Zhou Wei-jun

In vitro selection of herbicide resistance in microspore-derived embryos of oilseed rape ( Brassica napus L.)

Using four oilseed rape ( Brassica napus L.) F 1 hybrids (7039, 7040, 282 and 5102) as donor plants for microspore culture, the experiment was conducted to select glyphosate- and haloxyfop-resistant embryos through application of these substances to the cultural media with microspore-derived embryos in vitro . Genotypes 7039 and 7040 were used to select glyphosate-resistant regenerated plants, and genotypes 282 and 5102 to select haloxyfop-resistant plants. The embryos at cotyledonary stage were grown on glyphosate- and haloxyfop-containing MS-2 medium for 2 weeks. The non-resistant embryos collapsed after a short time, while the resistant ones turned green and survived for 2 weeks. Transferred into the normal MS-2 medium for further plant regeneration, the regenerated plants from green embryos showed tolerance to 0.25% sprayed glyphosate, indicating the effectiveness and reliability of this in vitro selection method. When the regenerated plants selected from 0.02% haloxyfop were sprayed with 0.05% haloxyfop, most of them grew well; however, the survival rate of the regenerated plants from 0.01% haloxyfop-containing medium was lower. The present experiment indicates that the use of 0.02% haloxyfop in the selection of haloxyfop-resistant plants was more promising than that of 0.01%. The chromosome doubling efficiency of regenerated plants reached 34% and 52% after being treated with 170 mg/l colchicine for 20 and 30 h, respectively.