Morphological, physiological and biochemical effects of short-term ozone stress in Strawberry (Fragaria anasassa) cvs. Aromas and Selva

Ozone (O3) is one of the important pollutants in lower atmosphere of earth which is created in the presence of sunlight from volatile substances and nitrogen oxide that emitted from the factories and cars. The aim of this research was to investigate the effect of ozone pollution on the growth and some traits of strawberry. In this study two strawberry cultivars `Aromas’ (suitable for field cultivation) and `Selva’ (suitable for greenhouse cultivation) were used as commercial cultivars, resistant and sensitive to environmental stresses, respectively. The present study was conducted to investigate the effect of ozone pollution on the growth and some other traits of plants which were pot-planted in a greenhouse and were treated with ozone. These cultivars were treated with three levels of ozone at concentrations of 0 (control – atmosphere with natural atmospheric ozone concentration), 50 and 100 mg.m-3 for a short period of 3 days. The treated plants showed ozone damage symptoms including chlorosis spots on the leaves, decreased amounts of chlorophylls a and b and total chlorophyll, decreased soluble carbohydrate and increased dry weight, dry matter percentage, total antioxidant capacity and proline contents. In Selva cultivar, after finishing of stress period and beginning of new growth, some morphological disorders were also observed in the produced flowers. Keeping in mind the smaller damage in Aromas cultivar during stress and growth period after the stress was finished and the ability of this cultivar to increase total antioxidant capacity and proline contents in dealing with 50 and 100 mgm-3 ozone stresses, it seems that this cultivar can have stronger tolerance against the mentioned stress compared to Selva cultivar.