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

Abstract

AbstractUsing four oilseed rape (Brassica napus L.) F1 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.