According to conventional theory, little genomic changes should occur in homozygous and stable amphiploids of the grass family, particularly those involving polyploid wheat as a parent. In the present study, however, ...According to conventional theory, little genomic changes should occur in homozygous and stable amphiploids of the grass family, particularly those involving polyploid wheat as a parent. In the present study, however, extensive genomic changes were detected in two octoploid partial amphiploids of common wheat (Triticum aestivum L.)_wheatgrass (Agropyron intermedium (Host) P.B.=Elytrigia intermedia (Host) Nevski=Thinopyrum intermedium (Host) Barkworth and Dewey), namely Zhong 3 and Zhong 5, by RFLP analysis using 10 low_copy, wheat chromosome_specific sequences and 33 representative homoeologous group_specific sequences as probes. Genomic changes involved loss of wheat hybridization fragment(s) and/or acquisition of new fragment(s). Uniformity of the RFLP patterns among 5 individual plants taken respectively from Zhong 3 and Zhong 5 in two successive generations, suggested that genomic changes probably had occurred in the early few generations after octoploid amphiploid formation, and remained essentially static thereafter. The highly similar RFLP patterns between Zhong 3 and Zhong 5, which had identical genomic constitution but differed from each other due to involvement of different wheat varieties as parents imply that genomic changes were probably not at random. Possible causes for the extensive and rapid genomic changes in the newly formed plant amphiploids, as well as their implications for polyploid genome evolution and breeding application are discussed.展开更多
A breast basic conserved 1 (BBC1) cDNA has been isolated from common wheat (Triticum aestivum L.). Analysis of amino acid sequence derived from the cDNA showed that the wheat BBC1 was highly hydrophilic and rich in al...A breast basic conserved 1 (BBC1) cDNA has been isolated from common wheat (Triticum aestivum L.). Analysis of amino acid sequence derived from the cDNA showed that the wheat BBC1 was highly hydrophilic and rich in alanine, lysine, glutamic acid and arginine residues. The transcription of wheat BBC1 mRNA was regulated by low temperature. Southern blotting analysis showed that BBC1 existed as a small family in common wheat genome.展开更多
In common wheat, insoluble glutenin （IG） is an important fraction of flour glutenin macropolymers, and insoluble glutenin content （IGC） is positively associated with key end-use quality parameters. Here, we presen...In common wheat, insoluble glutenin （IG） is an important fraction of flour glutenin macropolymers, and insoluble glutenin content （IGC） is positively associated with key end-use quality parameters. Here, we present a genetic analysis of the chromosomal loci affecting IGC with the data collected from 90 common wheat varieties cultivated in four environments. Statistical analysis showed that IGC was controlled mainly genetically and influenced by the environment. Among the major genetic components known to affect end-use quality, 1BL/1RS translocation had a significantly negative effect on IGC across all four environments. As to the different alleles of Glu-A1, -B1 and -D1 loci, Glu-Ala, Glu-Blb and Glu-Dld exhibited relatively strong positive effects on IGC in all environments. To identify new loci affecting IGC, association mapping with 1355 DArT markers was conducted. A total of 133 markers were found associated with IGC in two or more environments （P 〈 0.05）, ten of which consistently affected IGC in all four environments. The phenotypic variance explained by the ten markers varied from 4.66% to 8.03%, and their elite alleles performed significantly better than the inferior counterparts in enhancing IGC. Among the ten markers, wPt-3743 and wPt-733835 reflected the action of Glu-D1, and wPt-664972 probably indicated the effect of GIu-A1. The other seven markers, forming three clusters on 2AL. 3BL or 7BL chromosome arms, represented newly identified genetic determinants of IGC. Our work provided novel insights into the genetic control of IGC, which may facilitate wheat end- use quality improvement through molecular breeding in the future.展开更多
Pre-harvest sprouting(PHS) adversely affects wheat quality and yield, and grain color(GC) is associated with PHS resistance. However, the genetic relationship between GC and PHS resistance remains unclear. In this stu...Pre-harvest sprouting(PHS) adversely affects wheat quality and yield, and grain color(GC) is associated with PHS resistance. However, the genetic relationship between GC and PHS resistance remains unclear. In this study, 168 wheat varieties(lines) with significant differences in GC and PHS resistance were genotyped using an Illumina 90K iSelect SNP array. Genome-wide association study(GWAS) based on a mixed linear model showed that 67 marker-trait associations(MTAs) assigned to 29 loci, including 17 potentially novel loci, were significantly associated with GC, which explained 1.1–17.0% of the phenotypic variation. In addition, 100 MTAs belonging to 54 loci, including 31 novel loci, were significantly associated with PHS resistance, which accounted for 1.1–14.7% of the phenotypic variation. Subsequently, two cleaved amplified polymorphic sequences(CAPS) markers, 2B-448 on chromosome 2B and 5B-301 on chromosome 5B,were developed from the representative SNPs of the major common loci Qgc.ahau-2B.3/Qphs.ahau-2B.4controlling GC/PHS resistance and PHS resistance locus Qphs.ahau-5B.4, respectively. Further validation in 171 Chinese mini-core collections confirmed significant correlations of the two CAPS markers with GC and PHS resistance phenotypes under different environments(P<0.05). Furthermore, the wheat public expression database, transcriptomic sequencing, and gene allelic variation analysis identified TraesCS5B02G545100, which encodes glutaredoxin, as a potential candidate gene linked to Qphs.ahau-5B.4. The new CAPS marker CAPS-356 was then developed based on the SNP(T/C) in the coding sequences(CDS) region of TraesCS5B02G545100. The high-density linkage map of the Jing 411/Hongmangchun 21 recombinant inbred lines(RILs) constructed based on specific locus amplified fragment sequencing markers showed that CAPS-356 collocated with a novel QTL for PHS resistance, supporting the role of TraesCS5B02G545100 as the potential candidate gene linked to Qphs.ahau-5B.4. These results provide valuable information for the map-based cloning of Qphs.ahau-5B.4 and breeding of PHS resistant white-grained varieties.展开更多
Agropyron cristatum, a wild relative of common wheat(Triticum aestivum L.), provides many desirable genetic resources for wheat improvement, such as tolerance to cold, drought, and disease. To transfer and utilize the...Agropyron cristatum, a wild relative of common wheat(Triticum aestivum L.), provides many desirable genetic resources for wheat improvement, such as tolerance to cold, drought, and disease. To transfer and utilize these desirable genes, in this study, two wheat-A. cristatum derivatives II-13 and II-23 were identified and analyzed. We found that the number of root tip cell chromosomes was 44 in both II-13 and II-23, but there were four and six P genome chromosomes in II-13 and II-23, respectively, based on genomic in situ hybridization(GISH). The chromosome configurations of II-13 and II-23 were both 2 n=22 II by the meiotic analysis of pollen mother cells(PMCs) at metaphase I, indicating that there were two and three pairs of P chromosomes in II-13 and II-23, respectively. Notably, wheat chromosome 7 D was absent in derivative line II-13 while II-23 lacked chromosomes 4 B and 7 A based on SSR analysis combining fluorescence in situ hybridization(FISH) analysis with p As1 and p Sc119.2 as probes. Chromosomes 2 P and 7 P were detected in both II-13 and II-23. Another pair of P genome chromosomes in II-23 was determined to be 4 P based on expressed-sequences tags-sequence tagged sites(EST-STS) markers specific to A. cristatum and FISH with probes p Ac TRT1 and p Acp CR2. Overall, these results suggest that II-13 was a 7 P(7 D) substitution line with one pair of additional 2 P chromosomes and II-23 was a multiple 4 P(4 B), 7 P(7 A) substitution line with one pair of additional 2 P chromosomes. Moreover, we obtained six alien disomic addition lines and five alien disomic substitution lines by backcrossing. These new materials will allow desirable genes from A. cristatum to be used in common wheat.展开更多
[Objective] This study aimed to investigate the polymorphism of PBF en- coding genes from common wheat Chinese Spring （Triticum aestivum L.）. [Method] Using common wheat Chinese Spring as the experimental material, ...[Objective] This study aimed to investigate the polymorphism of PBF en- coding genes from common wheat Chinese Spring （Triticum aestivum L.）. [Method] Using common wheat Chinese Spring as the experimental material, gene-specific primers were designed and applied to amplify the genomic DNA of Chinese Spring. PCR products were isolated, purified and ligated into the cloning vector. Positive clones were randomly selected for sequencing. A series of softwares including DNAMAN, Signalp, PSIPRED, Nuc_PLoc and MEGA were employed for sequence assembly and alignment, signal peptide prediction, primary and secondary structure prediction, as well as analyses of subcellular location and phylogenetic relationships between the PBF family members in Poaceae. [Result] Twenty-five target sequences were obtained from the genome of hexaploid common wheat Chinese Spring, which were classified into three clusters based on the sequence similarity. SNPs exist at two loci of the subunit, resulting in the change of encoded amino acid residues and affecting the secondary structure of final product encoded. [Conclusion] PBF encoding sequences are extremely conservative in Chinese Spring with certain variations. This study provides theoretical reference to evaluate the expression efficiency of wheat storage proteins.展开更多
Wheat tiller angle(TA)is an important agronomic trait that contributes to grain production by affecting plant architecture.It also plays a crucial role in high-yield wheat breeding.An association panel and a recombina...Wheat tiller angle(TA)is an important agronomic trait that contributes to grain production by affecting plant architecture.It also plays a crucial role in high-yield wheat breeding.An association panel and a recombinant inbred line(RIL)population were used to map quantitative trait loci(QTL)for TA.Results showed that 470 significant SNPs with 10.4%–28.8%phenotypic variance explained(PVE)were detected in four replicates by a genome-wide association study(GWAS).Haplotype analysis showed that the TA_Hap_4B1 locus on chromosome 4B was a major QTL to regulate wheat TA.Ten QTL were totally detected by linkage mapping with the RIL population,and QTA.hau-4B.1 identified in six environments with the PVE of 7.88%–18.82%was a major and stable QTL.A combined analysis demonstrated that both TA_Hap_4B1 and QTA.hau-4B.1 were co-located on the same region.Moreover,QTA.hau-4B.1 was confirmed by bulked segregant RNA-Seq(BSR-Seq)analysis.Phenotypic analysis showed that QTA.hau-4B.1was also closely related to yield traits.Furthermore,Traes CS4B02G049700 was considered as a candidate gene through analysis of gene sequence and expression.This study can be potentially used in cloning key genes modulating wheat tillering and provides valuable genetic resources for improvement of wheat plant architecture.展开更多
The F 1 and F 4 plants of 'synthetic hexaploid wheat/common wheat'crosses and part of their parents were inoculated with Fusarium graminearum to evaluate FHB resistance.The results showed tht the scab resist...The F 1 and F 4 plants of 'synthetic hexaploid wheat/common wheat'crosses and part of their parents were inoculated with Fusarium graminearum to evaluate FHB resistance.The results showed tht the scab resistance in the F 1 varied with the synthetic wheat accessions used as crossing parents.In the F 4,some resistant head lines were generated from the crosses,although their parents had different scab resistance levels.It indicated that synthetic hexaploid wheat are useful in wheat breeding for scab resistance.展开更多
Miniature inverted-repeat transposable elements(MITEs) are a type of DNA transposon frequently inserted into promoters, untranslated regions(UTR), introns, or coding sequences of genes. We found a 276-bp tourist-like ...Miniature inverted-repeat transposable elements(MITEs) are a type of DNA transposon frequently inserted into promoters, untranslated regions(UTR), introns, or coding sequences of genes. We found a 276-bp tourist-like MITE insertion in the 3′-UTR of a 16.9 k Da small heat shock protein gene(TaH SP16.9-3A) on chromosome 3A of common wheat. Haplotype analysis revealed two haplotypes, s HSP-W(wild type without MITE insertion) and s HSP-M(mutant with MITE insertion), present in wheat germplasm. Both semiquantitative PCR and quantitative real-time PCR analyses showed increased transcription levels of TaH SP16.9-3A in s HSP-M compared with those of s HSP-W after heat treatment at 42 °C. It appeared that the MITE insertion into the 3′-UTR enhances the transcription of TaH SP16.9-3A.展开更多
By the modified ISSR-amplification method the comparison of the structural organization of enzyme loci in the initial common wheat cultivars and their genotrophs induced with epimutagens: plant niacin acid and niacin ...By the modified ISSR-amplification method the comparison of the structural organization of enzyme loci in the initial common wheat cultivars and their genotrophs induced with epimutagens: plant niacin acid and niacin acid and its derivatives produced from β-picoline fraction of coal-tar pitch (niacin acid nitrile, isocinchomeronic and benzoic acids) was carried out. It is shown that niacin acid influence causes in genotrophs specific band appearance in PCR-profiles obtained on the DNA of enzyme loci. All these before mentioned epimutagens induced in limits of each genotroph differently directed changes in number and intensity of bands of PCR-profiles.展开更多
The study of PCR-profiles of isozyme loci Me1 and Adh1 in common wheat lines obtained by means of treatment of initial cultivar Alem with detergent Tri-ton X-100 was carried out by the modified ISSR-amplification meth...The study of PCR-profiles of isozyme loci Me1 and Adh1 in common wheat lines obtained by means of treatment of initial cultivar Alem with detergent Tri-ton X-100 was carried out by the modified ISSR-amplification method. It was demonstrated that exposure to Triton X-100 causes changes of PCR-profiles of enzyme loci. The obtained data are suggestive of the role of chromatin and nuclear mem-brane interaction in structural-functional genome organization.展开更多
DNA-segment copy number variations(DSCNVs),such as deletions and duplications,are important sources of genomic structural variation.However,the types and sizes of DSCNVs,as well as their genome-wide distribution and p...DNA-segment copy number variations(DSCNVs),such as deletions and duplications,are important sources of genomic structural variation.However,the types and sizes of DSCNVs,as well as their genome-wide distribution and potential functions,are poorly understood in wheat.Here,we identified 198985 DSCNVs by investigating 491 genomes of common wheat and found that they account for 20%of the entire genome.Interestingly,approximately 38%of genes are linked to DSCNVs.The number of DSCNVs within each accession ranges from 47366 to 96342,and their total sizes vary from 421.3 to 1267.9 Mb.We found that 957 and 1304 DSCNVs have been favored by breeders in China and the United States,respectively.By conducting DSCNV-based genome-wide association studies for the principal components of plant developmental and yield-component traits,we identified 34 loci as directly or indirectly involved in controlling the formation of multiple traits.Notably,a newly discovered DSCNV covering TaFT-D1 is significantly associated with flowering time and other agronomic traits.Overall,our findings highlight the potential of DSCNVs to drive fundamental discoveries in plant science.The comprehensive DSCNV map and the DSCNV-associated genes will also facilitate future research efforts to improve wheat yield,quality,and adaptation.展开更多
Non-destructive time-series assessment of chlorophyll content in flag-leaf(FLC)accurately mimics the senescence rate and the identification of genetic loci associated with senescence provides valuable knowledge to imp...Non-destructive time-series assessment of chlorophyll content in flag-leaf(FLC)accurately mimics the senescence rate and the identification of genetic loci associated with senescence provides valuable knowledge to improve yield stability under stressed environments.In this study,we employed both unmanned aerial vehicles(UAVs)equipped with red–green–blue(RGB)camera and ground-based SPAD-502 instrument to conduct temporal phenotyping of senescence.A total of 262 recombinant inbred lines derived from the cross of Zhongmai 578/Jimai 22 were evaluated for senescence-related traits across three environments,spanning from heading to 35 d post-anthesis.The manual senescence rate(MSR)was quantified using the FLC and the active accumulated temperature,and UAV derived vegetation index were utilized to assess the stay-green rate(USG)facilitating the identification of senescent and stay-green lines.Results indicated that higher senescence rates significantly impacted grain yield,primarily by influencing thousand-kernel weight,and plant height.Quantitative trait loci(QTL)mapping for FLC,USG,and MSR using the 50K SNP array identified 38 stable loci associated with RGB-based vegetation indices and senescence-related traits:among which 19 loci related to senescence traits from UAV and FLC were consistently detected across at least two growth stages,with nine loci likely representing novel QTL.This study highlights the potential of UAV-based high-throughput phenotyping and phenology in identifying critical loci associated with senescence rates in wheat,validating the relationship between senescence rates and yield-related traits in wheat,offering valuable opportunities for gene discovery and significant applications in breeding programs.展开更多
Powdery mildew is a serious disease caused by Blumeria graminis f.sp.tritici(Bgt)that critically threatens the yield and quality of wheat(Triticum aestivum L.).Using effective powdery mildew resistance genes is the op...Powdery mildew is a serious disease caused by Blumeria graminis f.sp.tritici(Bgt)that critically threatens the yield and quality of wheat(Triticum aestivum L.).Using effective powdery mildew resistance genes is the optimal method for controlling this disease.Against the background of high genetic homogeneity among the modern commercial cultivars that are mainly derived from conventional interbreeding,the resistance genes from wheat relatives have especially prominent advantages.Octoploid triticale,produced from common wheat and rye(Secale cereale L.)through distant hybridization,is a new synthetic species and valuable gene donor for wheat improvement.In this study,we developed the wheat-rye line YT5 through the hybridization of octaploid triticale and two wheat lines.YT5 was confirmed to be a 6RL ditelosomic addition and 1R(1B)substitution line using genomic in situ hybridization(GISH),multicolor fluorescence in situ hybridization(mc-FISH),multicolor GISH(mc-GISH)and molecular marker analysis.Genetic analysis showed that the powdery mildew resistance in YT5 was derived from the rye chromosome arm 6RL.After inoculation with different Bgt isolates at the seedling stage,YT5 had compound reaction patterns with both obvious spores and hypersensitivity,and it gradually became highly resistant until the adult-plant stage,thus showing a resistance response significantly different from the reported Pm genes from rye chromosome 6RL.YT5 also showed promising agronomic performance,so it is expected to be an elite resistance donor for wheat improvement.To promote the transfer of the chromosome arm 6RL of YT5 in marker-assisted selection(MAS)breeding,we selected and verified two 6RL-specific kompetitive allelespecific PCR(KASP)markers that can be applied to efficiently detect this chromosome arm in different wheat backgrounds.展开更多
Genetic mapping provides a powerful tool for the analysis of quantitative trait loci （QTLs） at the genomic level. Herein, we report a new genetic linkage map developed from an F1-derived doubled haploid （DH） popul...Genetic mapping provides a powerful tool for the analysis of quantitative trait loci （QTLs） at the genomic level. Herein, we report a new genetic linkage map developed from an F1-derived doubled haploid （DH） population of 168 lines, which was generated from the cross between two elite Chinese common wheat （Triticum aestivum L.） varieties, Huapei 3 and Yumai 57. The map contained 305 loci, represented by 283 simple sequence repeat （SSR） and 22 expressed sequence tag （EST）-SSR markers, which covered a total length of 2141.7 cM with an average distance of 7.02 cM between adjacent markers on the map. The chromosomal locations and map positions of 22 new SSR markers were determined, and were found to distribute on 14 linkage groups. Twenty SSR loci showed different chromosomal locations from those reported in other maps. Therefore, this map offers new information on the SSR markers of wheat. This genetic map provides new opportunities to detect and map QTLs controlling agronomically important traits. The unique features of this map are discussed.展开更多
Symmetric and asymmetric protoplast fusion between long term cell suspension-derived protoplasts of Triticum aestivum (cv. Jinan 177) and protoplasts of Haynaldia villosa prepared from one-year-old embryogeneric calli...Symmetric and asymmetric protoplast fusion between long term cell suspension-derived protoplasts of Triticum aestivum (cv. Jinan 177) and protoplasts of Haynaldia villosa prepared from one-year-old embryogeneric calli was performed by PEG method. In asymmetric fusion, donor calli were treated with gamma ray at a dose of 40, 60, 80 Gy (1.3 Gy/min) respectively and then used to isolate protoplasts. Results of morphological, cytological, biochemical (isozyme) and 5S rDNA spacer sequence analysis revealed that we obtained somatic hybrid lines at high frequency from both symmetric and asymmetric fusion. Hybrid plants were recovered from symmetric and low dose γ-fusion combinations. GISH (genomic in situ hybridization) analysis proved exactly the existence of both parental chromosomes and the common occurrence of several kinds of translocation between them in the hybrid clones regenerated from symmetric and asymmetric fusion. And the elimination of donor DNA in hybrid clones regenerated from asymmetric fusion combinations was found to increase with the increasing gamma doses. It is concluded that transference and recombination of nuclear DNA can be achieved effectively by symmetric and asymmetric fusion, hybrids with small fragment translocation which are valuable in plant breeding can be obtained directly by asymmetric fusion.展开更多
Fusarium crown rot(FCR) and sharp eyespot(SE)are serious soil-borne diseases in wheat and its relatives that have been reported to cause wheat yield losses in many areas. In this study, the expression of a cell wall i...Fusarium crown rot(FCR) and sharp eyespot(SE)are serious soil-borne diseases in wheat and its relatives that have been reported to cause wheat yield losses in many areas. In this study, the expression of a cell wall invertase gene, TaCWI-B1,was identified to be associated with FCR resistance through a combination of bulk segregant RNA sequencing and genome resequencing in a recombinant inbred line population. Two biparental populations were developed to further verify TaCWI-B1 association with FCR resistance.Overexpression lines and ethyl methanesulfonate(EMS) mutants revealed TaCWI-B1 positively regulating FCR resistance. Determination of cell wall thickness and components showed that the TaCWI-B1-overexpression lines exhibited considerably increased thickness and pectin and cellulose contents. Furthermore, we found that TaCWI-B1 directly interacted with an alphagalactosidase(TaGAL). EMS mutants showed that TaGAL negatively modulated FCR resistance. The expression of TaGAL is negatively correlated with TaCWI-B1 levels, thus may reduce mannan degradation in the cell wall, consequently leading to thickening of the cell wall. Additionally, TaCWI-B1-overexpression lines and TaGAL mutants showed higher resistance to SE;however, TaCWI-B1 mutants were more susceptible to SE than controls.This study provides insights into a FCR and SE resistance gene to combat soil-borne diseases in common wheat.展开更多
The cytological instability of common wheat-rye addition lines was investigated in the present study. The chromosome numbers of almost all addition lines were considerably stable, but those of CS ＋ 5R were very varia...The cytological instability of common wheat-rye addition lines was investigated in the present study. The chromosome numbers of almost all addition lines were considerably stable, but those of CS ＋ 5R were very variable. The rye chromosome added in this line was found to be much shorter than expected. Fluorescent in situ hybridization with 5S rDNA and the centromere-speciflc probes clearly revealed that the short rye chromosome contains only a short arm of chromosome 5R （5RS）. In this line, chromosome numbers of both 5RS and common wheat were changeable. The chromosome numbers ranged from 2n = 36 to 2n = 44 in the cells carrying two 5RS, and ranged from 2n = 31 to 2n = 44 in one 5RS cells. In addition to the chromosome instability, the muIticells wrapped in a sac-like structure were frequently observed in the root meristematic tissues of CS ＋5RS after the enzyme treatment for chromosome preparation. Genomic in situ hybridization with rye DNA as a probe showed that all cells in sacs investigated were at the interphase stage and contained one or two 5RS chromosomes. An electron microscopic analysis revealed that the cells of CS＋5RS, particularly in sacs, have abnormal （irregular and curved） cell walls. These results indicate that 5RS has （a） specific factor（s） influencing the cell wall development as well as the genome stability.展开更多
As a novel post-translational modification(PTM),lysine 2-hydroxyisobutyrylation(Khib)is considered to regulate gene transcriptional activities in eukaryotic cells;however,the functions of Khib-modified proteins in pla...As a novel post-translational modification(PTM),lysine 2-hydroxyisobutyrylation(Khib)is considered to regulate gene transcriptional activities in eukaryotic cells;however,the functions of Khib-modified proteins in plants remain unknown.Here,we report that Khib is an evolutionarilyconserved PTM in wheat and its progenitors.A total of 3348 Khib sites on 1074 proteins are identified in common wheat(Triticum aestivum L.)by using affinity purification and mass spectroscopy of 2-hydroxyisobutyrylome.Bioinformatic data indicate that Khib-modified proteins participate in a wide variety of biological and metabolic pathways.Immunoprecipitation confirms that Khibmodified proteins are present endogenously.A comparison of Khib and other main PTMs shows that Khib-modified proteins are simultaneously modified by multiple PTMs.Using mutagenesis experiments and co-immunoprecipitation assays,we demonstrate that Khib on K206 of phosphoglycerate kinase(PGK)is a key regulatory modification for its enzymatic activity,and mutation on K206 affects the interactions of PGK with its substrates.Furthermore,Khib modification of low-molecular-weight proteins is a response to the deacetylase inhibitors nicotinamide and trichostatin.This study provides evidence to promote our current understanding of Khib in wheat plants,including the cooperation between Khib and its metabolic regulation.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
文摘According to conventional theory, little genomic changes should occur in homozygous and stable amphiploids of the grass family, particularly those involving polyploid wheat as a parent. In the present study, however, extensive genomic changes were detected in two octoploid partial amphiploids of common wheat (Triticum aestivum L.)_wheatgrass (Agropyron intermedium (Host) P.B.=Elytrigia intermedia (Host) Nevski=Thinopyrum intermedium (Host) Barkworth and Dewey), namely Zhong 3 and Zhong 5, by RFLP analysis using 10 low_copy, wheat chromosome_specific sequences and 33 representative homoeologous group_specific sequences as probes. Genomic changes involved loss of wheat hybridization fragment(s) and/or acquisition of new fragment(s). Uniformity of the RFLP patterns among 5 individual plants taken respectively from Zhong 3 and Zhong 5 in two successive generations, suggested that genomic changes probably had occurred in the early few generations after octoploid amphiploid formation, and remained essentially static thereafter. The highly similar RFLP patterns between Zhong 3 and Zhong 5, which had identical genomic constitution but differed from each other due to involvement of different wheat varieties as parents imply that genomic changes were probably not at random. Possible causes for the extensive and rapid genomic changes in the newly formed plant amphiploids, as well as their implications for polyploid genome evolution and breeding application are discussed.
文摘A breast basic conserved 1 (BBC1) cDNA has been isolated from common wheat (Triticum aestivum L.). Analysis of amino acid sequence derived from the cDNA showed that the wheat BBC1 was highly hydrophilic and rich in alanine, lysine, glutamic acid and arginine residues. The transcription of wheat BBC1 mRNA was regulated by low temperature. Southern blotting analysis showed that BBC1 existed as a small family in common wheat genome.
基金supported by the Ministry of Science and Technology of China (Grant No. 2014CB138104)Chinese Academy of Sciences (Grant No. XDA08010302)the National Science Foundation of China (Grant No. 31371611)
文摘In common wheat, insoluble glutenin （IG） is an important fraction of flour glutenin macropolymers, and insoluble glutenin content （IGC） is positively associated with key end-use quality parameters. Here, we present a genetic analysis of the chromosomal loci affecting IGC with the data collected from 90 common wheat varieties cultivated in four environments. Statistical analysis showed that IGC was controlled mainly genetically and influenced by the environment. Among the major genetic components known to affect end-use quality, 1BL/1RS translocation had a significantly negative effect on IGC across all four environments. As to the different alleles of Glu-A1, -B1 and -D1 loci, Glu-Ala, Glu-Blb and Glu-Dld exhibited relatively strong positive effects on IGC in all environments. To identify new loci affecting IGC, association mapping with 1355 DArT markers was conducted. A total of 133 markers were found associated with IGC in two or more environments （P 〈 0.05）, ten of which consistently affected IGC in all four environments. The phenotypic variance explained by the ten markers varied from 4.66% to 8.03%, and their elite alleles performed significantly better than the inferior counterparts in enhancing IGC. Among the ten markers, wPt-3743 and wPt-733835 reflected the action of Glu-D1, and wPt-664972 probably indicated the effect of GIu-A1. The other seven markers, forming three clusters on 2AL. 3BL or 7BL chromosome arms, represented newly identified genetic determinants of IGC. Our work provided novel insights into the genetic control of IGC, which may facilitate wheat end- use quality improvement through molecular breeding in the future.
基金supported by grants from the University Synergy Innovation Program of Anhui Province,China(GXXT-2021-058)the National Natural Science Foundation of China(Joint Fund Projects,U20A2033)+3 种基金the Natural Science Foundation of Anhui Province,China(2108085MC98)the Jiangsu Collaborative Innovation Center for Modern Crop Production,China(JCIC-MCP)the key scientific and technological breakthroughs of Anhui Province(2021d06050003)the joint key project of improved wheat variety of Anhui Province,China(21803003).
文摘Pre-harvest sprouting(PHS) adversely affects wheat quality and yield, and grain color(GC) is associated with PHS resistance. However, the genetic relationship between GC and PHS resistance remains unclear. In this study, 168 wheat varieties(lines) with significant differences in GC and PHS resistance were genotyped using an Illumina 90K iSelect SNP array. Genome-wide association study(GWAS) based on a mixed linear model showed that 67 marker-trait associations(MTAs) assigned to 29 loci, including 17 potentially novel loci, were significantly associated with GC, which explained 1.1–17.0% of the phenotypic variation. In addition, 100 MTAs belonging to 54 loci, including 31 novel loci, were significantly associated with PHS resistance, which accounted for 1.1–14.7% of the phenotypic variation. Subsequently, two cleaved amplified polymorphic sequences(CAPS) markers, 2B-448 on chromosome 2B and 5B-301 on chromosome 5B,were developed from the representative SNPs of the major common loci Qgc.ahau-2B.3/Qphs.ahau-2B.4controlling GC/PHS resistance and PHS resistance locus Qphs.ahau-5B.4, respectively. Further validation in 171 Chinese mini-core collections confirmed significant correlations of the two CAPS markers with GC and PHS resistance phenotypes under different environments(P<0.05). Furthermore, the wheat public expression database, transcriptomic sequencing, and gene allelic variation analysis identified TraesCS5B02G545100, which encodes glutaredoxin, as a potential candidate gene linked to Qphs.ahau-5B.4. The new CAPS marker CAPS-356 was then developed based on the SNP(T/C) in the coding sequences(CDS) region of TraesCS5B02G545100. The high-density linkage map of the Jing 411/Hongmangchun 21 recombinant inbred lines(RILs) constructed based on specific locus amplified fragment sequencing markers showed that CAPS-356 collocated with a novel QTL for PHS resistance, supporting the role of TraesCS5B02G545100 as the potential candidate gene linked to Qphs.ahau-5B.4. These results provide valuable information for the map-based cloning of Qphs.ahau-5B.4 and breeding of PHS resistant white-grained varieties.
基金supported by the National Key Research and Development Program of China (2016YFD0100102)
文摘Agropyron cristatum, a wild relative of common wheat(Triticum aestivum L.), provides many desirable genetic resources for wheat improvement, such as tolerance to cold, drought, and disease. To transfer and utilize these desirable genes, in this study, two wheat-A. cristatum derivatives II-13 and II-23 were identified and analyzed. We found that the number of root tip cell chromosomes was 44 in both II-13 and II-23, but there were four and six P genome chromosomes in II-13 and II-23, respectively, based on genomic in situ hybridization(GISH). The chromosome configurations of II-13 and II-23 were both 2 n=22 II by the meiotic analysis of pollen mother cells(PMCs) at metaphase I, indicating that there were two and three pairs of P chromosomes in II-13 and II-23, respectively. Notably, wheat chromosome 7 D was absent in derivative line II-13 while II-23 lacked chromosomes 4 B and 7 A based on SSR analysis combining fluorescence in situ hybridization(FISH) analysis with p As1 and p Sc119.2 as probes. Chromosomes 2 P and 7 P were detected in both II-13 and II-23. Another pair of P genome chromosomes in II-23 was determined to be 4 P based on expressed-sequences tags-sequence tagged sites(EST-STS) markers specific to A. cristatum and FISH with probes p Ac TRT1 and p Acp CR2. Overall, these results suggest that II-13 was a 7 P(7 D) substitution line with one pair of additional 2 P chromosomes and II-23 was a multiple 4 P(4 B), 7 P(7 A) substitution line with one pair of additional 2 P chromosomes. Moreover, we obtained six alien disomic addition lines and five alien disomic substitution lines by backcrossing. These new materials will allow desirable genes from A. cristatum to be used in common wheat.
基金Supported by National Natural Science Foundation of China(30900896)Special Fund for the Construction of Modern Agricultural Technology System(NYCYTX-001)Cyrus Tang Breeding Fund(A212020912)~~
文摘[Objective] This study aimed to investigate the polymorphism of PBF en- coding genes from common wheat Chinese Spring （Triticum aestivum L.）. [Method] Using common wheat Chinese Spring as the experimental material, gene-specific primers were designed and applied to amplify the genomic DNA of Chinese Spring. PCR products were isolated, purified and ligated into the cloning vector. Positive clones were randomly selected for sequencing. A series of softwares including DNAMAN, Signalp, PSIPRED, Nuc_PLoc and MEGA were employed for sequence assembly and alignment, signal peptide prediction, primary and secondary structure prediction, as well as analyses of subcellular location and phylogenetic relationships between the PBF family members in Poaceae. [Result] Twenty-five target sequences were obtained from the genome of hexaploid common wheat Chinese Spring, which were classified into three clusters based on the sequence similarity. SNPs exist at two loci of the subunit, resulting in the change of encoded amino acid residues and affecting the secondary structure of final product encoded. [Conclusion] PBF encoding sequences are extremely conservative in Chinese Spring with certain variations. This study provides theoretical reference to evaluate the expression efficiency of wheat storage proteins.
基金funded by the National Natural Science Foundation of China(31971947 and 32072057)Henan Major Science and Technology Projects(201300110800,201300111600)Key Scientific and Technological Project of Henan Province(222102110026)。
文摘Wheat tiller angle(TA)is an important agronomic trait that contributes to grain production by affecting plant architecture.It also plays a crucial role in high-yield wheat breeding.An association panel and a recombinant inbred line(RIL)population were used to map quantitative trait loci(QTL)for TA.Results showed that 470 significant SNPs with 10.4%–28.8%phenotypic variance explained(PVE)were detected in four replicates by a genome-wide association study(GWAS).Haplotype analysis showed that the TA_Hap_4B1 locus on chromosome 4B was a major QTL to regulate wheat TA.Ten QTL were totally detected by linkage mapping with the RIL population,and QTA.hau-4B.1 identified in six environments with the PVE of 7.88%–18.82%was a major and stable QTL.A combined analysis demonstrated that both TA_Hap_4B1 and QTA.hau-4B.1 were co-located on the same region.Moreover,QTA.hau-4B.1 was confirmed by bulked segregant RNA-Seq(BSR-Seq)analysis.Phenotypic analysis showed that QTA.hau-4B.1was also closely related to yield traits.Furthermore,Traes CS4B02G049700 was considered as a candidate gene through analysis of gene sequence and expression.This study can be potentially used in cloning key genes modulating wheat tillering and provides valuable genetic resources for improvement of wheat plant architecture.
文摘The F 1 and F 4 plants of 'synthetic hexaploid wheat/common wheat'crosses and part of their parents were inoculated with Fusarium graminearum to evaluate FHB resistance.The results showed tht the scab resistance in the F 1 varied with the synthetic wheat accessions used as crossing parents.In the F 4,some resistant head lines were generated from the crosses,although their parents had different scab resistance levels.It indicated that synthetic hexaploid wheat are useful in wheat breeding for scab resistance.
基金supported by the China Agricultural University Graduate Research and Innovation Project (kycx09019)
文摘Miniature inverted-repeat transposable elements(MITEs) are a type of DNA transposon frequently inserted into promoters, untranslated regions(UTR), introns, or coding sequences of genes. We found a 276-bp tourist-like MITE insertion in the 3′-UTR of a 16.9 k Da small heat shock protein gene(TaH SP16.9-3A) on chromosome 3A of common wheat. Haplotype analysis revealed two haplotypes, s HSP-W(wild type without MITE insertion) and s HSP-M(mutant with MITE insertion), present in wheat germplasm. Both semiquantitative PCR and quantitative real-time PCR analyses showed increased transcription levels of TaH SP16.9-3A in s HSP-M compared with those of s HSP-W after heat treatment at 42 °C. It appeared that the MITE insertion into the 3′-UTR enhances the transcription of TaH SP16.9-3A.
文摘By the modified ISSR-amplification method the comparison of the structural organization of enzyme loci in the initial common wheat cultivars and their genotrophs induced with epimutagens: plant niacin acid and niacin acid and its derivatives produced from β-picoline fraction of coal-tar pitch (niacin acid nitrile, isocinchomeronic and benzoic acids) was carried out. It is shown that niacin acid influence causes in genotrophs specific band appearance in PCR-profiles obtained on the DNA of enzyme loci. All these before mentioned epimutagens induced in limits of each genotroph differently directed changes in number and intensity of bands of PCR-profiles.
文摘The study of PCR-profiles of isozyme loci Me1 and Adh1 in common wheat lines obtained by means of treatment of initial cultivar Alem with detergent Tri-ton X-100 was carried out by the modified ISSR-amplification method. It was demonstrated that exposure to Triton X-100 causes changes of PCR-profiles of enzyme loci. The obtained data are suggestive of the role of chromatin and nuclear mem-brane interaction in structural-functional genome organization.
基金supported by the National Natural Science Foundation of China(grant nos.31991211,31921005,and 32201745)the Strategic Pri-ority Research Program of the Chinese Academy of Sciences(XDA24010104)+1 种基金the Hainan Seed Industry Laboratory(B23C1000402)the Major Basic Research Program of Shandong Natural Science Foundation(ZR2019ZD15).
文摘DNA-segment copy number variations(DSCNVs),such as deletions and duplications,are important sources of genomic structural variation.However,the types and sizes of DSCNVs,as well as their genome-wide distribution and potential functions,are poorly understood in wheat.Here,we identified 198985 DSCNVs by investigating 491 genomes of common wheat and found that they account for 20%of the entire genome.Interestingly,approximately 38%of genes are linked to DSCNVs.The number of DSCNVs within each accession ranges from 47366 to 96342,and their total sizes vary from 421.3 to 1267.9 Mb.We found that 957 and 1304 DSCNVs have been favored by breeders in China and the United States,respectively.By conducting DSCNV-based genome-wide association studies for the principal components of plant developmental and yield-component traits,we identified 34 loci as directly or indirectly involved in controlling the formation of multiple traits.Notably,a newly discovered DSCNV covering TaFT-D1 is significantly associated with flowering time and other agronomic traits.Overall,our findings highlight the potential of DSCNVs to drive fundamental discoveries in plant science.The comprehensive DSCNV map and the DSCNV-associated genes will also facilitate future research efforts to improve wheat yield,quality,and adaptation.
基金funded by the National Key Research and Development Program of China(2022ZD0115703)the National Natural Science Foundation of China(32372196)+1 种基金the Beijing Joint Research Program for Germplasm Innovation and New Variety Breeding(G20220628002)National Natural Science Foundation of China(32250410307)。
文摘Non-destructive time-series assessment of chlorophyll content in flag-leaf(FLC)accurately mimics the senescence rate and the identification of genetic loci associated with senescence provides valuable knowledge to improve yield stability under stressed environments.In this study,we employed both unmanned aerial vehicles(UAVs)equipped with red–green–blue(RGB)camera and ground-based SPAD-502 instrument to conduct temporal phenotyping of senescence.A total of 262 recombinant inbred lines derived from the cross of Zhongmai 578/Jimai 22 were evaluated for senescence-related traits across three environments,spanning from heading to 35 d post-anthesis.The manual senescence rate(MSR)was quantified using the FLC and the active accumulated temperature,and UAV derived vegetation index were utilized to assess the stay-green rate(USG)facilitating the identification of senescent and stay-green lines.Results indicated that higher senescence rates significantly impacted grain yield,primarily by influencing thousand-kernel weight,and plant height.Quantitative trait loci(QTL)mapping for FLC,USG,and MSR using the 50K SNP array identified 38 stable loci associated with RGB-based vegetation indices and senescence-related traits:among which 19 loci related to senescence traits from UAV and FLC were consistently detected across at least two growth stages,with nine loci likely representing novel QTL.This study highlights the potential of UAV-based high-throughput phenotyping and phenology in identifying critical loci associated with senescence rates in wheat,validating the relationship between senescence rates and yield-related traits in wheat,offering valuable opportunities for gene discovery and significant applications in breeding programs.
基金supported by the National Key Research and Development Program of China(2021YFD1200600)the National Natural Science Foundation of China(32272105).
文摘Powdery mildew is a serious disease caused by Blumeria graminis f.sp.tritici(Bgt)that critically threatens the yield and quality of wheat(Triticum aestivum L.).Using effective powdery mildew resistance genes is the optimal method for controlling this disease.Against the background of high genetic homogeneity among the modern commercial cultivars that are mainly derived from conventional interbreeding,the resistance genes from wheat relatives have especially prominent advantages.Octoploid triticale,produced from common wheat and rye(Secale cereale L.)through distant hybridization,is a new synthetic species and valuable gene donor for wheat improvement.In this study,we developed the wheat-rye line YT5 through the hybridization of octaploid triticale and two wheat lines.YT5 was confirmed to be a 6RL ditelosomic addition and 1R(1B)substitution line using genomic in situ hybridization(GISH),multicolor fluorescence in situ hybridization(mc-FISH),multicolor GISH(mc-GISH)and molecular marker analysis.Genetic analysis showed that the powdery mildew resistance in YT5 was derived from the rye chromosome arm 6RL.After inoculation with different Bgt isolates at the seedling stage,YT5 had compound reaction patterns with both obvious spores and hypersensitivity,and it gradually became highly resistant until the adult-plant stage,thus showing a resistance response significantly different from the reported Pm genes from rye chromosome 6RL.YT5 also showed promising agronomic performance,so it is expected to be an elite resistance donor for wheat improvement.To promote the transfer of the chromosome arm 6RL of YT5 in marker-assisted selection(MAS)breeding,we selected and verified two 6RL-specific kompetitive allelespecific PCR(KASP)markers that can be applied to efficiently detect this chromosome arm in different wheat backgrounds.
基金the National Natural Science Foundation of China (30671270)the Hi-Tech Research and Development (863) Program of China(2006AA10Z1E9 and 2006AA100101)
文摘Genetic mapping provides a powerful tool for the analysis of quantitative trait loci （QTLs） at the genomic level. Herein, we report a new genetic linkage map developed from an F1-derived doubled haploid （DH） population of 168 lines, which was generated from the cross between two elite Chinese common wheat （Triticum aestivum L.） varieties, Huapei 3 and Yumai 57. The map contained 305 loci, represented by 283 simple sequence repeat （SSR） and 22 expressed sequence tag （EST）-SSR markers, which covered a total length of 2141.7 cM with an average distance of 7.02 cM between adjacent markers on the map. The chromosomal locations and map positions of 22 new SSR markers were determined, and were found to distribute on 14 linkage groups. Twenty SSR loci showed different chromosomal locations from those reported in other maps. Therefore, this map offers new information on the SSR markers of wheat. This genetic map provides new opportunities to detect and map QTLs controlling agronomically important traits. The unique features of this map are discussed.
基金the National Natural Science Foundation of China (Grant Nos. 39570465, 30070397).
文摘Symmetric and asymmetric protoplast fusion between long term cell suspension-derived protoplasts of Triticum aestivum (cv. Jinan 177) and protoplasts of Haynaldia villosa prepared from one-year-old embryogeneric calli was performed by PEG method. In asymmetric fusion, donor calli were treated with gamma ray at a dose of 40, 60, 80 Gy (1.3 Gy/min) respectively and then used to isolate protoplasts. Results of morphological, cytological, biochemical (isozyme) and 5S rDNA spacer sequence analysis revealed that we obtained somatic hybrid lines at high frequency from both symmetric and asymmetric fusion. Hybrid plants were recovered from symmetric and low dose γ-fusion combinations. GISH (genomic in situ hybridization) analysis proved exactly the existence of both parental chromosomes and the common occurrence of several kinds of translocation between them in the hybrid clones regenerated from symmetric and asymmetric fusion. And the elimination of donor DNA in hybrid clones regenerated from asymmetric fusion combinations was found to increase with the increasing gamma doses. It is concluded that transference and recombination of nuclear DNA can be achieved effectively by symmetric and asymmetric fusion, hybrids with small fragment translocation which are valuable in plant breeding can be obtained directly by asymmetric fusion.
基金funded by the National Key Research and Development Program (2019YFE0118300)the National Natural Science Foundation (31861143008)Henan Major Science and Technology Projects (181100110200) of China。
文摘Fusarium crown rot(FCR) and sharp eyespot(SE)are serious soil-borne diseases in wheat and its relatives that have been reported to cause wheat yield losses in many areas. In this study, the expression of a cell wall invertase gene, TaCWI-B1,was identified to be associated with FCR resistance through a combination of bulk segregant RNA sequencing and genome resequencing in a recombinant inbred line population. Two biparental populations were developed to further verify TaCWI-B1 association with FCR resistance.Overexpression lines and ethyl methanesulfonate(EMS) mutants revealed TaCWI-B1 positively regulating FCR resistance. Determination of cell wall thickness and components showed that the TaCWI-B1-overexpression lines exhibited considerably increased thickness and pectin and cellulose contents. Furthermore, we found that TaCWI-B1 directly interacted with an alphagalactosidase(TaGAL). EMS mutants showed that TaGAL negatively modulated FCR resistance. The expression of TaGAL is negatively correlated with TaCWI-B1 levels, thus may reduce mannan degradation in the cell wall, consequently leading to thickening of the cell wall. Additionally, TaCWI-B1-overexpression lines and TaGAL mutants showed higher resistance to SE;however, TaCWI-B1 mutants were more susceptible to SE than controls.This study provides insights into a FCR and SE resistance gene to combat soil-borne diseases in common wheat.
基金the National Natural Science Foundation of China (30771316)the State Key Basic Research and Development Plan of China(2006CB100201).
文摘The cytological instability of common wheat-rye addition lines was investigated in the present study. The chromosome numbers of almost all addition lines were considerably stable, but those of CS ＋ 5R were very variable. The rye chromosome added in this line was found to be much shorter than expected. Fluorescent in situ hybridization with 5S rDNA and the centromere-speciflc probes clearly revealed that the short rye chromosome contains only a short arm of chromosome 5R （5RS）. In this line, chromosome numbers of both 5RS and common wheat were changeable. The chromosome numbers ranged from 2n = 36 to 2n = 44 in the cells carrying two 5RS, and ranged from 2n = 31 to 2n = 44 in one 5RS cells. In addition to the chromosome instability, the muIticells wrapped in a sac-like structure were frequently observed in the root meristematic tissues of CS ＋5RS after the enzyme treatment for chromosome preparation. Genomic in situ hybridization with rye DNA as a probe showed that all cells in sacs investigated were at the interphase stage and contained one or two 5RS chromosomes. An electron microscopic analysis revealed that the cells of CS＋5RS, particularly in sacs, have abnormal （irregular and curved） cell walls. These results indicate that 5RS has （a） specific factor（s） influencing the cell wall development as well as the genome stability.
基金funded by the National Key R&D Program of China(Grant No.2019YFE0118300)the National Natural Science Foundation of China(Grant Nos.U1804234,31901542,and 31861143008)the Henan Natural Science Foundation,China(Grant No.202300410196)。
文摘As a novel post-translational modification(PTM),lysine 2-hydroxyisobutyrylation(Khib)is considered to regulate gene transcriptional activities in eukaryotic cells;however,the functions of Khib-modified proteins in plants remain unknown.Here,we report that Khib is an evolutionarilyconserved PTM in wheat and its progenitors.A total of 3348 Khib sites on 1074 proteins are identified in common wheat(Triticum aestivum L.)by using affinity purification and mass spectroscopy of 2-hydroxyisobutyrylome.Bioinformatic data indicate that Khib-modified proteins participate in a wide variety of biological and metabolic pathways.Immunoprecipitation confirms that Khibmodified proteins are present endogenously.A comparison of Khib and other main PTMs shows that Khib-modified proteins are simultaneously modified by multiple PTMs.Using mutagenesis experiments and co-immunoprecipitation assays,we demonstrate that Khib on K206 of phosphoglycerate kinase(PGK)is a key regulatory modification for its enzymatic activity,and mutation on K206 affects the interactions of PGK with its substrates.Furthermore,Khib modification of low-molecular-weight proteins is a response to the deacetylase inhibitors nicotinamide and trichostatin.This study provides evidence to promote our current understanding of Khib in wheat plants,including the cooperation between Khib and its metabolic regulation.
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.
