Aegilops speltoides,the closest ancestor of the wheat B subgenome,has been well studied genomically.However,the epigenetic landscape of Ae.speltoides and the effects of epigenetics on its growth and development remain...Aegilops speltoides,the closest ancestor of the wheat B subgenome,has been well studied genomically.However,the epigenetic landscape of Ae.speltoides and the effects of epigenetics on its growth and development remain poorly understood.Here,we present a comprehensive multi-omics atlas of leaves and roots in Ae.speltoides,encompassing transcriptome,DNA methylation,histone modifications,and small RNA profiling.Divergent DNA methylation levels were detected between leaves and roots,and were associated with differences in accumulated 24-nt siRNAs.DNA methylation changes in promoters and gene bodies showed strong connections with altered expression between leaves and roots.Transcriptional regulatory networks(TRN)reconstructed between leaves and roots were driven by tissue-specific TF families.DNA methylation and histone modification act together as switches that shape root and leaf morphogenesis by modulating the binding of tissue-specific TFs to their target genes.The TRNs in leaves and roots reshaped during wheat polyploidization were associated with alterations in epigenetic modi-fications.Collectively,these results not only shed light on the critical contribution of epigenetic regulation in the morphogenesis of leaves and roots in Ae.speltoides but also provide new insights for future investigations into the complex interplay of genetic and epigenetic factors in the developmental biology of common wheat.展开更多
Pentaploid hybrids produced from crosses between hexaploid and tetraploid wheats combine the genetic variation of both parents.Crossing a synthetic hexaploid wheat LM/AT23 with its AB-genome donor,the durum wheat LM,a...Pentaploid hybrids produced from crosses between hexaploid and tetraploid wheats combine the genetic variation of both parents.Crossing a synthetic hexaploid wheat LM/AT23 with its AB-genome donor,the durum wheat LM,and selfing the pentaploid hybrids to the F7 generation yielded mostly euploid tetraploids and a few hexaploids.Two special derivatives of tetraploid were isolated,including a 4D(4B)substitution line with large panicles and high resistance to stripe rust and a 2DS.2AL translocation line with non-waxy epidermis.The discovery of small D-genome introgressions in the A and B genomes suggested that pentaploidization can be used to induce homoeologous recombination.The introgression of D genome from Aegilops tauschii to the AB genomes might promote the development of super tetraploid wheat with hexaploid biological characteristics(especially stress resistance)and quality functions and the functional study of the introduced chromosomes or fragments.展开更多
Aegilops variabilis(S^(v)S^(v)U^(v)U^(v))is a source of resistance to wheat stripe rust.The phKL locus in Chinese common wheat landrace Kaixian-Luohanmai(KL)can induce homoeologous wheat-alien chromosome pairing and r...Aegilops variabilis(S^(v)S^(v)U^(v)U^(v))is a source of resistance to wheat stripe rust.The phKL locus in Chinese common wheat landrace Kaixian-Luohanmai(KL)can induce homoeologous wheat-alien chromosome pairing and recombination.In this study,we confirmed that the whole 2S^(v)chromosome introgressed into wheat from Ae.variabilis accession AS116 conferred all-stage stripe rust resistance.The underlying gene(s),named YrAev,was mapped to the long arm 2S^(v)L using an F_(2)population.Two 2S^(v)-2B recombinants,derived from a cross of the 2S^(v)(2B)chromosome substitution line and KL,were confirmed to harbor the resistance locus.The physical region containing YrAev,determined from RNA-seq data,was 844.6-852.1 Mb on the chromosome arm 2S^(l)of the Ae.longissima(S^(v)genome donor species of Ae.variabilis)accession TL05 assembly v1.0.Differential gene expression analysis of post-inoculation with the Pst race has indicated two disease-resistance-related genes(annotated as mixed lineage kinase domain-like protein and nucleotide-binding leucine-rich repeat like protein,respectively)as promising candidates for YrAev.This study demonstrates the utility of the phKL gene system in alien gene localization and transfer.The resistant translocation line harboring YrAev can be exploited by wheat breeders as a novel source of resistance to stripe rust.展开更多
The constant evolution of pathogens poses a threat to wheat resistance against diseases,endangering food security.Developing resistant wheat varieties is the most practical approach for circumventing this problem.As a...The constant evolution of pathogens poses a threat to wheat resistance against diseases,endangering food security.Developing resistant wheat varieties is the most practical approach for circumventing this problem.As a close relative of wheat,Aegilops geniculata,particularly accession SY159,has evolved numerous beneficial traits that could be applied to improve wheat.In this study,we established the karyotype of SY159 by fluorescence in situ hybridization(FISH)using the oligonucleotide probes Oligo-pTa535 and Oligo-pSc119.2 and a complete set of wheat–Ae.geniculata accession TA2899 addition lines as a reference.Using specific-locus amplified fragment sequencing(SLAF-seq)technology,400 specific markers were established for detecting the SY159 chromosomes with efficiencies reaching 81.5%.The SY159-specific markers were used to classify the different homologous groups of SY159 against the wheat-Ae.geniculata addition lines.We used these specific markers on the 7Mg chromosome after classification,and successfully confirmed their suitability for studying the different chromosomes of SY159.This study provides a foundation for accelerating the application of SY159 in genetic breeding programs designed to improve wheat.展开更多
The high-molecular-weight (HMW) glutenin subunits and their coding genes from Aegilops umbellulata Zhuk. (UU, 2n = 2x = 14) were characterized using SDS-PAGE analysis and molecular approaches. SDS-PAGE analysis showed...The high-molecular-weight (HMW) glutenin subunits and their coding genes from Aegilops umbellulata Zhuk. (UU, 2n = 2x = 14) were characterized using SDS-PAGE analysis and molecular approaches. SDS-PAGE analysis showed that the 1Ux subunits from four different accessions possessed electrophoretic mobilities close to, or slower than, that displayed by the 1Dx2.2 subunit of common wheat. The electrophoretic mobilities of the 1Uy subunits were generally similar to those shown by the 1Dy subunits of common wheat. The complete open reading frames of the 1Ux and 1Uy genes were amplified by PCR and subsequently cloned and sequenced. Amino acid sequence comparisons suggested that the primary structure of the 1Ux and 1Uy subunits were identical to that of published HMW glutenin subunits from related species, Phylogenetic analysis indicated that the HMW glutenin subunits of Ae. umbellulata were most closely related to those encoded by the D genome of Triticeae.展开更多
Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD...Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD, 2n=14). An essential prerequisite for this evolutionary step is that the natural hybrids between tetraploid wheat and diploid Aegilops tauschii can produce relatively many filled seeds which germinated well. In this study, without special techniques, e.g. immature embryo culture, out of 22 Ae. tauschii accessions, the genotype AS60 produced relatively many filled seeds which germinated well. The seed germination percentages in the crosses of Ae. tauschii ×tetraploid wheat, tetraploid wheat× Ae. tauschii and Ae. tauschii ×common wheat were, respectively, 50.0%, 57.1% and 45.5%. It seems that Ae. tauschii accession AS60 has a unique genotype which facilitate hybrid seed development and viability, and which meets with the prerequisite for wheat evolutionary. Furthermore, the significance of this finding for common wheat improvement and evolution was discussed.展开更多
Introducing the 1S^1 chromosome of Aegilops longissima into wheat genome can significantly improve wheat grain quality and contents of iron and zinc. Therefore, the development of molecular markers specific to 1S^1 ch...Introducing the 1S^1 chromosome of Aegilops longissima into wheat genome can significantly improve wheat grain quality and contents of iron and zinc. Therefore, the development of molecular markers specific to 1S^1 chromosome of A. longissima is of important significance for breeding high-quality wheat with high contents of iron and zinc in grains. In this study, nine molecular markers specific to 1S^1 chromosome of A. longissima were developed, including two 1S^1S specific markers,six 1S^1L specific markers and one 1S^1 specific marker which was located on both short and long arms. The practicability of these molecular markers were verified using hybrid population as materials. The results showed that hybrid population could be effectively screened and identified, which indicated that the developed 1S^1 chromosome-specific molecular markers could be used for screening and identification of hybrid population and could be used in marker-assisted breeding of high-quality wheat with high contents of Fe and Zn in grains.展开更多
[Objective] The aim of this study is to investigate the chromosome pairing of F1 from Aegilops Ventricosa-Aegilops Cylindrica amphiploid × common wheat.[Method] Microsporogenesis and pollen development of Yannong...[Objective] The aim of this study is to investigate the chromosome pairing of F1 from Aegilops Ventricosa-Aegilops Cylindrica amphiploid × common wheat.[Method] Microsporogenesis and pollen development of Yannong15,SDAU18 and their hybrid F1 were observed cytologically by squash method.[Result] The results showed that microsporogenesis and pollen development of two parents including Yannong15 and SDAU18 were basically normal,and their seed setting was also basically normal.However,the microsporogenesis of their hybrid F1 was chaotic.Univalent and bivalent with high frequency of 10.11 and 18.29 per cell respectively occurred in meiotic MI（metphaseI） of PMC（pollen mother cell）.Nevertheless,only quite low frequency of multivalents occurred in meiotic PMC MI.The laggards at meiotic AI（anaphaseI） were 5 per cell on average.The number of micronucleoli in tetrad was 4.43 per cell averagely.The aborted pollen with different frequency occurred at every stage of hybrid F1 pollen development but mainly after single nucleus pollen stage.The fertile pollen rate of hybrid F1 was only 31% at 3-nucleated stage.[Conclusion] This study provides cytogenetics basis for further analysis and utilization of the amphiploid.展开更多
Fertile F1 hybrids were obtained between durum wheat （Triticum durum Desf.） Langdon （LDN） and its 10 disomic substitution （LDN DS） lines with Aegilops tauschii accession AS60 without embryo rescue. Selfed seedse...Fertile F1 hybrids were obtained between durum wheat （Triticum durum Desf.） Langdon （LDN） and its 10 disomic substitution （LDN DS） lines with Aegilops tauschii accession AS60 without embryo rescue. Selfed seedset rates for hybrids of LDN with AS60 were 36.87% and 49.45% in 2005 and 2006, respectively. Similar or higher selfed seedset rates were observed in the hybrids of 1D （1A）, 1D （1B）, 3D （3A）, 4D （4B）, 7D （7A）, and 2D （2B） with AS60, while lower in hybrids of 3D （3B） ＋ 3BL, 5D （5A） ＋ 5AL, 5D （5B） ＋ 5B and 6D （6B） ＋ 6BS with AS60 compared with the hybrids of LDN with AS60. Observation of male gametogenesis showed that meiotic restitution, both first-division restitution （FDR） and single-division meiosis （SDM） resulted in the formation of functional unreduced gametes, which in turn produced seeds. Both euhaploid and aneuhaploid gametes were produced in F1 hybrids. This suggested a strategy to simultaneously transfer and locate major genes from the ancestral species T. turgidum or Ae. tauschii. Moreover, there was no significant difference in the aneuhaploid rates between the F1 hybrids of LDN and LDN DS lines with AS60, suggesting that meiotic pairing between the two D chromosomes in the hybrids of LDN DS lines with AS60 did not promote the formation of aneuhaploid gametes.展开更多
Aegilops umbellulata(UU)is a wheat wild relative that has potential use in the genetic improvement of wheat.In this study,46 Ae.umbellulata accessions were investigated for stripe rust resistance,heading date(HD),and ...Aegilops umbellulata(UU)is a wheat wild relative that has potential use in the genetic improvement of wheat.In this study,46 Ae.umbellulata accessions were investigated for stripe rust resistance,heading date(HD),and the contents of iron(Fe),zinc(Zn),and seed gluten proteins.Forty-two of the accessions were classified as resistant to stripe rust,while the other four accessions were classified as susceptible to stripe rust in four environments.The average HD of Ae.umbellulata was significantly longer than that of three common wheat cultivars(180.9 d vs.137.0 d),with the exception of PI226500(138.9 d).The Ae.umbellulata accessions also showed high variability in Fe(69.74-348.09 mg kg^(-1))and Zn(49.83-101.65 mg kg^(-1))contents.Three accessions(viz.,PI542362,PI542363,and PI554399)showed relatively higher Fe(230.96-348.09 mg kg^(-1))and Zn(92.46-101.65 mg kg^(-1))contents than the others.The Fe content of Ae.umbellulata was similar to those of Ae.comosa and Ae.markgrafii but higher than those of Ae.tauschii and common wheat.Aegilops umbellulata showed a higher Zn content than Ae.tauschii,Ae.comosa,and common wheat,but a lower content than Ae.markgrafii.Furthermore,Ae.umbellulata had the highest proportion of γ-gliadin among all the species investigated(Ae.umbellulata vs.other species=mean 72.11%vs.49.37%;range:55.33-86.99%vs.29.60-67.91%).These results demonstrated that Ae.umbellulata exhibits great diversity in the investigated traits,so it can provide a potential gene pool for the genetic improvement of these traits in wheat.展开更多
Aegilops tauschii Ais a wild relative of common wheat(Triticum aestivum) and acts as an important resource of elite genes including genes for resistance to biotic and abiotic stresses. To improve the cadmium(Cd) toler...Aegilops tauschii Ais a wild relative of common wheat(Triticum aestivum) and acts as an important resource of elite genes including genes for resistance to biotic and abiotic stresses. To improve the cadmium(Cd) tolerance of wheat varieties using A. tauschii resources, we investigated the genetic variation of biomass-based Cd tolerance in 235 A. tauschii accessions treated with 0(control) and100 μmol L-1CdC l2(as Cd stress). Simultaneously, we performed a genomewide association study(GWAS) using a single-nucleotide polymorphism chip containing 7185 markers. Six markers were found to be significantly associated with Cd tolerance by a general linear model and a mixed linear model. These markers were close to several candidate/flanking genes associated with Cd tolerance according to results in public databases, including pdil5-1, Acc-1, DME-5A,TaA P2-D, TaA P2-B, Vrn-B1, and FtsH-like protein gene. The A. tauschii accessions were classified as high, moderate, and low Cd-tolerant according to a secondary index, the synthetic index(SI), in proportions of 9%, 57%, and 34%, respectively. By the average SI, accessions from Afghanistan,Turkey, Azerbaijan, and Iran showed relatively high Cd tolerance.展开更多
An artificial amphiploid RSP (2n = 42, AABBDD) between tetraploid landrace Ailanmai (Triticum turgidum L., 2n= 28, AABB) and Aegllops tauschii (DD, 2n = 14) expressed high tolerance to preharvest sprouting which deriv...An artificial amphiploid RSP (2n = 42, AABBDD) between tetraploid landrace Ailanmai (Triticum turgidum L., 2n= 28, AABB) and Aegllops tauschii (DD, 2n = 14) expressed high tolerance to preharvest sprouting which derived from Ae. tauschii. Tolerance to preharvest sprouting of RSP was examined by four ways in six varying periods after anthesis. The germination percentages of preharvest intact spikes were only 6.06% in its high peak period of germination. Its tolerance was mainly decided by the seed dormancy. It was showed that the tolerance to sprouting in ' RSP' derived from Ae. tauschii was inherited as a recessive trait which was controlled by one gene, located on chromosome 2D.展开更多
Aegilops tauschii,the wild progenitor of wheat D-genome and a valuable germplasm for wheat improvement,has a wide natural distribution from eastern Turkey to China.However,the phylogenetic relationship and dispersion ...Aegilops tauschii,the wild progenitor of wheat D-genome and a valuable germplasm for wheat improvement,has a wide natural distribution from eastern Turkey to China.However,the phylogenetic relationship and dispersion history of Ae.tauschii in China has not been scientifically clarified.In this study,we genotyped 208 accessions(with 104 in China)using dd RAD sequencing and 55K SNP array,and classified the population into six sublineages.Three possible spreading routes or events were identified,resulting in specific distribution patterns,with four sublineages found in Xinjiang,one in Qinghai,two in Shaanxi and one in Henan.We also established the correlation of SNP-based,karyotypebased and spike-morphology-based techniques to demonstrate the internal classification of Ae.tauschii,and developed consensus dataset with 1245 putative accessions by merging data previously published.Our analysis suggested that eight inter-lineage accessions could be assigned to the putative Lineage 3and these accessions would help to conserve the genetic diversity of the species.By developing the consensus phylogenetic relationships of Ae.tauschii,our work validated the hypothesis on the dispersal history of Ae.tauschii in China,and contributed to the efficient and comprehensive germplasm-mining of the species.展开更多
Seven important grain traits, including grain length（GL）, grain width（GW）, grain perimeter（GP）, grain area（GA）, grain length/width ratio（GLW）, roundness（GR）, and thousand-grain weight（TGW）, were analyzed...Seven important grain traits, including grain length（GL）, grain width（GW）, grain perimeter（GP）, grain area（GA）, grain length/width ratio（GLW）, roundness（GR）, and thousand-grain weight（TGW）, were analyzed using a set of 139 simple sequence repeat（SSR） markers in 130 hexaploid wheat varieties and 193 Aegilops tauschii accessions worldwide. In total, 1 612 alleles in Ae. tauschii and 1 360 alleles in hexaploid wheat（Triticum aestivum L.） were detected throughout the D genome. 197 marker-trait associations in Ae. tauschii were identified with 58 different SSR loci in 3 environments, and the average phenotypic variation value（R2） ranged from 0.68 to 15.12%. In contrast, 208 marker-trait associations were identified in wheat with 66 different SSR markers in 4 environments and the average phenotypic R2 ranged from 0.90 to 19.92%. Further analysis indicated that there are 6 common SSR loci present in both Ae. tauschii and hexaploid wheat, which are significantly associated with the 5 investigated grain traits（i.e., GA, GP, GR, GL, and TGW） and in total, 16 alleles derived from the 6 aforementioned SSR loci were shared by Ae. tauschii and hexaploid wheat. These preliminary data suggest the existence of common alleles may explain the evolutionary process and the selection between Ae. tauschii and hexaploid wheat. Furthermore, the genetic differentiation of grain shape and thousand-grain weight were observed in the evolutionary developmental process from Ae. tauschii to hexaploid wheat.展开更多
Bread wheat （Triticum aestivum, AABBDD） is an allohexaploid species derived from two rounds of interspecific hybridizations. A high-quality genome sequence assembly of diploid Aegilops tauschii, the donor of the whe...Bread wheat （Triticum aestivum, AABBDD） is an allohexaploid species derived from two rounds of interspecific hybridizations. A high-quality genome sequence assembly of diploid Aegilops tauschii, the donor of the wheat D genome, will provide a useful platform to study polyploid wheat evolution. A combined approach of BAC pooling and next-generation sequencing technology was employed to sequence the minimum tiling path （MTP） of 3176 BAC clones from the short arm ofAe. tauschii chromosome 3 （At3DS）. The final assembly of 135 super-scaffolds with an N50 of 4.2 Mb was used to build a 247-Mb pseudomolecule with a total of 2222 predicted protein-coding genes. Compared with the orthologous regions of rice, Brachypodium, and sorghum, At3DS contains 38.67% more genes. In comparison to At3DS, the short arm sequence of wheat chromosome 3B （Ta3BS） is 95-Mb large in size, which is primarily due to the expansion of the non-centromeric region, suggesting that transposable element （TE） bursts in Ta3B likely occurred there. Also, the size increase is accompanied by a proportional increase in gene number in Ta3BS. We found that in the sequence of short arm of wheat chromosome 3D （Ta3DS）, there was only less than 0.27% gene loss compared to At3DS. Our study reveals divergent evolution of grass genomes and provides new insights into sequence changes in the polyploid wheat genome.展开更多
To break the narrow diversity bottleneck of the wheat D genome, a set of Aegilops tauschii-wheat introgression(A-WI) lines was developed by crossing Ae. tauschii accession T015 with common wheat elite cultivar Zhoumai...To break the narrow diversity bottleneck of the wheat D genome, a set of Aegilops tauschii-wheat introgression(A-WI) lines was developed by crossing Ae. tauschii accession T015 with common wheat elite cultivar Zhoumai 18(Zhou18). A high-density genetic map was constructed based on Single Nucleotide Polymorphism(SNP) markers and 15 yield-related traits were evaluated in 11 environments for detecting quantitative trait loci(QTL). A total of 27 environmentally stable QTL were identified in at least five environments, 20 of which were derived from Ae. tauschii T015, explaining up to 24.27% of the phenotypic variations. The major QTL for kernel length(KL), QKl-2D.5, was delimited to a physical interval of approximately 2.6 Mb harboring 52 candidate genes. Three Kompetitive Allele Specific PCR(KASP)markers were successfully developed based on nonsynonymous nucleotide mutations of candidate gene AetT093_2Dv1G100900.1 and showed that A-WI lines with the T015 haplotype had significantly longer KL than the Zhou18 haplotype across all 11 environments. Four primary valuable A-WIs with good trait performance and carrying yield-related QTL were selected for breeding improvement. The results will facilitate the efficient transfer of beneficial genes from Ae. tauschii into wheat cultivars to improve wheat yield and other traits.展开更多
Exploring novel high molecular weight glutenin subunits(HMW-GSs)from wild related species is a strategy to improve wheat processing quality.The objective of the present investigation was to identify the chromosomes of...Exploring novel high molecular weight glutenin subunits(HMW-GSs)from wild related species is a strategy to improve wheat processing quality.The objective of the present investigation was to identify the chromosomes of the wheatalien introgression line N124,derived from the hybridization between Triticum aestivum with Aegilops kotschyi,and characterize the effects on quality-related traits.Fluorescence in situ hybridization karyotypes showed that N124 is a disomic 1U^(k)(1A)substitution line.Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE)and reversedphase high-performance liquid chromatography verified N124 expressed two HMW-GSs of the Ae.kotschyi parent.PacBio RNA sequencing and phylogenetic analysis confirmed that the two HMW-GSs were U^(k)x and U^(k)y.Compared to the wheat parent,the substitution line had no obvious agronomic defects except fewer grains per spike but improved several major quality parameters.It can be served as a donor or bridge material for wheat quality improvement.展开更多
Wheat bread-making quality can be improved by use of high-molecular-weight glutenin subunits(HMW-GSs)from wild relatives.Aegilops longissima is a close relative of wheat that contains a number of HMW-GS-encoding genes...Wheat bread-making quality can be improved by use of high-molecular-weight glutenin subunits(HMW-GSs)from wild relatives.Aegilops longissima is a close relative of wheat that contains a number of HMW-GS-encoding genes including 1S^(l)x2.3^(*).In this study,transgenic wheat lines overexpressing 1S^(l)x2.3^(*)were obtained by Agrobacterium-mediated transformation and used to investigate the genetic contribution of 1S^(l)x2.3^(*)to wheat flour-processing quality.The 1S^(l)x2.3^(*)transgene was stably inherited and expressed over generations.Expression of 1S^(l)x2.3^(*)increased the relative expression of 1Dx2 and 1Dy12 and reduced that of 1By18 during grain development.In general,integration of 1S^(l)x2.3^(*)stimulated the accumulation of endogenous HMW-GSs and low-molecular-weight glutenin subunits in wheat kernels,greatly increasing the glutenin:gliadin ratio and resulting in faster formation of protein bodies in the endosperm during grain development.A wheat material with improved flour-making quality was developed in which 1S^(l)x2.3^(*)improved wheat bread-making quality.展开更多
基金supported by the National Key Research and Development Program of China(2023YFD1200403).
文摘Aegilops speltoides,the closest ancestor of the wheat B subgenome,has been well studied genomically.However,the epigenetic landscape of Ae.speltoides and the effects of epigenetics on its growth and development remain poorly understood.Here,we present a comprehensive multi-omics atlas of leaves and roots in Ae.speltoides,encompassing transcriptome,DNA methylation,histone modifications,and small RNA profiling.Divergent DNA methylation levels were detected between leaves and roots,and were associated with differences in accumulated 24-nt siRNAs.DNA methylation changes in promoters and gene bodies showed strong connections with altered expression between leaves and roots.Transcriptional regulatory networks(TRN)reconstructed between leaves and roots were driven by tissue-specific TF families.DNA methylation and histone modification act together as switches that shape root and leaf morphogenesis by modulating the binding of tissue-specific TFs to their target genes.The TRNs in leaves and roots reshaped during wheat polyploidization were associated with alterations in epigenetic modi-fications.Collectively,these results not only shed light on the critical contribution of epigenetic regulation in the morphogenesis of leaves and roots in Ae.speltoides but also provide new insights for future investigations into the complex interplay of genetic and epigenetic factors in the developmental biology of common wheat.
基金funded by the Natural Science Foundation of Sichuan Province for Young Scholars(2024NSFSC1218)the HighLevel Talent Introduction Project of Sichuan Academy of Agricultural Sciences(NKYRCZX2024022)+1 种基金the Accurate Identification Project of Crop Germplasm from Sichuan Provincial Finance Department(1+3 ZYGG001)the Strategic Scientist Studio of Sichuan Academy of Agricultural Sciences.
文摘Pentaploid hybrids produced from crosses between hexaploid and tetraploid wheats combine the genetic variation of both parents.Crossing a synthetic hexaploid wheat LM/AT23 with its AB-genome donor,the durum wheat LM,and selfing the pentaploid hybrids to the F7 generation yielded mostly euploid tetraploids and a few hexaploids.Two special derivatives of tetraploid were isolated,including a 4D(4B)substitution line with large panicles and high resistance to stripe rust and a 2DS.2AL translocation line with non-waxy epidermis.The discovery of small D-genome introgressions in the A and B genomes suggested that pentaploidization can be used to induce homoeologous recombination.The introgression of D genome from Aegilops tauschii to the AB genomes might promote the development of super tetraploid wheat with hexaploid biological characteristics(especially stress resistance)and quality functions and the functional study of the introduced chromosomes or fragments.
基金supported by the National Natural Science Foundation of China(32172020,31971884)the National Key Research and Development Program of China(2024YFD1201202,2024YFD1200402)+4 种基金the Sichuan Science and Technology Program(2022ZDZX0014,2023YFN0085)the Qinghai Provincial Key Laboratory of Crop Molecular Breeding(2023-1-1)the State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China(SKLKF202409)the Alliance of National and International Science Organizations for the Belt and Road Regions(ANSO-CR-KP-202205)the International Partnership Program of Chinese Academy of Sciences(077GJHZ2023028GC)。
文摘Aegilops variabilis(S^(v)S^(v)U^(v)U^(v))is a source of resistance to wheat stripe rust.The phKL locus in Chinese common wheat landrace Kaixian-Luohanmai(KL)can induce homoeologous wheat-alien chromosome pairing and recombination.In this study,we confirmed that the whole 2S^(v)chromosome introgressed into wheat from Ae.variabilis accession AS116 conferred all-stage stripe rust resistance.The underlying gene(s),named YrAev,was mapped to the long arm 2S^(v)L using an F_(2)population.Two 2S^(v)-2B recombinants,derived from a cross of the 2S^(v)(2B)chromosome substitution line and KL,were confirmed to harbor the resistance locus.The physical region containing YrAev,determined from RNA-seq data,was 844.6-852.1 Mb on the chromosome arm 2S^(l)of the Ae.longissima(S^(v)genome donor species of Ae.variabilis)accession TL05 assembly v1.0.Differential gene expression analysis of post-inoculation with the Pst race has indicated two disease-resistance-related genes(annotated as mixed lineage kinase domain-like protein and nucleotide-binding leucine-rich repeat like protein,respectively)as promising candidates for YrAev.This study demonstrates the utility of the phKL gene system in alien gene localization and transfer.The resistant translocation line harboring YrAev can be exploited by wheat breeders as a novel source of resistance to stripe rust.
基金funded by the National Natural Science Foundation of China(31471481)the Project of Science and Technology of Shaanxi Province of China(2021NY-081 and 2023YBNY-033)。
文摘The constant evolution of pathogens poses a threat to wheat resistance against diseases,endangering food security.Developing resistant wheat varieties is the most practical approach for circumventing this problem.As a close relative of wheat,Aegilops geniculata,particularly accession SY159,has evolved numerous beneficial traits that could be applied to improve wheat.In this study,we established the karyotype of SY159 by fluorescence in situ hybridization(FISH)using the oligonucleotide probes Oligo-pTa535 and Oligo-pSc119.2 and a complete set of wheat–Ae.geniculata accession TA2899 addition lines as a reference.Using specific-locus amplified fragment sequencing(SLAF-seq)technology,400 specific markers were established for detecting the SY159 chromosomes with efficiencies reaching 81.5%.The SY159-specific markers were used to classify the different homologous groups of SY159 against the wheat-Ae.geniculata addition lines.We used these specific markers on the 7Mg chromosome after classification,and successfully confirmed their suitability for studying the different chromosomes of SY159.This study provides a foundation for accelerating the application of SY159 in genetic breeding programs designed to improve wheat.
文摘The high-molecular-weight (HMW) glutenin subunits and their coding genes from Aegilops umbellulata Zhuk. (UU, 2n = 2x = 14) were characterized using SDS-PAGE analysis and molecular approaches. SDS-PAGE analysis showed that the 1Ux subunits from four different accessions possessed electrophoretic mobilities close to, or slower than, that displayed by the 1Dx2.2 subunit of common wheat. The electrophoretic mobilities of the 1Uy subunits were generally similar to those shown by the 1Dy subunits of common wheat. The complete open reading frames of the 1Ux and 1Uy genes were amplified by PCR and subsequently cloned and sequenced. Amino acid sequence comparisons suggested that the primary structure of the 1Ux and 1Uy subunits were identical to that of published HMW glutenin subunits from related species, Phylogenetic analysis indicated that the HMW glutenin subunits of Ae. umbellulata were most closely related to those encoded by the D genome of Triticeae.
文摘Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD, 2n=14). An essential prerequisite for this evolutionary step is that the natural hybrids between tetraploid wheat and diploid Aegilops tauschii can produce relatively many filled seeds which germinated well. In this study, without special techniques, e.g. immature embryo culture, out of 22 Ae. tauschii accessions, the genotype AS60 produced relatively many filled seeds which germinated well. The seed germination percentages in the crosses of Ae. tauschii ×tetraploid wheat, tetraploid wheat× Ae. tauschii and Ae. tauschii ×common wheat were, respectively, 50.0%, 57.1% and 45.5%. It seems that Ae. tauschii accession AS60 has a unique genotype which facilitate hybrid seed development and viability, and which meets with the prerequisite for wheat evolutionary. Furthermore, the significance of this finding for common wheat improvement and evolution was discussed.
基金Supported by National Natural Science Foundation of China(31201203)Earmarked Fund for Modern Agro-industry Technology Research System(CARS-03-1-8)+3 种基金China Postdoctoral Science Foundation(2013T60850)Program for Youth Talent of Shandong Academy of Agricultural Sciences(1-18-024)Seed Industry Foundation Grant to Taishan ScholarAgricultural Improved Variety Industrialization Project of Shandong Province(2-B-08)~~
文摘Introducing the 1S^1 chromosome of Aegilops longissima into wheat genome can significantly improve wheat grain quality and contents of iron and zinc. Therefore, the development of molecular markers specific to 1S^1 chromosome of A. longissima is of important significance for breeding high-quality wheat with high contents of iron and zinc in grains. In this study, nine molecular markers specific to 1S^1 chromosome of A. longissima were developed, including two 1S^1S specific markers,six 1S^1L specific markers and one 1S^1 specific marker which was located on both short and long arms. The practicability of these molecular markers were verified using hybrid population as materials. The results showed that hybrid population could be effectively screened and identified, which indicated that the developed 1S^1 chromosome-specific molecular markers could be used for screening and identification of hybrid population and could be used in marker-assisted breeding of high-quality wheat with high contents of Fe and Zn in grains.
基金Supported by Doctor Scientific Research Fund from Zaozhuang University~~
文摘[Objective] The aim of this study is to investigate the chromosome pairing of F1 from Aegilops Ventricosa-Aegilops Cylindrica amphiploid × common wheat.[Method] Microsporogenesis and pollen development of Yannong15,SDAU18 and their hybrid F1 were observed cytologically by squash method.[Result] The results showed that microsporogenesis and pollen development of two parents including Yannong15 and SDAU18 were basically normal,and their seed setting was also basically normal.However,the microsporogenesis of their hybrid F1 was chaotic.Univalent and bivalent with high frequency of 10.11 and 18.29 per cell respectively occurred in meiotic MI（metphaseI） of PMC（pollen mother cell）.Nevertheless,only quite low frequency of multivalents occurred in meiotic PMC MI.The laggards at meiotic AI（anaphaseI） were 5 per cell on average.The number of micronucleoli in tetrad was 4.43 per cell averagely.The aborted pollen with different frequency occurred at every stage of hybrid F1 pollen development but mainly after single nucleus pollen stage.The fertile pollen rate of hybrid F1 was only 31% at 3-nucleated stage.[Conclusion] This study provides cytogenetics basis for further analysis and utilization of the amphiploid.
基金the National Natural Science Foundation of China (No 30700495)Education Department of Sichuan province (No 07ZZ025)Science and Technology Department of Sichuan province (No 08ZQ026-060)
文摘Fertile F1 hybrids were obtained between durum wheat （Triticum durum Desf.） Langdon （LDN） and its 10 disomic substitution （LDN DS） lines with Aegilops tauschii accession AS60 without embryo rescue. Selfed seedset rates for hybrids of LDN with AS60 were 36.87% and 49.45% in 2005 and 2006, respectively. Similar or higher selfed seedset rates were observed in the hybrids of 1D （1A）, 1D （1B）, 3D （3A）, 4D （4B）, 7D （7A）, and 2D （2B） with AS60, while lower in hybrids of 3D （3B） ＋ 3BL, 5D （5A） ＋ 5AL, 5D （5B） ＋ 5B and 6D （6B） ＋ 6BS with AS60 compared with the hybrids of LDN with AS60. Observation of male gametogenesis showed that meiotic restitution, both first-division restitution （FDR） and single-division meiosis （SDM） resulted in the formation of functional unreduced gametes, which in turn produced seeds. Both euhaploid and aneuhaploid gametes were produced in F1 hybrids. This suggested a strategy to simultaneously transfer and locate major genes from the ancestral species T. turgidum or Ae. tauschii. Moreover, there was no significant difference in the aneuhaploid rates between the F1 hybrids of LDN and LDN DS lines with AS60, suggesting that meiotic pairing between the two D chromosomes in the hybrids of LDN DS lines with AS60 did not promote the formation of aneuhaploid gametes.
基金supported by the National Natural Science Foundation of China(31771783)the Key Research and Development Program of Sichuan Province,China(2021YFYZ0002)the Sichuan Science and Technology Program,China(2018HH0130 and 2022YFH0105)。
文摘Aegilops umbellulata(UU)is a wheat wild relative that has potential use in the genetic improvement of wheat.In this study,46 Ae.umbellulata accessions were investigated for stripe rust resistance,heading date(HD),and the contents of iron(Fe),zinc(Zn),and seed gluten proteins.Forty-two of the accessions were classified as resistant to stripe rust,while the other four accessions were classified as susceptible to stripe rust in four environments.The average HD of Ae.umbellulata was significantly longer than that of three common wheat cultivars(180.9 d vs.137.0 d),with the exception of PI226500(138.9 d).The Ae.umbellulata accessions also showed high variability in Fe(69.74-348.09 mg kg^(-1))and Zn(49.83-101.65 mg kg^(-1))contents.Three accessions(viz.,PI542362,PI542363,and PI554399)showed relatively higher Fe(230.96-348.09 mg kg^(-1))and Zn(92.46-101.65 mg kg^(-1))contents than the others.The Fe content of Ae.umbellulata was similar to those of Ae.comosa and Ae.markgrafii but higher than those of Ae.tauschii and common wheat.Aegilops umbellulata showed a higher Zn content than Ae.tauschii,Ae.comosa,and common wheat,but a lower content than Ae.markgrafii.Furthermore,Ae.umbellulata had the highest proportion of γ-gliadin among all the species investigated(Ae.umbellulata vs.other species=mean 72.11%vs.49.37%;range:55.33-86.99%vs.29.60-67.91%).These results demonstrated that Ae.umbellulata exhibits great diversity in the investigated traits,so it can provide a potential gene pool for the genetic improvement of these traits in wheat.
基金supported by the International Science & Technology Cooperation Program of China (2015DFA30600)the National Natural Science Foundation of China (31301317)
文摘Aegilops tauschii Ais a wild relative of common wheat(Triticum aestivum) and acts as an important resource of elite genes including genes for resistance to biotic and abiotic stresses. To improve the cadmium(Cd) tolerance of wheat varieties using A. tauschii resources, we investigated the genetic variation of biomass-based Cd tolerance in 235 A. tauschii accessions treated with 0(control) and100 μmol L-1CdC l2(as Cd stress). Simultaneously, we performed a genomewide association study(GWAS) using a single-nucleotide polymorphism chip containing 7185 markers. Six markers were found to be significantly associated with Cd tolerance by a general linear model and a mixed linear model. These markers were close to several candidate/flanking genes associated with Cd tolerance according to results in public databases, including pdil5-1, Acc-1, DME-5A,TaA P2-D, TaA P2-B, Vrn-B1, and FtsH-like protein gene. The A. tauschii accessions were classified as high, moderate, and low Cd-tolerant according to a secondary index, the synthetic index(SI), in proportions of 9%, 57%, and 34%, respectively. By the average SI, accessions from Afghanistan,Turkey, Azerbaijan, and Iran showed relatively high Cd tolerance.
基金supported by the Natural Science Foundation of China(No.39870547)the Educational Committee of Sichuan Province.
文摘An artificial amphiploid RSP (2n = 42, AABBDD) between tetraploid landrace Ailanmai (Triticum turgidum L., 2n= 28, AABB) and Aegllops tauschii (DD, 2n = 14) expressed high tolerance to preharvest sprouting which derived from Ae. tauschii. Tolerance to preharvest sprouting of RSP was examined by four ways in six varying periods after anthesis. The germination percentages of preharvest intact spikes were only 6.06% in its high peak period of germination. Its tolerance was mainly decided by the seed dormancy. It was showed that the tolerance to sprouting in ' RSP' derived from Ae. tauschii was inherited as a recessive trait which was controlled by one gene, located on chromosome 2D.
基金supported by the National Natural Science Foundation of China(32001492)the Ministry of Agriculture of China(2016ZX08009)the Natural Science Foundation of Henan(202300410053)。
文摘Aegilops tauschii,the wild progenitor of wheat D-genome and a valuable germplasm for wheat improvement,has a wide natural distribution from eastern Turkey to China.However,the phylogenetic relationship and dispersion history of Ae.tauschii in China has not been scientifically clarified.In this study,we genotyped 208 accessions(with 104 in China)using dd RAD sequencing and 55K SNP array,and classified the population into six sublineages.Three possible spreading routes or events were identified,resulting in specific distribution patterns,with four sublineages found in Xinjiang,one in Qinghai,two in Shaanxi and one in Henan.We also established the correlation of SNP-based,karyotypebased and spike-morphology-based techniques to demonstrate the internal classification of Ae.tauschii,and developed consensus dataset with 1245 putative accessions by merging data previously published.Our analysis suggested that eight inter-lineage accessions could be assigned to the putative Lineage 3and these accessions would help to conserve the genetic diversity of the species.By developing the consensus phylogenetic relationships of Ae.tauschii,our work validated the hypothesis on the dispersal history of Ae.tauschii in China,and contributed to the efficient and comprehensive germplasm-mining of the species.
基金financial supports by the National 973 Program of China (2014CB138100)the National Natural Science Foundation of China (31171553, 31471488 and 31200982)the National High-Tech R&D Program of China (2011AA100102)
文摘Seven important grain traits, including grain length（GL）, grain width（GW）, grain perimeter（GP）, grain area（GA）, grain length/width ratio（GLW）, roundness（GR）, and thousand-grain weight（TGW）, were analyzed using a set of 139 simple sequence repeat（SSR） markers in 130 hexaploid wheat varieties and 193 Aegilops tauschii accessions worldwide. In total, 1 612 alleles in Ae. tauschii and 1 360 alleles in hexaploid wheat（Triticum aestivum L.） were detected throughout the D genome. 197 marker-trait associations in Ae. tauschii were identified with 58 different SSR loci in 3 environments, and the average phenotypic variation value（R2） ranged from 0.68 to 15.12%. In contrast, 208 marker-trait associations were identified in wheat with 66 different SSR markers in 4 environments and the average phenotypic R2 ranged from 0.90 to 19.92%. Further analysis indicated that there are 6 common SSR loci present in both Ae. tauschii and hexaploid wheat, which are significantly associated with the 5 investigated grain traits（i.e., GA, GP, GR, GL, and TGW） and in total, 16 alleles derived from the 6 aforementioned SSR loci were shared by Ae. tauschii and hexaploid wheat. These preliminary data suggest the existence of common alleles may explain the evolutionary process and the selection between Ae. tauschii and hexaploid wheat. Furthermore, the genetic differentiation of grain shape and thousand-grain weight were observed in the evolutionary developmental process from Ae. tauschii to hexaploid wheat.
基金supported by funding from the National Natural Science Foundation of China(Nos.31290210,31210103902)the Unites States National Science Foundation grant(No.IOS 1238231)+1 种基金the USDA-Agricultural Research Service CRIS project(No.5325-21000-019)the Ministry of Education of China(111 project)
文摘Bread wheat （Triticum aestivum, AABBDD） is an allohexaploid species derived from two rounds of interspecific hybridizations. A high-quality genome sequence assembly of diploid Aegilops tauschii, the donor of the wheat D genome, will provide a useful platform to study polyploid wheat evolution. A combined approach of BAC pooling and next-generation sequencing technology was employed to sequence the minimum tiling path （MTP） of 3176 BAC clones from the short arm ofAe. tauschii chromosome 3 （At3DS）. The final assembly of 135 super-scaffolds with an N50 of 4.2 Mb was used to build a 247-Mb pseudomolecule with a total of 2222 predicted protein-coding genes. Compared with the orthologous regions of rice, Brachypodium, and sorghum, At3DS contains 38.67% more genes. In comparison to At3DS, the short arm sequence of wheat chromosome 3B （Ta3BS） is 95-Mb large in size, which is primarily due to the expansion of the non-centromeric region, suggesting that transposable element （TE） bursts in Ta3B likely occurred there. Also, the size increase is accompanied by a proportional increase in gene number in Ta3BS. We found that in the sequence of short arm of wheat chromosome 3D （Ta3DS）, there was only less than 0.27% gene loss compared to At3DS. Our study reveals divergent evolution of grass genomes and provides new insights into sequence changes in the polyploid wheat genome.
基金financially supported by the National Natural Science Foundation of China (32230079, 32001492, 31871615, and31901547)Natural Science Foundation of Henan Province(222301420102)。
文摘To break the narrow diversity bottleneck of the wheat D genome, a set of Aegilops tauschii-wheat introgression(A-WI) lines was developed by crossing Ae. tauschii accession T015 with common wheat elite cultivar Zhoumai 18(Zhou18). A high-density genetic map was constructed based on Single Nucleotide Polymorphism(SNP) markers and 15 yield-related traits were evaluated in 11 environments for detecting quantitative trait loci(QTL). A total of 27 environmentally stable QTL were identified in at least five environments, 20 of which were derived from Ae. tauschii T015, explaining up to 24.27% of the phenotypic variations. The major QTL for kernel length(KL), QKl-2D.5, was delimited to a physical interval of approximately 2.6 Mb harboring 52 candidate genes. Three Kompetitive Allele Specific PCR(KASP)markers were successfully developed based on nonsynonymous nucleotide mutations of candidate gene AetT093_2Dv1G100900.1 and showed that A-WI lines with the T015 haplotype had significantly longer KL than the Zhou18 haplotype across all 11 environments. Four primary valuable A-WIs with good trait performance and carrying yield-related QTL were selected for breeding improvement. The results will facilitate the efficient transfer of beneficial genes from Ae. tauschii into wheat cultivars to improve wheat yield and other traits.
基金supported by the National Natural Science Foundation of China(91935303)the Sichuan Province Science and Technology Department Crops Breeding Project,China(2021YFYZ0002)+1 种基金the Crop Molecular Breeding Platform of Sichuan Province,China(2021YFYZ0027)the Foundation for Youth of Sichuan Academy of Agricultural Sciences and the Sichuan Provincial Agricultural Department Innovative Research Team,China(wheat-10)。
文摘Exploring novel high molecular weight glutenin subunits(HMW-GSs)from wild related species is a strategy to improve wheat processing quality.The objective of the present investigation was to identify the chromosomes of the wheatalien introgression line N124,derived from the hybridization between Triticum aestivum with Aegilops kotschyi,and characterize the effects on quality-related traits.Fluorescence in situ hybridization karyotypes showed that N124 is a disomic 1U^(k)(1A)substitution line.Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE)and reversedphase high-performance liquid chromatography verified N124 expressed two HMW-GSs of the Ae.kotschyi parent.PacBio RNA sequencing and phylogenetic analysis confirmed that the two HMW-GSs were U^(k)x and U^(k)y.Compared to the wheat parent,the substitution line had no obvious agronomic defects except fewer grains per spike but improved several major quality parameters.It can be served as a donor or bridge material for wheat quality improvement.
基金supported by the National Natural Science Foundation of China(31971945)the Department of Science and Technology of Ningxia in China(2019BBF02020)。
文摘Wheat bread-making quality can be improved by use of high-molecular-weight glutenin subunits(HMW-GSs)from wild relatives.Aegilops longissima is a close relative of wheat that contains a number of HMW-GS-encoding genes including 1S^(l)x2.3^(*).In this study,transgenic wheat lines overexpressing 1S^(l)x2.3^(*)were obtained by Agrobacterium-mediated transformation and used to investigate the genetic contribution of 1S^(l)x2.3^(*)to wheat flour-processing quality.The 1S^(l)x2.3^(*)transgene was stably inherited and expressed over generations.Expression of 1S^(l)x2.3^(*)increased the relative expression of 1Dx2 and 1Dy12 and reduced that of 1By18 during grain development.In general,integration of 1S^(l)x2.3^(*)stimulated the accumulation of endogenous HMW-GSs and low-molecular-weight glutenin subunits in wheat kernels,greatly increasing the glutenin:gliadin ratio and resulting in faster formation of protein bodies in the endosperm during grain development.A wheat material with improved flour-making quality was developed in which 1S^(l)x2.3^(*)improved wheat bread-making quality.
