Enhancing canola (Brassica napus L.) resilience to salt stress through foliar application of ascorbic acid

A b s t r a c t. Canola (Brassica napus L.), essential for food and biodiesel, suffers from productivity losses due to soil salinity.This study evaluated the effect of ascorbic acid (AsA) foliar spray on mitigating sodium chloride (NaCl)-induced salt stress in two canola varieties, Sandal (V1) and Rachna (V2).Plants were grown under control (0 mM NaCl) and salt stress (150 mM NaCl) conditions, with AsA treatments at 0, 15, and 30 mM concentrations.Salt stress can reduce canola's morphological traits and photosynthetic activity.However, AsA treatment increased total chlorophyll, chlorophyll a, chlorophyll b (each by 55%), and carotenoids (62.8%).Salt stress elevated reactive oxygen species (ROS) and Na + accumulation, but AsA application under stress enhanced glycine betaine (24%), proline (23.8%), anthocyanin (26%), total soluble sugars (24.6%), proteins (19.8%), endogenous AsA (26%), flavonoids (19.8%), total phenolics (29%), and antioxidant enzymes (SOD by 24%, POD by 19.7%, and CAT by 20%).The AsA treatments helped to control oxidative stress, regulate ion balance, and reduce lipid peroxidation, thereby preventing ROS overproduction.Out of two varieties, Rachna (V2) performed better than Sandal (V1) across all morphological and physiological parameters, demonstrating superior resilience under salinity.Ke y w o r d s: canola, salinity, ascorbic acid, antioxidants, ions