不同品种空心菜对重污染土壤砷的吸收累积及其亚细胞分布

采用水泥池小区试验研究了土壤As污染(66.4 mg·kg-1)胁迫对19种空心菜生长、As累积以及As的亚细胞分布的影响。结果表明,各品种空心菜均能生长,但不同品种空心菜生物量及As累积量存在显著差异(P0.05),地上部As含量范围为0.73~191.12 mg·kg-1,均超出食品中污染限量的标准(0.5 mg·kg-1)。台湾白骨柳叶空心菜、泰国白梗柳叶空心菜、油青空心菜3个品种为相对低累积品种;台湾大叶白骨空心菜、菜农D-95空心菜、港种青绿梗叶空心菜、泰国竹叶空心菜4个品种为相对高累积品种。19个品种空心菜亚细胞中固持As含量大小顺序为胞质(49.06%~77.44%)细胞器(19.90%~46.82%)细胞壁(2.22%~16.73%)。

Accumulation and subcellular distribution of arsenic in water spinach(Ipomoea aquatica) cultivars from arsenic contaminated soil

Comparison of uptake and distribution of arsenic(As) accumulation in different cultivars of water spinach and its mechanisms are poorly investigated. A plot experiment in soil pools was conducted to study the effect of soil As stress on plant growth, As accumulation and As distribution in subcellular fraction of nineteen water spinach(Ipomoea aquatica) cultivars. The results showed that all those 19 Ipomoea aquatica cultivars could be growth under 66.4 mg·kg^-1 As of soil stress treatment. However, there was significant difference in the biomass, As accumulation among Ipomoea aquatica cultivars. And the concentration of above-ground portion of Ipomoea aquatica cultivars varied from 0.73 to 191.12 mg·kg^-1 As, all beyond the limits of the standard GB 2012-2762. In addition, four high As accumulating cultivars and three low As accumulating cultivars from 19 cultivars of Ipomoea aquatica were screened out. During the 66.4 mg·kg^-1 As exposure, the proportion of each constituent was in the order of soluble fraction(49.06%~77.44%) > cell organ(19.90%~46.82%) > cell wall(2.22%~16.73%), and cytoplasmic organelles and the cell wall maintained low levels of As.