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