中文摘要：

为研究不同光照条件下,外源水杨酸（SA）和紫外辐射（UV）对海洋绿藻浒苔的复合效应,在两个光照强度（高光：160μmol·m-2·s-1;低光：70μmol·m-2·s-1）条件下,设置对照（CK）、SA、UV及UV＋SA处理（UV=3.2 W·m-2、SA=10μg·m L-1）,处理3 d后测定浒苔生长、叶绿素荧光参数、光合放氧速率、超氧化物歧化酶活性、可溶性糖和可溶性蛋白含量等的变化,探讨光照强度、UV及SA的复合效应.结果表明：低光无UV条件下,SA会促进浒苔生长,降低浒苔叶绿素a（Chl a）和可溶性蛋白含量;高光无UV条件下,SA会抑制其生长,但显著提高了Chl a含量、呼吸速率、光合放氧速率、可溶性糖和可溶性蛋白含量;高光和UV条件下,UV＋SA显著促进浒苔生长,提高Chl a和可溶性糖含量;低光和UV条件下,与UV相比,UV＋SA提高了浒苔最大光化学效率（Fv/Fm）和可溶性蛋白含量,涨幅分别为139.8%和32.2%.外源SA的加入在一定程度上缓解了UV对浒苔的胁迫作用,且在高光条件下的效果更为显著.

英文摘要：

To study the combined effects of exogenous salicylic acid （SA） and ultraviolet radiation （UV） on marine green algae Ulva prolifera under high （160 μmol · m-2 · s-1） and low （70 μmol· m-2 ·s-1 ） light intensities, the growth, chlorophyll fluorescence parameters, photosynthetic rate of oxygen, superoxide dismutase （SOD） activity, soluble polysaccharide and soluble protein contents were investigated after they grew with or without ultraviolet （UV, 3.2 W · m-2） radiation in the presence or absence of SA （ 10 μg · mL-1 ） for three days. The treatments included control group （CK）, SA, UV and UV＋SA treatments. Results showed that under the tow light intensity without UV condition, the relative growth rate was enhanced, Chl a and soluble protein contents were decreased by SA. Under the high light intensity without UV condition, the relative growth rate was decreased, Chl a content, respiratory rate, photosynthetic rate of oxygen, soluble polysaccha- ride and soluble protein contents were enhanced by SA. Under the high light intensity with UV con- dition, the relative growth rate, Chl a and soluble polysaccharide contents were enhanced by UV＋ SA. Additionally, under the low light intensity with UV condition, compared to UV treatment, the maximum photochemical efficiency （Fv/Fm ） and soluble protein contents were respectively in- creased by 139.8% and 32.2% under the UV＋SA treatment. In conclusion, SA reduced the inhibi- tory effects of U. prolifera induced by UV, and the effects were more significant under the high light intensity.