市售草甘膦除草剂对转基因抗草甘膦棉花幼苗生长的影响

 以转基因抗草甘膦棉花种质系G6-7和G6-8及其非转基因遗传背景亲本对照中棉所49为材料，研究了市售10%草甘膦水剂和95%的草甘膦粉剂对抗草甘膦棉花种子萌发和幼苗生长的影响。结果表明，中棉所49对于两种类型的草甘膦均很敏感，幼苗喷施0.2 mmol·L^-1 的10%草甘膦水剂和95%草甘膦粉剂均全部死亡。转EPSPS-G6基因抗草甘膦棉对95%草甘膦粉剂的抗性较好，但对10%草甘膦水剂的抗性较弱。就转基因棉花对两种剂型草甘膦的反应看，喷施2.4 mmol·L^-1的10%草甘膦水剂和95%草甘膦粉剂后，棉花幼苗全株鲜重、叶重、根重、下胚轴长、可溶性蛋白质增量和POD活性等各项指标在两种草甘膦制剂间的差异均达到显著水平。喷施12.0 mmol·L^-1 的10%草甘膦水剂，转基因抗草甘膦棉花的种子发芽率显著低于相同浓度的粉剂，两者之间的发芽率相差25%~75%。研究结果表明，10%的草甘膦水剂中可能含有对棉花幼苗生长发育有害的物质，影响抗草甘膦棉幼苗的生长，在转基因抗草甘膦棉花品种商业化应用时应谨慎使用。

The Effects of Commercial Glyphosate Herbicide on the Seedlings of Transgenic Cotton with Glyphosate Resistance

The effects of two commercial glyphosates, 10% glyphosate aqueous solution and 95% glyphosate powder, on the seed germination and seedling growth of transgenic cotton with glyphosate resistance were studied, using the transgenic glyphosate-resistant cotton germplasm lines, G6-7 and G6-8, as the materials, and their non-transgenic genetic background cultivar, CCRI-49, as control. All the seedlings of CCRI-49 died on the media with 0.2 mmol·L^-1 10% glyphosate aqueous solution or 0.2 mmol·L^-1 95% glyphosate powder, indicating that CCRI-49 is very sensitive to both types of glyphosate. The glyphosate resistant cotton germplasms with EPSPS-G6 gene expressed an excellent resistance to glyphosate when they were treated with 95% glyphosate powder, but were seriously damaged when treated with 10% glyphosate aqueous solution. The germination percentage of transgenic cotton germplasm with EPSPS-G6 gene declined by 25%~75% when they were treated with 12.0 mmol·L^-1 10% glyphosate aqueous solution, which was significantly lower than that with treatment of the same concentration of 95% glyphosate powder. The differences were also significant between the two types of glyphosates in fresh weight, leaf weight, root weight, hypocotyl length, soluble protein increment and POD activity of cotton seedlings. The present experiment indicated that some of commercial glyphosate products may contain some harmful substances affecting the growth and development of glyphosate-resistant cotton, and therefore should be used carefully in transgenic glyphosate-resistant cotton field.