Weed Survey In Fuyang Paddy Fields And Bar Gene Flow Of Herbicide Resistant Rice 99-1

This dissertation includes three parts: weed survey in Fuyang, Hangzhou; pollen mediated gene flow from transgenic rice 99-1 to male sterile rice II-32A, Echinochloa crus-galli var. mitis (Pursh) Peterm. and Leptochloa chinensis (L.) Nees,; studies on agronomic character differences of transgenic rice and non-transgenic rice.The weed survey was carried out in Fuyang, Hangzhou. It included five kinds of paddy fields: nursary bed, direct seeded, seedling-throwing transplant, transplant and post harvest. In direct seeded paddy field, the weed infestation was much severe than that in transplant and seedling-throwing transplant paddy fields. The weed species and density in seedling-throwing transplant field were similar with the seeded rice, and Monochoria vaginalis, Ludwigia prostrata, Rotala indica, which could accomodate themselves to the wet condition, were in large proportion. The percentage of each weed species was in an average level. As for the transplanted paddy field, the weeds were less harmness than in light cultured fields, for example, direct seeded paddy field. The weed species was fewer in comparison with the other four. Echinochloa crusgalli, Monochoria vaginalis and Ludwigia prostrata were main target for weed control in all four kinds of paddy fields. Both of their density and occuring frequency were high.According to the florescence survey on weeds, many species were found to have a long florescence period. During the time of rice's florescence, many weeds were in the same stage, thus increasing the possibility of crossing with the rice. The Echinochloa crus-galli var. mitis (Pursh) Peterm. and Leptochloa chinensis (L.) Nees had closest relationship with rice among all weeds in Fuyang, and their florescence were longer than that of rice. Therefore, these two weeds had the highest possibility of crossing with the rice.The herbicide resistance transgenic rice 99-1, male sterile rice II-32A, Echinochloa crus-galli var. mitis (Pursh) Peterm. and Leptochloa chinensis were used as the material for assessment of gene flow between transgenic rice and nontransgenic plants. By glufosinate bioassay and PCR analysis, the hybrids acquired from II-32A were found to have the resistance to 0.05% glufosinate and have the specific fragment of bar gene. This indicated that these seed were the hybrids of II-32A and 99-1, which had the traits of herbicide resistance and bar gene. But for Echinochloa crus-galli var. mitis (Pursh) Peterm. and Leptochloa chinensis, no such plant and fragment were found, which indicated that Echinochloa crus-galli var. mitis (Pursh) Peterm. and Leptochloa chinensis did not cross with 99-1.The research on the influence of rice on weed diversity and its quantity was carried out by using 4 rice species, including two transgenic rices with bar gene: 99-1, Jiahe 201 and two nontransgenic rices: Xiushui 11, Bung 94-02. Their agronomic characters were also measured. The results showed that the four rice species had no significant difference on influencing weed diversity and its quantity. The plant height and kernel weight of Xiushui 11 showed significant difference from another three species. But all four species showed no significant difference in tillering number, tillering angle and flag leaf angle. 99-1 and Jiahe 201 were in the middle range of the four species.