The effect of laser irradiation on the resistance to salinity of some physiological and biochemical characteristics of barley (Hordeum vulgare)

To evaluate laser irradiation effect on salinity tolerance in barley (Hordeum vulgare L.) at the germination phase and seedling, a CRD experiment in factorial arrangement experimental type was conducted at Tehran University, college of Abouraihan, in the year 2011. Experimental factors were four barley genotypes (Reihan, Afzal, Fajr30 and Nosrat), two radiation levels (no laser and laser irradiation in 780 nm wavelength for 15 minutes) and five levels of salinity (0, 80, 160, 240 and 320 mM of sodium chloride). In this research, physiological traits (Na+ content, K+ content, K+/Na+ ratio and proline content) and biochemical traits (ATP content and alpha amylase activity) in all genotypes were significantly affected by increasing salinity and laser irradiation (P<0/01). There was a reduction in ATP content and alpha amylase activity and K+/Na+ ratio. However, this reduction for treatment without radiation and salinity level of 160 mM in Afzal, Reihan, Fajr30 for ATP were 28%, 30% and 18% and for K+/Na+ were 80%, 82% and 86%. In this treatment Nosrat genotype was destroyed. The results showed that the laser pre-treatment caused an increase of ATP content and K+/Na+ ratio. In salinity level of 160 mM in Afzal, Reihan and fajr30 the increasing of ATP content were 12.8%, 6.9%, 8.2% and 18% and for K+/Na+ratio were 66.6%, 47.8%, 29.2% and 100%. Overall result showed that Laser irradiation treatment can be effective to increase crop tolerance to salinity.