Protoplasts derived from common wheat (Triticum aestivum L,. cv. Jinan 177) were fused with UV-treated protoplasts of Agropyron elongatum. (Host) Nevski by PEG method, and fertile asymmetric somatic hybrid plants rese...Protoplasts derived from common wheat (Triticum aestivum L,. cv. Jinan 177) were fused with UV-treated protoplasts of Agropyron elongatum. (Host) Nevski by PEG method, and fertile asymmetric somatic hybrid plants resembling wheat morphology were obtained. The F-2 hybrid plants could be divided into 3 types according to their morphology. Type I hybrids had high and loosely standing stalks with big spikes and grains. Type ii hybrids were dwarf and compact in shape with high tillering ability and smaller spikes. Type III hybrids were similar to type I as a whole but had more compact and erect spikes. All the F-2 hybrid lines were superior to wheat in seed protein content, although some difference existed between themselves. Protein analysis of immature embryos and flag leaves from hybrids by two-dimensional electrophoresis showed that they possessed characteristic proteins of both parents and some new proteins. There existed also some different kinds of proteins in different lines.展开更多
By measuring and comparing the contents of amino acids in Agropyron cristatum under grazing pressure, this study showed that the contents of total and each of the amino acids in A. cristatum changed little under grazi...By measuring and comparing the contents of amino acids in Agropyron cristatum under grazing pressure, this study showed that the contents of total and each of the amino acids in A. cristatum changed little under grazing pressure. How- ever, the contents of free glycine （Gly） and proline （Pro） were very sensitive to grazing. Glycine content in grazing population was higher than that in non-grazing population at flowering stage; the content of free proline in non-grazing population was higher than that in grazing population at tillering, heading and especially flower- ing stage; the content of free proline under grazing pressure at maturity stage was higher than that of non-grazing population.展开更多
Wheat is a staple food crop in the world as well as in China. Because of the progress of wheat breeding and other agricultural ＂sci-technologies, the wheat grain yield per unit area has increased more than five folds...Wheat is a staple food crop in the world as well as in China. Because of the progress of wheat breeding and other agricultural ＂sci-technologies, the wheat grain yield per unit area has increased more than five folds from 1952 to 2006 in China. The first part of this article briefly reviews the history of wheat breeding in China. Second, the establishment of ＂Triticum aestivum-Agropyron＂ distant hybridization system and its contribution to wheat production and breeding in China are summarized. Finally, the future challenges of wheat breeding are discussed, which include how to increase the utilization efficiencies of water, soil nutrient and light energy through breeding. As an example, our research progress on how to increase light use efficiency in wheat through breeding is introduced and discussed.展开更多
We report the production and characterization of somatic hybrids between Triticum aestivum L. and Agropyron elongatum (Host) Nevishi (the synonym is Thinopyrum ponticum). Asymmetric protoplast fusion was performed bet...We report the production and characterization of somatic hybrids between Triticum aestivum L. and Agropyron elongatum (Host) Nevishi (the synonym is Thinopyrum ponticum). Asymmetric protoplast fusion was performed between Agropyron elongatum protoplasts irradiated with a low UV dose and protoplasts of wheat taken from nonregenerable suspension cultures. More than 40 green plantlets were obtained from 15 regenerated clones and one of them produced seeds. The phenotypes of the hybrid plants and seeds were intermediate between wheat and Agropyron eIongatum. All of the regenerated calli and plants were verified as intergeneric hybrids on the basis of morphological observation and analysis of isozyme, cytological, 5SrDNA spacer sequences and random amplified polymorphic DNA (RAPD). RFLP analysis of the mitochondrial genome revealed evidence of random segregation and recombination of mtDNA.展开更多
The plants of hybrid wheatgrass （A. cristatum×A. desertorum cv. Hycrest-Mengnong） were directly induced from embryogenic callus regenerated from immature inflorescence. Immature inflorescence was cultured on im...The plants of hybrid wheatgrass （A. cristatum×A. desertorum cv. Hycrest-Mengnong） were directly induced from embryogenic callus regenerated from immature inflorescence. Immature inflorescence was cultured on improved MS medium containing 2.0-3.0 mg L^-1 2,4-D to regenerate callus. The calli were then transferred to hormone-free MS medium for differentiation and 1/2 MS medium for rooting. Results showed that callus initiation frequency was 83.4% and plant regeneration frequency was 59.6%. Phosphinothricin acetyltransferase （bar） gene was transformed into the hybrid wheatgrass by particle bombardment. Resistant callus was obtained using selecting agent, herbicide glufosinate of 0.5 mg L^-1, and some transgenic plants were recovered in vitro. The transgenic plants were identified by PCR and Southern blot analysis and these plants developed normally in the glufosinate medium, whereas the nontransgenic plants did not. The results demonstrated that bar cDNA integrated into the genomic DNA of the transgenic plants. The transgenic frequencies of bar gene were 1.1%.展开更多
As an important wild relative of wheat, Agropyron cristatum has been successfully used for wheat improvement. Currently, a few useful agronomic traits of A. cristatum, such as high grain number per spike and resistanc...As an important wild relative of wheat, Agropyron cristatum has been successfully used for wheat improvement. Currently, a few useful agronomic traits of A. cristatum, such as high grain number per spike and resistance to diseases, have been transferred into common wheat.However, the effective detection of small A. cristatum segmental introgressions in common wheat is still difficult. The objective of this study was to identify A. cristatum-specific single nucleotide polymorphisms(SNPs) for the detection of small alien segments in wheat. The transcriptome sequences of A. cristatum were aligned against wheat coding DNA sequences(CDS) for SNP calling. As a result, we discovered a total of 167,613 putative SNPs specific to the P genome of A. cristatum compared with the common wheat genomes. Among 230 selected SNPs with functional annotations related to inflorescence development and stress resistance,68 were validated as P genome-specific SNPs in multiple wheat backgrounds using Kompetitive Allele Specific PCR(KASP) assays. Among them, 55 SNPs were assigned to six homoeologous groups of the P genome using wheat-A. cristatum addition lines, and 6 P-specific SNP markers were further physically mapped on different segments of chromosome 6 P in 6 P translocation lines. The P genome-specific SNPs were also validated by Sanger sequencing and used to detect the P chromatin in wheat-A. cristatum cryptic introgression lines. Two SNP markers(Unigene20217-182 and Unigene20307-1420) were detected in two wheat-A. cristatum introgression lines that showed enhanced grain number per spike and high resistance to powdery mildew. Together, the developed P genome-specific SNP markers will accelerate the detection of large numbers of wheat-A. cristatum derivatives and will be helpful for marker-assisted transfer of desirable traits from A. cristatum into adapted wheat cultivars in wheat breeding programs.展开更多
Reference genes, stably expressing in different tissues and cells, are commonly used as the references in expression analysis. Selecting the optimum reference gene is crucial to the success of experiments. In this stu...Reference genes, stably expressing in different tissues and cells, are commonly used as the references in expression analysis. Selecting the optimum reference gene is crucial to the success of experiments. In this study, the expression stabilities of nine common reference genes, including ACT2, 18 S r RNA, APRT, EF-1α, RNA POL II, TUBα, TUBβ, GAPDH and TLF of Agropyron mongolicum, were studied under drought condition. Among them, 18 S r RNA was found to be the most optimum reference gene under drought stress by the analyzing of ge Norm and Norm Finder software. Quantitative expression levels of P5 CS using 18 S r RNA as the reference gene, and proline contents under drought stress in A. mongolicum were further operated, and we found the expression level of P5 CS gene and proline content had a significantly positive relationship（R^2=0.7763, P〈0.05）. This study established and validated 18 S r RNA as the reference genes in A. mongolicum under drought stress, providing a powerful tool for the quantitative expression analysis of drought genes in A. mongolicum.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
Agropyron cristatum(2n=4x=28,PPPP),which harbours many high-yield and disease-resistance genes,is a promising donor for wheat improvement.Narrow genetic diversity and the trade-off between grain weight and grain numbe...Agropyron cristatum(2n=4x=28,PPPP),which harbours many high-yield and disease-resistance genes,is a promising donor for wheat improvement.Narrow genetic diversity and the trade-off between grain weight and grain number have become bottlenecks for increasing grain yield in wheat.In this study,a novel translocation line,WAT650l,was derived from the chromosome 6P addition line 4844–12,which can simultaneously increase both grain number per spike(GNS)and thousand-grain weight(TGW).Cytological analysis and molecular marker analysis revealed that WAT650l was a 5BL.5BS-6PL(bin 12–17)translocation line.Assessment of agronomic traits and analysis of the BC4F2 and BC5F2 populations suggested that the 6PL terminal chromosome segment in WAT650l resulted in increased grain number per spike(average increased by 14.07 grains),thousand-grain weight(average increased by 4.31 g),flag leaf length,plant height,spikelet number per spike and kernel number per spikelet during the two growing seasons of 2020–2021 and 2021–2022.Additionally,the increased GNS locus and high-TGW locus of WAT650l were mapped to the bins 16–17 and 12–13,respectively,on chromosome 6PL by genetic population analysis of three translocation lines.In summary,we provide a valuable germplasm resource for broadening the genetic base of wheat and overcoming the negative relationship between GNS and TGW in wheat breeding.展开更多
Wide hybridization is a strategy for broadening the genetic basis of wheat. Because an efficient method for inducing wheat–alien chromosome translocations will allow producing useful germplasm, it is desirable to dis...Wide hybridization is a strategy for broadening the genetic basis of wheat. Because an efficient method for inducing wheat–alien chromosome translocations will allow producing useful germplasm, it is desirable to discover new genes that induce chromosomal variation. In this study, chromosome 5P from A.cristatum was shown to induce many types of chromosomal structural variation in a common wheat background, including nonhomoeologous chromosome translocations, as revealed by genomic in situ hybridization, fluorescence in situ hybridization, and DNA marker analysis. Aberrant meiosis was associated with chromosomal structural variation, and aberrant meiotic behavior was observed in wheat–A.cristatum 5P monosomic and disomic addition lines, suggesting that the effect of chromosome 5P was independent of the number of chromosome 5P copies. Chromosome 5P disturbed homologous chromosome pairing at pachytene stage in a common wheat background, resulting in a high frequency of univalent formation and reduced crossing over. Thirteen genes involved in DNA repair or chromatin remodeling, including RAD52-like and MSH6 genes, were differentially expressed(upregulated) in wheat–A. cristatum 5P addition lines according to transcriptome analysis, implicating chromosome 5P in the process of meiotic double-strand break repair. These findings provide a new, efficient tool for inducing wheat–alien chromosome translocations and producing new germplasm.展开更多
文摘Protoplasts derived from common wheat (Triticum aestivum L,. cv. Jinan 177) were fused with UV-treated protoplasts of Agropyron elongatum. (Host) Nevski by PEG method, and fertile asymmetric somatic hybrid plants resembling wheat morphology were obtained. The F-2 hybrid plants could be divided into 3 types according to their morphology. Type I hybrids had high and loosely standing stalks with big spikes and grains. Type ii hybrids were dwarf and compact in shape with high tillering ability and smaller spikes. Type III hybrids were similar to type I as a whole but had more compact and erect spikes. All the F-2 hybrid lines were superior to wheat in seed protein content, although some difference existed between themselves. Protein analysis of immature embryos and flag leaves from hybrids by two-dimensional electrophoresis showed that they possessed characteristic proteins of both parents and some new proteins. There existed also some different kinds of proteins in different lines.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201003023)~~
文摘By measuring and comparing the contents of amino acids in Agropyron cristatum under grazing pressure, this study showed that the contents of total and each of the amino acids in A. cristatum changed little under grazing pressure. How- ever, the contents of free glycine （Gly） and proline （Pro） were very sensitive to grazing. Glycine content in grazing population was higher than that in non-grazing population at flowering stage; the content of free proline in non-grazing population was higher than that in grazing population at tillering, heading and especially flower- ing stage; the content of free proline under grazing pressure at maturity stage was higher than that of non-grazing population.
基金Chinese Academy of Sciences (No. KSCXZ-YW-N-059 and KSCX1-YW-03)the National Natural Science Foundation of China (No. 30330390 and 30521001)the State Key Basic Research and Development Plan of China (No.2005CB 120904
文摘Wheat is a staple food crop in the world as well as in China. Because of the progress of wheat breeding and other agricultural ＂sci-technologies, the wheat grain yield per unit area has increased more than five folds from 1952 to 2006 in China. The first part of this article briefly reviews the history of wheat breeding in China. Second, the establishment of ＂Triticum aestivum-Agropyron＂ distant hybridization system and its contribution to wheat production and breeding in China are summarized. Finally, the future challenges of wheat breeding are discussed, which include how to increase the utilization efficiencies of water, soil nutrient and light energy through breeding. As an example, our research progress on how to increase light use efficiency in wheat through breeding is introduced and discussed.
基金supported by National Natural Science Foundation of China,No.30370857Trans-century Training Program Foundation for the Talents by the Ministry of Education in ChinaNational High Technology Research and Development Project No.2001AA241032
文摘We report the production and characterization of somatic hybrids between Triticum aestivum L. and Agropyron elongatum (Host) Nevishi (the synonym is Thinopyrum ponticum). Asymmetric protoplast fusion was performed between Agropyron elongatum protoplasts irradiated with a low UV dose and protoplasts of wheat taken from nonregenerable suspension cultures. More than 40 green plantlets were obtained from 15 regenerated clones and one of them produced seeds. The phenotypes of the hybrid plants and seeds were intermediate between wheat and Agropyron eIongatum. All of the regenerated calli and plants were verified as intergeneric hybrids on the basis of morphological observation and analysis of isozyme, cytological, 5SrDNA spacer sequences and random amplified polymorphic DNA (RAPD). RFLP analysis of the mitochondrial genome revealed evidence of random segregation and recombination of mtDNA.
文摘The plants of hybrid wheatgrass （A. cristatum×A. desertorum cv. Hycrest-Mengnong） were directly induced from embryogenic callus regenerated from immature inflorescence. Immature inflorescence was cultured on improved MS medium containing 2.0-3.0 mg L^-1 2,4-D to regenerate callus. The calli were then transferred to hormone-free MS medium for differentiation and 1/2 MS medium for rooting. Results showed that callus initiation frequency was 83.4% and plant regeneration frequency was 59.6%. Phosphinothricin acetyltransferase （bar） gene was transformed into the hybrid wheatgrass by particle bombardment. Resistant callus was obtained using selecting agent, herbicide glufosinate of 0.5 mg L^-1, and some transgenic plants were recovered in vitro. The transgenic plants were identified by PCR and Southern blot analysis and these plants developed normally in the glufosinate medium, whereas the nontransgenic plants did not. The results demonstrated that bar cDNA integrated into the genomic DNA of the transgenic plants. The transgenic frequencies of bar gene were 1.1%.
基金supported by the China Agriculture Research System(CARS-03)the National Key Research and Development Program of China(2016YFD0102000)
文摘As an important wild relative of wheat, Agropyron cristatum has been successfully used for wheat improvement. Currently, a few useful agronomic traits of A. cristatum, such as high grain number per spike and resistance to diseases, have been transferred into common wheat.However, the effective detection of small A. cristatum segmental introgressions in common wheat is still difficult. The objective of this study was to identify A. cristatum-specific single nucleotide polymorphisms(SNPs) for the detection of small alien segments in wheat. The transcriptome sequences of A. cristatum were aligned against wheat coding DNA sequences(CDS) for SNP calling. As a result, we discovered a total of 167,613 putative SNPs specific to the P genome of A. cristatum compared with the common wheat genomes. Among 230 selected SNPs with functional annotations related to inflorescence development and stress resistance,68 were validated as P genome-specific SNPs in multiple wheat backgrounds using Kompetitive Allele Specific PCR(KASP) assays. Among them, 55 SNPs were assigned to six homoeologous groups of the P genome using wheat-A. cristatum addition lines, and 6 P-specific SNP markers were further physically mapped on different segments of chromosome 6 P in 6 P translocation lines. The P genome-specific SNPs were also validated by Sanger sequencing and used to detect the P chromatin in wheat-A. cristatum cryptic introgression lines. Two SNP markers(Unigene20217-182 and Unigene20307-1420) were detected in two wheat-A. cristatum introgression lines that showed enhanced grain number per spike and high resistance to powdery mildew. Together, the developed P genome-specific SNP markers will accelerate the detection of large numbers of wheat-A. cristatum derivatives and will be helpful for marker-assisted transfer of desirable traits from A. cristatum into adapted wheat cultivars in wheat breeding programs.
基金supported by the Western Light Project of Chinese Academy of Sciencesthe National Natural Science Foundation of China(31060057)the National Natural Science Foundation of Inner Mongolia,China(2015MS0305)
文摘Reference genes, stably expressing in different tissues and cells, are commonly used as the references in expression analysis. Selecting the optimum reference gene is crucial to the success of experiments. In this study, the expression stabilities of nine common reference genes, including ACT2, 18 S r RNA, APRT, EF-1α, RNA POL II, TUBα, TUBβ, GAPDH and TLF of Agropyron mongolicum, were studied under drought condition. Among them, 18 S r RNA was found to be the most optimum reference gene under drought stress by the analyzing of ge Norm and Norm Finder software. Quantitative expression levels of P5 CS using 18 S r RNA as the reference gene, and proline contents under drought stress in A. mongolicum were further operated, and we found the expression level of P5 CS gene and proline content had a significantly positive relationship（R^2=0.7763, P〈0.05）. This study established and validated 18 S r RNA as the reference genes in A. mongolicum under drought stress, providing a powerful tool for the quantitative expression analysis of drought genes in A. mongolicum.
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financially supported by the National Natural Science Foundation of China(32171961)the Agricultural Science and Technology Innovation Program of CAAS(CAASASTIP-2021-ICS)。
文摘Agropyron cristatum(2n=4x=28,PPPP),which harbours many high-yield and disease-resistance genes,is a promising donor for wheat improvement.Narrow genetic diversity and the trade-off between grain weight and grain number have become bottlenecks for increasing grain yield in wheat.In this study,a novel translocation line,WAT650l,was derived from the chromosome 6P addition line 4844–12,which can simultaneously increase both grain number per spike(GNS)and thousand-grain weight(TGW).Cytological analysis and molecular marker analysis revealed that WAT650l was a 5BL.5BS-6PL(bin 12–17)translocation line.Assessment of agronomic traits and analysis of the BC4F2 and BC5F2 populations suggested that the 6PL terminal chromosome segment in WAT650l resulted in increased grain number per spike(average increased by 14.07 grains),thousand-grain weight(average increased by 4.31 g),flag leaf length,plant height,spikelet number per spike and kernel number per spikelet during the two growing seasons of 2020–2021 and 2021–2022.Additionally,the increased GNS locus and high-TGW locus of WAT650l were mapped to the bins 16–17 and 12–13,respectively,on chromosome 6PL by genetic population analysis of three translocation lines.In summary,we provide a valuable germplasm resource for broadening the genetic base of wheat and overcoming the negative relationship between GNS and TGW in wheat breeding.
基金financially supported by the National Key Research and Development Program of China (2021YFD1200605)the National Natural Science Foundation of China (32171961)。
文摘Wide hybridization is a strategy for broadening the genetic basis of wheat. Because an efficient method for inducing wheat–alien chromosome translocations will allow producing useful germplasm, it is desirable to discover new genes that induce chromosomal variation. In this study, chromosome 5P from A.cristatum was shown to induce many types of chromosomal structural variation in a common wheat background, including nonhomoeologous chromosome translocations, as revealed by genomic in situ hybridization, fluorescence in situ hybridization, and DNA marker analysis. Aberrant meiosis was associated with chromosomal structural variation, and aberrant meiotic behavior was observed in wheat–A.cristatum 5P monosomic and disomic addition lines, suggesting that the effect of chromosome 5P was independent of the number of chromosome 5P copies. Chromosome 5P disturbed homologous chromosome pairing at pachytene stage in a common wheat background, resulting in a high frequency of univalent formation and reduced crossing over. Thirteen genes involved in DNA repair or chromatin remodeling, including RAD52-like and MSH6 genes, were differentially expressed(upregulated) in wheat–A. cristatum 5P addition lines according to transcriptome analysis, implicating chromosome 5P in the process of meiotic double-strand break repair. These findings provide a new, efficient tool for inducing wheat–alien chromosome translocations and producing new germplasm.
