Differential phenotypic response of the black gram genotypes under salinity stress at the tissue level

Salinity stress in black gram is an important challenging issue, especially in delta regions. The independent evolving nature of the salt tolerance in each genotype is the main drawback of saline tolerance crop improvement. The previous study identified two tolerant and two susceptible black gram genotypes under salinity stress at the vegetative stage through hydroponics. In this study, these genotypes were screened for the accumulation of sodium and potassium ions and photosynthetic activity. Different parts of plants viz., roots, stems and leaves were analyzed with the internal sodium and potassium ions. The tolerant genotypes showed a low level of sodium accumulation and a higher level of potassium accumulation in all plant parts compared to the susceptible genotypes. The tolerant genotypes had higher SPAD and fluorescence values, which signify the photosynthetic activity. The tolerant genotypes had higher ion homeostasis compared to the susceptible genotypes. These findings can be adopted in the salinity tolerance breeding programme in black gram.