Effect of Laser Radiation on Germination and Growth Rate of Sorghum Vulgar Seeds

Abstract

Laser is one of the sources for inducing biostimulation effect and genetic changes in plants. In this study the IR laser (wavelength 915 nm) was usedto stimulateSorghum vulgar Sppseeds. Seeds were divided into two groups, the first was irradiated in dry condition and the other one was irradiated in wet condition (soaked in water for 24 hours). Both dry and wet seeds were irradiated separately with 5 laser doses according to the exposure times to laser (5, 10, 15, 20 and 25 seconds), with different irradiance (4, 8, 12, 16, and 20 W/cm2).As a control, untreated seeds were used.After sowing,germinated seeds were counted every 48 hours for 8 days. To monitor the growth rate of Sorghum Spp plant grown from treated and non-treated seeds, the laser induced chlorophyll fluorescence technique equipped with blue laser (405nm) as excitation source was used. The obtained results showed that theirradiation of dry seedsat 16W/cm2 for 20 seconds significantlyaffectsthe germination rate of seeds, but the growth rate was not good,while irradiation of wet seeds at 8 W/cm2 for 10 seconds enhanced thegermination rate and plant growth rate compared to other samples(treated and non-treated seeds).