The effects of cadmium (Cd) toxicity on plant growth and physiology were investigated in rice (Oryza sativa L.) grown in sand medium. Suwandel and Bg300 rice varieties were evaluated against 0, 0.5 and 3 mg kg-1 Cd levels using thirteen plant growth and physiological parameters. The only parameter that influenced by the rice variety and Cd level interaction effect was the transpiration rate. All other parameters were not changed significantly by the said interaction effect. Cadmium level of 3 mg kg-1 significantly decreased the shoot dry weight and photosynthetic rate. It also increased the transpiration rate of Suwandel variety. Hence, 3 mg kg-1 level was the most critical one for shoot dry weight, photosynthetic rate and transpiration rate. However, Cd levels were not significantly changed plant height, leaf area, root dry weight, death leaf percentage, relative leaf chlorophyll content, stomatal conductance to H2O, intercellular CO2 concentration, computed leaf temperature, cell membrane permeability and relative water content. This concluded that Bg300 and Suwandel can compensate the toxic effects exerted by 0.5 and 3 mg kg-1 Cd levels without affecting the plant growth and physiology.

Keywords:

Plant Cd responses, Growth, Photosynthesis, Water relations 

Wijayawardhana D, V. Herath and P. A. Weerasinghe (2019)Cadmium Tolerance of Rice (Oryza Sativa L.): Effects on Plant Growth, Photosynthesis, Cell Membrane Permeability and Relative Water Content.Sri Lankan Journal of Agriculture and Ecosystems, 1(2):80-93.www.rjt.ac.lk/agri/ sljae/2019_01_16.html

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