Effects of Different Doses of Low Power Continuous Wave He–Ne Laser Radiation on Some Seed Thermodynamic and Germination Parameters, and Potential Enzymes Involved in Seed Germination of Sunflower (Helianthus annuus L.)

Abstract In this study, water‐soaked seeds of sunflower were exposed to He–Ne laser irradiation of different energies to determine whether or not He–Ne laser irradiation caused changes to seed thermodynamic and germination parameters as well as effects on the activities of germination enzymes. The experiment comprised four energy levels: 0 (control), 100, 300 and 500 mJ of laser energy and each treatment replicated four times arranged in a completely randomized design. The experimentation was performed under the greenhouse conditions in the net‐house of the Department of Botany, University of Agriculture, Faisalabad. The seed thermodynamic parameters were calculated according to seed germination thermograms determined with a calorimeter at 25.8°C for 72 h. Various thermodynamic parameters of seed (Δ H , (Δ S ) e , (Δ S ) c , (Δ S ) e /Δ t and (Δ S ) c /Δ t ) were affected significantly due to presowing laser treatment. Significant changes in seed germination parameters and enzyme activities were observed in seeds treated with He–Ne laser. The He–Ne laser seed treatment resulted in increased activities of amylase and protease. These results indicate that the low power continuous wave He–Ne laser light seed treatment has considerable biological effects on seed metabolism. This seed treatment technique can be potentially employed to enhance agricultural productivity.