将6种不同浓度(0、0.1、0.2、0.4、0.8、1.6 mg/L)的植物生长调节剂吲哚丁酸(IBA)添加至霍格兰营养液中,研究其对烟草幼苗叶部保护性酶活性及丙二醛含量的影响。结果表明,烟草幼苗叶部保护性酶活性和丙二醛含量与 IBA 浓度有着密切的关系。综合来说,烟苗保护性酶活性趋势起初增强而后减弱,而丙二醛含量则与之相反,趋势为先下降而后上升。0.4 mg/L处理较其他处理显著提升了烟草幼苗叶部保护性酶活性,增幅达27.36%~35.44%。而1.6 mg/L处理较对照处理显著减弱了烟苗幼苗叶部保护性性酶活性。0.4 mg/L处理较其他处理减少了烟草幼苗叶部丙二醛的含量达到最低值。而1.6 mg/L吲哚丁酸处理较对照处理增加了烟苗幼苗叶部丙二醛含量,增幅达20.95%。0.4 mg/L吲哚丁酸处理提高了烟苗幼苗叶部保护性酶活性,降低了MDA含量。本试验表明,当烟草漂浮育苗营养液中吲哚丁酸浓度为0.4 mg/L时,可起到促进烟草幼苗叶部发育的作用。The effects of plant growth regulator indolebutyric acid (IBA) at different concentrations (0, 0.1, 0.2, 0.4, 0.8, 1.6 mg/L) on the activity of protective enzyme and the content of malondialdehyde in leaves of tobacco seedlings were studied. The results showed that there was a close relationship between the activity of protective enzyme and the content of malondialdehyde and the concentration of IBA. In general, the protective enzyme activity of tobacco seedlings increased at first and then decreased, while the malondialdehyde content decreased first and then increased. Compared with other treatments, 0.4 mg/L treatment significantly increased the activity of protective enzyme in leaves of tobacco seedlings by 27.36%~35.44%. Compared with the control treatment, 1.6 mg/L treatment significantly decreased the activity of protective enzyme in the leaves of tobacco seedlings. Compared with other treatments, 0.4 mg/L reduced the content of malondialdehyde in leaves of tobac