接种AM真菌和施加铁可协同降低水稻砷累积

Arbuscular mycorrhizal inoculation and ferrum addition synergistically reduce arsenic accumulation in Oryza sativa

采用外源添加砷(As)的土培模拟试验探究了接种丛枝菌根真菌(AMF)异形根孢囊霉Rhizophagus irregularis和外源添加铁(Fe)对水稻Oryza sativa根表铁膜形成以及水稻累积砷的影响。结果表明,根表铁膜能够吸附大量的磷和砷。添加砷促进了根表铁膜的形成,而接种AMF后铁膜厚度显著降低。接种AMF改善了植物的磷营养状况,显著提高了水稻根系砷浓度,但降低了地上部砷浓度;砷污染情况下施加铁显著降低了接种处理水稻地上部的砷浓度。接种AMF+施加铁处理降低水稻地上部砷浓度的效果最大。这表明AMF+施加铁可协同抑制水稻地上部砷积累。该研究结果为在高砷背景值土壤中种植粮食作物并保障食品安全提供了一条可供选择的技术途径。

A pot experiment was conducted to reveal the effects of arbuscular mycorrhizal fungus（AMF） Rhizophagus irregularis and ferrum（Fe） addition on the formation of root surface iron plaque and As accumulation in paddy rice Oryza sativa. The results indicated that iron plaque had the ability of adsorbing large amount of phosphorus and arsenic. Arsenic addition promoted the formation of iron plaque, while mycorrhizal inoculation significantly decreased the thickness of iron plaque. Mycorrhizal inoculation improved rice phosphorus nutrition and increased root but decreased shoot As concentration. Fe addition reduced shoot As concentration of inoculated rice under As exposure. The study demonstrated that combination of mycorrhizal inoculation and Fe addition could synergistically decrease As concentration in rice shoots, and provided a practical way for safe cultivation of paddy rice in As contaminated soil.