Effect of salt stress on genotypes of commercial (Fragaria x ananassa) and Chilean strawberry (F. chiloensis)

The commercial strawberry (Fragaria×ananassa Duch.) is a salt sensitive species, in which salinity adversely affects its growth and fruit production. Because of its varied geographic distribution, including coastal areas, the Chilean strawberry (Fragaria chiloensis) genotypes may be less sensitive to salt stress. The aim of this study was to determine the effect of salinity on vegetative growth, physiological parameters, as well as production and fruit quality of three genotypes of Fragaria spp. (one of commercial strawberry cv. Camarosa, and two Chilean strawberry genotypes of the botanical forms chiloensis and patagonica, respectively). Plants were subjected to 0, 30, or 60 mM NaCl. In 'Camarosa' plants, vegetative growth, leaf relative water content (LRWC), pigment concentrations, yield, and fruit size were reduced under salt stress, while proline and malondialdehyde (MDA) concentrations were increased. Although it has been suggested that F. chiloensis is more tolerant to salinity than F.×ananassa, similar effects were observed in the vegetative development of the plants of F. chiloensis f. chiloensis. No differences in fruit weight, size and firmness of this genotype were detected as a result of salt stress. However, salinity affected fruit quality attributes such as total soluble solids (TSS) and titratable acidity (TA). By contrast, morphological and physiological variables measured in the genotype of F. chiloensis f. patagonica were not affected by the stress imposed. In addition, salinity had no effect on weight, size, firmness and TSS of fruits, with only TA being increased. These results suggest a higher tolerance of patagonica genotype to salt stress.