干旱胁迫对云南松苗木生理特征的影响

Drought Stress on Physiological Characteristics of Pinus yunnanensis Seedlings

对云南松苗木进行干旱胁迫处理,探讨不同干旱胁迫天数对云南松苗木渗透调节物质与保护酶活性的影响。结果表明:在一定范围内,随着干旱胁迫天数的增加,云南松苗木质膜相对电导率、丙二醛、脯氨酸、可溶性糖含量及其超氧化物歧化酶活性均有不同程度的上升,但变化幅度因干旱胁迫程度、渗透调节物质类型的不同而有差异。不同干旱胁迫天数处理间的可溶性糖含量和超氧化物歧化酶活性差异极显著,丙二醛含量差异显著,脯氨酸与质膜相对电导率含量差异不显著。渗透物质调节能力表现为可溶性糖>脯氨酸,云南松苗木抗旱性相关性次序为丙二醛>质膜相对电导率,云南松苗木脯氨酸与质膜相对电导率变化对干旱胁迫处理响应较弱。在干旱胁迫下云南松苗木膜伤害与渗透调节、酶保护同步进行,具有一定的耐旱性。

Effects of drought stress on osmotic adjustment substance and protective enzyme activity of Pinus yunnanensis seedlings were studied by the design of the different drought interval days. The results showed that with- in a certain range, membrane relative conductivity, malondialdehyd, proline, soluble sugar content and superoxide dismutase activity of P. yunnartensis seedlings increased with the extension of the drought interval days. But ranges of the increases were different due to the difference of the drought interval days and the type of osmotic adjustment substance. There were significantly different among treatments （ drought interval days） in soluble sugar and superox- ide dismutase, malondialdehyd content had great differences and no obvious difference among treatments for proline and plasma membrane relative conductivity. Osmotic adjustment ability of soluble sugar was higher than proline. Malondialdehyd has higher correlation with the drought tolerance compared with plasma membrane relative conductivity. The response of drought stress was weak for proline and plasma membrane relative conductivity. The damage of plasma membrane, osmotic adjustment and superoxide dismutase protection were carried out simultaneously, which resulted in the drought tolerance of P. yunnanensis seedlings under drought stress.