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为明确典型抗生素残留对烟草的生态毒理效应,采用盆栽试验系统研究了不同剂量四环素添加对烤烟生长发育及光合作用的影响。结果表明:在烟草生长发育过程中,低量四环素添加(5 mg·kg~(-1))能促进烟草株高增加,中高量的四环素添加(50 mg·kg~(-1)及500 mg·kg~(-1))对株高具有明显抑制作用,但促进了茎围和叶片数的增加。此外,低量四环素对烟草根长及根体积有一定促进作用,高量则产生抑制作用,且抑制作用随生育进程而逐渐减弱,至生育后期已无明显影响。四环素添加各处理的烟草根冠比总体上均低于对照(团棵期除外),且根冠比随四环素添加量的增加而降低。四环素对烟草净光合速率、气孔导度和蒸腾速率的影响,随生育进程呈现前期抑制后期促进的趋势,对胞间CO_2浓度的影响则无明显规律性。该研究显示,四环素可能通过影响烟草光合作用而对烟草生长发育产生重要作用,同时烟草通过调控根系发育及根冠比来适应四环素的影响。因此,中高量的四环素添加对烟草生长发育及光合作用具有一定的生态毒性效应,但毒性效应随着烟草生育进程而减弱。
In order to clarify the ecotoxicological effects of typical antibiotic residues on tobacco, pot experiments were conducted to study the effects of different doses of tetracycline on the growth and photosynthesis of tobacco. The results showed that low levels of tetracycline (5 mg · kg -1) promoted the plant height of tobacco and the middle and high levels of tetracycline added (50 mg · kg -1 and 500 mg · kg -1) during tobacco growth and development. · Kg ~ (-1)) had a significant inhibitory effect on plant height, but increased the number of stems and leaves. In addition, low amount of tetracycline promoted the root length and root volume of tobacco, but inhibited the growth of tobacco at high volume, and the inhibition decreased gradually with the growth process until the late growth period. The root-shoot ratio of tobacco treated with tetracycline was generally lower than that of the control (excluding the flowering period), and the ratio of root to shoot decreased with the increase of tetracycline. The effects of tetracycline on the net photosynthetic rate, stomatal conductance and transpiration rate of tobacco showed the tendency of promoting the early prophase inhibition with the development of tetracycline, but there was no obvious regularity on the effect of tetracycline on the intercellular CO 2 concentration. The study shows that tetracycline may play an important role in the growth and development of tobacco by affecting tobacco photosynthesis, and tobacco adapts to tetracycline by regulating root development and root-shoot ratio. Therefore, medium and high levels of tetracycline addition have certain ecotoxicological effects on the growth and photosynthesis of tobacco, but the toxicity effect weakened with the growth of tobacco.