Seed priming with chitosan alleviates salinity stress by improving germination and early growth parameters in common vetch (Vicia sativa)

Soil salinity is a serious environmental threat with varied effects on several aspects of growth and production of plants. Recently, however, the utilization of chitosan in agriculture has increased as it enhances the resistance of crop plants to different stresses factors such as salinity. In this experiment, the effects of chitosan seed-priming on alleviation of salinity stress was investigated in common vetch (Vicia sativa L.) using a completely randomized design with six replications. Chitosan pretreatment was applied at three levels (2, 4, and 8 g/l) and salinity of sodium chloride (NaCl) was applied at four levels (50, 100 and 200, and 300 mM). Different variables have been measured, including germination percentage, hypocotyl length, radical length, hypocotyl dry weight and radical dry weight. Salinity is found to affect the germination percentage of vetch by decreasing germination with increasing in NaCl concentration (50, 100 and 200, and 300 mM). However, the results showed an increase in germination percentage upon priming seeds with different levels of chitosan (2, 4, and 8 g/l) even with increasing the concentration NaCl salinity. Additionally, all salinity levels caused a significant reduction in vetch hypocotyl and radical dry weight and resulted in a decrease in their length when compared with the water control. However, chitosan at all levels of concentration improved all of these growth parameters (hypocotyl length, radical length, hypocotyl dry weight and radical dry weight) irrespective of salinity level indicating a successful role of chitosan in alleviating salinity stress. In general, these results may suggest that in saline soil seed pretreatment in chitosan could be utilized successfully for alleviating the effect of salinity stress on germination and on some growth parameters of common vetch.