Abstract: The hypocotyls of 6 sea island cotton cultivars, i. e. , DJ-1(373), Tianchang 2(376), 5917(380), Achang-599(381), Ta 07-152(383), and S0717(408)were used as explant materials;calli were successfully induced with two optimized combinations of plant growth regulator(PGR)screened by the method of double factors randomized block, and the plants were regenerated successfully. The results showed that, the best PGR combination to induce callus for 380, 383, and 381 was 0.1 mg/L 2, 4-D + 0.1 mg/L KT, while that for 373, 376, and 408 was 0.3 mg/L NAA + 0.1 mg/L KT. The induced calli inoculated into the medium of double KNO₃ generated embryogenic ones, and inoculating them into the medium of 0.1 mg/L KT and 0.05 mg/L IBA promoted the somatic embryogenesis and their maturing. The culture of malformed seedlings shortened the cycle of regeneration system, and the regenerated plants were all obtained from 6 cultivars in 6 to 8 months. A stable and efficient regeneration system without genotype limit was established.

Key words: sea island cotton, plant growth regulator, embryogenic callus