Effect of Laser Biostimulation on Germination of Wheat

Abstract

HighlightsThe effect of laser biostimulation on wheat germination was explored using a single- and dual-wavelength (DW) laser.An 80 mW green-infrared DW laser treatment significantly enhanced several germination traits of wheat.The effect of a 100 mW single-wavelength red laser on wheat germination was non-significant.Abstract. Laser biostimulation of seeds has established itself as a safe and sustainable alternative to genetic modification or chemical use to enhance plant germination and growth. A knowledge gap, however, exists to define optimal laser parameters for different seeds as inappropriate irradiation may seriously damage or destroy germinability. To this end, the effect of laser biostimulation on germination of Canada Western Red Winter (CWRW) wheat seeds was evaluated using two low power portable lasers: 1) a single-wavelength red laser (659 nm) and 2) a dual-wavelength (DW) green/infrared laser [531 and 810 nm (ratio ~10:1)]. The seeds were pretreated with laser light before germination tests for 5, 10, and 15 minutes using total power densities of ~14.2 and 11.3 mW/cm2, respectively. Laser treatment with a DW laser for a duration of 10 min was found to be the most efficient as it significantly enhanced mean germination time, germination rate index, germination speed, number of roots, and hypocotyl length by 14.3%, 15.2%, 15.2%, 31.8%, and 60.9%, respectively, with respect to control samples. The effect of single-wavelength red laser on CWRW wheat seed germination traits was not statistically significant. To the best of our knowledge, this study is the first on evaluating the effect of DW laser treatments in plant biostimulation and introduces a new pathway for manipulating the germination, growth, and development of seeds/plants. Keywords: Agriculture, Biostimulation, Dual-wavelength laser, Laser, Wheat.