塑化剂对桑树幼苗生物量和氮素积累的影响

Effects of Plasticizer on Biomass and Nitrogen Accumulation of Mulberry(Morus alba L.)Seedlings

【目的】探明桑园中主要塑化剂类型对桑树幼苗生物量及氮积累的影响,为后期评估塑化剂对林木的生态毒理效应提供理论依据。【方法】采用5种外源化学生化试剂(油酸酰胺、芥酸酰胺、邻苯二甲酸二丁酯、棕榈油酸甲酯和邻苯二甲酸二甲酯)替代桑园塑化剂,用蒸馏水作对照(CK)进行室内盆栽试验,分析外源添加高浓度(0.05 mol/L)塑化剂对桑树幼苗生物量及氮积累的影响。【结果】棕榈油酸甲酯对桑树地上部生长有显著抑制作用,其桑树幼苗地上部生物量仅为0.56 g/株,比CK降低0.38 g/株,芥酸酰胺会造成桑树幼苗死亡;各塑化剂处理桑树地上部、根部总氮积累量分别为5.08~7.88 mg/株和4.65~7.73 mg/株,地上部、根部铵态氮积累量分别为0.81~32.02μg/株和9.75~20.99μg/株,地上部硝态氮积累量为54.52~106.89μg/株,均显著低于CK;各塑化剂处理桑树幼苗根部硝态氮积累量为7.38~15.5μg/株,均显著高于CK。【结论】5种塑化剂对桑树生物量和氮素积累有抑制作用,其中,芥酸酰胺施用直接造成桑树幼苗死亡,而邻苯二甲酸二丁酯对桑树地上部硝态氮积累抑制性最强。

【Objective】The effects of major plasticizer types on biomass and nitrogen accumulation of mulberry seedlings in mulberry gardens were explored to provide a theoretical basis for later assessment of the ecotoxicity effects of plasticizers on forest trees.【Method】Five exogenous chemical and biochemical reagents(oleamide,erucamide,dibutyl phthalate,methyl palmitoleate,and dimethyl phthalate)were used to replace plasticizers in mulberry gardens by using distilled water as CK to conduct indoor pot experiments,and then the effects of adding exogenous plasticizers with a high level of 0.05 mol/L on the biomass and nitrogen accumulation of mulberry seedlings were analyzed.【Result】Methyl palmitoleate had a significant inhibitory effect on the growth in the above-ground part of mulberry,and the biomass in the above-ground part of mulberry seedlings was only 0.56 g/plant,which was 0.38 g/plant lower than that of CK,and erucamide caused the death of mulberry seedlings;The total nitrogen accumulation in the above-ground part and roots of mulberry treated with the other four plasticizers was 5.08–7.88 mg/plant and 4.65–7.73 mg/plant respectively,the ammonium nitrogen accumulation in the above-ground part and roots was 0.81–32.02μg/plant and 9.75–20.99μg/plant,the nitrate nitrogen accumulation in the above-ground part was 54.52–106.89μg/plant,which was lower than that of CK significantly;The nitrate nitrogen accumulation of roots was 7.38–15.5μg/plant,which was higher than that of CK significantly.【Conclusion】The five plasticizers has inhibitory effect on the biomass and nitrogen accumulation of mulberry,among which erucamide caused the death of mulberry seedlings directly,while dibutyl phthalate has the strongest inhibitory effect on the nitrate nitrogen accumulation in the above-ground part of mulberry.