ORIGINAL ARTICLE

Priming of Long-Term Stored Cotton Seeds Using Combined UV-A, B and C Radiation and Its Influence on Germination

Seeds vigour and uniform germination across diverse environmental conditions is a primary objective in agriculture. Moisture and temperature are key factors affecting cotton seed quality during storage, where maintenance is rather difficult during long-term storage. To investigate the potential influence of UV radiation on enhancing cotton seed vigour after long-term storage, Deir Al-Zour 22 cotton variety was selected due to its reduced-vigour by time and its low germination rates. Germination rates of cotton seeds exposed to combined UV-A, B and C irradiation for different periods of time (4, 8, 12, and 16 min) were enhanced compared to non-irradiated seeds. Data showed improved growth of generated seedlings on PEG and NaCl supplemented media. Results showed no major changes on the expression of GA3ox1 gene, whereas, two stress-related genes DEH and VPP were temporarily activated after treatment with UV-irradiation supporting their function as scavenging and accumulating factors of ROS, a typical by-product of the photo-excitation under UV. Our results suggest the possibility of using combined UV-A, B and C radiation as a physical priming agent of cotton seeds to induce plant vigor and enhance germination under stress conditions without affecting normal growth.