生物质炭对土霉素胁迫下小白菜种子萌发的影响

采用土培模拟污染实验,将甘蔗渣炭、菠萝渣炭和木薯渣炭分别以0%、0.1%、0.5%和1.0%的炭土比添加到砖红壤中,研究土霉素胁迫下小白菜种子萌发效应。结果表明:(1)生物质炭促进种子萌发;土霉素在0~300 mg·kg~(-1)胁迫下种子发芽率未受明显影响,300~500 mg·kg~(-1)时受轻微抑制。(2)土霉素为0~100 mg·kg~(-1)时对种子根及芽伸长呈促进作用,促进率最高达33.05%。100~500 mg·kg~(-1)呈抑制效应,最大抑制率63.98%;种子对土霉素的敏感顺序依次为:根伸长>芽伸长>发芽率。(3)在土霉素胁迫下炭土比与种子根伸长呈显著正相关。3种生物质炭对小白菜种子根及芽伸长的促进效果呈:木薯渣炭>菠萝渣炭>甘蔗渣炭。(4)生物质炭和低浓度土霉素共同促进小白菜萌发,对高浓度土霉素毒性有缓解作用。

Effects of Biochar on Seed Germination of Cabbage under the Stress of Oxytetracycline

To explore the effects of oxytetracycline on the germination of cabbage seeds, soil culture experiment was used in the laterite soil in this study, with the supplement of bagasse biochar, pineapple biochar and cassava biochar at a carbon/soil ratio of 0, 0.1%, 0.5% and 1%, respectively. The results showed that: (1) Oxytetracycline had little effect on the germination rate of cabbage seeds at low concentration (i.e., 0-300 mg·kg^-1), while inhibited it lightly at higher concentrations (i.e., 300-500 mg·kg^-1); (2) Low concentrations of oxytetracycline (i.e., 0-100 mg·kg^-1) promoted the root/shoot elongation of cabbage seeds with the maximum promotion rate of 33.05%. However, high concentrations (i.e., 100-500 mg·kg^-1) of oxytetracycline had inhibitory effects on them and the inhibition rate raised up to 63.98%. On the other hand, seeds were sensitive to oxytetracycline, but the root elongation was more sensitive than shoot elongation and than germination rate; (3) Positive correlations between the ratio of biochar/soil and the root elongation of cabbage seed were also observed under oxytetracycline stress. All three types of biochars promoted the elongation, with more obvious promotion effect induced by cassava biochar than that of pineapple biochar, and than bagasse biochar;(4) Biochars combined with low concentrations of oxytetracycline jointly promoted the root and shoot elongation, and meanwhile alleviated the toxicity at high concentrations of oxytetracycline.