Development of salt tolerant lines of KDML and LPT rice cultivars through tissue culture.

Salt tolerant lines of indica rice (Oryza sativa L.) were selected out of KDML and LPT cultivars. The first selection was made in vitro by incorporating 1 or 2% NaCl in the culture media. Embryogenic calli from mature embryo were subjected to a salt stress for four weeks. Regeneration rates after salt stress were reduced to 0.076% or less as against regeneration rates of 8.3 to 30% normally obtained for non-stressed conditions. Seedlings of regenerants and of following generations were treated with 0.5% NaCl in water culture for four weeks. Definite salt tolerance of the progenies of selected and unselected plants appeared in both cultivars. The best survival rate of line LPT 171 in R3 was 94.3% while only 2% of the control survived. The result of the fourth generation was similar to the third.