In Vitro Seed Germination and Seedling Growth for Salt Tolerance in Rice Cultivars

Six selected cultivars of rice namely BPT-5204, MTU-7029, CSR-30, Narendra Usar Dhan-3, Rajendra Bhagwati and Pusa Basmati-1 were screened for salinity tolerance on the basis of in vitro seed germination and seedling growth under different salt stress (02.5%) created by a salt mixture of NaCl, CaCl2, and Na2SO4 in 7:2:1 ratio. At 2% salt stress, germination was only observed in cultivars CSR-30 and Narendra Usar Dhan-3, while at 2.5 % no seed germination was observed. The frequency of seed germination gradually decreased with increasing concentrations of salt stress. As observed with seed germination, seedling growth was also adversely affected with the increase of salt concentrations. The shoot growth was more affected than the root growth. The salt tolerance index (STI) of the rice cultivars was calculated on the basis of seed germination, seedling shoot and root dry weights at different levels of salt stress. Cultivars CSR-30 and Narendra Usar Dhan-3 were found to be salt tolerant, cvs. MTU7029 and BPT-5204 moderately salt tolerant and cvs. Rajendra Bhawati and Pusa Basmati-1 as salt susceptible respectively on the basis of STI. Thus in vitro study can be used for evaluation of salinity tolerance of rice cultivars.