Salinity Tolerance Evaluation of Rice (Oryza sativa L.) ‘Tubtim Chumphae’ Seedling and Early Vegetative Stage

Background and Objective: Salinity is abiotic stress that affects rice growth and results in lower yields. This research studied the effects of salinity on Tubtim Chumphae rice growth. Materials and Methods: Seedlings were cultivated for 35 days in the soil before being stressed by salinity (0, 25, 50, 75 and 100 mM NaCl) for 4 weeks. Growth performance and some physiological traits were recorded weekly for 4 weeks. Results: Under salinity stress, fresh and dry weight of shoot and root, relative dry weight, plant length and root length all decreased as salt solution concentration increased. Electrolyte leakage percentage and malondialdehyde content increased when rice was exposed to the salt solution for 4 weeks, indicating that high salinity damaged the lipid membrane. The PCA results revealed positive correlations among growth parameters that negatively correlated with MDA content and electrolyte leakage. The HCA results confirmed the PCA biplot showing decreasing expression of growth parameters with rising salt stress levels, while MDA content and electrolyte leakage continuously increased. Results suggested MDA content and electrolyte leakage as indicators for salt stress in Tubtim Chumphae rice at seedling and early vegetative stage. Conclusion: Findings in this study indicated that Tubtim Chumphae rice plants can grow in slight to moderate salinity soil. Results will deliver advantageous data that can be integrated with additional agronomical characters in rice growth or breeding plans for abiotic stress-tolerant cultivars improvement.