Transfer of iodine from soil to vegetables by applying exogenous iodine
Transfer of iodine from soil to vegetables by applying exogenous iodine
复制标题
通过施用外源碘将碘从土壤转移到蔬菜
DOI：
10.1051/agro:2008033
复制
发表时间：
2008-10-01
影响因子：
7.3
通讯作者：
Xie, Ling-Li
中科院分区：
文献类型：
--
作者：
Hong, Chun-Lai;Weng, Huan-Xin;Xie, Ling-Li
碘缺乏病是最常见的可预防的人类健康问题之一。在许多地区，生产富碘作物可能是降低碘中毒的有效方法。然而，关于这个问题的实际知识主要限于涉及粮食作物和无机碘肥料（如I-和IO 3-）的研究。此外，碘从土壤到植物的迁移、转化和分布还不清楚。在这里，我们研究了碘从土壤转移到蔬菜使用无机碘（KI）和有机，海藻碘。通过温室盆栽试验，研究了白菜、生菜、番茄和胡萝卜对碘的吸收和积累。研究了土壤中外源碘的动态变化规律。我们的研究结果首先表明，蔬菜中的碘含量随着碘添加量的增加而增加。第二，可食部分碘含量的大小顺序为：大白菜（高碘）>生菜>胡萝卜>番茄（低碘）。白菜可食部分的碘积累量分别是生菜和胡萝卜的2.25倍和4.45倍，是番茄的19.67倍。蔬菜组织中碘的分布顺序为：根（高碘）>叶>茎>果（低碘），胡萝卜除外，其根茎中的平均碘含量为地上部的50%。第三，当添加的碘浓度高于50 mg kg-1时，蔬菜生长受到抑制。对碘毒害的耐受性顺序为：胡萝卜（高耐受性）>白菜>生菜>番茄（低耐受性）。海藻复合碘肥比碘化钾具有更好的持久性。事实上，当KI以150 mg kg−添加到土壤中时，卷心菜、生菜、番茄和胡萝卜的生物量分别下降了34.8%、41.3%、46.8%和17.9%。相比之下，当施用海藻复合物时，生物量降低较低，分别为16.6%、22.9%、23.4%和9.7%。第五，收获后，土壤中的残留碘与碘化钾施肥只有56%的初始添加量，这是小于海藻复合。本研究对了解碘的生物化学及其迁移行为具有重要的理论意义，对寻找有效的碘生物强化替代方法防治碘缺乏病具有重要的现实意义。
Iodine deficiency disorders are one of the commonest preventable human health problems. Producing iodine-enriched crops could be an effective way to reduce their epidemicity in many regions. However, the actual knowledge on this issue is limited mostly to studies involving grain crops and inorganic iodine fertilizers such as I− and IO3−. Moreover, the translocation, transformation and distribution of iodine from soil to plants are not well understood. Here, we studied iodine transfer from soil to vegetables using both inorganic iodine (KI) and organic, seaweed iodine. Greenhouse culture experiments were undertaken to assess the absorption and accumulation of iodine by four vegetables: Chinese cabbage, lettuce, tomato and carrot. We also investigated the dynamic variation of exogenous iodine in soil by applying KI and a composite of seaweed and diatomite. Our results show first that iodine levels in vegetables increase with the increasing addition of iodine. Second, the iodine content in the edible portion ranks as follows: Chinese cabbage (high I) > lettuce > carrot > tomato (low I). The iodine accumulation in the edible portion of the cabbage is thus 2.25 and 4.45 times higher than that of lettuce and carrot, respectively, and 19.67 times higher than that of tomato. In vegetable tissues the iodine distribution is ranked as: root (high I) > leaf > stem > fruit (low I), except for carrot, where the average iodine level in the rhizome is 50% of the shoot. Third, vegetable growth is inhibited when the added iodine concentration is higher than 50 mg kg−1. The order of tolerance against iodine toxicity is ranked as: carrot (high tolerance) > Chinese cabbage > lettuce > tomato (low tolerance). Fourth, the seaweed composite iodine fertilizer demonstrates more potential of durability than KI. Indeed, when KI is added to the soil at 150 mg kg−, the biomass of cabbage, lettuce, tomato and carrot decreases by 34.8%, 41.3%, 46.8% and 17.9%, respectively. By comparison, the biomass decreases are lower, 16.6%, 22.9%, 23.4% and 9.7%, respectively, when applying the seaweed composite. Fifth, after harvest, the residual iodine in soil fertilized with KI is only 56% of the initial addition, which is less than that for seaweed composite. This study is of theoretical importance to understand iodine biogeochemistry and its transfer behavior, and also has practical implications for seeking effective alternatives of iodine biofortification to prevent iodine deficiency disorders.