转bar基因油菜对非选择性除草剂草丁膦的抗性研究

比较转bar基因油菜742R和普通油菜742对非选择性除草剂草丁膦(PPT)的抗性差异。通过田间浓度梯度试验和测定叶片谷氨酰胺合成酶(G S)活性,研究转bar基因油菜742R和普通油菜742对PPT的抗性差异及机理。结果发现普通油菜742子叶期、苗期、蕾期、花期和结果期PPT最低致死浓度分别为0.15%,0.15%,0.25%,0.3%和0.4%,而转bar基因油菜742R子叶期和苗期PPT最低致死浓度分别达2.5%和3.0%,约为普通油菜的20倍,蕾期、花期和结果期当PPT浓度达到30%时植株也未全部死亡,是普通油菜的100倍以上。叶片G S活性测定结果表明,正常生长的742R的G S活性比742高10%左右,PPT处理后,转bar基因油菜742R的G S活性降低20%左右,3 d后基本恢复正常,普通油菜742的G S活性降低90%以上,处理后第3天活性丧失。转bar基因油菜对PPT的抗性比普通油菜高20倍以上。

Resistance of Bar-transgenic Rapeseed (Brassica napus L.) to Herbicide PPT

Resistance to the herbicide PPT（glufosinate,dl-phosphinothricin ammonium） was compared between bar-transgenic rapeseed line 742R and its non-transgenic counterpart 742.Difference in resistance and the mechanism between 742R and 742 was compared by determining glutamine synthetase（GS） activity.Spraying of the herbicide at different concentrations in the field showed that the minimum lethal concentration（MLC） for 742 was 0.15%,0.15%,0.25%,0.3% and 0.4% at the cotyledon,seedling,bolting,flowering and seed-filling stage,respectively.While the MLC for bar-transgenic line 742R reached 2.5% and 3.0% at the cotyledon and seedling stage respectively,it was almost 20 times of that of 742.All the transgenic plants were not killed when sprayed at the bolting,flowering and seed-filling stage with 30% PPT,it was 100 times more than that of 742.Determination of GS activity from leaves showed that GS activity of 742R was about 10% higher than that of 742 under the untreated condition.The GS activity of 742R was restored to be normal three days after the PPT treatment although it decreased by about 20% after PPT treatment.In contrast,the GS activity of 742 decreased by over 90% after the PPT treatment and could not be deducted three days after PPT treatment.Resistance of the bar-transgenic rapeseed（Brassica napus L.） to the herbicide PPT was 20 times over 742.