紫甘薯对硒的吸收和累积特征

以紫甘薯为试验材料,采用盆栽试验的方法研究了基施硒酸钠Se(VI)]和亚硒酸钠Se(IV)]条件下,紫甘薯对外源硒的吸收累积规律,并比较了施用两种不同价态硒的紫甘薯富硒效果。结果表明:两种硒源均可显著提高紫甘薯各器官含硒量,且紫甘薯含硒量均随施硒量的增加而增大。当土壤施硒量为Se 8 mg/kg时,施用硒酸钠、亚硒酸钠收获期薯块的硒含量(干基)分别达到6.69、0.88 mg/kg。紫甘薯生育期40 d时各器官硒含量叶茎薯块,130 d时硒含量叶薯块茎。当硒酸钠施用量为Se 4 mg/kg时,紫甘薯薯块中的硒累积量最高达923.81μg/株,硒在紫甘薯块根中的分配率可达67%~70%,硒酸钠处理下,紫甘薯对硒的吸收利用率远远高于亚硒酸钠处理。综合紫甘薯含硒量和施硒量对生长的影响结果分析,施用硒酸钠和亚硒酸钠均能增加紫甘薯薯块的硒含量,紫甘薯对硒酸钠敏感性高于亚硒酸钠,生产过程中应充分考虑施用硒酸钠对作物造成的毒害。

The characteristics of selenium absorption and accumulation in purple sweet potato

Taking purple sweet potato as the experiment material, a pot experiment method was carried to study the character-istics of selenium absorption and accumulation in purple sweet potato. The selenium-enrichment difference of purple sweet pota-to under selenate Se ( VI) ] and selenite Se ( IV) ] treatment was compared. The results showed that both selenate and sel-enite increased the selenium concentration of the purple sweet potato significantly and the selenium concentrations in plant or-gans had a positive correlation with the selenium application. The highest selenium content of purple sweet potato in root-tuber were 6. 69 mg/kg ( DW) and 0. 88 mg/kg ( DW) , respectively, with application of Se 8 mg/kg soil by selenate and sele-nite. On 40 d of the growth, the selenium concentration order in different organs of purple sweet potato was leaf>stem>root-tuber, while the order on the 130 d of the growth was leaf> root-tuber>stem. The highest selenium accumulation of purple sweet potato root-tuber reached 923. 81 μg/plant under 4 mg/kg selenate treatment. The distribution rate of Se in root-tuber of purple sweet potato was between 67% ~70%, the absorption rate of selenate was significantly higher than that of selenite. Considering selenium enrichment and the growth of purple sweet potato, both selenate and selenite were helpful for selenium-enrichment purple sweet potato production, the sensibility of sweet potato to selenate exceeded that of selenite, and the biologi-cal safety for crops should be taken full account of in the production process.