马尾松幼苗生长及生理特性对铝胁迫的响应

以马尾松幼苗为试验材料，采用水培法研究铝胁迫（Al³⁺浓度为0、0.2、0.4、0.8、1.6 mmol·L^-1）对马尾松幼苗生长及其针叶中叶绿素、渗透调节物质（可溶性糖、可溶性蛋白、脯氨酸）、丙二醛（MDA）和超氧化物歧化酶（SOD）、过氧化物酶（POD）等保护酶活性的影响，为揭示马尾松铝毒害生理机制及提高马尾松的耐铝能力提供理论依据。结果显示：当Al³⁺处理浓度为0.2 mmol·L^-1时对马尾松株高和基径生长的影响较小，但对马尾松根系生长有一定的促进作用；Al³⁺处理浓度大于0.2 mmol·L^-1时对马尾松株高、基径和根长的生长均会产生一定的抑制作用，且这种抑制作用随着Al³⁺浓度的增大而增强。马尾松针叶中叶绿素含量和SOD、POD活性均随着Al³⁺处理浓度的增加呈先上升后下降的趋势；Al³⁺处理浓度大于0.2 mmol·L^-1时马尾松针叶中可溶性糖、可溶性蛋白、脯氨酸等渗透调节物质均呈上升趋势，且随着Al³⁺浓度的升高而增大；Al³⁺处理浓度大于0.2 mmol·L^-1时马尾松针叶中MDA含量也呈上升趋势，且随着Al³⁺浓度的增大而升高，说明大于0.2 mmol·L^-1的Al³⁺处理可导致马尾松膜脂产生氧化。研究表明，马尾松幼苗具有一定的耐铝能力，在铝胁迫生境下可通过提高自身SOD和POD等保护酶的合成和主动积累脯氨酸、蛋白质和可溶性糖等渗透物质，产生适应性生理响应以维持自身的生理平衡来降低铝毒害作用。

Impacts of Aluminum Stress on the Growth and Physiological Characteristics of Pinus massoniana Seedlings

The Pinus massoniana seedlings were treated with different Al³⁺ concentrations in order to investigate the effects of aluminum stress on growth and physiological characteristics including chlorophyll, osmo regulation substance(soluble sugar, protein, proline), MDA and protective enzyme(superoxide dismutase, peroxidase) activities in leaves, which were experimented and studied to provide theoretical basis for revealing aluminum toxicity physiological mechanism and improving the Al tolerant ability of P. massoniana. The results showed the treatment of 0.2 mmol·L^-1 Al³⁺ had no significant impact to the seedling height and basal diameter but some promotion on its root length; above 0.2 mmol·L^-1 Al³⁺, the growth of the seedling height, basal diameter, root length were inhibited, and the higher the concentration is, the stronger the inhibition is; The content of chlorophyll and the activities of SOD and POD in leaves climbed with the increase of Al³⁺ concentration before they declined; above 0.2 mmol·L^-1 Al³⁺, with the addition of Al³⁺ concentration, the contents of osmo regulation substances, such as soluble sugar, soluble protein and proline presented the upward trend; above 0.2 mmol·L^-1 Al³⁺, the content of MDA changed the same as the osmo regulation substances. It proved that P. massoniana membrane lipid could produce oxidation with the treatment of Al³⁺. P. massoniana seedlings had a certain Al tolerant ability. They could produced physiological adaptive response to balance and reduce the aluminum toxicity by increasing the synthesis of SOD and POD, and accumulating proline, protein and soluble sugar.