The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. ...The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. The germination and growth of rice pollen grains on barnyard grass stigmas at 30 rmin, and 1 -4 h after crossing by hand were observed with an optical microscope. The results were compared with the germination and growth of barnyard grass pollen grains at the corresponding time after self-pollination. The results showed that germination and growth of the pollen grains of the two varieties were similar on barnyard grass stigmas, but differed significantly from self-pollination of barnyard grass. Pollen grains germinated and pollen tubes penetrated stigmas normally, and the number of pollen grains being condensing or releasing their inclusions or having released them increased with the time after self-pollination. Pollen grains of transgenic rice on the stigmas of barnyard grass couldn't germinate or grow normally after crossing, neither could they penetrate the stigmas of barnyard grass. Therefore, it could be concluded that the sexual incompatibility between transgenic rice with bar gene and barnyard grass is due to the rice pollen being unable to penetrate the stigma of barnyard grass. Further proof of incompatibility lies in the fact that the emasculated barnyard grass pollinated with the rice pollen grains could not seed.展开更多
The pollen tube pathway method of transformation has been reported to be successful in most crops,but less successfu in maize.DNA can be transferred by cutting the stigma following pollination and applying the DNA sol...The pollen tube pathway method of transformation has been reported to be successful in most crops,but less successfu in maize.DNA can be transferred by cutting the stigma following pollination and applying the DNA solution in a suitable period DNA presumably reaches the ovary by flowing down the pollen tube and then integrates into the just fertilized but undivided zygotic cells.To provide the molecular evidence for this procedure,the plasmids pGBIRC carrying a CaMV35S promoter-PPT acetyle transferase(bar)gene-nos terminator gene fusion construct were used.Total 3 276 seeds were produced from the ears treated with DNA.It was found that 35 seedlings were GUS assay positive,but less intense than that of the positive controls,of which 17 were PCR amplification positive.But,only 13 of the seeds from the plants treated with DNA containing the bar gene were found to be resistant compared with the negative control.Less than 1.07% of progeny seedlings tested expressed a herbicide positive reaction and polymerase chain reaction(PCR)with seedling DNA did detect the bar gene.Morphological variation was observed in six plants.We succeed in obtain PPT-resistant maize inbred lines via pollen tube pathway.展开更多
基金the Ministry ofScience and Technology,P.R.ChinaEvaluation of Safety of Transgenic Crops(E200102).
文摘The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. The germination and growth of rice pollen grains on barnyard grass stigmas at 30 rmin, and 1 -4 h after crossing by hand were observed with an optical microscope. The results were compared with the germination and growth of barnyard grass pollen grains at the corresponding time after self-pollination. The results showed that germination and growth of the pollen grains of the two varieties were similar on barnyard grass stigmas, but differed significantly from self-pollination of barnyard grass. Pollen grains germinated and pollen tubes penetrated stigmas normally, and the number of pollen grains being condensing or releasing their inclusions or having released them increased with the time after self-pollination. Pollen grains of transgenic rice on the stigmas of barnyard grass couldn't germinate or grow normally after crossing, neither could they penetrate the stigmas of barnyard grass. Therefore, it could be concluded that the sexual incompatibility between transgenic rice with bar gene and barnyard grass is due to the rice pollen being unable to penetrate the stigma of barnyard grass. Further proof of incompatibility lies in the fact that the emasculated barnyard grass pollinated with the rice pollen grains could not seed.
文摘The pollen tube pathway method of transformation has been reported to be successful in most crops,but less successfu in maize.DNA can be transferred by cutting the stigma following pollination and applying the DNA solution in a suitable period DNA presumably reaches the ovary by flowing down the pollen tube and then integrates into the just fertilized but undivided zygotic cells.To provide the molecular evidence for this procedure,the plasmids pGBIRC carrying a CaMV35S promoter-PPT acetyle transferase(bar)gene-nos terminator gene fusion construct were used.Total 3 276 seeds were produced from the ears treated with DNA.It was found that 35 seedlings were GUS assay positive,but less intense than that of the positive controls,of which 17 were PCR amplification positive.But,only 13 of the seeds from the plants treated with DNA containing the bar gene were found to be resistant compared with the negative control.Less than 1.07% of progeny seedlings tested expressed a herbicide positive reaction and polymerase chain reaction(PCR)with seedling DNA did detect the bar gene.Morphological variation was observed in six plants.We succeed in obtain PPT-resistant maize inbred lines via pollen tube pathway.
