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
Protoplasts of common wheat ( Triticum aestivum L.2 n =42) cv. Jinan 177 were fused with ultraviolet (UV) irradiated protoplasts of Agropyron elongatum (2 n =70) via a PEG method. Sterile hybrid plants were regenerate...Protoplasts of common wheat ( Triticum aestivum L.2 n =42) cv. Jinan 177 were fused with ultraviolet (UV) irradiated protoplasts of Agropyron elongatum (2 n =70) via a PEG method. Sterile hybrid plants were regenerated from the fused product and their ovaries were induced to form calli.From the resulted callus tissue, green plants were differentiated. These somaclonal plants (SF0) were investigated using chromosome and isozyme analysis. The results showed that they contained chromosomes from both donors (i.e., Triticum aestivum and Agropyron elongatum ). Two of the SF0 plants grew to maturity and set seeds. The analysis of phenotype, chromosome constitution, isozyme pattern and RAPD polymorphism of the F 1 plants confirmed their hybrid nature. Collectively, these results demonstrated that fertile hybrid plants could be produced from the procedure described above. Three different phenotypes were observed in F2 progenies. The type I and II plants had higher stalks (average 75～85 cm) and big ears and grains, but plants of the former phenotype possessed fewer tillers. Type III plants had short stalks (average 55 cm) but possessed high ability of tillering. Cytogenetical analysis of F 1 plants and their successive generations showed that in F 1 to F 3 generations the chromosome numbers of root tip cells varied in the range of 36～44, and many cells contained 1 4 micro chromosomes (mc). In PMC MI stage of the F2 plants, the chromosome configuration was mainly 17II 22II with 1 4 additional micro chromosomes. Comparing to F 2, more chromosome configuration of 20II 21II occurred in F 3, and over 70% of cells had the chromosome configurations of 21II+1 2 mcs. A large population of the different hybrid lines have been obtained through propagation and selection in successive generations. Their agronomic traits have been studied and will be reported in a separate paper.展开更多
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Protoplasts of common wheat ( Triticum aestivum L.2 n =42) cv. Jinan 177 were fused with ultraviolet (UV) irradiated protoplasts of Agropyron elongatum (2 n =70) via a PEG method. Sterile hybrid plants were regenerated from the fused product and their ovaries were induced to form calli.From the resulted callus tissue, green plants were differentiated. These somaclonal plants (SF0) were investigated using chromosome and isozyme analysis. The results showed that they contained chromosomes from both donors (i.e., Triticum aestivum and Agropyron elongatum ). Two of the SF0 plants grew to maturity and set seeds. The analysis of phenotype, chromosome constitution, isozyme pattern and RAPD polymorphism of the F 1 plants confirmed their hybrid nature. Collectively, these results demonstrated that fertile hybrid plants could be produced from the procedure described above. Three different phenotypes were observed in F2 progenies. The type I and II plants had higher stalks (average 75～85 cm) and big ears and grains, but plants of the former phenotype possessed fewer tillers. Type III plants had short stalks (average 55 cm) but possessed high ability of tillering. Cytogenetical analysis of F 1 plants and their successive generations showed that in F 1 to F 3 generations the chromosome numbers of root tip cells varied in the range of 36～44, and many cells contained 1 4 micro chromosomes (mc). In PMC MI stage of the F2 plants, the chromosome configuration was mainly 17II 22II with 1 4 additional micro chromosomes. Comparing to F 2, more chromosome configuration of 20II 21II occurred in F 3, and over 70% of cells had the chromosome configurations of 21II+1 2 mcs. A large population of the different hybrid lines have been obtained through propagation and selection in successive generations. Their agronomic traits have been studied and will be reported in a separate paper.
