中文摘要：

为明确生物炭对植物的毒性效应,以石英砂＋生物炭水浸提液培养方法研究不同剂量生物炭对小麦种子萌发与幼苗生长的影响。结果表明：在不同剂量（0.0、10.0、20.0、40.0、80.0、160.0 g·kg^-1）生物炭水浸提液处理下,虽然小麦发芽率较对照组无显著性变化（P〉0.05）,但根、芽生长表现出低剂量促进高剂量抑制,且在160.0 g·kg^-1时抑制率最大,分别为18.11%和22.22%。在幼苗的生长期（11 d）,高剂量生物炭对幼苗根生长的抑制作用增强,160.0 g·kg^-1处理下抑制率显著增加至55.59%（P〈0.05）。此外,当生物炭剂量较低时,小麦幼苗根、叶中超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）活力增加;随生物炭剂量的增加,3种抗氧化酶活力降低,丙二醛（MDA）含量升高,幼苗生长出现生理损伤,表现出明显植物毒性效应。

英文摘要：

In order to elucidate biochar toxicity to plant,phytotoxic effects on wheat seeds germination and early growth were investigated via the soilless-culture of quartz plus aqueous extract（AE）of biochar at different dosages.Results indicated that no negative effects on seed germination rate were observed with different dosages comparing with the blank.However,the root and shoot growth at lower dosages were stimulated,and serious inhibition happened at higher dosages.The maximum inhibition ratio of root and shoot length were recorded by 18.11%and22.22%,respectively,at biochar dosage of 160.0 g·kg^-1.During the seedling growth period（the 11thday）,the inhibition ratio of root length at high biochar dosages tended to be more serious.It was significantly increased to55.59%when biochar dosage was 160.0 g·kg^-1.Additionally,the enhanced activities of antioxidant enzymes and low levels of MDA content in roots and leaves can be observed at lower dosages.When biochar dosage was at higher levels,the activities of antioxidant enzymes（superoxide dismutase,peroxidase and catalase）exhibited an obvious decrease,and moreover,the increased malondialdehyde content in roots and leaves was detected,which suggested serious physiological damage to wheat seedlings at higher dosages.