The response of photosynthetic parameters of Triticum aestivum L. and Pisum sativum L. to different levels of salinity stress at different climate conditions

Abstract

The aim of this work was to investigate the response of physiological parameters of winter wheat (Triticum aestivum L. cv. ʾAdaʾ) and pea (Pisum sativum L. cv. ’Early onward’) to different levels of salinity stress under changing climate conditions. Experimental plants were grown in growth chambers under the conditions of current climate (400 µmol mol^-1 CO₂ and day/night temperatures of 21/14 °C) and warmed climate (800 µmol mol^-1 CO₂ and day/night temperatures of 25/18 °C). Under both climate conditions plants were exposed to 100 mM and 200 mM concentrations of sodium chloride. Exposure to salinity stress was initiated when plants developed the second true leaf or their pair. After salinity treatments, which lasted 2 weeks, the response of photosynthetic and transpiration rate, stomatal conductivity, intracellular content of CO₂, water use efficiency, II photosystem quantum efficiency rate and photosynthesis performance index were measured. Physiological parameters of pea plants were mostly affected at current climate conditions. The biggest reductions were found in photosynthetic and transpiration rate, which decreased by 57.0 %, and 71.5 %, under 200mM effect respectively. Assessment of intensity of fluctuation of wheat and pea physiological parameters at current climate has shown that changes were bigger in pea plants (51.3 %), in comparison with wheat (29.3 %). While at warmed climate conditions, the changes in physiological parameters of pea and wheat were the opposite: for wheat they have increased and became 52.6 %, and for pea they have decreased till 41.1 %, in comparison with the control plants (p <0.05).

DOI: http://dx.doi.org/10.5755/j01.erem.73.4.19444