TIME-DEPENDENT DETERMINATIVE BIOCHEMICAL TRAITS FOR SALT TOLERANCE MECHANISM IN MUNGBEAN (Vigna radiata (L.) R. WILCZEK)

Mungbean is one of the commercially valuable pulse crops. Time-dependent biochemical modulations in the mungbean varieties PKV AKM 12-28 and VBN (Gg)3 exposed to 75, 100, and 125 mM NaCl were estimated, and the results were concluded through multivariate modeling. The cluster analysis gave two fairly distinct clusters that had similar biochemical responses. Results on the principal component analysis suggested that protein content (PC), total phenolic content (TPC), total flavonoid content (TFC), DPPH radical scavenging activity, ABTS radical scavenging activity, proline content (PRC), total free amino acid (TFAA) content, and malondialdehyde (MDA) contents were dominant traits in the shoot as compared to the root. These can be taken as the primary indicators to assess the effect of salt stress on mungbean varieties. The discriminant analysis had identified TFC, MDA, and total sugar content (TSC) as discriminating variables between the roots and shoots. Further, MDA and TFC were identified as discriminating variables under different salt concentrations, and TSC was identified as a discriminating variable at different exposure durations. Discriminant partial least squares analysis further identified optimum biochemical modulations in the shoots of PKV AKM 12-28 and 75 mM NaCl. The salt treatment produced a strong biochemical modulation after 30 and 45 days, which helped plants survive under salt stress. The multivariate approaches efficiently interpreted time-dependent biochemical modulations in shoots and roots of mungbean varieties under salt stress.