采用砂基培养法,对不同浓度镉(Cd)(0、25 和150 mg·L^-1 )和萘(Nap)(0 和10 mg·L^-1)单一及复合胁迫45 和90 d 后红树植物白骨壤[Avicennia marina (Forsk.) Vierh.]的叶片叶绿素含量,根尖和叶片的MDA、AsA 和可溶性蛋白质含量及SOD 和POD 活性,根、茎、子叶和叶片中的Cd 含量进行了比较分析。结果表明:胁迫处理45 d时,Cd-Nap 复合胁迫处理组的叶片叶绿素a 含量、根尖和叶片的可溶性蛋白质含量及SOD 和POD 活性大多显著高于相同浓度Cd 单一胁迫处理组,叶片叶绿素b 含量显著低于后者,Chla / Chlb 值显著高于后者。胁迫处理90 d时,与相同浓度Cd 单一胁迫处理组相比,Cd-Nap 复合胁迫处理组叶片的叶绿素a、叶绿素b 和总叶绿素含量以及Chla / Chlb 值,根尖和叶片的MDA 和AsA 含量总体上无显著差异,而根尖和叶片的可溶性蛋白质含量和POD 活性及根尖的SOD 活性均显著提高。经Cd-Nap 复合胁迫处理后白骨壤幼苗的根、茎、子叶和叶片中的Cd 含量总体上高于相同浓度Cd 单一胁迫处理组,且随胁迫时间延长其差异越来越明显。研究结果显示:在Cd-Nap 复合胁迫条件下Cd 和Nap 具有协同作用,随胁迫时间延长和Cd 浓度提高,Cd-Nap 复合胁迫对白骨壤幼苗的伤害逐渐增强,并能够促进各器官对Cd 的累积。

Chlorophyll content in leaf, MDA, AsA, soluble protein contents and SOD and POD activities in root tip and stem, Cd contentin root, stem, cotyledon and leaf of mangrove Avicennia marina (Forsk.)Vierh. of different treatment groups after single and combination stressed for 45 and 90 d with different concentrations of cadmium ( Cd) ( including 0, 25 and 150 mg ·L^-1 ) and naphthalene ( Nap) (including 0 and 10 mg·L^-1) were comparatively analyzed by sand culture method. The results show that when stressed for 45 d, Chla content in leaf, soluble protein content and SOD and POD activities in root tip and leaf of Cd-Nap combination stress treatment group are mostly significantly higher than those of single stress treatment group with the same concentration of Cd, Chlb content in leaf is significantly lower than that of the latter, and Chla / Chlb ratio is significantly higher than that of the latter. When stressed for 90 d, compared with single stress treatment group with the same concentration of Cd, there are generally no significant differences in Chla, Chlb and total chlorophyll contents and Chla / Chlb ratio of leaf, MDA and AsA contents in root tip and leaf of Cd-Nap combination stress treatment group, while soluble protein content and POD activity in root tip and leaf and SOD activity in root tip are all increased significantly. After treated by Cd-Nap combination stress, Cd content in root, stem, cotyledon and leaf of A. marina seedlings is generally higher than that of single stress treatment group with the same concentration of Cd, and their differences are more and more obvious with prolonging of stress time. It is suggested that under condition of Cd-Nap combination stress, Cd and Nap have a synergistic effect, with prolonging of stress time and increasing of Cd concentration, damage of Cd-Nap combination stress to A. marina seedlings enhances gradually and Cd-Nap combination stress can promote the accumulation of Cd in different organs.