The Asiatic hybrid lily cultivar Lilium dazzling(family Liliaceae)is a perennial herbaceous bulbous plant with bright yellow flowers of ornamental values.It also shows resistance to diseases and abiotic stress,making ...The Asiatic hybrid lily cultivar Lilium dazzling(family Liliaceae)is a perennial herbaceous bulbous plant with bright yellow flowers of ornamental values.It also shows resistance to diseases and abiotic stress,making it an ideal parent for breeding studies.This study established a sterile culture system using scales of dazzling lily as explants to induce polyploidy.Adventitious buds growing to 1 cm were treated with different concentrations of colchicine(125,250 and 500μmol·L-1),pendimethalin or trifluralin(100,200 and 300μmol·L-1,respectively)for 12,24 and 36 h.Flow cytometry and chromosome counting were used to identify ploidy,and the phenotype of the polyploids was examined by stomatal observation and leaf index determination.With increasing mutagen concentration and exposure time,the mortality and mutagenic rate increased.The optimal treatment group was:300μmol·L-1 trifluralin for 12 h,which resulted in 15.55%mortality rate and 42.22%induction rate.The polyploid plants showed a significant increase in stomata length,leaf length and leaf width,with a decrease in stomatal density compared with the control plants.This study provided a basis for polyploid breeding.展开更多
With apical leaves of Lycium ruthenicum Murr as experimental material, the polyploids of L. ruthenicum were induced with colchicine solution, and total four polyploidy plants were identified by chromosome courts. The ...With apical leaves of Lycium ruthenicum Murr as experimental material, the polyploids of L. ruthenicum were induced with colchicine solution, and total four polyploidy plants were identified by chromosome courts. The results showed that tetraploid plants of L. ruthenicum were successfully induced with 300 mg/L of colchicine solution after 7 and 21 d of induction, with 400 mg/L of colchicine solution after 14 days of induction, and with 500 mg/L of colchicine solution after 7 days of induction, respectively.展开更多
Sequence-specific nucleases(SSN) that generate double-stranded DNA breaks(DSBs) in genes of interest are the key to site-specific genome editing in plants. Genome editing has developed into one method of reducing unde...Sequence-specific nucleases(SSN) that generate double-stranded DNA breaks(DSBs) in genes of interest are the key to site-specific genome editing in plants. Genome editing has developed into one method of reducing undesirable traits in crops by the induction of knockout mutations. Different SSN-mediated genome-editing systems, including LAGLIDADG homing endonucleases or meganucleases, zinc-finger nucleases, transcription activator-like effector nucleases and clustered regularly interspaced short palindromic repeats, are emerging as robust tools for introducing functional mutations in polyploid crops including citrus, wheat, cotton, soybean, rapeseed, potato, grapes, Camelina sativa,dandelion, and tobacco. The approach utilizes knowledge of biological mechanisms for targeted induction of DSBs and their error-prone repair, allowing highly specific changes at designated genome loci. In this review, we briefly describe genome-editing technologies and their application to genetic improvement of polyploid crops.展开更多
[Objective] This study aimed to explore the origin and evolution of poly- poids in Parakmeria Hu et Cheng through LEAFY gene clone and sequence analysis. [Method] In this study, LEAFY gene in Parakmeria species and it...[Objective] This study aimed to explore the origin and evolution of poly- poids in Parakmeria Hu et Cheng through LEAFY gene clone and sequence analysis. [Method] In this study, LEAFY gene in Parakmeria species and its relative genera was cloned and sequenced using molecular biology methods. With reference to LEAFY gene sequence published by NCBI, the origin pattern of polypoids in Parakmeria was explored and reasons for the distribution layout of different polypoids were analyzed through sequence alignment and phylogenetic analysis. [Result] Different Magnoliaceae species can be distinguished using the LEAFY gene, and there was a length polymorphism found in the 3＋ end of the LEAFY gene, which can be used to divide Magnoliaceae plants of different species or in different genera, thus of high application value. [Conclusion] Most Parakmeria tetraploids are produced by polyploidization of homologous chromosomes, while Parakmeria hexaploids are chiefly produced by both polyploidization of homologous chromosomes and heterologous hybridization.展开更多
Most Rhododendron species are ornamental flowering species widely distributed in Asia,North America,and West Europe.Rhododendron fortunei,one of the endemic Rhododendron species in China,has beautiful flowers with bri...Most Rhododendron species are ornamental flowering species widely distributed in Asia,North America,and West Europe.Rhododendron fortunei,one of the endemic Rhododendron species in China,has beautiful flowers with bright colors and is being exploited to meet the needs of the flower market.Polyploid plants usually show superiority in growth,disease resistance,and adaption over their diploid relatives.Here,we report the first case of polyploid induction in R.fortunei.In order to induce polyploidy in R.fortunei,germinating seeds were treated with different concentrations of oryzalin for 16 h.By evaluating ploidy level with flow cytometry,a total of 34 polyploid R.fortunei lines,including 27 tetraploid lines and seven octoploid lines,were obtained.A comparison of treatments indicated that 7.5 mg L^-1 oryzalin was the optimal concentration for polyploid induction in seeds of R.fortunei.Compared with diploid plants,tetraploid and octoploid plants exhibited slower growth rates and had thicker and rounder curled leaves with more leaf epidermal hairs.Moreover,larger stomata at lower density were also observed in the leaves of polyploid plants.Chlorophyll contents were also significantly increased in polyploid plants,which leads to a darker green leaf color.Both small and large individuals exhibiting the same characteristics were observed among the obtained tetraploid plants.Overall,our study establishes a feasible method for polyploid induction in R.fortunei,thus providing a basis for breeding new R.fortunei varieties.展开更多
Polyploidization is one of the most crucial pathways in introducing speciation and broadening biodiversity, especially in the Plant Kingdom. Although the majority of studies have focused only on allopolyploid or disom...Polyploidization is one of the most crucial pathways in introducing speciation and broadening biodiversity, especially in the Plant Kingdom. Although the majority of studies have focused only on allopolyploid or disomic polyploids, polysomic polyploid species have occurred frequently in higher plants. Due to the occurrence of the capabilities of more copies of alleles in a locus which can have additive dosage effects and/or allelic interactions, polysomic polyploids can lead to unique gene regulations to silence or adjust the expression level to create variations in organ size, metabolic products, and abiotic stress tolerance and biotic stress resistance, etc. This review aims to comprehensively summarize the contemporary understanding and findings concerning the molecular mechanisms of gene expression as well as gene regulation in natural typed and resynthesized polysomic polyploid plants. The review investigates the molecular level of phenomena in polysomic polyploid plants such as 1) typically enlarging organ size and stabilizing meiosis, 2) increasing phytochemical content and metabolic products, 3) enhancing the ability to adapt with biotic and abiotic stress, and 4) changing in gene regulation to silence or adjust the expression levels involve in sequence elimination, methylation, gene suppression, subfunctionalization, neo-functionalization, and transposon activation.展开更多
Lycophytes are an ancient clade of the non-flowering vascular plants with chromosome numbers that vary from tens to hundreds.They are an excellent study system for examining whole-genome duplications(WGDs),or polyploi...Lycophytes are an ancient clade of the non-flowering vascular plants with chromosome numbers that vary from tens to hundreds.They are an excellent study system for examining whole-genome duplications(WGDs),or polyploidization,in spore-dispersed vascular plants.However,a lack of genome sequence data limits the reliable detection of very ancient WGDs,small-scale duplications(SSDs),and recent WGDs.Here,we integrated phylogenomic analysis and the distribution of synonymous substitutions per synonymous sites(Ks)of the transcriptomes of 13 species of lycophytes to identify,locate,and date multiple WGDs in the lycophyte family Lycopodiaceae.Additionally,we examined the genus Phlegmariurus for signs of genetic discordance,which can provide valuable insight into the underlying causes of such conflict(e.g.,hybridization,incomplete lineage sorting,or horizontal gene transfer).We found strong evidence that two WGD events occurred along the phylogenetic backbone of Lycopodiaceae,with one occurring in the common ancestor of extant Phlegmariurus(Lycopodiaceae)approximately 22-23 million years ago(Mya)and the other occurring in the common ancestor of Lycopodiaceae around 206-214 Mya.Interestingly,we found significant genetic discordance in the genus Phlegmariurus,indicating that the genus has a complex evolutionary history.This study provides molecular evidence for multiple WGDs in Lycopodiaceae and offers phylogenetic clues to the evolutionary history of Lycopodiaceae.展开更多
Cell-cell fusion is a normal biological process playing essential roles in organ formation and tissue differentiation,repair and regeneration.Through cell fusion somatic cells undergo rapid nuclear reprogramming and e...Cell-cell fusion is a normal biological process playing essential roles in organ formation and tissue differentiation,repair and regeneration.Through cell fusion somatic cells undergo rapid nuclear reprogramming and epigenetic modifications to form hybrid cells with new genetic and phenotypic properties at a rate exceeding that achievable by random mutations.Factors that stimulate cell fusion are inflammation and hypoxia.Fusion of cancer cells with non-neoplastic cells facilitates several malignancy-related cell phenotypes,e.g.,reprogramming of somatic cell into induced pluripotent stem cells and epithelial to mesenchymal transition.There is now considerable in vitro,in vivo and clinical evidence that fusion of cancer cells with motile leucocytes such as macrophages plays a major role in cancer metastasis.Of the many changes in cancer cells after hybridizing with leucocytes,it is notable that hybrids acquire resistance to chemo-and radiation therapy.One phenomenon that has been largely overlooked yet plays a role in these processes is polyploidization.Regardless of the mechanism of polyploid cell formation,it happens in response to genotoxic stresses and enhances a cancer cell’s ability to survive.Here we summarize the recent progress in research of cell fusion and with a focus on an important role for polyploid cells in cancer metastasis.In addition,we discuss the clinical evidence and the importance of cell fusion and polyploidization in solid tumors.展开更多
An induced polyploid plant through colchicine treatment offers probably the best scope for improvement in flower size and fruit weight.Thus,in the present study,an attempt was made to induce polyploidy in Cape goosebe...An induced polyploid plant through colchicine treatment offers probably the best scope for improvement in flower size and fruit weight.Thus,in the present study,an attempt was made to induce polyploidy in Cape gooseberry using colchicine with the objective of creating more genetic variability.The colchicine concentrations were used as 0.10%(C1),0.20%(C2)and 0.40%(C3)for the duration 12(H1),24(H2)and 36(H3)hours for each concentration with seedling apex dip method(M1),cotton plug method(M2)and lanolin paste method(M3).The plants treated with 0.10%of colchicine by cotton plug method for 12 h showed the better performance during the years 2017-2018 and 2018-2019 in respect of more delay in the flower bud emergence(54 d and 53 d from the date of transplanting),anthesis(19 d and 20 d from the first appearance of bud to full anthesis of flower)and fruit setting(8.00 d and 9.00 d from the date of anthesis),bigger flower size(2.93 cm2 and 3.00 cm2)than the untreated plants.The lower percentage of pollen viability(40.33%and 40.67%)was noticed in the same treatment in comparison to control(70.33%and 72.33%).The fruit maturity was also extended(59 d and 60 d from the date of fruit set)with bigger sized fruits(length:2.53 cm and 2.57 cm,breadth:2.27 cm and 2.33 cm)as well as more fruit weight(8.70 g and 8.33 g)by the application of colchicine at 0.10%with cotton plug method for 12 h.On the basis of results obtained,the application of colchicine at 0.10%for 12 h duration with cotton plug method was found to be the best and effective treatment for induction of polyploidy as well as more flower size and fruit weight in Cape gooseberry.展开更多
Based on a series of polyploid indica-japonica hybrid plant lines obtained from a new breeding strategy of using double predominance of wide cross and polyploidization to breed super flee, two polyploid indica-japonic...Based on a series of polyploid indica-japonica hybrid plant lines obtained from a new breeding strategy of using double predominance of wide cross and polyploidization to breed super flee, two polyploid indica-japonica hybrids, PSR073 and PSR120 were studied in their growth periods to show the powerful heterosis in a larger scale and to study the characteristics of polyploid indica-japonica hybrids more elaborately. The leaf age, tiller growth, flowering habits, and agronomic traits of them were observed to analyze their growth habits and characteristics. The results showed that the.agronomic traits of PSR073 and PSR120, such as the plant height, panicle length, grain length, grain width, and 1000-grain weight, all acquired obvious predominance of polyploidy, and that the seed setting rate was more than 83%. No significant difference was observed between the two tetraploids and common diploids in the leaf age, tiller growth, and flowering habits. It was concluded that the characteristics of the two powerful heterosis polyploid hybrids were different from those of the polyploid rice reported earlier. Wide cross and polyploidization had no negative effects on their growth habits and characteristics; on the contrary these had powerful heterosis. This had provided theoretic and practical evidences for their application to agricultural production.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
The sugarcane genome polyploidization can reduce the pressure of gene evolution selection,promote the fixation of fine traits,and increase the biomass and economic value of sugarcane.This paper mainly introduced the o...The sugarcane genome polyploidization can reduce the pressure of gene evolution selection,promote the fixation of fine traits,and increase the biomass and economic value of sugarcane.This paper mainly introduced the origin of the sugarcane genome,the chromosome composition,the research progress of polyploidization genetic mechanism,in the hope of providing theoretical reference for sugarcane polyploidization breeding.展开更多
Polyploidy is common among agriculturally important crops. Popular genetic methods and their implementations cannot always be applied to polyploid genetic data. We give an overview about available tools and their limi...Polyploidy is common among agriculturally important crops. Popular genetic methods and their implementations cannot always be applied to polyploid genetic data. We give an overview about available tools and their limitations in terms of levels of ploidy, auto- and allo-ploidy. The main classes of tools are genotype calling, linkage mapping and haplotyping. The usability of the tools is discussed with a focus on their applicability to data sets produced by state of the art technologies. We show that many challenges remain until the toolset for polyploidy provides similar functionalities as those which are already available for diploids. Some tools have been developed over a decade ago and are now outdated. In addition, we discuss necessary steps to overcome this shortage in the future.展开更多
[ Objectives] This study was conducted to provide high-quality polyploid for returning the grain plots to forestry and promote the rapid development of Lonicera edulis Turcz. [ Methods] With superior individuals of wi...[ Objectives] This study was conducted to provide high-quality polyploid for returning the grain plots to forestry and promote the rapid development of Lonicera edulis Turcz. [ Methods] With superior individuals of wild L. edulis in Changbai Mountains as experimental materials and colchicine as inducer, polyploid induction was performed twice on diploid plants by addition method, and 7 polyploidy plants were identified from 11 regenerated plantlets. [Results] Among the 7 polyploidy plants, four materials were tetraploid, the concentration and treatment time of which were 300 mg/L and 7 and 14 d, respectively; and three materials were octaploid, the concentrations and treatment time of which were 300 and 500 mg/L and 14 d, respectively. [ Conclusions] The results of this study showed that colchicine had a higher polyploid induction rate for L. edulis with lower toxic and side effects, and the polyploidy plants could restore to normal growth state after several times of cubculture. Therefore, colchicine is an polyploid inducer suitable for L. edulis.展开更多
Non-B-form DNA differs from the classic B-DNA double helix structure and plays a crucial regulatory role in replication and transcription.However,the role of non-B-form DNA in centromeres,especially in polyploid wheat...Non-B-form DNA differs from the classic B-DNA double helix structure and plays a crucial regulatory role in replication and transcription.However,the role of non-B-form DNA in centromeres,especially in polyploid wheat,remains elusive.Here,we systematically analyzed seven non-B-form DNA motif profiles(A-phased DNA repeat,direct repeat,G-quadruplex,inverted repeat,mirror repeat,short tandem repeat,and Z-DNA)in hexaploid wheat.We found that three of these non-B-form DNA motifs were enriched at centromeric regions,especially at the CENH3-binding sites,suggesting that non-B-form DNA may create a favorable loading environment for the CENH3 nucleosome.To investigate the dynamics of centromeric non-B form DNA during the alloploidization process,we analyzed DNA secondary structure using CENH3 ChIP-seq data from newly formed allotetraploid wheat and its two diploid ancestors.We found that newly formed allotetraploid wheat formed more non-B-form DNA in centromeric regions compared with their parents,suggesting that non-B-form DNA is related to the localization of the centromeric regions in newly formed wheat.Furthermore,non-B-form DNA enriched in the centromeric regions was found to preferentially form on young LTR retrotransposons,explaining CENH3's tendency to bind to younger LTR.Collectively,our study describes the landscape of non-B-form DNA in the wheat genome,and sheds light on its potential role in the evolution of polyploid centromeres.展开更多
Bread wheat(Triticum aestivum)is an important crop and serves as a significant source of protein and calories for humans,worldwide.Nevertheless,its large and allopolyploid genome poses constraints on genetic improveme...Bread wheat(Triticum aestivum)is an important crop and serves as a significant source of protein and calories for humans,worldwide.Nevertheless,its large and allopolyploid genome poses constraints on genetic improvement.The complex reticulate evolutionary history and the intricacy of genomic resources make the deciphering of the functional genome considerably more challenging.Recently,we have developed a comprehensive list of versatile computational tools with the integration of statistical models for dissecting the polyploid wheat genome.Here,we summarize the methodological innovations and applications of these tools and databases.A series of step-by-step examples illustrates how these tools can be utilized for dissecting wheat germplasm resources and unveiling functional genes associated with important agronomic traits.Furthermore,we outline future perspectives on new advanced tools and databases,taking into consideration the unique features of bread wheat,to accelerate genomic-assisted wheat breeding.展开更多
Genome polyploidy has been revealed to result in evolutionary advantages and novelties,and therefore,polyploid aquatic animals may possess excellent traits of economic interest including rapid growth,extensive adaptab...Genome polyploidy has been revealed to result in evolutionary advantages and novelties,and therefore,polyploid aquatic animals may possess excellent traits of economic interest including rapid growth,extensive adaptability and disease resistance.For this reason,numerous species of natural polyploid fishes,such as common carp,gibel carp,crucian carp,salmon,and sturgeon,were chosen as important target species for aquaculture.Many artificial polyploids have been commercially utilized for aquaculture and most of them were created from natural polyploid fishes of the Cyprinidae and Salmonidae.Thanks to the easy mass production and better economic traits in growth and flesh quality,the synthetized autopolyploids or allopolyploids from natural polyploid species in cyprinid fishes have been extensively applied to aquaculture throughout China.This review outlines polyploidy advantages and innovative opportunities,lists natural polyploid species used in aquaculture,and summarizes artificial polyploids that have been induced or synthetized,and used in aquaculture.Moreover,some main research trends on polyploid utilization and ploidy manipulation of aquaculture animals are also introduced and discussed in the review.展开更多
Orychophragmus violaceus,referred to as‘‘eryuelan’’(February orchid)in China,is an early-flowering ornamental plant.The high oil content and abundance of unsaturated fatty acids in O.violaceus seeds make it a pote...Orychophragmus violaceus,referred to as‘‘eryuelan’’(February orchid)in China,is an early-flowering ornamental plant.The high oil content and abundance of unsaturated fatty acids in O.violaceus seeds make it a potential high-quality oilseed crop.Here,we generated a whole-genome assembly for O.violaceus using Nanopore and Hi-C sequencing technologies.The assembled genome of O.violaceus was~1.3 Gb in size,with 12 pairs of chromosomes.Through investigation of ancestral genome evolution,we determined that the genome of O.violaceus experienced a tetraploidization event from a diploid progenitor with the translocated proto-Calepineae karyotype.Comparisons between the reconstructed subgenomes of O.violaceus identified indicators of subgenome dominance,indicating that subgenomes likely originated via allotetraploidy.O.violaceus was phylogenetically close to the Brassica genus,and tetraploidy in O.violaceus occurred approximately 8.57 million years ago,close in time to the whole-genome triplication of Brassica that likely arose via an intermediate tetraploid lineage.However,the tetraploidization in Orychophragmus was independent of the hexaploidization in Brassica,as evidenced by the results from detailed phylogenetic analyses and comparisons of the break and fusion points of ancestral genomic blocks.Moreover,identification of multi-copy genes regulating the production of high-quality oil highlighted the contributions of both tetraploidization and tandem duplication to functional innovation in O.violaceus.These findings provide novel insights into the polyploidization evolution of plant species and will promote both functional genomic studies and domestication/breeding efforts in O.violaceus.展开更多
"Synthetic"allopolyploids recreated by interspecific hybridization play an important role in providing novel genomic variation for crop improvement.Such synthetic allopolyploids often undergo rapid genomic s..."Synthetic"allopolyploids recreated by interspecific hybridization play an important role in providing novel genomic variation for crop improvement.Such synthetic allopolyploids often undergo rapid genomic structural variation(SV).However,how such SV arises,is inherited and fixed,and how it affects important traits,has rarely been comprehensively and quantitively studied in advanced generation synthetic lines.A better understanding of these processes will aid breeders in knowing how to best utilize synthetic allopolyploids in breeding programs.Here,we analyzed three genetic mapping populations(735 DH lines)derived from crosses between advanced synthetic and conventional Brassica napus(rapeseed)lines,using whole-genome sequencing to determine genome composition.We observed high tolerance of large structural variants,particularly toward the telomeres,and preferential selection for balanced homoeologous exchanges(duplication/deletion events between the A and C genomes resulting in retention of gene/chromosome dosage between homoeologous chromosome pairs),including stable events involving whole chromosomes("pseudoeuploidy").Given the experimental design(all three populations shared a common parent),we were able to observe that parental SV was regularly inherited,showed genetic hitchhiking effects on segregation,and was one of the major factors inducing adjacent novel and larger SV.Surprisingly,novel SV occurred at low frequencies with no significant impacts on observed fertility and yield-related traits in the advanced generation synthetic lines.However,incorporating genome-wide SV in linkage mapping explained significantly more genetic variance for traits.Our results provide a framework for detecting and understanding the occurrence and inheritance of genomic SV in breeding programs,and support the use of synthetic parents as an important source of novel trait variation.展开更多
Plant polyploidy often occurs in conjunction with higher yield and superior quality.Therefore,obtaining polyploid germplasms is a significant part of breeding.The oil-tea Camellia tree is an important native woody pla...Plant polyploidy often occurs in conjunction with higher yield and superior quality.Therefore,obtaining polyploid germplasms is a significant part of breeding.The oil-tea Camellia tree is an important native woody plant that produces high-quality edible oil and includes many species of Camellia with different ploidies.However,whether higher ploidy levels in oil-tea Camellia trees are related to better traits remains unclear.In this study,the ploidy levels of 30 different oil-tea Camellia strains in three different species in the Sect.Paracamellia were determined by flow cytometry and chromosome preparation,and the phenotypic characteristics and fatty acid compositions of the fruits were examined by field observations and laboratory analyses.The correlations between the ploidy level of oil-tea Camellia and the main traits of the fruit were investigated.Our results showed that 10 Camellia lanceoleosa strains were diploid,10 Camellia meiocarpa strains were tetraploid and 10 Camellia oleifera strains were hexaploid.Hexaploid C.oleifera had larger fruit size and weight,more seeds per fruit,greater seed weight per fruit,higher oil content and greater yield per crown width than tetraploid C.meiocarpa and diploid C.lanceoleosa,but their fruit peel thickness and fresh seed rate were significantly lower,and these traits were significantly correlated with ploidy level.In addition,in terms of fatty acid composition,hexaploid C.oleifera had a higher oleic acid content than tetraploid C.meiocarpa and diploid C.lanceoleosa,but their linoleic acid,linolenic acid and arachidonic acid contents were lower.The contents of palmitic acid,stearic acid and total unsaturated fatty acids were not significantly correlated with ploidy level.In conclusion,certain correlations exist between the main characteristics of oil-tea Camellia fruit and the ploidy level,and increasing the ploidy level led to an increase in fruit yield with no effect on oil composition.The discovery of variations in the main characteristics of oil-tea Camellia fruit with different ploidies will facilitate germplasm innovation and lay a foundation for ploidy breeding and mechanistic research on fruit traits.展开更多
文摘The Asiatic hybrid lily cultivar Lilium dazzling(family Liliaceae)is a perennial herbaceous bulbous plant with bright yellow flowers of ornamental values.It also shows resistance to diseases and abiotic stress,making it an ideal parent for breeding studies.This study established a sterile culture system using scales of dazzling lily as explants to induce polyploidy.Adventitious buds growing to 1 cm were treated with different concentrations of colchicine(125,250 and 500μmol·L-1),pendimethalin or trifluralin(100,200 and 300μmol·L-1,respectively)for 12,24 and 36 h.Flow cytometry and chromosome counting were used to identify ploidy,and the phenotype of the polyploids was examined by stomatal observation and leaf index determination.With increasing mutagen concentration and exposure time,the mortality and mutagenic rate increased.The optimal treatment group was:300μmol·L-1 trifluralin for 12 h,which resulted in 15.55%mortality rate and 42.22%induction rate.The polyploid plants showed a significant increase in stomata length,leaf length and leaf width,with a decrease in stomatal density compared with the control plants.This study provided a basis for polyploid breeding.
基金Supported by 2016 College Students’Innovative Entrepreneurial Training Program of Yanbian University(ydbksky2016127)~~
文摘With apical leaves of Lycium ruthenicum Murr as experimental material, the polyploids of L. ruthenicum were induced with colchicine solution, and total four polyploidy plants were identified by chromosome courts. The results showed that tetraploid plants of L. ruthenicum were successfully induced with 300 mg/L of colchicine solution after 7 and 21 d of induction, with 400 mg/L of colchicine solution after 14 days of induction, and with 500 mg/L of colchicine solution after 7 days of induction, respectively.
基金supported by the National Natural Science Foundation of China(No.31700316)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(Group No.118)+2 种基金the Earmarked Fund for China Agriculture Research System(CARS-12)the Fundamental Research Funds for Central Non-Profit Scientific Institution(1610172018009)Graduate School of Chinese Academy of Agricultural Sciences
文摘Sequence-specific nucleases(SSN) that generate double-stranded DNA breaks(DSBs) in genes of interest are the key to site-specific genome editing in plants. Genome editing has developed into one method of reducing undesirable traits in crops by the induction of knockout mutations. Different SSN-mediated genome-editing systems, including LAGLIDADG homing endonucleases or meganucleases, zinc-finger nucleases, transcription activator-like effector nucleases and clustered regularly interspaced short palindromic repeats, are emerging as robust tools for introducing functional mutations in polyploid crops including citrus, wheat, cotton, soybean, rapeseed, potato, grapes, Camelina sativa,dandelion, and tobacco. The approach utilizes knowledge of biological mechanisms for targeted induction of DSBs and their error-prone repair, allowing highly specific changes at designated genome loci. In this review, we briefly describe genome-editing technologies and their application to genetic improvement of polyploid crops.
基金Supported by the National Natural Science Foundation of China(NSFC31160432)the Key Project of Department of Education,Yunnan Province(2011Z108)~~
文摘[Objective] This study aimed to explore the origin and evolution of poly- poids in Parakmeria Hu et Cheng through LEAFY gene clone and sequence analysis. [Method] In this study, LEAFY gene in Parakmeria species and its relative genera was cloned and sequenced using molecular biology methods. With reference to LEAFY gene sequence published by NCBI, the origin pattern of polypoids in Parakmeria was explored and reasons for the distribution layout of different polypoids were analyzed through sequence alignment and phylogenetic analysis. [Result] Different Magnoliaceae species can be distinguished using the LEAFY gene, and there was a length polymorphism found in the 3＋ end of the LEAFY gene, which can be used to divide Magnoliaceae plants of different species or in different genera, thus of high application value. [Conclusion] Most Parakmeria tetraploids are produced by polyploidization of homologous chromosomes, while Parakmeria hexaploids are chiefly produced by both polyploidization of homologous chromosomes and heterologous hybridization.
基金supported by the Tree Breeding Research Project of Zhejiang Province,China(2016C02056-12)。
文摘Most Rhododendron species are ornamental flowering species widely distributed in Asia,North America,and West Europe.Rhododendron fortunei,one of the endemic Rhododendron species in China,has beautiful flowers with bright colors and is being exploited to meet the needs of the flower market.Polyploid plants usually show superiority in growth,disease resistance,and adaption over their diploid relatives.Here,we report the first case of polyploid induction in R.fortunei.In order to induce polyploidy in R.fortunei,germinating seeds were treated with different concentrations of oryzalin for 16 h.By evaluating ploidy level with flow cytometry,a total of 34 polyploid R.fortunei lines,including 27 tetraploid lines and seven octoploid lines,were obtained.A comparison of treatments indicated that 7.5 mg L^-1 oryzalin was the optimal concentration for polyploid induction in seeds of R.fortunei.Compared with diploid plants,tetraploid and octoploid plants exhibited slower growth rates and had thicker and rounder curled leaves with more leaf epidermal hairs.Moreover,larger stomata at lower density were also observed in the leaves of polyploid plants.Chlorophyll contents were also significantly increased in polyploid plants,which leads to a darker green leaf color.Both small and large individuals exhibiting the same characteristics were observed among the obtained tetraploid plants.Overall,our study establishes a feasible method for polyploid induction in R.fortunei,thus providing a basis for breeding new R.fortunei varieties.
文摘Polyploidization is one of the most crucial pathways in introducing speciation and broadening biodiversity, especially in the Plant Kingdom. Although the majority of studies have focused only on allopolyploid or disomic polyploids, polysomic polyploid species have occurred frequently in higher plants. Due to the occurrence of the capabilities of more copies of alleles in a locus which can have additive dosage effects and/or allelic interactions, polysomic polyploids can lead to unique gene regulations to silence or adjust the expression level to create variations in organ size, metabolic products, and abiotic stress tolerance and biotic stress resistance, etc. This review aims to comprehensively summarize the contemporary understanding and findings concerning the molecular mechanisms of gene expression as well as gene regulation in natural typed and resynthesized polysomic polyploid plants. The review investigates the molecular level of phenomena in polysomic polyploid plants such as 1) typically enlarging organ size and stabilizing meiosis, 2) increasing phytochemical content and metabolic products, 3) enhancing the ability to adapt with biotic and abiotic stress, and 4) changing in gene regulation to silence or adjust the expression levels involve in sequence elimination, methylation, gene suppression, subfunctionalization, neo-functionalization, and transposon activation.
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA19050404)National Natural Science Foundation of China(No.31800174).
文摘Lycophytes are an ancient clade of the non-flowering vascular plants with chromosome numbers that vary from tens to hundreds.They are an excellent study system for examining whole-genome duplications(WGDs),or polyploidization,in spore-dispersed vascular plants.However,a lack of genome sequence data limits the reliable detection of very ancient WGDs,small-scale duplications(SSDs),and recent WGDs.Here,we integrated phylogenomic analysis and the distribution of synonymous substitutions per synonymous sites(Ks)of the transcriptomes of 13 species of lycophytes to identify,locate,and date multiple WGDs in the lycophyte family Lycopodiaceae.Additionally,we examined the genus Phlegmariurus for signs of genetic discordance,which can provide valuable insight into the underlying causes of such conflict(e.g.,hybridization,incomplete lineage sorting,or horizontal gene transfer).We found strong evidence that two WGD events occurred along the phylogenetic backbone of Lycopodiaceae,with one occurring in the common ancestor of extant Phlegmariurus(Lycopodiaceae)approximately 22-23 million years ago(Mya)and the other occurring in the common ancestor of Lycopodiaceae around 206-214 Mya.Interestingly,we found significant genetic discordance in the genus Phlegmariurus,indicating that the genus has a complex evolutionary history.This study provides molecular evidence for multiple WGDs in Lycopodiaceae and offers phylogenetic clues to the evolutionary history of Lycopodiaceae.
文摘Cell-cell fusion is a normal biological process playing essential roles in organ formation and tissue differentiation,repair and regeneration.Through cell fusion somatic cells undergo rapid nuclear reprogramming and epigenetic modifications to form hybrid cells with new genetic and phenotypic properties at a rate exceeding that achievable by random mutations.Factors that stimulate cell fusion are inflammation and hypoxia.Fusion of cancer cells with non-neoplastic cells facilitates several malignancy-related cell phenotypes,e.g.,reprogramming of somatic cell into induced pluripotent stem cells and epithelial to mesenchymal transition.There is now considerable in vitro,in vivo and clinical evidence that fusion of cancer cells with motile leucocytes such as macrophages plays a major role in cancer metastasis.Of the many changes in cancer cells after hybridizing with leucocytes,it is notable that hybrids acquire resistance to chemo-and radiation therapy.One phenomenon that has been largely overlooked yet plays a role in these processes is polyploidization.Regardless of the mechanism of polyploid cell formation,it happens in response to genotoxic stresses and enhances a cancer cell’s ability to survive.Here we summarize the recent progress in research of cell fusion and with a focus on an important role for polyploid cells in cancer metastasis.In addition,we discuss the clinical evidence and the importance of cell fusion and polyploidization in solid tumors.
文摘An induced polyploid plant through colchicine treatment offers probably the best scope for improvement in flower size and fruit weight.Thus,in the present study,an attempt was made to induce polyploidy in Cape gooseberry using colchicine with the objective of creating more genetic variability.The colchicine concentrations were used as 0.10%(C1),0.20%(C2)and 0.40%(C3)for the duration 12(H1),24(H2)and 36(H3)hours for each concentration with seedling apex dip method(M1),cotton plug method(M2)and lanolin paste method(M3).The plants treated with 0.10%of colchicine by cotton plug method for 12 h showed the better performance during the years 2017-2018 and 2018-2019 in respect of more delay in the flower bud emergence(54 d and 53 d from the date of transplanting),anthesis(19 d and 20 d from the first appearance of bud to full anthesis of flower)and fruit setting(8.00 d and 9.00 d from the date of anthesis),bigger flower size(2.93 cm2 and 3.00 cm2)than the untreated plants.The lower percentage of pollen viability(40.33%and 40.67%)was noticed in the same treatment in comparison to control(70.33%and 72.33%).The fruit maturity was also extended(59 d and 60 d from the date of fruit set)with bigger sized fruits(length:2.53 cm and 2.57 cm,breadth:2.27 cm and 2.33 cm)as well as more fruit weight(8.70 g and 8.33 g)by the application of colchicine at 0.10%with cotton plug method for 12 h.On the basis of results obtained,the application of colchicine at 0.10%for 12 h duration with cotton plug method was found to be the best and effective treatment for induction of polyploidy as well as more flower size and fruit weight in Cape gooseberry.
文摘Based on a series of polyploid indica-japonica hybrid plant lines obtained from a new breeding strategy of using double predominance of wide cross and polyploidization to breed super flee, two polyploid indica-japonica hybrids, PSR073 and PSR120 were studied in their growth periods to show the powerful heterosis in a larger scale and to study the characteristics of polyploid indica-japonica hybrids more elaborately. The leaf age, tiller growth, flowering habits, and agronomic traits of them were observed to analyze their growth habits and characteristics. The results showed that the.agronomic traits of PSR073 and PSR120, such as the plant height, panicle length, grain length, grain width, and 1000-grain weight, all acquired obvious predominance of polyploidy, and that the seed setting rate was more than 83%. No significant difference was observed between the two tetraploids and common diploids in the leaf age, tiller growth, and flowering habits. It was concluded that the characteristics of the two powerful heterosis polyploid hybrids were different from those of the polyploid rice reported earlier. Wide cross and polyploidization had no negative effects on their growth habits and characteristics; on the contrary these had powerful heterosis. This had provided theoretic and practical evidences for their application to agricultural production.
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 National High-tech R&D Program of China(863 Program)Project of Natural Science Foundation of Hainan Province(20163124)Special Project of Fundamental Research Funds for Central Public Welfare Research Institutes(ITBB2015RC04 & ITBB2015ZY12)
文摘The sugarcane genome polyploidization can reduce the pressure of gene evolution selection,promote the fixation of fine traits,and increase the biomass and economic value of sugarcane.This paper mainly introduced the origin of the sugarcane genome,the chromosome composition,the research progress of polyploidization genetic mechanism,in the hope of providing theoretical reference for sugarcane polyploidization breeding.
文摘Polyploidy is common among agriculturally important crops. Popular genetic methods and their implementations cannot always be applied to polyploid genetic data. We give an overview about available tools and their limitations in terms of levels of ploidy, auto- and allo-ploidy. The main classes of tools are genotype calling, linkage mapping and haplotyping. The usability of the tools is discussed with a focus on their applicability to data sets produced by state of the art technologies. We show that many challenges remain until the toolset for polyploidy provides similar functionalities as those which are already available for diploids. Some tools have been developed over a decade ago and are now outdated. In addition, we discuss necessary steps to overcome this shortage in the future.
基金Supported by The Cooperative Project between the Yanbian University,ChinaNational Institute of Horticultural and Herbal Science of the Rural Development Administration(RDA)of the Republic of Korea
文摘[ Objectives] This study was conducted to provide high-quality polyploid for returning the grain plots to forestry and promote the rapid development of Lonicera edulis Turcz. [ Methods] With superior individuals of wild L. edulis in Changbai Mountains as experimental materials and colchicine as inducer, polyploid induction was performed twice on diploid plants by addition method, and 7 polyploidy plants were identified from 11 regenerated plantlets. [Results] Among the 7 polyploidy plants, four materials were tetraploid, the concentration and treatment time of which were 300 mg/L and 7 and 14 d, respectively; and three materials were octaploid, the concentrations and treatment time of which were 300 and 500 mg/L and 14 d, respectively. [ Conclusions] The results of this study showed that colchicine had a higher polyploid induction rate for L. edulis with lower toxic and side effects, and the polyploidy plants could restore to normal growth state after several times of cubculture. Therefore, colchicine is an polyploid inducer suitable for L. edulis.
基金supported by the National Natural Science Foundation of China(31991212)the National Key Research and Development Program of China(2022YFF1003303)。
文摘Non-B-form DNA differs from the classic B-DNA double helix structure and plays a crucial regulatory role in replication and transcription.However,the role of non-B-form DNA in centromeres,especially in polyploid wheat,remains elusive.Here,we systematically analyzed seven non-B-form DNA motif profiles(A-phased DNA repeat,direct repeat,G-quadruplex,inverted repeat,mirror repeat,short tandem repeat,and Z-DNA)in hexaploid wheat.We found that three of these non-B-form DNA motifs were enriched at centromeric regions,especially at the CENH3-binding sites,suggesting that non-B-form DNA may create a favorable loading environment for the CENH3 nucleosome.To investigate the dynamics of centromeric non-B form DNA during the alloploidization process,we analyzed DNA secondary structure using CENH3 ChIP-seq data from newly formed allotetraploid wheat and its two diploid ancestors.We found that newly formed allotetraploid wheat formed more non-B-form DNA in centromeric regions compared with their parents,suggesting that non-B-form DNA is related to the localization of the centromeric regions in newly formed wheat.Furthermore,non-B-form DNA enriched in the centromeric regions was found to preferentially form on young LTR retrotransposons,explaining CENH3's tendency to bind to younger LTR.Collectively,our study describes the landscape of non-B-form DNA in the wheat genome,and sheds light on its potential role in the evolution of polyploid centromeres.
基金supported by the National Natural Science Foundation of China (32322059 and 32272124)China Postdoctoral Science Foundation (2023M733807)+2 种基金Frontiers Science Center for Molecular Design Breeding (2022TC152)Pinduoduo-China Agricultural University Research Fund (PC2023B01016)the 2115 Talent Development Program of China Agricultural University.
文摘Bread wheat(Triticum aestivum)is an important crop and serves as a significant source of protein and calories for humans,worldwide.Nevertheless,its large and allopolyploid genome poses constraints on genetic improvement.The complex reticulate evolutionary history and the intricacy of genomic resources make the deciphering of the functional genome considerably more challenging.Recently,we have developed a comprehensive list of versatile computational tools with the integration of statistical models for dissecting the polyploid wheat genome.Here,we summarize the methodological innovations and applications of these tools and databases.A series of step-by-step examples illustrates how these tools can be utilized for dissecting wheat germplasm resources and unveiling functional genes associated with important agronomic traits.Furthermore,we outline future perspectives on new advanced tools and databases,taking into consideration the unique features of bread wheat,to accelerate genomic-assisted wheat breeding.
基金This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA08030202 and XDA08030201)the earmarked fund for Modern Agro-industry Technology Research System(NYCYTX-49)the Autonomous Project of the State Key Laboratory of Freshwater Ecology and Biotechnology(2016FBZ01).
文摘Genome polyploidy has been revealed to result in evolutionary advantages and novelties,and therefore,polyploid aquatic animals may possess excellent traits of economic interest including rapid growth,extensive adaptability and disease resistance.For this reason,numerous species of natural polyploid fishes,such as common carp,gibel carp,crucian carp,salmon,and sturgeon,were chosen as important target species for aquaculture.Many artificial polyploids have been commercially utilized for aquaculture and most of them were created from natural polyploid fishes of the Cyprinidae and Salmonidae.Thanks to the easy mass production and better economic traits in growth and flesh quality,the synthetized autopolyploids or allopolyploids from natural polyploid species in cyprinid fishes have been extensively applied to aquaculture throughout China.This review outlines polyploidy advantages and innovative opportunities,lists natural polyploid species used in aquaculture,and summarizes artificial polyploids that have been induced or synthetized,and used in aquaculture.Moreover,some main research trends on polyploid utilization and ploidy manipulation of aquaculture animals are also introduced and discussed in the review.
基金supported by the National Natural Science Foundation of China(NSFC grants 31722048 and 31972411)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences,and the Key Laboratory of Biology and Genetic Improvement of Horticultural Crops,Ministry of Agriculture and Rural Affairs,P.R.Chinasupported by the China Agricultural Research System—Green Manure(CARS-22).
文摘Orychophragmus violaceus,referred to as‘‘eryuelan’’(February orchid)in China,is an early-flowering ornamental plant.The high oil content and abundance of unsaturated fatty acids in O.violaceus seeds make it a potential high-quality oilseed crop.Here,we generated a whole-genome assembly for O.violaceus using Nanopore and Hi-C sequencing technologies.The assembled genome of O.violaceus was~1.3 Gb in size,with 12 pairs of chromosomes.Through investigation of ancestral genome evolution,we determined that the genome of O.violaceus experienced a tetraploidization event from a diploid progenitor with the translocated proto-Calepineae karyotype.Comparisons between the reconstructed subgenomes of O.violaceus identified indicators of subgenome dominance,indicating that subgenomes likely originated via allotetraploidy.O.violaceus was phylogenetically close to the Brassica genus,and tetraploidy in O.violaceus occurred approximately 8.57 million years ago,close in time to the whole-genome triplication of Brassica that likely arose via an intermediate tetraploid lineage.However,the tetraploidization in Orychophragmus was independent of the hexaploidization in Brassica,as evidenced by the results from detailed phylogenetic analyses and comparisons of the break and fusion points of ancestral genomic blocks.Moreover,identification of multi-copy genes regulating the production of high-quality oil highlighted the contributions of both tetraploidization and tandem duplication to functional innovation in O.violaceus.These findings provide novel insights into the polyploidization evolution of plant species and will promote both functional genomic studies and domestication/breeding efforts in O.violaceus.
基金supported by the National Natural Science Foundation of China(NSFC,31970564,32000397,32171982)the Fundamental Research Funds for the Central Universities(2662023PY004)。
文摘"Synthetic"allopolyploids recreated by interspecific hybridization play an important role in providing novel genomic variation for crop improvement.Such synthetic allopolyploids often undergo rapid genomic structural variation(SV).However,how such SV arises,is inherited and fixed,and how it affects important traits,has rarely been comprehensively and quantitively studied in advanced generation synthetic lines.A better understanding of these processes will aid breeders in knowing how to best utilize synthetic allopolyploids in breeding programs.Here,we analyzed three genetic mapping populations(735 DH lines)derived from crosses between advanced synthetic and conventional Brassica napus(rapeseed)lines,using whole-genome sequencing to determine genome composition.We observed high tolerance of large structural variants,particularly toward the telomeres,and preferential selection for balanced homoeologous exchanges(duplication/deletion events between the A and C genomes resulting in retention of gene/chromosome dosage between homoeologous chromosome pairs),including stable events involving whole chromosomes("pseudoeuploidy").Given the experimental design(all three populations shared a common parent),we were able to observe that parental SV was regularly inherited,showed genetic hitchhiking effects on segregation,and was one of the major factors inducing adjacent novel and larger SV.Surprisingly,novel SV occurred at low frequencies with no significant impacts on observed fertility and yield-related traits in the advanced generation synthetic lines.However,incorporating genome-wide SV in linkage mapping explained significantly more genetic variance for traits.Our results provide a framework for detecting and understanding the occurrence and inheritance of genomic SV in breeding programs,and support the use of synthetic parents as an important source of novel trait variation.
基金supported by the Special Funds for Construction of Innovative Provinces in Hunan Province,China(2021NK1007)the Hunan Provincial Innovation Foundation for Postgraduate,China(CX20230779)the Scientific Innovation Fund for Post-graduates of Central South University of Forestry and Technology,China(2023CX01009)。
文摘Plant polyploidy often occurs in conjunction with higher yield and superior quality.Therefore,obtaining polyploid germplasms is a significant part of breeding.The oil-tea Camellia tree is an important native woody plant that produces high-quality edible oil and includes many species of Camellia with different ploidies.However,whether higher ploidy levels in oil-tea Camellia trees are related to better traits remains unclear.In this study,the ploidy levels of 30 different oil-tea Camellia strains in three different species in the Sect.Paracamellia were determined by flow cytometry and chromosome preparation,and the phenotypic characteristics and fatty acid compositions of the fruits were examined by field observations and laboratory analyses.The correlations between the ploidy level of oil-tea Camellia and the main traits of the fruit were investigated.Our results showed that 10 Camellia lanceoleosa strains were diploid,10 Camellia meiocarpa strains were tetraploid and 10 Camellia oleifera strains were hexaploid.Hexaploid C.oleifera had larger fruit size and weight,more seeds per fruit,greater seed weight per fruit,higher oil content and greater yield per crown width than tetraploid C.meiocarpa and diploid C.lanceoleosa,but their fruit peel thickness and fresh seed rate were significantly lower,and these traits were significantly correlated with ploidy level.In addition,in terms of fatty acid composition,hexaploid C.oleifera had a higher oleic acid content than tetraploid C.meiocarpa and diploid C.lanceoleosa,but their linoleic acid,linolenic acid and arachidonic acid contents were lower.The contents of palmitic acid,stearic acid and total unsaturated fatty acids were not significantly correlated with ploidy level.In conclusion,certain correlations exist between the main characteristics of oil-tea Camellia fruit and the ploidy level,and increasing the ploidy level led to an increase in fruit yield with no effect on oil composition.The discovery of variations in the main characteristics of oil-tea Camellia fruit with different ploidies will facilitate germplasm innovation and lay a foundation for ploidy breeding and mechanistic research on fruit traits.
