3K27me3 deposition increased jasmonic acid contents and maintained male fertility under HT.In summary,our study provides new insights into the regulation of male fertility by histone modifications under HT and suggests a potential strategy for improving cotton HT tolerance.
基金supported by the National Natural Science Foundation of China (32170645)the National Key Research and Development Program of China (2021YFF1000900).
文摘Centromere positioning and organization are crucial for genome evolution;however,research on centro-mere biology is largely influenced by the quality of available genome assemblies.Here,we combined Oxford Nanopore and Pacific Biosciences technologies to de novo assemble two high-quality reference genomes for Gossypium hirsutum(TM-1)and Gossypium barbadense(3-79).Compared with previously published reference genomes,our assemblies show substantial improvements,with the contig N50 improved by 4.6-fold and 5.6-fold,respectively,and thus represent the most complete cotton genomes to date.These high-quality reference genomes enable us to characterize 14 and 5 complete centromeric regions for G.hirsutum and G.barbadense,respectively.Our data revealed that the centromeres of allotetraploid cotton are occupied by members of the centromeric repeat for maize(CRM)and Tekay long terminal repeat families,and the CRM family reshapes the centromere structure of the At subgenome after polyploidization.These two intertwined families have driven the convergent evolution of centromeres between the two subgenomes,ensuring centromere function and genome stability.In addition,the reposi-tioning and high sequence divergence of centromeres between G.hirsutum and G.barbadense have contributed to speciation and centromere diversity.This study sheds light on centromere evolution in a sig-nificant crop and provides an alternative approach for exploring the evolution of polyploid plants.
基金the project“National Key Research and Development Program of China,No.2018YFD1100803”.
文摘The issue of unoccupied or abandoned homesteads(courtyards)in China emerges given the increasing aging population,rapid urbanization and massive rural-urban migration.From the aspect of rural vitalization,land-use planning,and policy making,determining the number of unoccupied courtyards is important.Field and questionnaire-based surveys were currently the main approaches,but these traditional methods were often expensive and laborious.A new workflow is explored using deep learning and machine learning algorithms on unmanned aerial vehicle(UAV)images.Initially,features of the built environment were extracted using deep learning to evaluate the courtyard management,including extracting complete or collapsed farmhouses by Alexnet,detecting solar water heaters by YOLOv5s,calculating green looking ratio(GLR)by FCN.Their precisions exceeded 98%.Then,seven machine learning algorithms(Adaboost,binomial logistic regression,neural network,random forest,support vector machine,decision trees,and XGBoost algorithms)were applied to identify the rural courtyards’utilization status.The Adaboost algorithm showed the best performance with the comprehensive consideration of most metrics(Accuracy:0.933,Precision:0.932,Recall:0.984,F1-score:0.957).Results showed that identifying the courtyards’utilization statuses based on the courtyard built environment is feasible.It is transferable and cost-effective for large-scale village surveys,and may contribute to the intensive and sustainable approach to rural land use.
基金supported by the National Key Research and Devel.opment Program of China(Grant No.2017YFB0403000)the National Natural Science Foundation of China(Grants No.61774002 and 11634002).
文摘In this study,the physical properties of F ion-implanted GaN were thoroughly studied,and the related electric-field modulation mechanisms in ion-implanted edge termination were revealed.Transmission electron microscopy re.sults indicate that the ion-implanted region maintains a single-crystal structure even with the implantation of high-energy F ions,indicating that the high resistivity of the edge termination region is not induced by amorphization.Alternately,ion implantation-induced deep levels could compensate the electrons and lead to a highly resistive layer In addition to the bulk ffect,the direct bombardment of high-energy F ions resulted in a rough and nitrogen-deficient surface,which was confirmed via atomic force microscopy(AFM)and X-ray photoelectron spectroscopy,The implanted surface with a large density of nitrogen vacancies can accommodate electrons,and it is more conductive than the bulk in the implanted region,which is validated via spreading resistance profiling and conductive AFM measurements.Under reverse bias,the implanted surface can spread the potential in the lateral direction,whereas the acceptor traps capture electrons acting as space charges,shifting the peak electric field into the bulk region in the vertical direction.As a result,the Schottky barrier diode terminated with high-energy F ion-implanted regions exhibits a breakdown voltage of over 1.2 kv.
