In order to reveal the origin and evolutionary relationship between two CCDD genome species, Oryza alta and Oryza latifolia, fluorescence in situ hybridization （FISH） was adopted to analyze the genomes of the two sp...In order to reveal the origin and evolutionary relationship between two CCDD genome species, Oryza alta and Oryza latifolia, fluorescence in situ hybridization （FISH） was adopted to analyze the genomes of the two species with C0t-1 DNA from O. alta as a probe. Karyotype was also comparatively analyzed between O. alta and O. latifolia based on their similar band patterns of the hybridization signals. There were a high homology and close relationship between O. alta and O. latifolia, however, the distinction between the hybridization signals was also clear. C0t-1 DNA was proved to be species- and genome type-specific. It is suggested that C0t-1 DNA-FISH could be more efficient to analyze the genomic relationship between different species. According to the comparative analysis of highly and moderately repetitive DNA sequences between the two allotetraploidy species, O. alta and O. latifolia, the possible origin and evolutionary mechanism of allotetraploidy of Oryza were discussed.展开更多
To transfer desirable resistance traits from O. minuta to O. sativa, intergeneric hybrid plants between O. sativa (AA, 2n=2X=24) and O. minuta (BBCC, 2n=4X=48) were produced by embryo rescue after sexual cross. Morpho...To transfer desirable resistance traits from O. minuta to O. sativa, intergeneric hybrid plants between O. sativa (AA, 2n=2X=24) and O. minuta (BBCC, 2n=4X=48) were produced by embryo rescue after sexual cross. Morphological observation and chromosome counts indicated their hybrid status (ABC, 2n=3X=36). Genomic in situ hybridization (GISH) was further applied to confirm the parentage of the chromosomes of F 1 hybrids. Chromosomes of O. minuta and O. sativa were distinguishable in the hybrids in different fluorescence colors. GISH indicated that A and BC chromosomes were not randomly assembled in a cell. RAPD profiles unequivocally revealed their hybrids with double parent patterns. The results of blast tests showed that the hybrids had obtained disease resistance from O. minuta, and had a level of susceptibility between the parents.展开更多
Oryza ridleyi is an allotetraploid wild species with the HHJJ genome, and Oryza sativa is a diploid cultivated rice that has the AA genome. Although the wide hybrid between the two species is difficult to obtain, we o...Oryza ridleyi is an allotetraploid wild species with the HHJJ genome, and Oryza sativa is a diploid cultivated rice that has the AA genome. Although the wide hybrid between the two species is difficult to obtain, we overcome this difficulty by young embryo rescue. An obvious heterosis was primarily found for the plant height, tillering ability, vegetative vigor, etc. However, the hybrid panicle and culm traits were found to resemble that of the wild rice parent, O. ridleyi, for the long awns, exoteric purple stigma, grain shattering, dispersed panicles, and culm mechanical strength. Genomic in situ hybridization （GISH） analysis was subsequently performed on the mitotic metaphase chromosome of the root tips, and we determined that the hybrid is an allotriploid with 36 chromosomes and its genomic constitution is AHJ. Chemical analyses conducted on the culm of O. sativa, O. ridleyi, and their interspecific hybrids showed that major changes occurred in the xylose, glucose, and arabinose concentrations, which are correlated with the specific hemicellulose polymer and cellulose components that are important in the primary cell walls of green plants. Meanwhile, the culm anatomical analyses indicated that additional large vascular bundles and an extra sclerenchyma cell layer were found in O. ridleyi. Additionally, further thickening of the secondary cell walls of the cortical fiber sclerenchyma cells and the phloem companion cells was discovered in O. ridleyi and in the interspecific hybrids. These results imply that there may be a potential link between culm mechanical strength and culm anatomical structure.展开更多
In the genus Oryza, interspecific hybrids are useful bridges for transferring the desired genes from wild species to cultivated rice （Oryza sativa L.）. In the present study, hybrids between O. sativa （AA genome） a...In the genus Oryza, interspecific hybrids are useful bridges for transferring the desired genes from wild species to cultivated rice （Oryza sativa L.）. In the present study, hybrids between O. sativa （AA genome） and three Chinese wild rices, namely O. rufipogon （AA genome）, O. officinalis （CC genome）, and O. meyeriana （GG genome）, were produced. Agricultural traits of the F1 hybrids surveyed were intermediate between their parents and appreciably resembled wild rice parents. Except for the O. sativa × O. rufipogon hybrid, the other F1 hybrids were completely sterile. Genomic in situ hybridization （GISH） was used for hybrid verification. Wild rice genomic DNAs were used as probes and cultivated rice DNA was used as a block. With the exception of O. rufipogon chromosomes, this method distinguished the other two wild rice and cultivated rice chromosomes at the stage of mitotic metaphase with different blocking ratios. The results suggest that a more distant phylogenetic relationship exists between O. meyeriana and O. sativa and that O. rufipogon and O. sativa share a high degree of sequence homology. The average mitotic chromosome length of O. officinalis and O. meyeriana was 1.25- and 1.51-fold that of O. sativa, respectively. 4＇,6＇-Diamidino- 2-phenylindole staining showed that the chromosomes of O. officinalis and O. meyeriana harbored more heterochromatin, suggesting that the C and G genomes were amplified with repetitive sequences compared with the A genome. Although chromocenters formed by chromatin compaction were detected with wild rice-specific signals corresponding to the C and G genomes in discrete domains of the F1 hybrid interphase nuclei, the size and number of O. meyeriana chromocenters were bigger and greater than those of O. officinalis. The present results provide an important understanding of the genomic relationships and a tool for the transfer of useful genes from three native wild rice species in China to cultivars.展开更多
Oryza sativa and O. latifolia belong to the AA and CCDD genomes of Oryza, respectively. In this study, interspecific hybrids of these species were obtained using the embryo rescue technique. Hybrid panicle traits, suc...Oryza sativa and O. latifolia belong to the AA and CCDD genomes of Oryza, respectively. In this study, interspecific hybrids of these species were obtained using the embryo rescue technique. Hybrid panicle traits, such as long awns, small grain, exoteric large purple stigma, grain shattering and dispersed panicles, resemble that of the paternal parent, O. latifolia, whereas there is obvious heterosis in such respects as plant height, tillering ability and vegetative vigor. Chromosome pairing and the genomic components of the hybrid were subsequently investigated using genomic in situ hybridization (GISH) and fluorescent in situ hybridization (FISH) analysis. Based on the mitotic metaphase chromosome numbers of the root tips investigated, the hybrid is a triploid with 36 chromosomes. The genomic constitution of the hybrid is ACD. In the meiotic metaphase I of the hybrid pollen mother cell, poor chro- mosome pairing was identified and most of the chromosomes were univalent, which resulted in com- plete male sterility in the hybrid.展开更多
Fluorescence in situ hybridization (FISH)was applied to somatic chromosomes preparations of Oryza officinalis Wall. (CC), O. sativa L. (AA)×O. offi-cinalis F1 hybrid (AC), backcross progenies BC1 (AAC and ACC), O...Fluorescence in situ hybridization (FISH)was applied to somatic chromosomes preparations of Oryza officinalis Wall. (CC), O. sativa L. (AA)×O. offi-cinalis F1 hybrid (AC), backcross progenies BC1 (AAC and ACC), O. latifolia Desv. (CCDD), O. alta Swallen (CCDD) and O. punctata Kotschy (BBCC) with a labelled probe of C0t-1 DNA from O. officinalis. In O. officinalis, the homologous chromosomes showed similar signal bands probed by C0t-1 DNA and karyotype analysis was conducted based on the band patterns. Using no blocking DNA, the probe identified the chromosomes of C genome clearly, but detected few signals on chromosomes of A genome in the F1 hybrid and two backcross progenies of BC1. It is obvious that the highly and moderately repetitive DNA sequences were considerably different between C and A genomes. The chromosomes of C genome were also discriminated from the chromosomes of D- and B-genome in the tetraploid species O. latifolia, O. alta and O. punctata by C0t-1 DNA-FISH. Compari-son of the fluorescence intensity on the chromo-somes of B, C and D genomes in O. latifolia, O. alta, and O. punctata indicated that the differentiations between C and D genomes are less than that be-tween C and B genomes. The relationship between C and D genomes in O. alta is closer than that of C and D genomes in O. latifolia. This would be one of thecauses for the fact that both the genomes are of the same karyotype (CCDD) but belong to different spe-cies. The above results showed that the C0t-1 DNA had a high specificity of genome and species. In this paper, the origin of allotetraploid in genus Oryza is also discussed.展开更多
[Objective] Genomic in situ hybridization (GISH) was used to study the relationship between the two CCDD genomes of Oryza alta and Oryza latifolia. [Method] Total DNA of Oryza officinalis (C-genome) was used as a prob...[Objective] Genomic in situ hybridization (GISH) was used to study the relationship between the two CCDD genomes of Oryza alta and Oryza latifolia. [Method] Total DNA of Oryza officinalis (C-genome) was used as a probe for genomic in situ hybridization on metaphase chromosomes from Oryza alta and Oryza latifolia, respectively. [Result] Under certain post-hybridization washing stringencies, C- and D-genome could be distinguished in CCDD genome type; there were huge differences in some CC chromosomes of Oryza alta, Oryza latifolia, and Oryza officinalis. The genome of Oryza latifolia was more original. [Conclusion] Comparative analysis of the Oryza species with identical genome type may facilitate to elucidate the possible approaches to plant genome evolution and species evolution.展开更多
基金supported by the Science Foundation of South-Central University for Nationalities, China (Grant No. YZY10007)
文摘In order to reveal the origin and evolutionary relationship between two CCDD genome species, Oryza alta and Oryza latifolia, fluorescence in situ hybridization （FISH） was adopted to analyze the genomes of the two species with C0t-1 DNA from O. alta as a probe. Karyotype was also comparatively analyzed between O. alta and O. latifolia based on their similar band patterns of the hybridization signals. There were a high homology and close relationship between O. alta and O. latifolia, however, the distinction between the hybridization signals was also clear. C0t-1 DNA was proved to be species- and genome type-specific. It is suggested that C0t-1 DNA-FISH could be more efficient to analyze the genomic relationship between different species. According to the comparative analysis of highly and moderately repetitive DNA sequences between the two allotetraploidy species, O. alta and O. latifolia, the possible origin and evolutionary mechanism of allotetraploidy of Oryza were discussed.
基金The work was supported by National High Technology Development Program of China(Z16-02-01-02).
文摘To transfer desirable resistance traits from O. minuta to O. sativa, intergeneric hybrid plants between O. sativa (AA, 2n=2X=24) and O. minuta (BBCC, 2n=4X=48) were produced by embryo rescue after sexual cross. Morphological observation and chromosome counts indicated their hybrid status (ABC, 2n=3X=36). Genomic in situ hybridization (GISH) was further applied to confirm the parentage of the chromosomes of F 1 hybrids. Chromosomes of O. minuta and O. sativa were distinguishable in the hybrids in different fluorescence colors. GISH indicated that A and BC chromosomes were not randomly assembled in a cell. RAPD profiles unequivocally revealed their hybrids with double parent patterns. The results of blast tests showed that the hybrids had obtained disease resistance from O. minuta, and had a level of susceptibility between the parents.
基金supported by the National Natural Science Foundation of China(31571624 and 31071382)the National Key Research and Development Program of China(2016YFD0102001-006)+2 种基金the National Basic Research(973)Program of China(2010CB125904-3,2013CBA01405)the Key Natural Science Project in University of Jiangsu Province,China(15KJA210004)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(PAPD)
文摘Oryza ridleyi is an allotetraploid wild species with the HHJJ genome, and Oryza sativa is a diploid cultivated rice that has the AA genome. Although the wide hybrid between the two species is difficult to obtain, we overcome this difficulty by young embryo rescue. An obvious heterosis was primarily found for the plant height, tillering ability, vegetative vigor, etc. However, the hybrid panicle and culm traits were found to resemble that of the wild rice parent, O. ridleyi, for the long awns, exoteric purple stigma, grain shattering, dispersed panicles, and culm mechanical strength. Genomic in situ hybridization （GISH） analysis was subsequently performed on the mitotic metaphase chromosome of the root tips, and we determined that the hybrid is an allotriploid with 36 chromosomes and its genomic constitution is AHJ. Chemical analyses conducted on the culm of O. sativa, O. ridleyi, and their interspecific hybrids showed that major changes occurred in the xylose, glucose, and arabinose concentrations, which are correlated with the specific hemicellulose polymer and cellulose components that are important in the primary cell walls of green plants. Meanwhile, the culm anatomical analyses indicated that additional large vascular bundles and an extra sclerenchyma cell layer were found in O. ridleyi. Additionally, further thickening of the secondary cell walls of the cortical fiber sclerenchyma cells and the phloem companion cells was discovered in O. ridleyi and in the interspecific hybrids. These results imply that there may be a potential link between culm mechanical strength and culm anatomical structure.
文摘In the genus Oryza, interspecific hybrids are useful bridges for transferring the desired genes from wild species to cultivated rice （Oryza sativa L.）. In the present study, hybrids between O. sativa （AA genome） and three Chinese wild rices, namely O. rufipogon （AA genome）, O. officinalis （CC genome）, and O. meyeriana （GG genome）, were produced. Agricultural traits of the F1 hybrids surveyed were intermediate between their parents and appreciably resembled wild rice parents. Except for the O. sativa × O. rufipogon hybrid, the other F1 hybrids were completely sterile. Genomic in situ hybridization （GISH） was used for hybrid verification. Wild rice genomic DNAs were used as probes and cultivated rice DNA was used as a block. With the exception of O. rufipogon chromosomes, this method distinguished the other two wild rice and cultivated rice chromosomes at the stage of mitotic metaphase with different blocking ratios. The results suggest that a more distant phylogenetic relationship exists between O. meyeriana and O. sativa and that O. rufipogon and O. sativa share a high degree of sequence homology. The average mitotic chromosome length of O. officinalis and O. meyeriana was 1.25- and 1.51-fold that of O. sativa, respectively. 4＇,6＇-Diamidino- 2-phenylindole staining showed that the chromosomes of O. officinalis and O. meyeriana harbored more heterochromatin, suggesting that the C and G genomes were amplified with repetitive sequences compared with the A genome. Although chromocenters formed by chromatin compaction were detected with wild rice-specific signals corresponding to the C and G genomes in discrete domains of the F1 hybrid interphase nuclei, the size and number of O. meyeriana chromocenters were bigger and greater than those of O. officinalis. The present results provide an important understanding of the genomic relationships and a tool for the transfer of useful genes from three native wild rice species in China to cultivars.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 30771210, 30500317 and 30600345)National Basic Research Program of China (Grant No. 2006CB101701)
文摘Oryza sativa and O. latifolia belong to the AA and CCDD genomes of Oryza, respectively. In this study, interspecific hybrids of these species were obtained using the embryo rescue technique. Hybrid panicle traits, such as long awns, small grain, exoteric large purple stigma, grain shattering and dispersed panicles, resemble that of the paternal parent, O. latifolia, whereas there is obvious heterosis in such respects as plant height, tillering ability and vegetative vigor. Chromosome pairing and the genomic components of the hybrid were subsequently investigated using genomic in situ hybridization (GISH) and fluorescent in situ hybridization (FISH) analysis. Based on the mitotic metaphase chromosome numbers of the root tips investigated, the hybrid is a triploid with 36 chromosomes. The genomic constitution of the hybrid is ACD. In the meiotic metaphase I of the hybrid pollen mother cell, poor chro- mosome pairing was identified and most of the chromosomes were univalent, which resulted in com- plete male sterility in the hybrid.
基金supported by the National Program of High Technology Development(Grant No.2004AA227120)the Scientific Research Foundation for the Returned 0verseas Chinese Scholars,State Education Ministry(Grant No.BZY04003)+1 种基金China Postdoctoral Science Foundation(Grant No.20040350574)the Project of Science and Technology for Youth,Wuhan,China(Grant No.2004500607135).
文摘Fluorescence in situ hybridization (FISH)was applied to somatic chromosomes preparations of Oryza officinalis Wall. (CC), O. sativa L. (AA)×O. offi-cinalis F1 hybrid (AC), backcross progenies BC1 (AAC and ACC), O. latifolia Desv. (CCDD), O. alta Swallen (CCDD) and O. punctata Kotschy (BBCC) with a labelled probe of C0t-1 DNA from O. officinalis. In O. officinalis, the homologous chromosomes showed similar signal bands probed by C0t-1 DNA and karyotype analysis was conducted based on the band patterns. Using no blocking DNA, the probe identified the chromosomes of C genome clearly, but detected few signals on chromosomes of A genome in the F1 hybrid and two backcross progenies of BC1. It is obvious that the highly and moderately repetitive DNA sequences were considerably different between C and A genomes. The chromosomes of C genome were also discriminated from the chromosomes of D- and B-genome in the tetraploid species O. latifolia, O. alta and O. punctata by C0t-1 DNA-FISH. Compari-son of the fluorescence intensity on the chromo-somes of B, C and D genomes in O. latifolia, O. alta, and O. punctata indicated that the differentiations between C and D genomes are less than that be-tween C and B genomes. The relationship between C and D genomes in O. alta is closer than that of C and D genomes in O. latifolia. This would be one of thecauses for the fact that both the genomes are of the same karyotype (CCDD) but belong to different spe-cies. The above results showed that the C0t-1 DNA had a high specificity of genome and species. In this paper, the origin of allotetraploid in genus Oryza is also discussed.
文摘[Objective] Genomic in situ hybridization (GISH) was used to study the relationship between the two CCDD genomes of Oryza alta and Oryza latifolia. [Method] Total DNA of Oryza officinalis (C-genome) was used as a probe for genomic in situ hybridization on metaphase chromosomes from Oryza alta and Oryza latifolia, respectively. [Result] Under certain post-hybridization washing stringencies, C- and D-genome could be distinguished in CCDD genome type; there were huge differences in some CC chromosomes of Oryza alta, Oryza latifolia, and Oryza officinalis. The genome of Oryza latifolia was more original. [Conclusion] Comparative analysis of the Oryza species with identical genome type may facilitate to elucidate the possible approaches to plant genome evolution and species evolution.
