Sodium, Potassium Accumulation, Photosynthesis and Growth of Sugarcane (Saccharum spp. Complex cv. Co 99004) Mutant's Lines in Response to Salt Stress

Tissue culture technique used to obtain salt tolerant mutants from EMS (0.5% for 2 hours) treated embryogenic calli of sugarcane (Saccharum spp. Complex, cv. Co 99004). Calli were cultured on a selective medium containing different levels of NaCl (0, 50, 100, 150 and 200 mM). The 100 mM concentration of NaCl was decided LD₅₀ of NaCl on the basis of survival per cent of callus. The calli treated with EMS(LD₅₀) placed on shoot regeneration media containing LD₅₀ concentration of NaCl. The plants which regenerated from the tolerant calli were selected and grown in pot culture system under salinity stress as compared to normal plants (source variety). With increasing supply of NaCl in both systems, root growth was more adversely affected than shoot growth. Chlorophyll content, photosynthesis rate, stomatal conductance and dry matter showed a decreasing trend but in a slow rate in tolerant mutants than normal plants. The tissues analysis showed that at high salt concentration Na⁺ content in shoot of tolerantmutantand but was lessthan the normal plant. While, K⁺ content in shoot was high in tolerant mutants than normal plants.