The effect of a biostimulant on salinity plant stress.

In this study the effects of salinity on the germinability and growth of three Lolium perenne cultivars (Barminton, Barrage and Barlennium), differing in tolerance to salinity, were considered. Twelve-days-old plants were grown in aerated nutrient solution (NS) free of (control) or supplemented with 10, 15, or 20 g L-1 NaCl, or with two different concentrations of biostimulant. The germinability and the growth of seedlings were both increased in the presence of the biostimulant, while the salinity influenced the two parameters in relation to cv and NaCl concentrations. In particular 10 and 15 g L-1 NaCl decreased the growth of three cultivars, while the presence of the biostimulant mitigated the toxic effect of salt. 20 g L-1 NaCl did not allow seed germination. In order to better understand the physiological action of NaCl, two different enzymes (-amylase, invertase) involved in seed germination and plant development, were analyzed. In particular, -amylase activity is involved in the hydrolysis of sucrose into hexose substrate, while invertase is implicated in differentiation and growth processes. The roles of NaCl and biostimulant on these activities are investigated.