Chaudhary Shikha, Sharma Yogesh Kumar
Department of Environment Science, Faculty of Science, University of Lucknow, Lucknow, India.
J Environ Biol. 2009 May;30(3):427-32.
In the present study a novel approach has been made to evaluate the toxicity of cadmium in maize (Zea mays L. cv KJ9451) in terms of germination, seedling growth, pigment development and relevant enzyme activity and the possible remedial approach using potassium and copper to reduce cadmium toxicity. For the present investigations maize seeds were sown in petridishes on filter paper in triplicate containing different doses of cadmium viz. 0.05, 0. 10, 0.25, 0.50, 0.75 and 1.0 mM and for interactive studies maize seeds sown in 0.50, 0.75 and 1.00 mM Cd concentration were subjected to 0.50 and 1.00 mM concentration of potassium and copper respectively. At the high cadmium concentrations, germination percentage was decreased. I also showed considerable reduction in plumule length, radicle length and number of lateral roots while the potassium and copper combination with cadmium increased the seedling growth. The calculated values of SVI were found to be decreased with increase in the concentration of cadmium. Decreased GRI values were observed in maize treated with three higher concentrations of cadmium but the combination of potassium and copper showed recovery in GRI values. The fresh weight, dry weight and moisture contents were also found reduced with higher cadmium concentrations but the potassium and copper combination showed recovery when used with higher concentration of cadmium. Declined chlorophyll contents were noticed under the influence of higher cadmium concentrations. Both the combination of potassium and copper used with 0.50, 0.75 and 1.00 mM cadmium concentrations resulted in increased chlorophyll and pheophytin contents and decreased in Cu combination respectively. The potassium and copper (both 0.50 and 1.00 mM) with 0.75 and 1.00 mM cadmium increased the carotenoid contents although lone cadmium decreased it. Amylase activity was found to be gradually reduced at all concentrations of cadmium. The 0.50 mM and 1.00mM potassium combination improved amylase activity. Marked increase in catalase and peroxidase activity by the application of test chemical was observed in different doses of cadmium. The potassium and copper combination used with cadmium concentration reduced catalase activity while peroxidase activity was promoted.
在本研究中，采用了一种新方法来评估镉对玉米（Zea mays L. cv KJ9451）的毒性，该方法涉及发芽、幼苗生长、色素发育和相关酶活性，以及使用钾和铜降低镉毒性的可能补救方法。在本研究中，将玉米种子播种在培养皿中的滤纸上，一式三份，每份含有不同剂量的镉，即0.05、0.10、0.25、0.50、0.75和1.0 mM；为了进行交互研究，将播种在镉浓度为0.50、0.75和1.00 mM的玉米种子分别置于浓度为0.50和1.00 mM的钾和铜中。在高镉浓度下，发芽率降低。同时还显示出胚轴长度、胚根长度和侧根数量显著减少，而钾和铜与镉的组合增加了幼苗生长。发现随着镉浓度的增加，种子活力指数（SVI）的计算值降低。在用三种较高浓度镉处理的玉米中观察到发芽速率指数（GRI）值降低，但钾和铜的组合使GRI值恢复。较高的镉浓度也使鲜重、干重和水分含量降低，但钾和铜与较高浓度镉一起使用时显示出恢复作用。在较高镉浓度的影响下，叶绿素含量下降。钾和铜与0.50、0.75和1.00 mM镉浓度一起使用时，叶绿素和脱镁叶绿素含量均增加，而铜组合时则降低。钾和铜（0.50和1.00 mM）与0.75和1.00 mM镉一起使用时，类胡萝卜素含量增加，尽管单独的镉会使其降低。在所有镉浓度下，淀粉酶活性均逐渐降低。0.50 mM和1.00 mM钾的组合提高了淀粉酶活性。在不同剂量的镉中，通过施用受试化学品观察到过氧化氢酶和过氧化物酶活性显著增加。钾和铜与镉浓度一起使用时降低了过氧化氢酶活性，而过氧化物酶活性则得到促进。
