含土霉素土壤添加不同基质后对玉米生理特性的影响

Effects of Adding Different Substrates on Physiological Traits of Maize in a Oxytetracycline Contaminated Soil

为了解兽用抗生素污染对作物生长的潜在影响,选择四环素类抗生素土霉素作为目标污染物,通过玉米盆栽试验探讨含土霉素土壤(50mg/kg)施用不同基质(菌剂、蚯蚓粪、生物质炭等单施及其配施菌肥)对玉米生育期生物量、光合参数和酶活性的影响。结果表明:土霉素对玉米根的抑制作用大于植株,菌糠(JK)、菌剂+蚯蚓粪(JQ)和菌剂+生物质炭(JS)处理比OTC处理的玉米根长和根干重分别提高9.1%,9.4%,13.7%和66.46%,183.4%,46.72%;不同基质处理可有效减少土霉素对玉米的净光合速率、气孔导度和蒸腾速率的抑制作用;与OTC处理相比,菌剂(JK)处理均能显著提高玉米3个时期的叶绿素含量,幼苗期、拔节期和成熟期升幅依次为7.78%,33.33%和12.03%。成熟期菌剂+生物质炭(JS)处理比OTC处理分别提高玉米CAT活性48%和POD活性43.2%;幼苗期、拔节期和成熟期生物质炭(S)、菌剂+蚯蚓粪(JQ)和菌剂(JK)处理比OTC处理分别减少脯氨酸59%,16.5%和55.4%。总趋势为土霉素对玉米生长有明显抑制作用,但添加不同基质均能不同程度缓解土霉素对玉米生理特性的影响,菌糠(JK)、菌剂+生物质炭(JS)、生物质炭(S)和菌剂+蚯蚓粪(JQ)等处理优为明显。研究可为筛选减少抗生素对植物生长的基质提供理论依据,也可为土霉素对农作物的风险评价提供科学意义。

A kind of tetracyclines-oxytetracycline was used as target pollutant to analyze the potential influences of veterinary antibiotics pollution on maize growth.A potted maize experiment was conducted to study the influences of oxytetracycline-contained soils on the biomass,photosynthesis parameters and antioxidant enzymes during the growth stage of maize in the soils with different substrates：microbial inoculants（JF）mushroom bran（JK）,wormcast（QY）,and biomass charcoal（S）etc.with the single and combined application.The results showed that oxytetracycline had a greater inhibiting effect on the roots of maize than on the aboveground.The length and dry weight of maize roots under the treatments of JK,microbial inoculants＋wormcast（JQ）,microbial inoculants＋biomass charcoal（JS）increased by 9.1%,9.4%,13.7% and 66.46%,183.4%,46.72% respectively than the OTC treatment.The addition of substrates reduced the inhibiting effect of Oxytetracycline on the net photosynthetic rate,stomatal conductance and transpiration rate of maize effectively.JK increased the chlorophyll contents in three stages of maize,the increases in seedling,jointing and maturation stages were 7.78%,33.33% and 12.03% respetively.The CAT and POD activities under JS increased by about 48% and 43.2% than the OTC.The addition of S,JQ and JK reduced the proline contents by 59%,16.5% and 55.4% respectively than the OTC in the seeding,jointing and maturation stages.In general,doxycycline had an obvious inhibiting effect on maize growth,but adding different substrates could alleviate the adverse effects on maize＇s physiological traits.The addition of JK,JS,S and JQ had significant positive effect on maize＇s growth.These findings provided the theoretical basis for screening the substrates that could reduce antibiotics＇ influences on maize＇s growth,as well as for the assessment of oxytetracycline risk to crops.