EVALUATION OF SALT TOLERANCE OF MUNGBEAN CULTIVARS AT THE SEEDLING STAGE USING POTENTIAL GROWTH INDICES

Soil salinity is a significant abiotic factor that lowers crop productivity. In the sub-tropical countries of Asia, mungbean is grown as a marginal crop in rice-based agricultural ecosystems, where salts get deposit in the upper layer. Therefore, robust criteria are essential to screen high yielding salt-tolerant cultivars of mungbean. The current study is an effort to assess the salt tolerance potential of twelve mungbean genotypes under laboratory environment at control (0), 50, 75, and 100 mM NaCl salinity level using stress tolerance indices. The findings showed that in all cultivars, with the increase in level of stress there is a significant reduction in the germination (GSI), fresh (FWSI) and dry biomass (DWSI), length of root (SLSI) and shoot stress tolerance indices (RLSI). NM-2021 showed 98% GSI followed by AbbasMung (89%), however, NM-54 showed the lowest value for GSI (62%). NM-98 exhibited 74% FWSI followed by Abbas Mung 73%. Abbas Mung was at the top with 82% DWSI followed by NM 19-19 (81%). NM 19-19 exhibited the highest value for SLSI (69%) and RLSI (81%). There is a correlation between the fresh and dry biomass tolerance indices of seedlings. The data was categorized into three clusters using the multivariate cluster analysis approach in order to assess the similarities between mungbean cultivars. Cluster-I exhibited the salt-tolerant cultivars NM-2021, NM-98, NM-92, Abbas Mung and NM-19-19, Cluster-II classified medium-tolerant cultivars NM-121-2, NM-2021, NM-2006 and NM-2016, and Cluster-III showed salt-sensitive cultivars NM-51, NM-2011 and NM-54. The growth indicators could be utilized as selection criteria to assess salt tolerance in mungbean cultivars.