为认识橡胶废水沼液中外源溶解性有机物(dissolved organic matter,DOM)对抗生素污染生物效应的影响,本文采用水培和土培两种方法研究土霉素(oxytetracycline,OTC)对小白菜种子的萌发效应,在此基础上探讨外源DOM输入后土霉素对小白菜发芽率和胚根、芽伸长的影响。结果表明:(1)水培中DOM促进种子萌发,土培中抑制萌发;土霉素在水培0~50 mg/L、土培0~100 mg/kg胁迫下小白菜种子发芽率影响差异不显著;(2)在水培中,外源土霉素浓度与小白菜的胚根、芽长抑制率之间均呈显著正相关性;在土培中,外源性土霉素浓度与小白菜的胚根、芽长抑制率呈显著负相关性;(3)在水培和土培中,与对照组相比,DOM对小白菜的胚根伸长和芽伸长均起促进作用,水培促进率最高达55.05%,土培促进率最高达27.46%;(4)水培条件下,土霉素与DOM共存时对小白菜胚根伸长的抑制作用更明显;土培条件下,土霉素与DOM共存时,低浓度的DOM促进小白菜的胚根伸长,随着浓度的升高,促进作用下降。
In order to understand the effects of exogenous DOM on the biological effects of antibiotic contamination,the effects of oxytetracycline(OTC) on the germination of Chinese cabbage seeds were studied by two methods: hydroponics and soil cultivation. The effects of oxytetracycline on germination rate, elongation of cabbage after exogenous DOM input were discussed also. DOM promoted seed germination in hydroponics and inhibited seed germination in soil culture. Oxytetracycline had no significant effect on seed germination rate under 0-50 mg/L and 0-100 mg/kg of soil cultivation. In hydroponics the concentration of exogenous oxytetracycline was positively correlated with the inhibition rate of radicle and bud length of cabbage, while in soil cultivation, the concentration of exogenous oxytetracycline was negatively correlated with the inhibition rate of radicle and bud length of cabbage. Compared with the control group,DOM could promote the radicle and bud elongation of cabbage in hydroponics and soil cultivation, with the highest promotion rate of 55.05% and 27.46%. The inhibitory effect of oxytetracycline and DOM on the elongation of cabbage was more obvious under hydroponics. Under soil cultivation, when oxytetracycline co-existed with DOM, low concentration of DOM promoted radicle elongation of cabbage, and the promotion effect decreased with the increase of concentration.
Chinese Journal of Tropical Crops