论文部分内容阅读
Recent study reported that mercury levels in field-collected brown rice tended to decrease with increased soil selenium(Se)concentrations.This study temped to validate the possibility of Se application in the mercury contaminated paddy soils to reduce methylmercury(MeHg)accumulation in rice grains.Mercury contaminated paddy soil was added with selenite(SeIV)or selenate(SeVI)and cultured for rice in glasshouse.Mercury levels in rice root,stem,flag leaf and harvested rice grain(brown rice and polished white rice)were determined.Methylmercury levels in brown rice decreased by 34-38%in SeIV amended treatments.In addition,MeHg levels in white rice correlated negatively with white Se concentrations in rice,root or soil,indicating antagonism of Se on MeHg accumulation in rice.Our results suggested that such effect could be associated with selenium-mercury antagonistic interaction in soil(indicated by the significant decrease of soil MeHg levels under SeIV amendment),root(indicated by the reduced MeHg accumulation in root from soil)as well as within plant(indicated by the decrease in rice MeHg levels).The present study has taken an important first step to reduce mercury accumulation in rice and its consequent risk to the public health in mercury contaminated area by direct fertilization of Se.