Pb胁迫条件下旱柳扦插苗生长过程生理生化响应机制研究

为研究旱柳对铅的耐受机制，以2年生旱柳(Salix matsudana)扦插苗为材料，进行盆栽实验，分析研究生长6个月后的扦插苗在铅浓度为0、200、600、1000、1200 mg/kg时的生理生化响应机制。结果表明：随着土壤铅浓度的增加，植株长势、根茎叶中的SOD、POD、CAT活性、可溶性蛋白含量以及叶中的叶绿素含量均呈先升后降的变化趋势，MDA含量呈上升趋势。各项生理指标：根＞茎＞叶。该实验表明：旱柳根系为重金属铅的主要累积部位，只有少量的铅转移到地上部分且600 mg/kg铅胁迫下旱柳幼苗有最佳耐性机制。

Physiological and Biochemical Response Mechanism in Growth Process of Salix matsudana Cutting Seedlings Under Lead Stress

The authors studied the tolerance of Salix matsudana to lead. Two-year-old Salix matsudana cutting seedlings were taken as the materials in a pot experiment, and treated under lead concentrations of 0, 200, 600, 1000 and 1200 mg/kg after growing for 6 months. Then the authors analyzed their physiological and biochemical response mechanism to lead stress. The results showed that along with the lead concentration increase, the plant growth and the SOD, POD, CAT activity, the soluble protein content in the root, stem and leaf and the content of chlorophyll in leaf increased first and then decreased, but the activity of MDA kept an increasing trend. The physiological and biochemical indexes of different organs was in an order as root＞ stem＞ leaf. The results indicated that the root system of Salix matsudana was the main accumulation organ, and only a little Pb was transferred to the aboveground parts. From the physiological and biochemical changing trend, it was proved that the seedlings of Salix matsudana had the best lead tolerance under 600 mg/kg lead concentration.