Characterization of rice genotypes in relation to salt tolerance related response at early seedling stage

Abstract

Eighteen rice genotypes were evaluated to assess the seed germination and growth performance of seedlings using two salinity levels (4 and 8 dSm-1). In general, the genotypes exhibited sensitivity to salt stress at germination stage, but greater sensitivity was noticed at early seedling stage. Root length was more affected compared to shoot length followed by shoot fresh and dry weight, root fresh weight and dry weight and K/Na ratio. Using eight morpho-physiological parameters, the rice genotypes were categorized into three groups based on the relative mean performance. The genotypes CSR-13, CSR- 23, CSR-27, CSR-30, CSR-36, CST7-1 and CSR-2K-262 showed considerably higher level of tolerance to salt stress in comparison to the genotypes NDRK-11-1, NDRK-11-3, NDRK-11-4, NDRK-11-5, NDRK-11-6, NDRK-11-7, CSR-2K-219 and CSR-2K-242, which were found to be moderately tolerant. The remaining three genotypes, namely, IR-36, IR-64 and Swarna, were observed to be susceptible to salt stress. Screening under laboratory condition provided a rapid and efficient method for the evaluation of salt tolerance status of genotypes.