Abstract: In order to explore the effects of foliar application of exogenous salicylic acid (SA) on Primula forbesii Franch. under cadmium (Cd) stress,a pot experiment was performed with P. forbesii seedlings as materials. The effects of different concentrations of exogenous salicylic acid (0,10,100,1 000 μmol·L^-1) on P. forbesii growth and physiological characteristics under 150 mg·kg^-1 soil Cd stress were investigated. The results showed that low concentrations of SA (10,100 μmol·L^-1) increased the plant height,crown width,aboveground biomass and promoted photosynthesis. Furthermore,exogenous SA application reduced the content of hydrogen peroxide and malondialdehyde in P. forbesii seedlings under Cd stress. The activities of SOD,POD and CAT,and the contents of the soluble sugar and soluble protein in Cd-treated P. forbesii seedlings were increased by SA application. Meanwhile,SA application also decreased the contents of Cd,Ca and Mg but increased K and Zn contents in leaves of P. forbesii seedlings under Cd stress. However,1 000 μmol·L^-1 SA treatment was found to inhibite the plant growth. This study showed that 100 μmol·L^-1exogenous SA treatment alleviated the toxic effects of 150 mg·kg^-1 soil Cd stress on P. forbesii seedlings,and reduced Cd accumulation.

Key words: Exogenous salicylic acid, Cadmium, Primula forbesii Franch., Antioxidant system, Photosynthetic parameters, Nutrient elements

摘要： 为了探究叶面喷施外源水杨酸（Salicylic acid，SA）对小报春（Primula forbesii Franch.）镉（Cadmium，Cd）胁迫的缓解作用，本研究以小报春幼苗为试验材料，采用盆栽试验方法，在土壤Cd胁迫（150 mg·kg^-1）下，测定不同浓度（0，10，100，1 000 μmol·L^-1） SA处理下的小报春植株生长和生理特性指标。结果表明，低浓度SA （10，100 μmol·L^-1）能够使小报春株高、冠幅和地上部生物量增加，促进光合作用；低浓度SA能降低过氧化氢和丙二醛含量，提高超氧化物歧化酶（Superoxide dismutase，SOD）、过氧化物酶（Peroxidase，POD）和过氧化氢酶（Catalase，CAT）活性，促进可溶性糖和可溶性蛋白的产生；同时低浓度SA还能显著降低小报春幼苗叶片中的Cd含量，增加叶片中的钾和锌含量，降低钙和镁含量。而高浓度SA （1 000 μmol·L^-1）缓解作用下降，甚至对植株生长产生抑制作用。本研究表明，100 μmol·L^-1外源SA处理可以显著缓解150 mg·kg^-1土壤Cd胁迫对小报春幼苗的毒害作用，并降低植株镉积累。

关键词: 外源水杨酸, 镉, 小报春, 抗氧化系统, 光合参数, 营养元素