不同外源硒对镉污染土壤中小白菜生长及镉吸收的影响  

Effects of Different Exogenous Selenium Species Application on Growth and Cadmium Uptake of Pak Choi in Cadmium Contaminated Soil

作　　者：刘杨 齐明星 王敏[1] 刘娜娜[1] Pornpimol Kleawsampanjai 周菲 翟辉[1] 王梦柯 任蕊 梁东丽[1,3] LIU Yang;QI Ming-xing;WANG Min;LIU Na-na;Pornpimol Kleawsampanjai;ZHOU Fei;ZHAI Hui;WANG Meng-ke;REN Rui;LIANG Dong-li(College of Natural Resources and Environment,Northwest A&F University,Yangling 712100,China;Shaanxi Hydrogeological Engneering Geology and Environment Geology Survey Center,Xi'an 710068,China;Key Laboratory of Plant Nutrition and the Agienvironment in Northwest China,Ministry of Agriculture,Yangling 712100,China)

机构地区：[1]西北农林科技大学资源环境学院,杨凌712100 [2]陕西省水工环地质调查中心,西安710068 [3]农业部西北植物营养与农业环境重点实验室,杨凌712100

出　　处：《环境科学》2021年第4期2024-2030,共7页Environmental Science

基　　金：陕西省地质调查院公益性地质调查项目(20180307);国家自然科学基金项目(41571454)。

摘　　要：为探究不同外源硒对镉的解毒作用的差异,并为土壤镉污染控制与农作物安全生产提供科学依据.采用土培盆栽试验,对比了不同施用量(0、0.5、1.0和2.5 mg·kg^(-1))的亚硒酸盐和硒酸盐施入天然镉污染土壤,对小白菜生长(根长、株高、生物量和光合指标)及镉吸收、转运的影响.结果表明,低硒处理(≤1.0 mg·kg^(-1))对镉的解毒作用优于高硒处理(2.5 mg·kg^(-1)),亚硒酸盐对镉的解毒作用大于硒酸盐.其中,外源施入≤1.0 mg·kg^(-1)的亚硒酸盐和硒酸盐均提高了小白菜的SPAD值、净光合速率、气孔导度、胞间CO_(2)浓度及生物量和株高,且以1.0 mg·kg^(-1)亚硒酸盐处理的效果最为显著(胞间CO_(2)浓度除外);而高硒处理小白菜的各光合指标均显著低于低硒处理(蒸腾速率除外,P<0.05).与未施硒处理(对照)相比,各硒处理均降低了小白菜对镉的吸收.其中,施入1.0 mg·kg^(-1)的亚硒酸盐和硒酸盐使得小白菜地上部的镉含量较对照处理分别显著降低了40.0%和20.5%(P<0.05),但当施硒量为2.5 mg·kg^(-1)时两种外源硒均促进了镉向地上部转运,使更多的镉累积在小白菜的地上部.总之,施入适量外源硒对土壤镉有一定的解毒作用,表现为小白菜生物量的提高和镉的积累下降.推荐施用1.0mg·kg^(-1)的亚硒酸盐用于镉污染土壤中镉的控制及安全利用.This study explored the discrepancy in the detoxification effects of different exogenous selenium(Se)species in cadmium(Cd)-contaminated soil to provide a scientific basis for the control of Cd pollution in the soil and the safe production of crops.A pot experiment was conducted to compare the effects of different concentrations(0,0.5,1.0,and 2.5 mg·kg^(-1))of selenite and selenate on the growth(root length,shoot height,biomass,and photosynthetic parameters),uptake,and translocation of Cd on pak choi in Cdcontaminated soil.The results indicated that the detoxification effect of a low Se concentration(≤1.0 mg·kg^(-1))treatment on Cd was better than that with a high Se concentration(2.5 mg·kg^(-1))treatment,and the selenite treatment demonstrated a greater detoxification effect on Cd than the corresponding selenate treatment.Meanwhile,the application of low-concentration selenite and selenate both increased the SPAD value,P_(n),G_(s),C_(i),biomass,and shoot length of the pak choi,and the 1.0 mg·kg^(-1)selenite treatment had the most significant(P<0.05)effect(except C_(i)).Nevertheless,the photosynthetic parameters of the pak choi under the highconcentration Se were significantly lower than those under the low Se concentration treatment(except Tr,P<0.05).Compared with the treatment without Se(control),the uptake of Cd in the pak choi was reduced under different Se treatments.Compared with the control,the Cd concentration in the shoots of the pak choi treated with 1.0 mg·kg^(-1)of selenite and selenate decreased by 40.0%and 20.5%(P<0.05),respectively.In addition,the translocation of Cd from the root to the shoot was significantly reduced under the 0.5 mg·kg^(-1)selenate treatment,while the high-concentration treatments of either exogenous Se promoted the translocation of Cd.Overall,applying the appropriate amount of exogenous Se could promote the photosynthesis and biomass of pak choi,and reduce the accumulation of Cd in pak choi.Therefore,the 1.0 mg·kg^(-1)selenite treatment is recommended for the control a

关 键 词：镉 污染土壤 外源硒 小白菜 光合作用 转运 

分 类 号：X171.5[环境科学与工程—环境科学]