Applying iodine fertilizers to cultivate iodine-rich crops for daily intake is an effective approach for iodine supplementation,especially for aromatic rice.Field experiments were conducted during the early growing se...Applying iodine fertilizers to cultivate iodine-rich crops for daily intake is an effective approach for iodine supplementation,especially for aromatic rice.Field experiments were conducted during the early growing seasons of 2021 and 2022 to evaluate the impacts of foliar application of iodine fertilizer on aromatic rice and to explore the optimal iodine fertilizer concentration.At the full heading stage,six different concentrations of sodium iodide solutions of 0%(CK),0.010%(T1),0.025%(T2),0.050%(T3),0.075%(T4),and 0.100%(T5)were applied to indica aromatic rice cultivars Meixiangzhan 2 and Xiangyaxiangzhan.The results showed that sodium iodide treatments significantly increased the iodine and sodium contents in both leaves and grains.Compared with the CK,the T1 and T2 treatments increased the 2-acetyl-1-pyrroline(2-AP)content in mature grains by 8.41%-101.66%and 13.58%-74.60%,respectively.Improvements in the contents of 1-pyrroline-5-carboxylic acid,proline,1-pyrroline,and methylglyoxal,as well as the activity of proline dehydrogenase were also detected.Additionally,sodium iodide treatments remarkably decreased the chalky grain rate,chalkiness area,and chalkiness degree of aromatic rice,with the T2 treatment exhibiting a 17.79%-47.42%decrease in chalkiness degree compared with the CK.Meanwhile,T1 and T2 treatments showed beneficial impacts on chlorophyll content,photosynthetic characteristics,and yield components,while T3,T4,and T5 treatments exhibited adverse effects on leaf and grain yields.The linear discriminant analysis revealed significant differences between treatments.The correlation analysis and piecewise structural equation modeling showed that the iodine and sodium influenced the photosynthetic characteristics and chlorophyll content of the leaves,thereby regulating the 2-AP biosynthesis and yield components,ultimately affecting the 2-AP content and yield.Overall,this study suggests that foliar application of 0.025%sodium iodide is an effective method to enrich the iodine content in rice grains,improve the grain aroma and appearance quality of aromatic rice,without detrimental effects on grain yield.展开更多
The speciation of heavy metals such as thallium,cadmium and lead existing in pyrite and pyrite cinder was analyzed by ICP-MS with a sequential extraction procedure.The distribution patterns of these metals including e...The speciation of heavy metals such as thallium,cadmium and lead existing in pyrite and pyrite cinder was analyzed by ICP-MS with a sequential extraction procedure.The distribution patterns of these metals including exchangeable,reducible,oxidizable and residual fractions were obtained.Tl,Cd and Pb in pyrite and pyrite cinder samples from each extraction step were determined by inductively coupled plasma mass spectrometry(ICP-MS).Under the optimized instrumental conditions,detection limits of Tl,Cd and Pb in different matrices were within the range of 0.006-0.07 μg/L,and the relative standard deviations ranged from 0.8% to 1.2%.The accuracy of Tl,Cd and Pb determination was checked by analyzing two certified reference materials.The results demonstrate that trace Tl,Cd and Pb in the samples can be accurately determined.The sequential extraction results revealed that the percent contents of Tl,Cd and Pb in exchangeable,reducible and oxidizable fractions in pyrite cinder are different from those in pyrite and in pyrite cinder.Tl,Cd and Pb mostly are distributed in residual fraction.Therefore,the mobility of metals in pyrite is higher than that in pyrite cinder.Although distributions of Tl,Cd and Pb in the non-residual fraction are not dominant in pyrite cinder,the total concentrations of them could not be ignored.Consequently,attention must be paid to the risk of potential pollution by pyrite cinder.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.31971843)the Technology System of Modern Agricultural Industry in Guangdong Province,China(Grant No.2020KJ105)+1 种基金the Guangzhou Science and Technology Project,Guangdong Province,China(Grant No.202103000075)the Special Rural Revitalization Funds of Guangdong Province,China(Grant No.2021KJ382)。
文摘Applying iodine fertilizers to cultivate iodine-rich crops for daily intake is an effective approach for iodine supplementation,especially for aromatic rice.Field experiments were conducted during the early growing seasons of 2021 and 2022 to evaluate the impacts of foliar application of iodine fertilizer on aromatic rice and to explore the optimal iodine fertilizer concentration.At the full heading stage,six different concentrations of sodium iodide solutions of 0%(CK),0.010%(T1),0.025%(T2),0.050%(T3),0.075%(T4),and 0.100%(T5)were applied to indica aromatic rice cultivars Meixiangzhan 2 and Xiangyaxiangzhan.The results showed that sodium iodide treatments significantly increased the iodine and sodium contents in both leaves and grains.Compared with the CK,the T1 and T2 treatments increased the 2-acetyl-1-pyrroline(2-AP)content in mature grains by 8.41%-101.66%and 13.58%-74.60%,respectively.Improvements in the contents of 1-pyrroline-5-carboxylic acid,proline,1-pyrroline,and methylglyoxal,as well as the activity of proline dehydrogenase were also detected.Additionally,sodium iodide treatments remarkably decreased the chalky grain rate,chalkiness area,and chalkiness degree of aromatic rice,with the T2 treatment exhibiting a 17.79%-47.42%decrease in chalkiness degree compared with the CK.Meanwhile,T1 and T2 treatments showed beneficial impacts on chlorophyll content,photosynthetic characteristics,and yield components,while T3,T4,and T5 treatments exhibited adverse effects on leaf and grain yields.The linear discriminant analysis revealed significant differences between treatments.The correlation analysis and piecewise structural equation modeling showed that the iodine and sodium influenced the photosynthetic characteristics and chlorophyll content of the leaves,thereby regulating the 2-AP biosynthesis and yield components,ultimately affecting the 2-AP content and yield.Overall,this study suggests that foliar application of 0.025%sodium iodide is an effective method to enrich the iodine content in rice grains,improve the grain aroma and appearance quality of aromatic rice,without detrimental effects on grain yield.
基金supported by the Union Foundation of NSFC-Guangdong Province (Grant No. U0633001)
文摘The speciation of heavy metals such as thallium,cadmium and lead existing in pyrite and pyrite cinder was analyzed by ICP-MS with a sequential extraction procedure.The distribution patterns of these metals including exchangeable,reducible,oxidizable and residual fractions were obtained.Tl,Cd and Pb in pyrite and pyrite cinder samples from each extraction step were determined by inductively coupled plasma mass spectrometry(ICP-MS).Under the optimized instrumental conditions,detection limits of Tl,Cd and Pb in different matrices were within the range of 0.006-0.07 μg/L,and the relative standard deviations ranged from 0.8% to 1.2%.The accuracy of Tl,Cd and Pb determination was checked by analyzing two certified reference materials.The results demonstrate that trace Tl,Cd and Pb in the samples can be accurately determined.The sequential extraction results revealed that the percent contents of Tl,Cd and Pb in exchangeable,reducible and oxidizable fractions in pyrite cinder are different from those in pyrite and in pyrite cinder.Tl,Cd and Pb mostly are distributed in residual fraction.Therefore,the mobility of metals in pyrite is higher than that in pyrite cinder.Although distributions of Tl,Cd and Pb in the non-residual fraction are not dominant in pyrite cinder,the total concentrations of them could not be ignored.Consequently,attention must be paid to the risk of potential pollution by pyrite cinder.
