Evaluation of agronomic and molecular biological characteristics of theherbicide resistance transgenic rice

摘要

Agronomic characteristics of transgenic herbicide-resistant rice lines were evaluated under field condition. Differences in agronomic traits and rice quality were observed between transgenic plants and the corresponding untransformed controls. Transgenic Ilpumbyeo lines flowered earlier than untransformed controls, whereas transgenic Nagdongbyeo flowered at the same time as untransformed control. With regard to the yield and rice quality, most of the transgenic lines showed lower yield than control except some selected transgenic lines. Selected Nagdongbyeo transgenic line also showed good eating quality comparable to the control although most selected Ilpumbyeo transgenic lines showed slightly lower eating quality and increased white center/belly in the rice grain. In order to find the main factor leading to somaclonal variation among transgenic lines, Tosl7, a rice retrotransposon activated by prolonged tissue culture period was investigated. Although the transgenic lines carried only one or twoof transformed bar gene, the copy number of Tosl 7 increased in most transgenic lines compared with control. The activation of Tosl 7 was not detected in selected promising transgenic lines such as ND115-15-1-B and IP23-3-3, suggesting that the increasedcopy number of Tosl 7 may have negatively affected agronomic characteristics of transgenic rice.