To evaluate the possibility of gene flow through observation of the sexual compatibilities of transgenic herbicide-resistant rice with wild relatives by using isotope tracer to label pollen grains

the experiments on radioactivity

tracer mode

autoradiography film and time were conducted. Better procedure was to label pollen grains of transgenic herbicide-resistant rice by culturing the rice in a 1.48 × 107 Bq /L 32P nutrient liquid

to pollinate the labelled pollen grains on the stigmas of barnyard grass (Echinochloa crusgalli var. mitis)

Oryza officinalis and weedy rice(Oryza saliva) respectively

and then 3 hour later

to fix these pistils on a piece of glass plate and cover the film of Luck 400 on it for autoradiography . The autoradiographs show that the tube of the transgenic rice’s pollens cannot penetrate the stigma of barnyard grass and arrive at embryo sacs to fertilize

so that the possibility of gene flow between them is the lowest; the tube of the labelled pollens can penetrate the stigma of O.officinalis and enter the style but can not arrive at embryo sacs to fertilize

so the possibility of gene flow between them is relatively low; and the pollen tube can arrive at the embryo sacs of the weedy rice

so that the possibility of gene flow is relatively high from transgenic herbicide-resistant rice to weedy rice.