锑胁迫对玉米生物量、光合特性及锑积累的影响

Effects of Antimony Stress on the Biomass,Photosynthetic Characteristics and Antimony Accumulation of Maize

为了探讨锑污染对经济作物玉米的生长及光合生理的影响,以高产多抗玉米品种滑玉14为材料,通过盆栽试验的方法研究了不同浓度[0(CK)、50、250、500和1 000 mg·kg^(-1)]重金属锑(Sb)胁迫对玉米生物量、气体交换参数、叶绿素荧光参数以及锑积累特征的影响。结果表明,随着生长介质中Sb浓度的增加,玉米生物量、叶绿素含量、气体交换参数(净光合速率、气孔导度、蒸腾速率)和PSⅡ最大光能交换效率(Fv/Fm)均呈下降趋势,瞬时水分利用效率(i WUE)和丙二醛(MDA)含量均呈上升趋势。高浓度Sb(1 000 mg·kg^(-1))胁迫下,玉米的生物量,叶绿素含量、净光合速率和Fv/Fm显著减少(P<0.05),分别比CK下降了47.90%、34.22%、52.70%和7.84%;iWUE和MDA显著升高(P<0.05),分别比CK升高66.71%和34.02%。随着生长介质中Sb浓度的增加,玉米地下及地上部分锑含量均呈现增加的趋势,各处理之间的差异均达到显著水平(P<0.05),转运系数也呈现逐渐增加的趋势,然而其值(在0.52~0.82之间)均小于1,表明高产多抗玉米品种滑玉14向地上部位转运锑相对较少,这可能有利于保护该玉米品种叶片的光合机构,增强植株对锑的耐受能力。本研究结果为经济作物玉米应用于重金属污染土壤修复提供了一定的参考依据。

In order to investigate effects of antimony（ Sb） pollution on the growth and photosynthesis of economic cropmaize,the effects of different Sb concentrations [0（ CK）,50,250,500 and 1 000 mg·kg-1] on the biomass,gas exchange parameters,chlorophyll fluorescence and antimony accumulation of maize plants（ cv. Huayu 14） were investigated in a pot experiment. The biomass,chlorophyll content,gas exchange parameters（ net photosynthetic rate,stomatal conductance and transpiration rate） and the maximum quantum yield of PS Ⅱ（ Fv/Fm） all exhibited a decreasing trend with an increasing Sb level in the growth medium whereas instantaneous water use efficiency（ i WUE）and malondialdehyde（ MDA） content displayed an opposite tendency. At a high concentration of Sb（ 1000 mg·kg-1）,maize biomass,total chlorophyll content,net photosynthetic rate and Fv/Fmdecreased by 47. 90%,34. 22%,52. 70%and 7. 84% as compared with CK,respectively; i WUE and MDA content increased by 66. 71% and 34. 02% as compared with CK,respectively. Besides,with increasing Sb level,the Sb content was increased in the underground part and aboveground part of maize,and the differences among Sb treatments were significant（ P〈0. 05）. The translocation coefficient from underground part to aboveground part also exhibited an increasing trend and its values（ between 0. 52 and 0. 82） were lower than 1. 0,indicating that a relatively small amount of Sb could be transferred from underground part to aboveground part,which may help this maize variety to protect its photosynthetic apparatus and enhance its tolerance to heavy-metal tolerance. This study provides some useful information based on the economic crop,maize,that can be applied to the remediation of heavy metal contaminated soils.