在蒙导条件下转bar基因水稻与无芒稗间的基因漂移

Gene Flow Between Herbicide-Resistant Transgenic Rice and Echinochloa crusgalli var. mitis Under Mentor Pollen Inducement

以转基因水稻Y0 0 0 3和 99 t为父本 ,无芒稗为母本 ,在蒙导条件下研究转基因水稻与无芒稗间潜在的基因漂移可能性。用光学显微镜观察了用不同方法 (紫外灯照射 ,反复冻融 ,黑暗放置 )制备的蒙导花粉蒙导条件下转基因水稻花粉在无芒稗柱头上的萌发生长情况 ,并与无芒稗自花授粉的情况相比较。结果表明 ,在供试的所有蒙导花粉蒙导条件下 ,两种转基因水稻的花粉在无芒稗柱头上虽能萌发 ,但花粉管扭曲成各种形状而不能进入无芒稗柱头。与无芒稗自花授粉的花粉萌发生长有极明显的差异。杂交也不结实。说明蒙导花粉不能克服转基因水稻和无芒稗的不亲和性 ,转基因水稻与无芒稗间基因漂移的可能性极小。

The potential gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyardgrass (Echinochloa crusgalli var. mitis) (female) was studied by means of reproductive biology. The germination and growth of rice pollen grains on barnyardgrass stigmas at 30 minutes,1-4 hours after artificial crossing under mentor pollen inducement produced with different methods(irradiated under ultraviolet radiation, repeated freezing and thawing, and put in dark condition) were observed with light-microscope, and compared with those of self-pollination at the corresponding time. Results demonstrated that the pollen grains of transgenic rice on the barnyardgrass stigmas could neither germinate nor grow normally after crossing, and couldn’t penetrate the barnyardgrass stigmas even under mentor pollen inducement conditions. Furthermore, emasculated barnyardgrass pollinated with the rice pollen grains under mentor pollen inducement conditions couldn’t seed. It was showed that the mentor pollen inducement couldn’t break the sexual incompatibility between herbicide-resistant transgenic rice and barnyardgrass, the possibility of gene flow between them was very low.