Effect of different levels of treated urban wastewater on growth and some physiological characteristics of Althaea officinalis

Treated wastewater is important for plant irrigation in arid and semi-arid regions. Althaea officinalis belongs to the Malvaceae family and contains high levels of glazed compounds and mucilage. The aim of this study was to investigate the effect of different levels of ‏ ‏urban wastewater on growth and some ‎physiological characteristics of Althaea officinalis. The seeds of A. officinalis were cultured in the pots containing perlite. The plants were treated with different levels of urbane wastewater of Yasouj (0, 25, 50, 75 and 100%) in three replications. The experiment was conducted in the form of randomized complete blocks design. The plants were harvested after three weeks’ irrigation with different concentrations of wastewater for further analysis. The results have shown that wastewater treatments increased the fresh and dry weight of shoots, the leaf area, the height of plant and roots length. The highest growth rate was obtained in plants irrigated with un-diluted wastewater. In response to wastewater treatment, the amount of photosynthetic pigments including chlorophylls a, b, a+b, and carotenoids increased and the highest level of increase was observed at 100% of wastewater. Anthocyanins and flavonoids increased in response to wastewater irrigation while proteins decreased. No cadmium and lead were detected in the leaves and roots of wastewater-irrigated plants. Overall, the results of this study showed a positive response of A. officinalis to urbane-wastewater-irrigation.