We attempted to study the response of six rice cultivars, viz., BPT 5204, CR 1009, TRY 1, CO 50, Jodimattai, and CO 46, to salt stress under in vitro conditions. In this study, we report the highest relative growth rate (RGR) in BPT 5204 and TRY1, suggesting that these could maintain a higher relative fresh mass of the callus to survive salt stress. For regeneration frequency (RF), genotype TRY 1 registered the highest RF (35%) in the control (0 mM NaCl), but a significant reduction in RF (66%) was observed at 90, 120, and 150 mM NaCl. The genotypes CO 50, CR 1009, and BPT 5204 registered the lowest regeneration frequency (6.7%) and produced a moderate number of shoots. The biochemical nature of stress implies that proline content decreases in the control and progressively increases from 30 to 90 mM but gradually decreases with higher salt concentrations. The proline content was high for both tolerant (BPT 5204) and sensitive (CO-46) cultivars, implying that proline gives adaptiveness rather than growth. Our results provide unique insight into the antioxidant (catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD)) properties of callus culture. Antioxidants act as potential reactive oxygen species (ROS) scavengers and provide adaptive mechanisms to plants. The antioxidant enzyme activities increased progressively with increasing NaCl concentration in the medium, showing that antioxidants augment the stress and provide an adaptive mechanism. The genotypes BPT 5204 and TRY1 had a significant level of enzyme activities at 90, 120, and 150 mM NaCl treatment, whereas the other genotypes seemed to have reduced enzymatic activities. Hence, the genotypes BPT 5204 and TRY1 were better in their performance for the above parameters, which showed growth and biochemical homeostasis in response to salt stress.

我们试图研究六个水稻品种（即 BPT 5204、CR 1009、TRY 1、CO 50、Jodimattai 和 CO 46）在体外条件下对盐胁迫的反应。在这项研究中，我们报告了 BPT 5204 和 TRY1 中最高的相对生长率 (RGR)，表明它们可以维持较高的愈伤组织相对新鲜质量以抵御盐胁迫。对于再生频率 (RF)，基因型 TRY 1 在对照 (0 mM NaCl) 中记录了最高的 RF (35%)，但在 90、120 和 150 mM NaCl 时观察到 RF 显着降低 (66%)。基因型 CO 50、CR 1009 和 BPT 5204 的再生频率最低 (6.7%)，并产生中等数量的芽。胁迫的生化性质意味着脯氨酸含量在对照中降低，并从 30 mM 逐渐增加到 90 mM，但随着盐浓度的升高而逐渐降低。耐受品种 (BPT 5204) 和敏感品种 (CO-46) 的脯氨酸含量都很高，这意味着脯氨酸具有适应性而不是生长作用。我们的结果为愈伤组织培养物的抗氧化（过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）和超氧化物歧化酶（SOD））特性提供了独特的见解。抗氧化剂充当潜在的活性氧（ROS）清除剂，并为植物提供适应机制。随着培养基中氯化钠浓度的增加，抗氧化酶活性逐渐增加，表明抗氧化剂增强了应激并提供了适应性机制。基因型 BPT 5204 和 TRY1 在 90、120 和 150 mM NaCl 处理下具有显着水平的酶活性，而其他基因型似乎具有降低的酶活性。因此，基因型 BPT 5204 和 TRY1 在上述参数方面表现更好，显示出响应盐胁迫的生长和生化稳态。