铀胁迫对2种植物荧光生理及累积特性的影响

Effects of Uranium Stress on Fluorescence Physiology and Accumulation Characteristics of Oenanthe javanica and Hydrocotyle vulgaris

针对放射性污染水体富集水生植物的筛选及核素处理能力关键技术问题,通过水培试验,研究了铀胁迫对水芹和铜钱草的生理特性、叶绿素荧光特性及吸收富集能力的影响。结果表明:(1)在55 mg/L铀处理下水芹和铜钱草的叶绿素a、叶绿素b和类胡萝卜素含量下降最为显著,与对照组相比分别下降了52.54%、65.27%、67.89%和63.20%、79.82%、45.19%,与对照组相比水芹和铜钱草最大光化学效率(Fv/Fm)分别下降了2.3%和1.3%,光和性能指数(PIABS)分别下降了24.3%和30.9%;(2)在铀处理下,2种植物的抗氧化酶系统均受到不同程度影响,SOD、POD和CAT活性均呈先升后降的趋势,在55 mg/L的铀处理下MDA含量达到最高,分别比对照上升了118.63%和91.72%。(3)水芹和铜钱草对铀的富集浓度在55 mg/L处理下达到最大,根、茎和叶各部铀浓度分别达到3 637.2、322.9、373.4 mg/kg和2 908.8、262.7、136.5 mg/kg;水芹和铜钱草对铀均有一定的富集能力和耐受性。

In terms of screening of aquatic plants and key technical issues of radionuclide treatment for the concentration of radioactive polluted water, hydroponic experiment was done to study the effects of uranium stress on physiological characteristics,Oenanthe javanica and Hydrocotyle vulgaris chlorophyll fluorescence and absorption ability. Result showed that in 55 mg/L Oenanthe javanica and Hydrocotyle vulgaris under the treatment of uranium,chlorophyll a,chlorophyll b and carotenoid content decreased most significantly,52.54%,65.27%,67.89% and 63.20%,79.82%,45.19% decline compared with the control group. Compared with the control group,the maximum photochemical efficiency（Fv/Fm） of Oenanthe javanica and Hydrocotyle vulgaris decreased by 2.3% and 1.3%,and the optical performance index（PIABS）decreased by 24.3% and 30.9%. In uranium processing,antioxidant system of two species were affected to varying degrees.The activity of SOD,POD and CAT showed the trend of first increasing and then descending. The content of MDA reached the highest at 55 mg/L of uranium processing,which increased by 118.63% and 91.72% respectively comparing with the control group. Oenanthe javanica and Hydrocotyle vulgaris on uranium enrichment in the processing of 55 mg/L reached the maximum,the concentrations of uranium in roots,stems and leaves were 3 637.2 mg/kg,322.9 mg/kg,373.4 mg/kg and2 908.8 mg/kg,262.7 mg/kg,136.5 mg/kg,respectively. Oenanthe javanica and Hydrocotyle vulgaris of uranium has certain enrichment ability and tolerance.