Abstract
Background: Ultraviolet (UV) radiation can act as an abiotic elicitor influencing seed germination and early seedling development in economically important crops such as saffron (Crocus sativus L.).
Objective: To evaluate the effect of different durations of ultraviolet radiation on the germination behavior and early growth dynamics of saffron seeds.
Methodology: This laboratory-based experimental study was conducted over six months using saffron seeds obtained from a certified gene bank. A total of 30 seeds were used, divided into six groups (n = 5 per group): control (no UV exposure) and UV-treated groups exposed for 10, 20, 30, 40, and 50 minutes. Following UV treatment, seeds were germinated under controlled conditions, and germination percentage was recorded. Germinated seedlings were transferred to pots for assessment of morphological parameters (plant height, leaf number, leaf length and width, root traits) and biochemical attributes (chlorophyll and proline content) over a two-month period.
Results: Germination was observed in all groups, but timing and percentage varied with UV exposure duration. Seeds exposed to 20 and 30 minutes UV showed the highest and earliest germination (up to ~80–90%) within 48 hours, compared to delayed germination in the control group (~60–65% by day 6). Prolonged exposure (50 minutes) resulted in slower and reduced germination (~50–55%). Seedlings from the 20-minute UV group exhibited superior growth, with the greatest plant height (17 cm), highest leaf number (8), enhanced root development, increased chlorophyll content, and maximum proline accumulation, while longer exposures showed inhibitory effects.
Conclusion: Moderate UV exposure, particularly for 20 minutes, optimally enhances saffron seed germination and early seedling vigor, whereas prolonged exposure adversely affects growth.