بررسي اثر تغذيه اي سيليسيم بر كاهش خسارات اكسيداتيو فلزات سنگين نيكل و كادميوم در دو رقم گندم در محيط آبكشت

چكيده انگليسي :

Effect of Silicon Nutrition on Alleviation of the Oxidative Damages Related to Nickel and Cadmium Toxicity in Two Wheat Cultivars Saeid Amani am sa242@gmail com January 15 2013 Department of soil science college of Agriculture Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi H Shariatmadari shariat@cc iut ac ir Abstract Silicon Si is the second most abundant element in the soil presents as silicic acid in soil solution Although silicon has not been considered as an essential element for higher plants it has been proved to be beneficial for the healthy growth and development of many plant species particularly graminaceous plants The beneficial effects of silicon are distinct in plants exposed to abiotic and biotic stresses Heavy metals such as nickel and cadmium are entered to the soils as the results of human activities causing great environmental problems In fact heavy metals by accumulation in plants not only causing damage to the plants but also directly or indirectly enter to the the human and animal food chain and threaten their health The main objective of the present study was to elucidate the beneficial effects of silicon on alleviation of oxidative damages caused by nickel and cadmium toxicity in two wheat cultivars durum and back cross in a hydroponic experiment In this study silicon was supplied as sodium silicate solution in two levels 0 and 1 Mm Six concentration levels of nickel and cadmium 0 2 5 5 10 30 and 50 4M and 0 5 10 30 50 and 100 4M were supplied as NiCl2 and CdCl2 respectivily After 60 days the plants were harvested and the dry weight concentrations of nickel cadmium silicon iron and zinc in shoot and root antioxidant enzyms activity CAT and POX and electrolyte leakage EL were determined The results of this study indicated that regardless of cultivar Si at 0 2 5 and 5 4M of Ni treatments and at 0 5 and 10 4M of Cd treatments increased shoot dry weight and Si at 2 5 and 5 4M of Ni treatments and at 5 and 10 4M of Cd treatments increased root dry weight Not regarding the cultivar Si at 2 5 and 5 4M of Ni treatments and 5 and 10 4M of Cd treatments decreased shoot Cd and Ni concentrations In durum cultivar Si at 0 and 50 4M of Ni treatments and in back cross cultivar at 0 30 and 50 4M of Ni levels increased shoot iron concentration and Si at all Cd levels increased shoot iron concentration In durum cultivar Si at 0 and 2 5 4M of Ni and in back cross cultivar in all Ni levels except for 10 4M level increased shoot zinc concentration Regardless of cultivar Si at 0 and 5 4M of Cd treatments increased and in the other Cd levels decreased shoots zinc concentration In durum cultivar Si at all Ni levels except for 30 and 50 4M of Ni concentrations and in back cross at 0 2 5 and 5 4M of Ni levels increased catalase activity While in durum cultivar Si at all Ni levels except for 2 5 and 5 4M increased peroxidase activity in back cross cultivar Si at all Ni treatment levels decreased peroxidase activity In durum cultivar Si at all Cd treatments except for 5 and 10 4M and in back cross cultivar at all Cd levels increased catalase activity Also in durum cultivar Si at all Cd levels except for 100 4M and in back cross cultivar at 0 and 5 4M of Ni increased peroxidase activity Regardless of cultivar Si at 0 2 5 and 5 4M of Ni treatments and 0 5 and 10 4M of Cd concentrations decreased electrolyte leakage and in the other levels increased electrolyte leakage According to the results the effects of silicon on alleviation of heavy metal toxicity depending on the type and concentrations of heavy metal and wheat cultivars were different Key Words Heavy metal pollution Silicon Nickel Cadmium Oxidative damage Durum Back cross Wheat

اماني، سعيد

بررسي اثر تغذيه اي سيليسيم بر كاهش خسارات اكسيداتيو فلزات سنگين نيكل و كادميوم در دو رقم گندم در محيط آبكشت

آلودگي فلزات سنگين , سيليس , رقم دوروم , رقم بك كراس