Influence of proline and ascorbic acid on seed germination behaviour of tomato (Solanum lycopersicum L.) under salt stress

An experiment was performed to assess the effect of proline and ascorbic acid as seed treatment on tomato (Solanmum lycopersicum L.) under salt stress. Seeds of tomato variety Punjab Varkha Bahar-4 (PVB-4) were pre-treated for 2 h with different concentrations of proline (5mM and 10mM) and ascorbic acid (1mM and 4mM). The treated seeds were subjected to salinity stress of 25mM, 50mM and 75mM. Various estimates were done from treated seedlings after 14 days of germination. All seed treatments of proline and ascorbic acid increased the percent of germination and various biochemical parameters (total soluble sugars, total soluble proteins and activities of antioxidant enzymes) of seedlings as compared to control at all salinity levels. Overall results showed that proline 10mM or ascorbic acid 4mM were more effective than proline 5mM and ascorbic acid 1mM at all salinity levels. The present study indicated that the negative effects of salinity on emergence and early seedling growth of tomato could be alleviated with exogenous application of proline (10mM) and ascorbic acid (4mM).