砷对水稻根部渗氧分布和铁膜形成的影响

摘要

The effects of different arsenic (As) treatments on spatial pattern of radial oxygen loss (ROL), iron (Fe) plaque formation and As accumulation in rice were investigated using three rice genotypes, planted under greenhouse conditions. Arsenic was applied to soil at 50 and 100 mg/kg, with untreated soil used as a control having an average As concentration of 8.5 mg/kg. It was demonstrated that the ratio of ROL in root tips to that at the root base slightly decreased with increasing As concentration, suggesting that the spatial ROL patterns in these groups may be shifted from the "tight" barrier towards the "partial" barrier form. Furthermore, increasing As concentration led to a increase in Fe plaque formation on root surfaces. In addition, root As concentrations of genotypes in 50 and 100 mg/kg As treatments were significantly higher than that of control treatment (P<0.05). Grain As concentration of genotype Nanyangzhan (with lower ROL)was significantly higher (P<0.05) than that of genotype CNT87059-3 with higher ROL.%研究砷对三种水稻品种(玉香油占、CNT87059和南洋占)生物量、根部渗氧径向分布、根表铁膜形成以及砷在植物体内积累的影响.在土壤中分别添加50和100 mg/kg砷、并以未经处理的含砷8.5 mg/kg的土壤作为对照,结果表明,随着砷处理浓度的增加,水稻根表铁膜的含量增加;水稻根尖渗氧率与根基部渗氧率的比值随着砷处理浓度的增加而降低,水稻根部渗氧模式从"紧密型"向"疏松型"转变;与对照样品相比,50和100 mg/kg砷处理能显著增加水稻根部的砷积累(P<0.05);低渗氧能力水稻品种(南洋占)谷粒砷含量显著高于高渗氧能力水稻品种(CNT87059,P<0.05)的谷粒砷含量.