| 来源于土壤和灌溉水的砷在水稻根表及其体内的富集特性 |
| 摘要点击 2929 全文点击 1623 投稿时间：2007-05-05 修订日期：2007-07-09 |
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| 中文关键词 砷 铁氧化物 水稻 含砷灌溉水 |
| 英文关键词 arsenic iron plaque rice irrigation-water with arsenic |
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| 中文摘要 |
| 采用土壤-玻璃珠联合培养的方式，选择2个氧化能力不同的水稻品种YY-1、94D-64（品系）和采自浙江富阳的土壤（砷的本底值为13.8 mg·kg-1），并设灌溉清水和含砷水2个处理（即在分蘖期、拔节期、孕穗期、开花期和灌浆期5个生育阶段灌溉含砷污水，随灌溉水进入土壤中砷的浓度为3.2 mg·kg-1），研究了砷在土壤-根表铁氧化物-水稻系统中的累积规律以及土壤和灌溉水对水稻秸秆和籽粒富集砷的贡献程度.结果表明，水稻的秸秆生物量及其籽粒产量并没有受到不同来源砷的显著影响；灌溉含砷水处理的两品系水稻根表铁氧化物沉积的数量（YY-1:196 g·kg-1, 94D-64:75.8 g·kg-1）高于对照(YY-1:175 g·kg-1, 94D-64:60.1 g·kg-1)，但差异不显著.然而，在水稻5个不同的生育期灌溉含砷水均显著增加了砷在其根表及其体内不同部位的富集（94D-64籽粒中砷含量除外）.没有灌溉含砷水的对照其秸秆和籽粒中累积的砷来源于土壤，而砷处理的水稻其秸秆和籽粒中富集的砷则来源于土壤和灌溉的含砷水.土壤对YY-1和94D-64秸秆中富集砷的贡献率分别为76.5%和71.0%，灌溉水的贡献率分别为23.5%和29.0%，2个水稻品系之间没有明显差异.YY-1籽粒中的砷66.4%来源于土壤，33.6%来源于含砷灌溉水，灌溉水对该品系籽粒中砷的富集贡献率较高.另一品系94D-64籽粒中砷84.8%来源于土壤，15.2%由灌溉水贡献，灌溉水对此品系籽粒累积砷的贡献率较低.来源于土壤和灌溉水的砷在水稻籽粒中的富集没有超出我国的国家食品卫生标准（0.7 mg·kg-1）. |
| 英文摘要 |
| A compartmented soil-glass bead culture system was used to investigate characteristics of arsenic accumulation in iron plaque and in mature rice plants irrigated using water with arsenic in greenhouse. Arsenic was supplied as a solution of Na3AsO4·12H2O at the following stages: tillering, stem elongation, booting, flowering and grain filling. The whole plant was separated into four parts and As concentrations were analyzed in DCB (dithionite-citrate-bicarbonate)-extraction, root, straw, rice husk and grain respectively. The results show that irrigation-water with arsenic has no significant effect on biomass of straw and grain. Arsenic concentrations are distributed in different components of mature rice with the ranking of iron plaque>root>straw>husk>grain. Arsenic in straw and grain just derive from soil in control, and derive from soil and irrigation-water in arsenic treatment. About 76.5% and 71.0% of total arsenic in rice straw are from soil for lines of YY-1 and 94D-64 respectively. There is no significant difference between two lines. However, about 33.6% of total arsenic in grain of YY-1 comes from irrigation-water with arsenic, and only 15.2% of total arsenic in grain of 94D-64 is from irrigation-water with arsenic. There is a significant difference between YY-1 and 94D-64. Arsenic concentrations in rice grain are lower than the food safety limitation in China (0.7 mg·kg-1). |
