Silicon alleviates salt stress, decreases malondialdehyde content and affects petal color of salt-stressed cut rose (Rosa xhybrida L.) 'Hot Lady'

A greenhouse experiment was conducted to investigate the effects of different levels of silicon (Si) application on cut rose (Rosa xhybrida L.) 'Hot Lady' under two levels of salt stress. Four Si concentrations (0, 50, 100 and 150 ppm) as Si were combined with a 25 mM NaCl (EC approximately 3.8) level in the nutrient solution supplied to the plants. Addition of Si partially maintained membrane permeability but only fully restored it to control levels in the Si50 and Si100 treatments. 150 ppm Si with or without NaCl could not alleviate or decrease cell wall damages. Inclusion of Si significantly reduced malondialdehyde content and chlorophyll content of salt-stressed plants in all treatments except that of 150 ppm. Maximum chlorophyll content was noticed when 50 ppm Si was supplied. Addition of 50 ppm Si increased the flower number in both plants grown under salinity and unstressed conditions. However, no significant difference was observed between 100 and 50 ppm Si accompanying with NaCl. Plants treated with NaCl alone showed a reduction in plant leaf area, while the reduction in plants treated with NaCl plus 50 and 100 ppm Si were like control and other unstressed plants.