The present study was carried out to examine salt-induced modulation in growth, photosynthetic
characteristics and antioxidant system in two cultivars of Brassica juncea Czern and
Coss varieties (Varuna and RH-30). The surface sterilized seeds of these varieties were sown in
the soil amended with different levels (2.8, 4.2 or 5.6 dsm1) of sodium chloride under a simple randomized
block design. The salt treatment significantly decreased growth, net photosynthetic rate
and its related attributes, chlorophyll fluorescence, SPAD value of chlorophyll, leaf carbonic anhydrase
activity and leaf water potential, whereas electrolyte leakage, proline content, and activity of
catalase, peroxidase and superoxide dismutase enzymes increased in both the varieties at 30 d stage
of growth. The variety Varuna was found more resistant than RH-30 to the salt stress and possessed
higher values for growth, photosynthetic attributes and antioxidant enzymes. Out of the graded
concentrations (2.8, 4.2 or 5.6 dsm1) of sodium chloride, 2.8 sm1 was least toxic and 5.6 dsm1
was most harmful. The variation in the responses of these two varieties to salt stress is attributed
to their differential photosynthetic traits, SPAD chlorophyll value and antioxidant capacity, which
can be used as potential markers for screening mustard plants for salt tolerance.