Growth and Physiological Responses of Two Rice Varieties to Applied Lead in Normal and Salt-Affected Soils

In arid and semi-arid regions of the world, soil salinity and heavy metal pollution occurring through various natural and anthropogenic means, is becoming major threat to safe crop production.The most feasible and effective approach is screening, breeding and cultivation of food crop varieties with low toxic metal accumulation.A pot study was conducted to investigate the growth and physiological responses of rice exposed to applied lead (Pb) in normal and salt-affected soils comprising four levels of Pb (0, 50, 100 and 150 mg kg -1 soil), two rice varieties (Shaheen basmati and KS-282) and two types of soil as normal and salt-affected soils.Increasing level of Pb decreased plant height, straw and paddy yields, photosynthetic and transpiration rates and stomatal conductance, more under salt-affected conditions.The cv. Shaheen basmati showed better response for growth, yield, physiological attributes and had lower Pb concentration in straw and paddy compared to cv.KS-282, at all levels of applied Pb in both normal and salt-affected soils.Thus, Shaheen basmati was found to be grown for Pb risk-free rice production and can be a good source for future rice breeding programs with the aim to produce low Pb accumulation and salt-tolerant rice varieties.