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
Heritable alteration in DNA methylation patterns was detected in all five rice lines with introgressed DNA segments from wild rice(Zizania latifolia(Griseb.))by DNA gel blotting analys iswith an endogenous retrotransp...Heritable alteration in DNA methylation patterns was detected in all five rice lines with introgressed DNA segments from wild rice(Zizania latifolia(Griseb.))by DNA gel blotting analys iswith an endogenous retrotransposon Tos/7as a probe.The changing patterns include simultaneous loss of parental fragments and appearance of novel fragments in each of the four methylation-sensitive enzyme digests.Methylation modifications include cytosines at both symmetrical and asymmetrical sites,as well as adenine bases.Sequence ana lysis at two critical regions of Tos/7,i.e.the 5'-LTR region(region I)and the reverse transcriptase region(region II)showed complete conservation for all five introgression lines compared with the parent.Sequence-specific PCR assay,however,confirmed that methylation changes occurred in both regions,Moreover,concordance in the collective methylation changes between 5'-LTR and RT regions was observed in two of the introgression lines.The methylation changes are stably inherited to the next generation.Because earlier studies showed that there had been activation and mobilization of Tos/7 in these introgression lines following alien DNA integration,it appears likely that DNA methylation may have played some roles in controlling activity of Tos/7in rice,although the exact relationship between the two phenomena remains to be established.展开更多
The objectives of the present study were to estimate genetic diversity and genetic changes of introgression lines （ILs） which derived from cultivated rice （Oryza sativa L. cv. Xieqingzao B, XB） mating with common ...The objectives of the present study were to estimate genetic diversity and genetic changes of introgression lines （ILs） which derived from cultivated rice （Oryza sativa L. cv. Xieqingzao B, XB） mating with common wild rice （O. rufipogon Griff., CWR）. The genetic data of 239 ILs were based on a total of 131 polymorphic microsatellite （SSR） markers distributed across the 12 chromosomes of rice. On average, these ILs possessed 77.1 and 14.31% homozygous bands from XB and CWR, respectively. Most of the ILs were clustered together with XB individual, which was revealed by principal coordinate analysis （PCA） and the program STRUCTURE analysis. The result from PCA demonstrated that some intermediate genotypes between XB and CWR were also found. Moreover, there were some genomic sequence changes including parental bands elimination and novel bands emergence in the ILs. The average Nei＇s gene diversity （He） was 0.296, which was higher than that of cultivated rice. It suggested that interspecific hybridization and gene introgression could broaden the base of genetic variation and lay an important foundation for rice genetic improvement. These different genotypic ILs would provide a better experimental system for understanding the evolution of rice species and the mechanism of alien gene introgression.展开更多
Plant somatic hybridization has progressed steadily over the past 35 years. Many hybrid plants have been generated from fusion combinations of different phylogenetic species, some of which have been utilized in crop b...Plant somatic hybridization has progressed steadily over the past 35 years. Many hybrid plants have been generated from fusion combinations of different phylogenetic species, some of which have been utilized in crop breeding programs. Among them, asymmetric hybrid, which usually contains a fraction of alien genome, has received more attention because of its importance in crop improvement. However, few studies have dealt with the heredity of the genome of somatic hybrid for a long time, which has limited the progress of this approach. Over recent ten years, along with the development of an effective cytogenetical tool ＂in situ hybridization （ISH）＂, asymmetric fusion of common wheat （Triticum aestivum L.） with different grasses or cereals has been greatly developed. Genetics, genomes, functional genes and agricultt, ral traits of wheat asymmetric hybrids have been subject to systematic investigations using gene cloning, genomic in situ hybridization （GISH） and molecular makers. The future goal is to fully elucidate the functional relationships among improved agronomic traits, the genes and underlying molecular mechanisms, and the genome dynamics of somatic introgression lines. This will accelerate the development of elite germplasms via somatic hybridization and the application of these materials in the molecular improvement of crop plants.展开更多
A backcross recombinant inbred line population consisting of 202 lines was developed from Xieqingzao B//Xieqingzao B / Dongxiang wild rice. The population was assayed with DNA markers and phenotyped on planthopper res...A backcross recombinant inbred line population consisting of 202 lines was developed from Xieqingzao B//Xieqingzao B / Dongxiang wild rice. The population was assayed with DNA markers and phenotyped on planthopper resistance and yield traits. A linkage map consisting of 119 DNA markers and spanned for 1188 cM over the 12 rice chromosomes was constructed. Thirty-two chromosomal segment substitution lines were selected based on the percentage of Xieqingzao B allele at marker loci. These lines are of great potential for gene mapping and alien gene introgression.展开更多
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 Science Fund for Distinguished Young Scholars of China(30225003)the Outstanding Youth Research Plans of the Jilin Provincial Government
文摘Heritable alteration in DNA methylation patterns was detected in all five rice lines with introgressed DNA segments from wild rice(Zizania latifolia(Griseb.))by DNA gel blotting analys iswith an endogenous retrotransposon Tos/7as a probe.The changing patterns include simultaneous loss of parental fragments and appearance of novel fragments in each of the four methylation-sensitive enzyme digests.Methylation modifications include cytosines at both symmetrical and asymmetrical sites,as well as adenine bases.Sequence ana lysis at two critical regions of Tos/7,i.e.the 5'-LTR region(region I)and the reverse transcriptase region(region II)showed complete conservation for all five introgression lines compared with the parent.Sequence-specific PCR assay,however,confirmed that methylation changes occurred in both regions,Moreover,concordance in the collective methylation changes between 5'-LTR and RT regions was observed in two of the introgression lines.The methylation changes are stably inherited to the next generation.Because earlier studies showed that there had been activation and mobilization of Tos/7 in these introgression lines following alien DNA integration,it appears likely that DNA methylation may have played some roles in controlling activity of Tos/7in rice,although the exact relationship between the two phenomena remains to be established.
基金partially supported by the National Natural Science Foundation of China (30860120 and 30900781)the Natural Science Foundation of Jiangxi Province, China(2008GQN0059)the Development Program for Young Scientists of Jiangxi Province, China (20112BCB23007)
文摘The objectives of the present study were to estimate genetic diversity and genetic changes of introgression lines （ILs） which derived from cultivated rice （Oryza sativa L. cv. Xieqingzao B, XB） mating with common wild rice （O. rufipogon Griff., CWR）. The genetic data of 239 ILs were based on a total of 131 polymorphic microsatellite （SSR） markers distributed across the 12 chromosomes of rice. On average, these ILs possessed 77.1 and 14.31% homozygous bands from XB and CWR, respectively. Most of the ILs were clustered together with XB individual, which was revealed by principal coordinate analysis （PCA） and the program STRUCTURE analysis. The result from PCA demonstrated that some intermediate genotypes between XB and CWR were also found. Moreover, there were some genomic sequence changes including parental bands elimination and novel bands emergence in the ILs. The average Nei＇s gene diversity （He） was 0.296, which was higher than that of cultivated rice. It suggested that interspecific hybridization and gene introgression could broaden the base of genetic variation and lay an important foundation for rice genetic improvement. These different genotypic ILs would provide a better experimental system for understanding the evolution of rice species and the mechanism of alien gene introgression.
基金supported by the National Basic Research 973 Program of China (No. 2009CB118300 and 2006CB100100)the Major Program of the Natural Science Foundation of China (No. 30530480)+2 种基金the Major Science Foundation of Shandong Province (No. Q2006D02)the National Natural Science Foundation of China (No. 30871320 and 30370857)the National 863 High Tech-nology Research and Development Project (No. 2006AA100102)
文摘Plant somatic hybridization has progressed steadily over the past 35 years. Many hybrid plants have been generated from fusion combinations of different phylogenetic species, some of which have been utilized in crop breeding programs. Among them, asymmetric hybrid, which usually contains a fraction of alien genome, has received more attention because of its importance in crop improvement. However, few studies have dealt with the heredity of the genome of somatic hybrid for a long time, which has limited the progress of this approach. Over recent ten years, along with the development of an effective cytogenetical tool ＂in situ hybridization （ISH）＂, asymmetric fusion of common wheat （Triticum aestivum L.） with different grasses or cereals has been greatly developed. Genetics, genomes, functional genes and agricultt, ral traits of wheat asymmetric hybrids have been subject to systematic investigations using gene cloning, genomic in situ hybridization （GISH） and molecular makers. The future goal is to fully elucidate the functional relationships among improved agronomic traits, the genes and underlying molecular mechanisms, and the genome dynamics of somatic introgression lines. This will accelerate the development of elite germplasms via somatic hybridization and the application of these materials in the molecular improvement of crop plants.
文摘A backcross recombinant inbred line population consisting of 202 lines was developed from Xieqingzao B//Xieqingzao B / Dongxiang wild rice. The population was assayed with DNA markers and phenotyped on planthopper resistance and yield traits. A linkage map consisting of 119 DNA markers and spanned for 1188 cM over the 12 rice chromosomes was constructed. Thirty-two chromosomal segment substitution lines were selected based on the percentage of Xieqingzao B allele at marker loci. These lines are of great potential for gene mapping and alien gene introgression.
