Red rice (Oryza glaberrima L.) is a main food ingredient with some special characteristics and health benefits; therefore, enhancing its grain yield is necessary. However, the limited fertile land causes cultivation in the sub-optimal land, such as saline soil. Saline stress can cause damage to plant cells; hence, it is vital to apply exogenous antioxidants that can act as osmoprotectants. The presented study sought to determine the physiological characteristics of red rice under salinity stress conditions with ascorbic acid applications. The study commenced in a factorial separate plot design (SPD) with three features. The salinity levels (3-4 and >4-5 mho/cm) comprised the main plots, red rice cultivars (Inpari 24, Inpari 7, Pamelen, and MSP17) in the subplots, with the ascorbic acid concentrations (0, 500, 1000, and 1500 ppm) kept in the sub-sub-plots. The results showed that the studied red rice cultivars differed in responses to ascorbic acid concentrations under saline soil conditions. Cultivar MSP17 was the most tolerant genotype to salinity stress compared with the three other red rice cultivars based on physiological attributes. Applying ascorbic acid improved red rice genotypes’ physiological characteristics (especially chlorophyll content and nutrient uptake) under saline stress conditions.

Keywords: Red rice (O. glaberrima L.), cultivars, salinity, ascorbic acid, physiological characteristics, grain yield

Key findings: Ascorbic acid is vital in improving the physiological characteristics of red rice (O. glaberrima L.) genotypes under salinity stress conditions.