Estimation of genetic diversity among parents and F3 mapping population developed between a salt tolerant and salt susceptible rice variety

Hybridization was made between a high yielding, salt susceptible rice variety IR 28 and a salt tolerant rice cultivar Pokkali to generate a mapping population aiming to tag the salt tolerant gene(s) in rice. Phenotyping of 129 F3 segregants was done which showed varying degree of tolerance towards excess salt (12 dSm-1 NaCl) provided artificially. Phenotyping of the segregants and parents was done based upon tolerance (0-9 scale) towards salt stress. Three groups (highly tolerant, 0-1, moderately tolerant, 2-4 and susceptible 5-9) were formed based upon tolerance norms. Genetic analysis using RAPD grouped the segregants cultivar into two major classes with two sub-classes each. RAPD was found to be potential to tag the gene(s) as indicated by character analysis using UPGMA.