Ecophysiological Responses of Some Lamiaceae Species (Mentha × piperita, Ocimum basilicum, Salvia officinalis, and Thymus vulgaris) to UV Light and Their Potential Uses in Astrobotanical Applications

Abstract Ultraviolet radiation poses a significant risk, particularly on various plant species in space agriculture. The experiments were conducted using the following taxa from Lamiaceae family: Mentha × piperita, Ocimum basilicum, Salvia officinalis, and Thymus vulgaris. The experiments were conducted within sterile Petri dishes, with distilled water as a medium. The experiments were conducted in climate chamber, at a constant temperature of 21°C. The experiment involved exposing seeds to UV light (UV-A, UV-B, and UV-A + UV-B) for various durations (15, 20, 30, 45, and 60 mn). At the end of the fourth week, germination percentages, biomass, seedling vigour, tolerance index, root and shoot growth were measured. The findings demonstrated that the highest values for germination percentage (92.5%), radicle growth (10 cm), biomass (1189 g/cm2), and seedling vigour index (821.96) were determined in S. officinalis taxon. However, the highest values for hypocotyl growth (8 cm) and tolerance index (1733) were observed in the T. vulgaris taxon. The findings indicated that S. officinalis exhibited a higher capacity to adapt and survive to UV stress. S. officinalis was evaluated as an antioxidant source in space, has the potential to make significant contributions to the nutrition and health prevention of astronauts.