Effects of laser irradiation on phytochemical composition, histological anatomy, genetic diversity, and food safety of Ocimum basilicum L.

Enhancing crop productivity and sustainability remains a major challenge due to the environmental impact of conventional chemical methods. Laser seed bio-stimulation offers an eco-friendly approach to improve plant growth, quality, and stress tolerance. Laser irradiation as a seed pre-treatment offers a sustainable, non-chemical approach that may contribute to improved quality and safety of medicinal and aromatic plants. This study evaluated the effects of red (650 nm) and blue (450 nm) laser irradiation for 5 and 10 min on sweet basil (Ocimum basilicum L.) seeds by analyzing vegetative growth, biochemical composition, phytohormones, and genetic variation compared to the control. Results demonstrated that 10-min laser treatment significantly enhanced plant growth, including parameters such as plant height, main stem length, number of leaves per plant, fresh and dry shoot weight, and root length, relative to the control. Laser exposure also strengthened basil leaf anatomy by thickening conducting tissues and increasing total phenolic content, antioxidant activity, pigment concentrations, phytohormone levels (GA₃ and IAA), essential oil yield, and antioxidant enzyme activity. Laser treatment modulated the essential oil composition, with variable responses among individual constituents. The impact of laser irradiation on Ocimum basilicum to induce genetic variability and enhance its physiological performance. Basil seeds were exposed to different laser type and wave length, and the resulting plants were evaluated for morphological changes and genomic polymorphism using SCoT and ISSR markers. SCoT and ISSR markers revealed that 10-min laser irradiation induced the most distinct genetic variations. SCoT primers produced 6 polymorphic bands (60%, 290–1300 bp), while ISSR primers detected 82 bands, with 22% polymorphism (150–1700 bp). Cluster analysis showed that 10-min treatments had the lowest genetic similarity, whereas 5-min treatments were more similar to the control. Combining data from both markers confirmed that red and blue laser exposure for 10 min resulted in the lowest similarity scores, while 5-min treatments exhibited the highest similarity. The present findings validate that laser irradiation can act as an eco-friendly bio-stimulation tool to enhance basil growth and biochemical composition. These results highlight its potential applications in sustainable agriculture, though further validation under open-field conditions is still required. “Laser irradiation significantly enhanced basil morphology, phytochemical profile, some essential oil composition, and genetic expression, providing novel insights for improving Ocimum basilicum growth and bioactive compounds.”