Salinity is a major constraint for plant growth, development and yield worldwide. Evaluation of a large number of germplasms in salt-stressed environments may help identify superior salt-tolerant genotypes. The present study dissects the genetic diversity of 33 pearl millet genotypes (landraces and inbred lines) for salinity tolerance through in vitro screening at the seedling stage. Our results revealed a significant reduction in total biomass and shoot growth of the salt-sensitive genotypes upon exposure to 150 mM NaCl, in contrast to the tolerant genotypes showing better growth characteristics. A significant differential effect of salt treatment on morphological traits was observed by analysis of variance (ANOVA), confirming substantial genetic diversity among all genotypes for salt tolerance. The genotypes were clustered into three groups based on multiple stress indices. The genotypes were also evaluated using principal component analysis (PCA) to identify the key contributing traits for stress tolerance. Based on these results, a total of four contrasting genotypes were selected for further biochemical and molecular analysis. Physiological studies confirmed that salt tolerance might be due to the higher content of osmolytes and the activity of antioxidant enzymes. Similarly, gene expression profiling of catalase (CAT), glutamate dehydrogenase (GDH), glutathione reductase (GR), and nitrate reductase (NR) revealed a profound increase in NR and GDH transcript levels in the tolerant genotypes, suggesting their major role as reactive oxygen species (ROS) scavengers under salinity. The overall findings of this study could be utilized further for candidate gene mining through “omics” approaches, aiming toward development of salinity resilient crop plants.

盐度是全球植物生长、发育和产量的主要制约因素。评估盐胁迫环境中的大量种质可能有助于确定优良的耐盐基因型。本研究通过幼苗期的体外筛选分析了 33 个珍珠粟基因型（地方品种和近交系）耐盐性的遗传多样性。我们的结果显示，暴露于 150 mM NaCl 后，盐敏感基因型的总生物量和枝条生长显着降低，而耐受基因型则显示出更好的生长特性。通过方差分析（ANOVA）观察到盐处理对形态性状的显着差异影响，证实了所有耐盐基因型之间的实质性遗传多样性。根据多个压力指数将基因型分为三组。还使用主成分分析 (PCA) 对基因型进行了评估，以确定抗压性的关键贡献性状。基于这些结果，总共选择了四种对比基因型进行进一步的生化和分子分析。生理学研究证实，耐盐性可能是由于较高的渗透物含量和抗氧化酶的活性。同样，过氧化氢酶的基因表达谱 生理学研究证实，耐盐性可能是由于较高的渗透物含量和抗氧化酶的活性。同样，过氧化氢酶的基因表达谱 生理学研究证实，耐盐性可能是由于较高的渗透物含量和抗氧化酶的活性。同样，过氧化氢酶的基因表达谱(CAT)、谷氨酸脱氢酶(GDH)、谷胱甘肽还原酶(GR)和硝酸还原酶 ( NR)显示耐受基因型中NR和GDH转录水平的显着增加，表明它们作为活性氧 (ROS) 清除剂的主要作用盐度。这项研究的整体发现可以通过“组学”方法进一步用于候选基因挖掘，旨在开发耐盐度作物。