Infrared laser radiation (L=980nm) application for photobiostimulation of wheat seeds (triticum aestivum L)

In the present work an infrared laser diode with wavelength λ=980 nm and power of 200 mW was used to produce stimulation of wheat seeds. Wheat seeds were supplied by the National Institute of Forest, Agriculture and Livestock researches of Mexico (INIFAP). Wheat variety was Nahuati F2000, developed by the institute above mentioned and the International Maize and Wheat Improvement Center (CIMMYT). Germination and growth tests were carried out under laboratory conditions and according to the guidelines issued by the International Seed Testing Association (ISTA 2009). In the case of germination the percentage of normally germinated seeds, the percentage of abnormally germinated seeds and the percentage of non-germinated seeds were analyzed. To evaluate the growth of wheat seeds the total length of the wheat seedlings was measured. Wheat seeds were irradiated with one of the three intensities: 15mW/cm2, 30mW/cm2 and 60mW/cm2 for five different exposition times: 15s, 30s, 60s, 120s and 240s. For each laser treatment 400 wheat seeds divided into groups of 25 seeds according to the International Seed Testing Association (ISTA 2009) were used. The same quantity of non-radiated seeds was used as a control The germination data were analyzed using the Student t-test to find statistical significant differences. For the growth data an ANOVA analysis was done to detect differences between average values. Average values were compared using Tukey test (multiple comparisons) to detect differences between control and treated seedlings.