通过转bar基因水稻与稗草杂交的亲和性研究评价基因漂移

Assessment on Gene Flow Through Detection of Sexual Compatibility Between Transgenic Rice with bar Gene and Echinochloa crusgalli var. mitis

采用生殖生物学方法研究了转bar基因水稻品种Y0 0 0 3和 99 t(父本 )与无芒稗 (母本 )的基因漂移。通过光学显微镜观察稗草与转bar基因水稻手工杂交后 30min、1～ 4h水稻花粉在稗草柱头上的萌发、生长情况 ,并与稗草开花后相应时间的花粉萌发、生长情况相比较。结果表明 ,2个水稻品种的花粉在稗草柱头上的萌发生长情况相似 ,且与稗草自花授粉相应时间的花粉萌发、生长情况有极明显差异。稗草自花授粉后花粉粒萌发生长正常 ,在 30min时 85 %的花粉粒花粉管穿过柱头 ,正在凝缩和释放内容物或内容物已经释放的花粉粒百分率逐渐增加 ;杂交后转基因水稻花粉在稗草柱头上都不能正常萌发生长并未能穿过稗草柱头。从而判定稗草与转bar基因水稻的不亲和性 ,表现在水稻花粉不能在稗草柱头上正常萌发生长 ,更不能穿过稗草柱头。

The gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99 t) (♂) and barnyard grass(Echinochloa crusgalli var. mitis) (♀) were studied by means of reproductive biology. The germination and growth of rice pollen grains on barnyard grass stigmas at 30 min, 1-4 h after crossing by hand were observed with optical microscope. The cross results were compared with the germination and growth of barnyard grass pollen grains at the corresponding time after self pollination. The results showed that the pollen grains germination and growth of the two varieties were similar on barnyard grass stigmas and differed from self pollination of barnyard grass significantly. 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 during experimental period. Pollen grains of transgenic rice on the stigmas of barnyard grass could not germinate or grow normally after cross, nor could they penetrate the stigmas of barnyard grass. From above results, it could be concluded that the sexual incompatibility lay in the rice pollen could not penetrate the stigma of barnyard grass. The fact that emasculated barnyard grass pollinated with the rice pollen grains could not seed, and further proved the incompatibility of between them.