2种堇菜镉耐性和抗氧化酶活性分析

目的]探讨重金属镉（Cd）对2种堇菜Cd耐性和抗氧化酶活性的影响。方法]采用水培试验和理化测试比较分析宝山堇菜和长萼堇菜的Cd积累、根伸长率、MDA浓度以及抗氧酶活性。结果]在300μmol/L Cd添加溶液中生长12 d后,宝山堇菜和长萼堇菜地上部积累的Cd分别为2 595和3 330 mg/kg,说明它们都具有较强的Cd吸收能力;300μmol/L Cd处理,显著抑制长萼堇菜根伸长率和显著增高该植物MDA浓度,对宝山堇菜根伸长率没有明显影响和明显降低该植物MDA浓度,说明宝山堇菜具有更强的Cd耐性;2种堇菜的SOD、POD和CAT活性与中、低浓度（5、50μmol/L）Cd处理浓度没有线性关系,一般在100或300μmol/L Cd添加组中达到最高值,但在500μmol/L Cd处理组中酶活性表现出回落,说明抗氧化酶在2种堇菜Cd耐性中的作用较为有限,长萼堇菜对中、低浓度Cd也有较强的适应能力。结论]堇菜属植物可作为潜在的资源植物用于中、低浓度Cd污染农业区的植物修复实践。

Comparative Analysis on Cadmium Tolerance and Antioxidant Enzymatic Activities of Two Viola Species

Objective] This study aimed at exploring the physiological properties of the known Cd hyperaccumulator Viola baoshanensis and the control plant Viola inconspicua to cadmium stress.Method] After a hydroponic experiment carried in a greenhouse,plant Cd accumulations,root elongation rates,MDA contents,and antioxidant enzyme activities were determinined.Result] Both Viola baoshanensis and Viola inconspicua showed high levels of Cd uptake growing in Cd-supplemented solution of 300 μmol/L for 12 d with Cd accumulations of 2 595 and 3 330 mg/kg in the shoots,respectively.In the cultural solution supplemented with 300 μmol/L of Cd,the root elongation rates were not affected and the MDA contents decreased significantly in Viola baoshanensis,while the root elongation rates were significantly inhibited and the MDA contents increased remarkably in Viola inconspicua,which indicated that Viola baoshanensis had the higher Cd tolerance.The superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT) activities of two Viola species were not linearly related to the middle and low Cd-supplemented concentrations(5,50 μmol/L) and had attained the tiptop in cultural solution supplemented with 100 or 300 μmol/L of Cd but declined in cultural solution supplemented with 500 μmol/L of Cd,suggesting that the contribution of antioxidative enzymes was limited to the Cd tolerance of Viola plants.The Viola inconspicua showed a strong adaptability to the middle and low concentrations of Cd.Conclusion] Viola species could be used as potential plant resources for the phytoremediation of agriculture areas polluted with low and even middle levels of Cd.