Enhancing drought stress tolerance of NIL-SUB1DRO1 rice strain through different seed priming treatments

Drought stress is a major abiotic factor that significantly reduces rice yield and productivity. This study analyzed the effectiveness of various seed priming techniques in enhancing drought stress tolerance in NIL-SUB1DRO line with an IR64 genetic background, known for its combined tolerance to flooding and drought stress. A complete randomized factorial design with five replications was employed, testing osmo-priming, halo priming, hydro priming, and non-primed control under drought and well-watered conditions. Drought stress markedly reduced plant height, shoot, and root biomass, leaf area, photosynthetic activities, and water relations traits (relative water content and leaf water potential) in non-primed seedlings, whereas seed priming treatments, especially osmo-priming and halo-priming treatments, significantly enhanced plant height, shoot, and root biomass, SPAD value, Fv/Fm, relative water content, leaf water potential, and photosynthetic rate in NIL-SUB1DRO1. Strong positive correlations between SPAD value, photosynthetic rate, Fv/Fm, biomass biomass-related traits. These findings suggest that seed osmo-priming is a promising strategy to enhance drought stress tolerance in NIL-SUB1DRO rice line.