Abstract
Selection of soybean (Glycine max L. cv. Enrei) cells tolerant to oxyfluorfen, imazaquin, or fluazifop-P-butyl was attempted using suspension cultures induced from their cotyledons. The concentration required to inhibit the growth of non-selected cells by 50% was 5×10-8M, 5×10-7M, and 10-5M for oxyfluorfen, imazaquin and fluazifop-P-butyl, respectively. By a stepwise selection with increasing concentration, cells tolerant to 10-7M oxyfluorfen, 5×10-7M imazaquin, and 5×10-5M fluazifop-P-butyl, respectively, were obtained. In the selection of imazaquin-and fluazifop-P-butyl-tolerant cells, the tolerance was very slight and the growth of cells was completely stopped when the cells were transferred into 10-6M imazaquin or 10-4M fluazifop-P-butyl.
The concentration required to inhibit growth of oxyfluorfen-tolerant cells by 50% was 5×10-6M, indicating a 100-fold greater tolerance than normal cells. A subsequent study showed that the acquired tolerance was stable for at least 6 months when the cells were retained in the medium without the herbicide.
