Effect of foliar or soil application of selenium on some morphological and physiological traits of garden pansy (Viola x wittrockiana Gams) grown under salinity stress

Abstract

Salinity stress is one of the most important plant stresses in Iran. In this regard, a factorial experiment was conducted to investigate the effects of salinity stress on the garden pansy. The investigated factors were containing sodium selenate (0, 2, 4 and 8 mg l-1), its method of application (foliar and soil applications) and salinity stress (0, 3 and 6 dS m-1). The obtained results indicated that salinity leads to the significant reduction in morphological traits, chlorophyll a and b contents. Under the salinity of 6 dS m-1, when sodium selenate was used in the soil, the fresh and dry mass of flower increased by 11.34 and 10.39 %, respectively, compared to the control. However, the use of sodium selenate by foliar application led to the increasing fresh and dry mass of garden pansy's flower by 25.10 and 25.41 %, respectively. Also, the content of chlorophyll a increased by 12.93 % under the salinity of 6 dS m-1 with applying 8 mg l-1sodium selenate compared to the case of nonapplication. The superoxide dismutase activity decreased by 26.13 % compared to the non-sodium selenate usage treatment. In conclusion the foliar application of sodium selenate at the concentraion of 8 mg l-1 resulted in the garden pansy's growth improvement.