Naeem Asif, Ghafoor Abdul, Farooq Muhammad
Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan.
Soil Science Division, Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, Pakistan.
J Sci Food Agric. 2015 Sep;95(12):2467-72. doi: 10.1002/jsfa.6976. Epub 2014 Nov 25.
Cadmium concentration in food grains could be minimised through application of beneficial plant nutrients such as silicon. Therefore, the impact of silicon application on immobilisation of Cd in soil and its concentration in low and high shoot-Cd (LSCd and HSCd, respectively) cultivars of wheat were evaluated in a pot experiment. Selected LSCd cultivars (Iqbal-2000 and Lasani-2008) and HSCd cultivars (Inqlab-91 and Sehar-2006) were grown on artificially Cd contaminated soil at 10 mg Cd kg(-1) . Three levels of Si (50, 100 and 150 mg kg(-1) soil), applied as calcium silicate (CaSiO3 ), were tested.
None of the wheat cultivars showed any symptoms of toxicity or growth retardation against applied Cd stress. Silicon applied to Cd-treated plants did not improve root and shoot dry matter; however, it increased grain yield significantly at the highest rate of application (150 mg kg(-1) soil). Similarly, Si application at 150 mg kg(-1) decreased plant available soil Cd without affecting soil pH. Silicon application not only caused a linear decrease in Cd contents of shoots and grains but also decreased its translocation from roots to shoots and grains. Decrease in shoot Cd concentration was higher in HSCd than LSCd cultivars whereas the reverse was true for Cd concentration in grains.
Si addition decreased Cd concentration in wheat cultivars by causing a decrease in both plant-available soil Cd and its translocation from roots to shoots. Application of Si at 150 mg kg(-1) proved to be an effective level of Si that could significantly lower Cd concentration in wheat grains.
通过施用有益植物养分如硅，可以使粮食作物中的镉浓度降至最低。因此，在盆栽试验中评估了施用硅对土壤中镉的固定及其在小麦低镉和高镉（分别为LSCd和HSCd）品种地上部镉浓度的影响。选用LSCd品种（Iqbal - 2000和Lasani - 2008）和HSCd品种（Inqlab - 91和Sehar - 2006）种植在镉人工污染土壤上，镉含量为10 mg Cd kg(-1)。测试了三种硅水平（50、100和150 mg kg(-1)土壤），以硅酸钙（CaSiO3）形式施用。
没有一个小麦品种表现出针对施加的镉胁迫的任何毒性症状或生长迟缓。施用于镉处理植物的硅并没有提高根和地上部干物质；然而，在最高施用量（150 mg kg(-1)土壤）时显著提高了籽粒产量。同样，施用150 mg kg(-1)的硅降低了植物有效态土壤镉含量，而不影响土壤pH值。施用硅不仅使地上部和籽粒中的镉含量呈线性下降，还降低了镉从根向地上部和籽粒的转运。HSCd品种地上部镉浓度的降低高于LSCd品种，而籽粒中镉浓度则相反。
添加硅通过降低植物有效态土壤镉及其从根向地上部的转运，降低了小麦品种中的镉浓度。施用150 mg kg(-1)的硅被证明是一个有效的硅水平，可以显著降低小麦籽粒中的镉浓度。
