Plant Regeneration from 6 Cotton (Gossypium hirsutum L.) Genotypes Through Somatic Embryogenesis

Optimization of regeneration methods in cotton is necessary to improve and successful production of transgenic cotton cultivars by tissue culture techniques. Present study was conducted to determine the callus induction and plant regeneration of cotton genotypes through In vitro culture and this carried out using hypocotyl and cotyledon explants from 7-14 day-old. For callus induction the explants were cultured on MS1 medium using a factorial experiment based on completely randomized design with three replications and supplemented with a combination of auxin and cytokinin hormones for 10 weeks. Cultures were incubated at 28±2ºC under a light intensity of approximately 2000 lux with 16/8 light/dark photoperiod for callus induction. For embryogenesis, embryogenic calli were transferred on a hormone-free MS medium supplemented with NH4NO3 and KNo3. Although, KNO3 is less efficient for somatic embryo induction but it was the best for embryo maturation. For germination of somatic embryos all produced embryogenic calli were cultured on a MS medium supplemented with GA3. Genotype 4-S-4 was better than the other genotypes with both kinds of explants (hypocotyl and cotyledon) in callus initiation, callus induction and embryogenic callus production.