SALT-INDUCED VARIATION IN SOME POTENTIAL PHYSIOCHEMICAL ATTRIBUTES OF TWO GENETICALLY DIVERSE SPRING WHEAT (TRITICUM AESTIVUM L.) CULTIVARS: PHOTOSYNTHESIS AND PHOTOSYSTEM II EFFICIENCY

Abstract

Variation in salt tolerance potential of two contrasting wheat cultivars (salt tolerant S-24 and moderately salt sensitive MH-97) at different growth stages was observed when these wheat cultivars were exposed to salinity stress in hydroponic culture. Salinity caused a marked reduction in photosynthetic pigments, transpiration and photosynthetic rates, and stomatal conductance at early growth stages in both wheat cultivars, being more prominent in cv. MH-97. In addition, a marked saltinduced alteration was observed in different attributes of chlorophyll fluorescence. On the basis of physiological characterization of these two wheat cultivars at different growth stages, it was inferred that cv. S-24 exhibited higher salinity tolerance at all growth stages in terms of less salinity-induced degradation of photosynthetic pigments, higher photosynthetic rates, maintenance of photosystem II under salinity stress as compared to that in cv. MH-97. In view of the results presented here, it is evident that wheat plants were prone to adverse effects of salinity at early growth stages as compared to later growth stages.