PEG－6000模拟干旱胁迫对紫甘薯幼苗生理生化指标的影响

摘要

采用聚乙二醇PEG（PEG－6000）模拟干旱胁迫处理5个紫甘薯品种的幼苗，对其丙二醛（MDA）含量、超氧化物歧化酶（ SOD）活性、游离脯氨酸含量和质膜相对电导率进行了测定。结果表明：与对照相比，干旱胁迫极显著地提高了甘薯幼苗的质膜相对电导率、MDA含量和脯氨酸含量，极显著地降低了SOD活性；随着干旱胁迫时间的延长，甘薯幼苗的质膜相对电导率、MDA含量和脯氨酸含量总体上均呈上升趋势，而SOD活性呈上升－下降－再上升－再下降的变化规律。%The seedlings of five purple sweet potato varieties were stressed by drought which was simulated by polyethylene gly -col (PEG-6000), and their MDA content, SOD activity, free proline content and plasmalemma relative conductivity were deter-mined.The results showed that:in comparison with the control , drought stress significantly increased the plasmalemma relative con-ductivity, MDA content and free proline content of sweet potato seedlings , but significantly decreased the SOD activity .When the time of drought stress was lengthened , the plasmalemma relative conductivity , MDA content and free proline content of sweet potato seedlings generally revealed a rising trend , while the SOD activity presented the changing rule of rising -decline-rising again-de-cline again.