Barnyard millet (Echinochloa frumentacea) is a minor millet known for its nutritional value and adaptability to adverse environments. However, soil salinity significantly hinders its early growth, germination, and productivity. The present study evaluated 100 genotypes of Barnyard millet under six salinity treatments (0, hydro-primed, 50, 100, 150, and 200 mM NaCl) using a factorial completely randomized design. Key early growth parameters including percentage of germination, root and shoot length, fresh weight, dry weight and vigour index were assessed. Dendrogram clustering and principal component analysis revealed genotypic variability in response to salinity stress. The genotypes G34 (IEc 688), G25 (IEc 675), G18 (IEc 154), G44 (IEc 360) and G43 (IEc 356) performed well consistently upon exposure to salt levels. Certain genotypes maintained higher germination and vigour under stress, indicating physiological adaptations such as osmotic regulation and reactive oxygen species (ROS) detoxification. PCA identified vigour index and root length as discriminative traits for salinity tolerance. The study highlights the importance of genotype screening and phenotypic clustering in identifying salt-tolerant lines, aiding breeding programs aimed at enhancing millet productivity in salt-prone regions

Salinity stress, genotype screening, vigour index, dendrogram clustering, Principal Component Analysis

The present study demonstrated significant genotypic variability among Barnyard millet accessions under different salinity stress levels. The important traits such as germination percentage, root and shoot length, fresh and dry weight, and vigour index were adversely affected as salinity increased. Dendrogram analysis effectively grouped genotypes based on tolerance levels, while PCA identified vigour index as the principal component that contributes to variability. Certain genotypes consistently performed well, indicating inherent physiological and biochemical mechanisms for salt tolerance, including osmotic adjustment and ROS detoxification. The genotypes G34 (IEc 688), G25 (IEc 675), G18 (IEc 154), G44 (IEc 360) and G43 (IEc 356) performed well consistently upon exposure to salt levels. These findings are crucial for selecting and breeding salt-tolerant genotypes to ensure stable millet production in saline-prone regions, thereby supporting food security under environmental stress conditions

Vasudev Ramaraj, Jegadeeswaran Mokkaraj, Thirugnanakumar Sivagurunathan, Geetha S., Vinothini Nedunchezhiyan, Sathees Kumar Kathirvel, Susi Sivakumar and Tamilarasan Arikrishnan (2025). Assessment of Salinity Tolerance in Barnyard millet (Echinochloa frumentacea Roxb.) Genotypes using Dendrogram and PCA Biplot. Biological Forum, 17(7): 148-154