Effect of foliar application of Brassinosteroids on growth, yield and fruit quality of two strawberry cultivars under salt stress in soilless culture

Due to lack of fresh water sources, and the inevitability of using unconventional waters, a study was conducted to determine the tolerance of strawberry to salinity for ʻParosʼ and ʻAromasʼ cultivars and the possible role of brassinosteroids in reducing the negative effects of salinity. In this study the effect of 24-epibrassinolide concentrations (0, 0.25, 0.5 and 1 mg/L as foliar spray) and salinity levels (0, 20, 40 and 60 mM in nutrient solution) were evaluated on growth, yield and fruit quality of strawberry in soilless culture under greenhouse conditions. Rooted daughter plants of 'Aromas’ and ‘Paros’ strawberry cultivars were potted in 4 L plastic pots filled with cocopeat and perlite (1:1 V/V). Results showed that salinity (60 mM) reduced 44% of strawberry yield. The use of brassinosteroid could reduce the negative effect of salinity on reducing yield and all the concentrations used of BRs could increase the yield compared to the control. Foliar application of brassinosteroids at 0.5 and 1 mg / L resulted in increased leaf area, shoot and root dry weight and yield. Foliar application of brassinosteroids at 0.5 and 1 mg / L levels reduced the effects of salinity stress. In general, BRs could mitigate the detrimental effect of saline conditions on growth of strawberry plants, especially at 0.5 and 1 mg/L concentrations. In general, the use of brassinosteroids, especially at a concentration of 1 mg / L, under mild salinity conditions could reduce the effect of salinity stress on strawberry growth, and this effect was more pronounced on the cultivar ʻAromasʼ. Therefore, based on the results, this method is a suitable solution for solving problems caused by salt stress.