<p>Globally, salinity presents a major obstacle for land and water resources. The genetic diversity within crop species provides valuable opportunities to enhance adaptability to saline conditions. This research examined the effects of salt stress on dragon fruit genotypes and their response. Four dragon fruit genotypes having white (Andaman white, local white) and red flesh (regular red and Andaman red) were irrigated at 0, 25, 50, 75, and 100 mM saline water. Salt stress decreased new sprout formation, growth, and above- and below-ground biomass, except root elongation in genotypes. The stress delayed sprouting in cutting by four and seven days at 50 mM and 100 mM respectively, compared to the control. The highest plant mortality (15.00%-16.66%) was observed at 75 and 100 mM salt stress. White-fleshed genotypes exhibited the highest mortality (21.33% to 25.33%). In this study, salt stress reduced chlorophyll pigments, NDVI, maximum quantum yield of PS II, and water use efficiency in studied dragon fruit genotypes. White-fleshed genotypes (Andaman white and local white) accumulated significantly more Na⁺ in their stems (54.19 ppm and 40.85 ppm, respectively) compared to red-fleshed genotypes (18.90 ppm and 9.81 ppm). Additionally, white-fleshed genotypes (Andaman white, local white) showed higher Cl^– accumulation in roots (0.36% and 0.27%, respectively). The regular red accumulated the most stem K⁺ (219.83 ppm), followed by Andaman red (206.32 ppm), while white-fleshed genotypes had the lowest. Consequently, ‘regular red’ and ‘Andaman red’ can be classified as efficient Na⁺ and moderately efficient Cl⁻ excluders, respectively, enabling them to maintain normal morphological growth, physiological and biochemical processes under salt stress.</p>