Effects of water management combined with manganese fertilizer on regulation of cadmium uptake by rice with application of oyster shell powder
This study was conducted to study the effect of water management combined with Mn fertilizer on the regulation of Cd uptake and transport in rice.In this study,oyster shell powder was applied to a pot experiment under different water management conditions(continuous flooding and alternating flooding and drying).The effects of oyster shell powder combined with different amounts of manganese sulfate fertilizer(0,50,100 mg·kg-1)on the morphology and content of Cd and Mn in rhizosphere soil,content of Cd and Mn in rice,and the expression of OsNramp5 gene in root were analyzed.The results showed that a single application of oyster shell powder(OS treatment)could significantly decrease soil available Cd and available Mn contents under both water management conditions.Under continuous flooding conditions,OS treatment had no significant effect on Cd content in brown rice,but significantly reduced Cd content in brown rice under alternating flooding and drying conditions compared with CK treatment.Under continuous flooding conditions,compared with OS treatment,oyster shell powder combined with manganese sulfate fertilizer(OSMn treatment)could significantly increase the soil available Mn content by 5.4%-10.9%.The relative expression of OsNramp5 in roots treated with OSMn was upregulated by 85.6%-105.9%,which promoted the absorption of Cd in rice.OSMn50 treatment increased the content of Cd in iron plaque,root and straw by 46.9%,52.9%,and 33.7%,respectively,but decreased the transfer coefficient of Cd in straw-brown rice by 47.8%and the content of Cd in brown rice by 30.0%.The transfer coefficients of Cd in iron plaque-root and straw-brown rice were increased by 35.3%and 23.9%,respectively,and the content of Cd in brown rice increased by 25.2%when treated with OSMn100.Under alternating flooding and drying,OSMn treatment significantly increased the content of available Mn,amorphous,and free Mn oxides in soil,while the content of soil available Cd decreased gradually with the increase of Mn fertilizer addition.Compared with OS treatment,OSMn50 treatment up-regulated the relative expression of OsNramp5 in root by 256.8%-322.8%,which significantly increased Mn content in different parts of rice,but had no significant effect on Cd content in brown rice and root.The transfer coefficient of Cd in straw-brown rice increased by 38.9%,and the Cd content in straw-brown rice increased by 15.3%when treated with OSMn100.The above results showed that oyster shell powder combined with 50 mg·kg-1 Mn fertilizer further reduced the Cd content in brown rice,but excessive Mn fertilizer promoted the accumulation of Cd in rice grains under continuous flooding conditions.In addition,compared with alternate flooding and drying,oyster shell powder combined with Mn fertilizer was more effective in reducing the accumulation of Cd in brown rice under continuous flooding conditions.
riceCd uptake and translocationoyster shell powdermanganese fertilizer
万方数据
维普
