Different biochemical and morphological responses of the strawberry cultivars to salicylic acid and heat shock

This research aimed to improve heat shock tolerance and survival rates of strawberry Camarosa and Paros cultivars using salicylic acid (SA) for off-season cultivation in subtropical climates under greenhouse conditions. A factorial experiment conducted with two SA concentrations (0 and 1 mM), two temperature treatments including control (20/25 ºC -night/day) and heat shock (42 °C for eight hours), and four replications in a completely randomized design. Our results indicated that heat shock significantly decreased shoot fresh weight and root dry weight by 19 and 17% in Paros cultivar. Additionally, it reduced leaf area, root fresh weight, relative water content (RWC), chlorophyll b, and carotenoid levels in both cultivars. While it significantly increased proline content by 66%, leaf numbers by 26% root dry weight by17% in Camarosa, and SOD activity by 37 and 33%, and TPC by 32 and 38% in Paros and Camarosa, respectively. SA under heat shock yielded mixed results; it mitigated RWC reduction in Paros, and enhanced TPC content, activities of SOD and APX in the both cultivar, and increased activities of POD, in Camarosa. In summary, this study highlights cultivar-specific responses to heat shock and SA, emphasizing potential strategies to enhance strawberry tolerance and optimize agricultural practices under changing climatic conditions.